NHS Choices

Milk may be linked to bone fractures and early death

NHS Choices - Behind the Headlines - Wed, 29/10/2014 - 12:15

"Drinking more than three glasses of milk a day may not protect bones against breaking – and may even lead to higher rates of death," the Mail Online reports.

Do not be alarmed – your milkman is no Hallowe'en death-bringer. In fact, there are many reasons to treat this news – and the research behind it – with some caution.

The research comprised an analysis of two large Swedish cohort studies, in which a group of men and a group of women were given food questionnaires and then followed up for an average of 20 years. Researchers looked at whether how much milk they drank was linked to fractures or death during follow-up.

In women, drinking any more than 200g of milk daily (less than one glass) was linked to increased risk of dying during follow-up. This increased risk ranged from 21% for one to two glasses to an increased risk of 93% for three or more.

More than one glass a day was also linked to an increased risk of fractures in women. There wasn't such a clear link with either early death or fractures in men.

However, people involved in the study may not have been able to reliably estimate their volume of milk intake per day, and there may have been various unmeasured factors influencing the outcomes.

This was also a Swedish population, who may have distinct health and lifestyle factors or environmental influences, which means the results are not applicable to other populations.

For example, milk in Sweden is fortified with vitamin A (unlike the UK), and high levels of vitamin A intake have been linked to an increased risk of fracture.

These findings are undoubtedly worthy of further research, but people should not feel the need to drink less milk based on this study alone.

 

Where did the story come from?

The study was carried out by researchers from Uppsala University and the Karolinska Institutet in Sweden.

It was funded by the Swedish Research Council, and one of the researchers was reported to be an employee of the Swedish National Food Agency.

The study was published in the peer-reviewed British Medical Journal. This article is open access, meaning it can be accessed and read for free online.

The majority of the UK's media headlines are needlessly alarmist, although the actual reporting of the study tended to be more restrained. Many of the sources include quotes from independent experts, who discuss the limitations of the study and highlight the fact Swedish milk is fortified with vitamin A.

 

What kind of research was this?

This was an examination of the findings of two Swedish cohort studies – one in men and one in women – which aimed to investigate whether drinking more milk is linked to outcomes of fracture or mortality (death) from any cause.

The researchers say it is well known that a diet rich in dairy, containing high amounts of essential nutrients such as calcium and vitamin D, is considered to reduce the risk of osteoporotic fractures.

However, they say there may be undesirable effects because milk contains D-galactose, a type of sugar (although it tastes much less sweet than other types of sugar).

Experimental evidence in animals has suggested D-galactose is associated with ageing, with observations including oxidative stress (where damage occurs at the molecular level) to tissues, and changes to gene activity and the immune system.

The researchers say an injected dose of 100mg/kg of D-galactose has been shown to accelerate biological signs of ageing in mice, which is equivalent to 6 to 10g in humans, or the amount found in one to two glasses of milk.

The researchers therefore wanted to test their theory that a high consumption of milk may increase oxidative stress and inflammation in humans, and so increase the risk of mortality and fracture.

Cohort studies are a good way of looking at whether particular exposures are associated with disease outcomes. However, they cannot prove cause and effect.

In this study, important limitations include that the food questionnaire may not give a reliable indication of milk intake or of lifetime patterns.

Also, there may be a variety of other health and lifestyle factors (confounders) that are influencing any association between milk intake and fractures or mortality, which the study has not been able to take into account.

 

What did the research involve?

This study used data from two community-based Swedish cohorts:

  • The Swedish Mammography Cohort, which recruited more than 90,000 middle-aged to elderly women from two Swedish counties from 1987-90. Food frequency questionnaires were given to the women at enrolment and again in 1997. The current study included 61,433 women who completed both of these questionnaires.
  • The Cohort of Swedish Men, which recruited more than 100,000 middle-aged to elderly men from two counties in Sweden in 1997. The men were given a single food frequency questionnaire at enrolment, and this study is representative of 45,339 men who completed this questionnaire.

In both studies, the food frequency surveys questioned up to 96 foods and drinks consumed over the past year, including how many servings of the item per day or per week.

Dairy items included milk, fermented milk, yoghurt and cheese, with instructions that one serving of milk equalled one 200ml glass.

The researchers say milk intake was specified according to fat content, and they summed intake into a single measure representing total milk intake on a continuous scale.

Looking at outcomes, the researchers examined those recorded between enrolment for the two studies and the end of December 2010. All participants were linked to the Swedish Cause of Death Registry, so the researchers could identify any deaths related to all causes, cardiovascular diseases or cancers.

Fractures were identified by linking all participants to the Swedish National Patient Registry and by looking for any hospital admissions or outpatient visits with diagnostic codes related to fracture.

Regarding adjustment for confounders, the researchers adjusted their analyses for many factors, including age, body mass index (BMI), total energy intake, healthy dietary pattern, calcium and vitamin D supplementation, and physical activity levels.

The researchers assessed the risk of mortality or fracture according to categories of milk intake (less than 200g per day, 200-399g per day, 400-599g per day, and 600g per day or more) and for each additional 200g of milk per day corresponding to each additional glass of milk. They also looked at the effects of other dairy items, such as cheese and fermented milk products.

 

What were the basic results?

The women's cohort consumed, on average, 240g milk per day, and the men 290g – around one to two glasses day. The researchers observed a general trend that increased milk intake was associated with increased energy intake overall and increased intake of most other nutrients, while alcohol intake tended to decrease.

Deaths

During an average 22 years of follow-up, 15,541 women died (25% of the cohort), with a third of these deaths as a result of cardiovascular disease and a fifth related to cancer.

The men were followed for an average of 13 years, during which time 10,112 died (22% of the cohort), with just under half of these deaths as a result of cardiovascular disease and just over a quarter caused by cancer.

In the women's cohort, compared with drinking less than one glass of milk a day (less than 200g/day), each increasing category of intake was associated with a 21% increased risk of death from any cause for one to two glasses, and 93% increased risk for three or more glasses.

Any intake above one glass a day was associated with an increased risk of cardiovascular death, but an increased risk of cancer death was only seen with intakes above two glasses a day.

In the men's cohort, the link with all-cause death was less strong. Intakes above two glasses of milk per day were associated with a 5-10% increased risk of death from any cause, but the links were only of borderline statistical significance, meaning these may be chance findings.

Looking at cause of death for men, there was a just significant increased risk of cardiovascular death above two glasses a day, but no significant link with cancer deaths.

Fractures

In the women's cohort, 17,252 had a fracture (28%) during follow-up, while in the men's cohort, 5,379 had a fracture (12%).

In women, each increasing category of milk intake above less than one glass a day was associated with an increased risk of fracture of 7% for one to two glasses, and 16% for two or more. Risk of hip fracture specifically also increased with each intake above less than one glass.

In men, there was no significant link between milk intake and any fracture, or hip fracture specifically.

Other milk products

No increased risk was found with increased intake of other dairy products, such as cheese or fermented milk – in fact, the opposite was seen.

Higher intakes of other dairy products were associated with a lower risk of mortality and fractures in women. Risk reductions in men were more modest or were non-existent.

 

How did the researchers interpret the results?

The researchers concluded that, "High milk intake was associated with higher mortality in one cohort of women and in another cohort of men, and with higher fracture incidence in women."

However, they give due caution that, "Given the observational study design with the inherent possibility of residual confounding and reverse causation, a cautious interpretation of the results is recommended. The findings merit independent replication before they can be used for dietary recommendations."

 

Conclusion

This Swedish study found women who drink more than 200g (less than one glass) of milk a day have an increased risk of death and fractures. In men, the link between milk and risk of death or fractures was less strong.

There was no link between milk intake and fractures, and the risk increases for death above two glasses a day were small and of borderline statistical significance.

The study has various strengths, including its large population size of both men and women, and long-term follow-up. Also, the Swedish registries used to identify causes of death and hospital attendances for fracture are likely to be accurate and reliable.

However, there are important limitations to bear in mind when interpreting meaning from this study, as follows:

  • The study cannot prove direct cause and effect between milk and these outcomes. Although the researchers have tried to take account of various health and lifestyle factors, the study may not have been able to fully account for the influence of these factors (for example, former or current smoking categories were considered, but within these there is going to be a wide range of frequency and duration). There may also be other unmeasured factors influencing the association.
  • There may also be the possibility for reverse causation. For example, postmenopasual women who were at risk of, or had been diagnosed with, osteoporosis could have been at an increased risk of having a fracture and may have been increasing their milk intake to try to boost their calcium levels.
  • It may be hard to reliably estimate milk intake, particularly if you consider that people do not necessarily consume measured glasses of milk per day. Milk is added to drinks or cereal, or is used in cooking. Overall, this could make it difficult to give a reliable indication of milk intake. It is also hard to know whether these food frequency questionnaires represent a lifelong pattern.
  • Also, the study relates to a specific population of Swedish middle-aged to elderly men and women. This population may have particular health, lifestyle and environmental influences, meaning their results are not generalisable to all other populations. For example, Swedish milk is fortified with vitamin A, so results may not apply to the UK, where we do not have fortified milk as standard.

The reverse pattern – decreased risk of death and fractures in women with higher intakes of other dairy products such as cheese and yoghurt – further highlights the uncertain picture painted by these results.

The researchers clearly acknowledge the potential limitations of their research, saying that, "Given the inherent possibility of confounding and reverse causation, a cautious interpretation of the results is recommended."

The findings are undoubtedly worthy of further research, but people should not be overly concerned or feel the need to alter their milk intake as a result of this single study.

A balanced lifestyle is most important for health, including taking regular exercise, not drinking too much alcohol, avoiding smoking and having a healthy, balanced diet – milk contains many important nutrients and can be part of this. 

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Dangers of more than 3 glasses of milk a day: High intake may not protect against broken bones and could actually increase chance of death. Mail Online, October 28 2014

Three glasses of milk a day can lead to early death, warn scientists. The Daily Telegraph, October 28 2014

High milk diet 'may not cut risk of bone fractures'. BBC News, October 29 2014

Milk might not be as good for us as we thought, study suggests. The Independent, October 28 2014

Three glasses of milk a day linked to earlier death. Daily Express, October 29 2014

Links To Science

Michaëlsson K, Wolk A, Langenskiöld S, et al. Milk intake and risk of mortality and fractures in women and men: cohort studies. British Medical Journal. Published online October 28 2014

Categories: NHS Choices

Could sex with 21 women 'cut prostate risk'?

NHS Choices - Behind the Headlines - Wed, 29/10/2014 - 10:30

"Sleeping with more than 20 women protects men against prostate cancer, academics find," The Daily Telegraph reports.

The study in question included more than 1,500 men diagnosed with prostate cancer and a matched group of men without prostate cancer from the general population. Researchers then interviewed the men about their sexual activity.

The study concluded that having more than 20 female partners over a man’s lifetime was associated with a decreased risk of prostate cancer, while having several male partners seemed to increase the risk.

However, studies like this one cannot prove that having several female partners reduces the risk of prostate cancer, or that having more male partners increases risk.

If having multiple female partners reduced prostate cancer risk, it would be expected that the more partners you had, the lower your risk would be. However, this study did not find such a relationship between the number of female partners and associated risk. The protective effect was only seen in men in the upper category of having 21 or more female partners, and strangely, no other category.

The findings do not give a clear or coherent picture, and there may be many other factors influencing the relationship.

The most important thing to remember – regardless of number, or gender, of partners – is to practice safe sex with a condom to reduce the risk of sexually transmitted infections (STIs).

 

Where did the story come from?

The study was carried out by researchers from the Université du Québec, the University of Montreal and the University of Montreal Hospital Research Centre. It was funded by the Canadian Cancer Society, the Cancer Research Society, the Fonds de la recherche du Québec-Santé (FRQS), the FRQS-RRSE, and the Ministére du Développement économique, de l’Innovation et de l’Exportation du Québec.

The study was published in the peer-reviewed medical journal Cancer Epidemiology.

The media coverage of this story was almost universally poor, with news articles reporting non-significant findings or omitting the fact that some associations were only found in a sub-type of prostate cancer, or omitting the comparator.

For example, The Independent, the Mail Online and the Telegraph report that men who slept with more than 20 women were 19% less likely to develop an aggressive type of cancer than those who had only one female sexual partner, whereas this association was actually not statistically significant.

They go on to say that having more than 20 male partners doubled the risk of prostate cancer. In the Mail and Telegraph, this is compared to men who had never slept with a man. This is again incorrect. Having more than 20 male partners compared to having one was associated with an increased risk of less-aggressive prostate cancer, but it was not significantly associated with prostate cancer risk overall or risk of aggressive prostate cancer. Having more than 20 male partners compared to only having female partners was not significantly associated with any type of prostate cancer.

It would appear that most media outlets simply took the accompanying press release at face value, without actually bothering to read the study or subject it to any kind of critical analysis – a practice that is sadly all too common these days.

 

What kind of research was this?

This was a case-control study comparing sexual activity and STIs in men diagnosed with prostate cancer (the cases) and men matched by age from the electoral registry (the controls). 

Case-control studies like this one cannot prove that the number of sexual partners, or their gender, is directly associated with risk of prostate cancer. There may be many factors (confounders) influencing the relationships observed in this study.

 

What did the research involve?

The researchers compared 1,590 men diagnosed with prostate cancer in a Montreal hospital between 2005 and 2009 (the cases) and 1,618 randomly selected age-matched men from the electoral list (the controls).

The men were interviewed to obtain information on sociodemographic factors (for example, highest level of education, family income, marital status), lifestyle (including sexual activity and STIs), medical and environmental factors.

Men were asked whether they had ever had sexual intercourse, the age they first had sexual intercourse, the number of female partners they had and the number of male partners they had.

Men were also asked to describe their sexual orientation in terms of the following categories:

  • heterosexual
  • bisexual, with a preference for women
  • bisexual, with a preference for men
  • bisexual, with no preference for women or men
  • homosexual

Men were also asked whether they had ever had the following STIs:

The researchers looked to see if there was an association between sexual activity and STIs and developing prostate cancer. The researchers also divided prostate cancer into aggressive (Gleason score =>7) and less-aggressive (Gleason score <7) forms of prostate cancer to see if there were different associations. (See Diagnosing prostate cancer for more information about Gleason scores)

The researchers adjusted their analyses for age, whether the men were of European, Black, Asian or other ancestry, family history of prostate cancer, and prostate cancer screening history.

 

What were the basic results?

Men with prostate cancer, compared to controls, were more likely to be Canadian-born and to be of European or Black ancestries, and less often of Asian ancestry. Twice as many men with prostate cancer had a first-degree relative (for example, brother or father) with prostate cancer than controls. Almost all men with prostate cancer reported being screened for prostate cancer within two years before being diagnosed with prostate cancer, whereas 76% of controls reported being screened in the preceding two years. Cases and controls had similar family income, marital status, smoking history and alcohol use.

Never having sexual intercourse was not associated with a difference in risk of prostate cancer overall. The age men first had intercourse was also not associated with a difference in risk of prostate cancer.

Compared with having one female sexual partner, having more than 20 female sexual partners was associated with a decreased risk of prostate cancer (odds ratio [OR] 0.72, 95% confidence interval [CI] 0.56 to 0.94). Men who have sex with men were included in this analysis.

Compared with having one male sexual partner, having more male sexual partners did not alter the risk of prostate cancer.

There was no association found between individual types of STIs, or with all STIs combined, and prostate cancer. However, the researchers state that this might have been because few men had an STI.

When aggressive and less-aggressive prostate cancer were analysed separately, the researchers observed no associations with aggressive prostate cancer. Never having sex, having had two to three male partners compared to never having had one, and having two to three or 21 male partners or more compared to having had one were associated with increased risk of less-aggressive prostate cancer; having more than 20 partners of either gender or more than 20 female partners compared to having one was associated with reduced risk of less-aggressive prostate cancer.

 

How did the researchers interpret the results?

The researchers conclude that “our findings are in support of a role for the number of sexual partners in prostate cancer development.”

 

Conclusion

This case-control study has suggested that having several female partners over a man’s lifetime is associated with a protective effect against prostate cancer, whereas having several male partners increased the risk.

However, case-control studies like this one cannot prove that having several female partners reduces the risk of prostate cancer, or that having more male partners increases risk. When it comes to complex issues such as lifestyle, sexuality and cancer outcomes, there could be a wide range of contributing factors.

If having multiple female partners reduced prostate cancer risk, it would be expected that the more partners you had the lower your risk would be. However, this study did not find such a relationship between number of female partners and associated risk. The protective effect was confined to men in the upper category of having more than 20 female partners.

You would reasonably expect to see a kind of dose-dependent relationship, so, for example, having 15 or 16 partners would also have a protective effect. No such relationship was seen, raising the possibility that the “21 or more” outcome was a statistical fluke; a confidence interval of 0.56 to 0.94 is of borderline statistical significance.

Similarly, the results are confusing for men who had male partners. Having two to three, or more than 20, male partners increased risk of less-aggressive prostate cancer compared to one male partner. However, between four and 20 was not associated with increased risk.

It seems possible that the associations seen in this study were the result of performing multiple comparisons. That is, where performing an increasing number of comparisons increases the chances that you will find some significant associations, even if there is not truly a significant link. If there were truly significant links, you would expect to see more consistent trends.

If these are real links, there could still be other factors that are influencing the relationship. It is difficult to know whether face-to-face interviews of sexual activity will have given reliable results, and also possible that a man’s knowledge of his cancer status could have influenced his recall.

Further work is required to determine whether having multiple female partners really is associated with a reduced risk of prostate cancer, and to see whether the gender of partners really makes a difference.

The most important thing to remember – regardless of the number or gender of partners – is to practice safe sex with a condom to reduce the risk of STIs.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Sex with 21 women lowers risk of prostate cancer, academics find. The Daily Telegraph, October 28 2014

Sex with more than 20 women reduces risk of prostate cancer, according to study. The Independent, October 28 2014

Men who sleep with multiple women REDUCE their risk of prostate cancer. Mail Online, October 28 2014

Is sleeping around good for you? Sex with more than 20 women could 'lower prostate cancer risk'. Daily Mirror, October 28 2014

Links To Science

Spence AR, Rousseau M, Parent M. Sexual partners, sexually transmitted infections, and prostate cancer risk. Cancer Epidemiology. Published online September 29 2014

Categories: NHS Choices

Agave syrup no better than placebo cough remedy

NHS Choices - Behind the Headlines - Tue, 28/10/2014 - 12:00

“Placebo cough treatment benefits children and their parents, study suggests,” The Daily Telegraph reports.

A US study found that children’s reported cough symptoms improved even though they were just given a dummy treatment (placebo).

The study compared the effectiveness of agave nectar (a sweet syrup similar to honey, from the agave plant), placebo (flavoured coloured water) or no treatment for night-time cough in 119 children aged between two and 47 months old. Parents were given surveys to record cough symptoms over two days.

Agave nectar and placebo both provided more relief from cough symptoms than no treatment, but there was no difference in relief between agave nectar and placebo.

It is possible that as parents were assessing their children’s symptoms, this could be an example of the placebo effect. That is, parents who thought they were giving their child some syrup, rather than giving nothing, felt that it helped their child’s symptoms. The placebo effect, where people get better because they expect to get better, may sound unlikely, but it has been well documented for decades.

It is also possible that giving something to swallow – either syrup or plain water – is better than nothing when trying to ease a child’s cough.

The best thing that you can do to help a young child with a cough or cold is to make sure that they stay well hydrated with plenty of warm drinks. Honey shouldn't be given to babies under the age of one, due to the risk of infant botulism.

 

Where did the story come from?

The study was carried out by researchers from Penn State College of Medicine, Pennsylvania, and was funded by an unrestricted grant to the Penn State College of Medicine by Zarbee’s Inc, which makes a number of products, including cough syrups. One of the study’s authors has worked as a paid consultant for Zarbee’s Inc, which represents a potential conflict of interest. However, seeing as the main result of the study was that placebos were as effective as agave syrup in treating coughs, it would appear that the study was free of any commercial interference or influence.

The study was published in the peer-reviewed medical journal JAMA Pediatrics. This article was open access, so can be read for free online.

The research was well covered by The Daily Telegraph, though it should be noted that the research article is published in JAMA Pediatrics rather than JAMA Neurology, as the paper wrongly stated.

While the focus of the news - and indeed the title of the research paper - suggest that scientists were looking at whether placebos work for cough mixture, by definition placebos don’t work (except via the placebo effect). In fact, the researchers were testing whether a new formulation of agave syrup could improve cough symptoms. It didn’t improve symptoms any more than placebo.

 

What kind of research was this?

This was a randomised controlled trial (RCT) that aimed to compare the effectiveness of novel pasteurised agave nectar, compared to placebo or no treatment, on nocturnal cough and sleep difficulty associated with acute cough in infants and toddlers.

Agave nectar is a syrup similar to honey that is produced in Central and South America. Unlike honey, it hasn’t been associated with botulism.

An RCT is the ideal way to compare the effectiveness of different treatments.

 

What did the research involve?

The researchers studied 119 children aged between two and 47 months old, who had a cough for seven days or less and visited their GP. Children had a non-specific cough, meaning it was not thought to be due to any particular disease or condition and most likely due to a viral infection. These types of infections are common in young children, as their immune systems are underdeveloped.

They could have other symptoms of a temperature, runny nose or congestion, but were excluded from the study if they had symptoms suggesting more serious conditions, such as asthma or pneumonia.

Children were also ineligible if they had used any medication or honey to treat their cough within six hours of bedtime on the evening before or on the day of enrolment.

Parents were asked to complete a questionnaire about their child’s symptoms the night before. They were asked to rate between one (not at all) to seven (very often/severe):

  • how often did your child cough last night?
  • how severe was your child’s cough last night?
  • how bothersome was your child’s cough last night?
  • how severe was your child’s stuffy nose last night?
  • how severe was your child’s runny nose last night?
  • how much did last night’s cough affect your child’s ability to sleep?
  • how much did your child’s cough affect your own ability to sleep last night?

The parents of the studied children reported at least “moderately often” or “moderately severe” (a score of four or more) on at least two of three questions related to cough frequency, cough effect on child sleep and cough effect on parent sleep.

The children were randomised to:

  • grape-flavoured pasteurised agave nectar (from Zarbee’s Inc, which funded the study)
  • coloured grape-flavoured water (placebo)
  • no treatment

The children received one of these options 30 minutes before bedtime.

Within 30 minutes of waking, the parents again completed the same questionnaire about their child’s symptoms.

The researchers compared the change in symptoms between nights for the three different groups.

 

What were the basic results?

Within each study group, symptoms significantly improved from baseline.

When treatment-night effects of agave nectar, placebo and no treatment were compared, agave syrup and placebo were both superior to no treatment for all symptoms apart from how bothersome the cough was.

However, there were no significant differences in any outcome when agave syrup was compared to placebo.

 

How did the researchers interpret the results?

The researchers concluded that “in a comparison of agave nectar, placebo and no treatment, a placebo effect was demonstrated, with no additional benefit offered by agave nectar. Health care professionals should consider the potential benefits and costs when recommending a treatment with only a placebo effect for infants and toddlers with non-specific acute cough.”

 

Conclusion

This RCT compared the efficacy of agave nectar, placebo or no treatment for night-time cough in children aged between two and 47 months old.

Agave nectar and placebo both provided more relief from cough symptoms than no treatment, but there was no difference in relief between agave nectar and placebo.

It's possible that as parents were assessing their children’s symptoms, this study could be an example of the placebo effect. That is, parents who thought that they were giving their child some syrup, rather than giving nothing, felt that it helped their child’s symptoms. Equally, it is possible that giving something to swallow – either syrup or plain water – is better than nothing at helping to ease a child’s cough.

All children included in this study had a cough for less than a week and other cold-like symptoms, such as runny nose or congestion. This is likely due to a viral infection and requires no specific treatment. There is no good evidence that over-the-counter cough medicines actually work against an acute cough. The Medicines Regulatory Agency in the UK currently advises that over-the-counter cough and cold medicines shouldn’t be given to children under six years. Honey also shouldn’t be given to children aged under one.

The best thing you can do to help a young child with a cough or cold is to make sure that they stay well hydrated with plenty of warm drinks.

The study does highlight the remarkable impact the placebo effect can have in certain cases. There are libraries full of evidence showing how symptoms can dramatically improve for a range of conditions, even though a patient was given a sugar pill or a salt water injection. This may suggest that the mind can have a considerable effect on the symptoms of the body in some cases.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Placebo cough treatment benefits children and their parents, study suggests. The Daily Telegraph, October 27 2014

Links To Science

Paul IM, Beiler JS, Vallati JR, et al. Placebo Effect in the Treatment of Acute Cough in Infants and Toddlers - A Randomized Clinical Trial. JAMA Pediatrics. Published online October 27 2014

Categories: NHS Choices

Drugs may work better at certain times of the day

NHS Choices - Behind the Headlines - Tue, 28/10/2014 - 11:00

“Take your medication at the right time of day or it might not work,” The Independent reports.

The news is based on a study which looked at the pattern of genes made in 12 different mouse organs, to see if any of the genes showed a circadian rhythm (the “body clock”: where the body reacts to a day and night cycle).

Nearly half of genes that code for proteins showed a circadian rhythm in at least one mouse organ. 

In most organs, such as the liver, the researchers noted that the expression (activity) of many genes peaked during “rush hours” before dawn and dusk.

The researchers found that the majority of best-selling drugs, and medicines listed as “essential” by the World Health Organization (WHO), directly target products of rhythmic genes. As some of these drugs remain active for short periods (have short "half-lives"), the time the drug is taken could impact on how well it works.

However, in the wild, mice are primarily nocturnal (mainly active at night), in contrast to people who are diurnal (mainly active during the day), so the genes that are expressed in a circadian rhythm might be different.

Although this study suggests that medication timing could be modified to improve effectiveness, further studies will be required to determine optimal drug timing. 

 

Where did the story come from?

The study was carried out by researchers from the University of Pennsylvania and the University of Missouri, and was funded by the US National Heart, Lung and Blood Institute, and by the Defense Advanced Research Planning Agency (DARPA).

The study was published in the peer-reviewed scientific journal PNAS. This article is open access, meaning that it can be read for free online.

This study was well covered by the UK media. BBC News also featured a useful infographic about the body clock and its impact on biological function.

 

What kind of research was this?

This was an animal study, which aimed to look at the pattern of the genes made in mice over a 24-hour period.

It should be noted that mice in the wild are primarily nocturnal, in contrast to people, who are diurnal, so the genes expressed in a circadian rhythm might be different. Although this study suggests medication timing could be modified to improve effectiveness, further studies will be required to determine optimal drug timing. 

 

What did the research involve?

The researchers looked at the genes that were being made in 12 different mouse organs every two hours over a 48-hour period. The organs that they examined were the:

  • brainstem
  • cerebellum
  • hypothalamus
  • heart
  • aorta
  • kidney
  • adrenal gland
  • liver
  • lung
  • skeletal muscle
  • brown fat
  • white fat

They looked for genes that cycled over a 24-hour (one-day) period.

 

What were the basic results?

The researchers found that 43% of the genes that code for proteins show a circadian rhythm somewhere in the body.

The liver had the most circadian genes, whereas the hypothalamus (part of the brain) had the fewest.

In most organs, the researchers noted that the expression of many oscillating genes peaked during “rush hours”, before dawn and dusk.

The researchers also found that some genes that don’t code for proteins get expressed in a circadian rhythm.

The researchers found that the majority of best-selling drugs, and medicines listed as “essential” by the WHO, directly target products of rhythmic genes. As some of these drugs have short half-lives, the time the drug is taken could impact on how effective they are.

 

How did the researchers interpret the results?

This study found that nearly half of all genes in the mice oscillated with a circadian rhythm somewhere in the body. They go on to say that "a majority of best-selling drugs in the United States target circadian gene products. Many of these drugs have relatively short half-lives, and our data predict which may benefit from timed dosing.”

 

Conclusion

This study looked at the pattern of genes made in 12 different mouse organs, to see if any of the genes showed a circadian, or 24-hour, rhythm.

43% of the genes that code for proteins showed a circadian rhythm in at least one mouse organ. The liver had the most circadian genes, whereas the hypothalamus (part of the brain) had the fewest.

In most organs, the researchers noted that the expression of many oscillating genes peaked during “rush hours” before dawn and dusk.

Although this study suggests that medication timing could be modified to improve effectiveness, further studies will be required to determine optimal drug timing. 

Until further evidence is forthcoming, you should follow the advice that comes with your medication in terms of when to take it.

Analysis by Bazian. Edited by NHS ChoicesFollow Behind the Headlines on TwitterJoin the Healthy Evidence forum.

Links To The Headlines

Take your medication at the right time of day or it might not work, scientists say. The Independent, October 27 2014

Body clock: 'Rush hour' transformation discovered. BBC News, October 28 2014

Drugs may work better depending on time of day. The Daily Telegraph, October 27 2014

Links To Science

Zhang R, Lahens NF, Balance HI, et al. A circadian gene expression atlas in mammals: Implications for biology and medicine. PNAS. Published online October 27 2014

Categories: NHS Choices

Lab-grown killer cells could treat brain tumours

NHS Choices - Behind the Headlines - Mon, 27/10/2014 - 11:00

"Scientists … have discovered a way of turning stem cells into killing machines to fight brain cancer," BBC News reports. While the results of this study were encouraging, the research involved mice, not humans.

The headline is prompted by the creation of stem cells genetically engineered to produce a type of poison known as pseudomonas exotoxin. This poison was made to target a specific type of brain tumour cell (glioblastoma) by linking it to antibody fragments.

This technique has been used with great success to treat blood cancers such as leukaemia, but has been less successful at treating solid tumours. The researchers suggest this is because it only remains active for a short amount of time (has a short half-life) and because it may be difficult to reach the tumour.

To overcome these problems, the researchers genetically engineered neural stem cells, which could make pseudomonas exotoxin while being resistant to the poison themselves.

The poison-making stem cells were able to kill these brain cancer cells both in the laboratory and in mice engineered to develop brain tumours.

The results are promising, but, as the researchers themselves point out, "Translation into human patients would need to be adapted to tackle the challenges imposed by the new host [a human being]".

 

Where did the story come from?

The study was carried out by researchers from Massachusetts General Hospital, the Dana-Farber Cancer Institute, and Harvard University.

It was funded by the US National Institutes of Health.

The study was published in the peer-reviewed biological journal, Stem Cells.

The story was well covered by BBC News and The Independent. Both make it clear this was a mouse study.

 

What kind of research was this?

This mouse study aimed to develop and test genetically engineered neural stem cells, which can make the poison pseudomonas exotoxin while being resistant to the poison themselves.

Pseudomonas exotoxin blocks cells from making proteins, which leads to the death of the targeted cells. The pseudomonas exotoxin was linked to an antibody fragment to target it at cells that had specific receptors present on their surfaces. These particular receptors are often present in glioblastomas (a specific type of brain tumour) and not on normal cells.

The researchers say pseudomonas exotoxin linked to antibody fragments have been used with great success to treat blood cancers, but have been less successful at treating solid tumours. They suggest this is because it only remains active for a short amount of time and it may be difficult to reach the tumour.

To overcome these problems, the researchers genetically engineered neural stem cells. So far the technique has only been tested in mice and on these specific cancer cells in the laboratory, so much more work will need to be done to ensure it is safe and effective in people.

 

What did the research involve?

Briefly, the researchers genetically engineered neural stem cells to make the poison pseudomonas exotoxin.

The researchers tested the activity of the poison-making stem cells on cells grown in the laboratory and on mice.

 

What were the basic results?

The researchers initially tested their poison-making stem cells on glioblastoma cells grown in the laboratory. When the stem cells and the glioblastoma cells were grown together, the glioblastoma cells died. The glioblastoma cells expressing the highest amount of the tumour-specific receptor were most sensitive to the stem cells.

The researchers then looked at whether the poison-making stem cells would work in animals. They mixed tumour cells and the poison-making stem cells and put them under the skin of mice. The poison-making stem cells were able to kill the tumour cells.

According to the researchers, one of the major limitations of current glioblastoma therapy is the inadequate distribution of chemotherapy drugs to the tumour that remains after surgery.

Surgery aims to remove all of the tumour, but cannot always remove all of it safely. Some tumours develop deep inside the brain, so removing them completely could lead to significant brain damage.

After surgery to remove a tumour, the researchers inserted poison-making stem cells in mice that were engineered to develop glioblastomas.

No tumours could be detected in mice who had the poison-making stem cells inserted by 21 days after surgery, but tumour masses could be detected in the control mice.

The poison-making stem cells also improved average survival from 26 days in the control group to 79 days in the treated mice.

The researchers finally tested the poison-making stem cells on glioblastoma cells from human patients. The poison-making stem cells were able to kill the glioblastoma cells that expressed the tumour-specific receptor.

 

How did the researchers interpret the results?

The researchers concluded that stem cell-based delivery of pseudomonas exotoxin can increase the likelihood of anti-tumour response by increasing the amount of time the poison is delivered for, and by eliminating the need for multiple invasive administrations.

 

Conclusion

This study has described the creation of genetically engineered neural stem cells that make the poison pseudomonas exotoxin. The stem cells were also made resistant to the poison themselves. The poison was linked to an antibody fragment to target it towards a specific type of brain tumour cell (glioblastoma).

Glioblastoma are usually very aggressive cancers, and the current treatment would usually involve surgical removal followed by radiotherapy and chemotherapy to try to kill the residual cancer cells.

This treatment regime can result in significant side effects, and there is no guarantee of achieving a complete cure.

In this study, the poison-making stem cells were able to kill these brain tumour cells both in the laboratory and in a mouse model.

So far the technique has only been tested in mice and on these specific brain cancer cells in the laboratory. This means much more work is needed to ensure it is safe and effective in people with brain cancer.

Glioblastomas also only account for a portion of all brain cancers. It is not known whether the treatment could ever be developed to treat other types of brain cancer.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Cancer-killing stem cells engineered in lab. BBC News, October 25 2014

Stem cells that can kill cancer have been engineered by scientists. The Independent, October 25 2014

Links To Science

Stuckey DW, Hingtgen SD, Karakas N, et al. Engineering toxin-resistant therapeutic stem cells to treat brain tumors. Stem Cells. Published online October 25 2014

Categories: NHS Choices

A mug of cocoa is not a cure for memory problems

NHS Choices - Behind the Headlines - Mon, 27/10/2014 - 10:00

"Cup of cocoa could give the elderly the memory of a 'typical 30 or 40-year-old'," The Independent reports.

Before you race down to the supermarket to pick up a tub of chocolatey powder, you might want to pause to consider some facts that rather undermine this headline.

The news is based on a small study that found a specially formulated cocoa-based drink high in "flavanols" made older people slightly faster, but no more accurate, in memory tests.

The research, which happened over a period of just three months, also looked at brain scans of the test subjects. It found increased activity in an area of the brain thought to be involved in cognition and memory – the dentate gyrus.

It is difficult to gauge whether the modest improvements seen in testing would have a significant impact on a person's daily life or functioning.

The prospect of halting or reversing dementia or age-related cognitive decline through simple changes in your diet is incredibly appealing. But while the results of this study suggest the particular product tested could improve cognition and memory, it certainly does not prove this.

 

Where did the story come from?

The study was carried out by researchers from universities based in New York, and was funded by US National Institutes of Health grants, as well as what was described as an "unrestricted grant" from Mars Incorporated.

One of the study authors declared a financial conflict of interest as they were also employed by Mars. As Mars is one of the globe's leading makers of chocolate products, this may represent a potential conflict of interest.

The study was published in the peer-reviewed journal, Nature Neuroscience.

The majority of the media coverage portrayed this study as showing cocoa was effective at improving memory, which you might assume means a better and more accurate recall of things. In reality, the research was more limited and the improvements were only seen in the speed of memory tasks, not in the accuracy of tasks.

The most frivolous headlines came from The Independent, with "Cup of cocoa could give the elderly the memory of a 'typical 30 or 40-year-old'," and the Daily Express, with its front page headline claiming that, "new study proves cup of cocoa can boost the brain". These statements are premature, potentially misleading and are not justified by this research alone.

The Independent's unfortunate headline may simply have parroted a press release on the research from Columbia University. In the press release, one of the researchers was quoted as saying, "If a participant had the memory of a typical 60-year-old at the beginning of the study, after three months that person on average had the memory of a typical 30- or 40-year-old."

The study did not recruit anyone aged 30 to 40 to test this directly, so it appears to be an assumption. The main study publication itself also did not make these bold claims – they were confined to the press release.

Larger long-term trials may show whether more rounded improvement in cognitive ability and memory are possible using high flavanol supplements.

 

What kind of research was this?

This was a small randomised control trial testing the effect of a low- or high-cocoa diet on age-related memory decline in older adults.

The researchers state the function of a brain region called the dentate gyrus declines as people age, and is therefore considered to be a possible source of age-related memory decline.

This study first looked to find evidence that lower dentate gyrus function was indeed related to memory decline and, secondly, to test an intervention to stop the decline or reverse it.

A randomised control trial is one the best study designs to investigate whether dietary interventions such as this can influence cognitive ability.

The downside is that they tend to be very expensive to set up and run, so are often short and involve small numbers (as was the case with this study), which limits the applicability of the results to other populations.

 

What did the research involve?

The study involved asking volunteers aged 50 to 70, who were free from cognitive impairment, to follow a three-month lifestyle intervention containing diet and exercise elements.

Before and after the intervention, the research team compiled brain scans of the dentate gyrus region of the volunteers and tested their cognitive abilities to see if the diet, exercise or both elements together were influencing signs of age-related cognitive decline.

The study participants were free from illness, but were selected to be physically inactive and not to be above-average fitness. They were also excluded if they had a medical condition that didn't allow them to undertake aerobic activity. Anyone who routinely took dietary or herbal supplements was also excluded from the study.

The volunteers were randomised into one of four groups:

  • high flavanol with aerobic exercise (eight people)
  • high flavanol without aerobic exercise (11 people)
  • low flavanol with aerobic exercise (nine people)
  • high flavanol without aerobic exercise (nine people)

The people in the groups were similar in terms of age, educational level and gender.

The prescribed anaerobic exercise was one hour a day, four days a week. The high-flavanol intake group took 900mg cocoa flavanols with 138mg of epicatechin (another flavanol) every day, compared with the low-flavanol group, who consumed 10mg cocoa flavanols and less than 2mg epicatechin per day.

It isn't completely clear how the diet supplement element was delivered, but the researchers describe how participants were given the flavanols as a packet, possibly to dissolve in water like an instant chocolate drink.

Brain scans used a high-resolution variant of functional magnetic resonance imaging (fMRI) to map the precise site of age-related dentate gyrus dysfunction. fMRI allows scientists to see blood flow and volume in the brain as a sign of activity.

Cognitive abilities were assessed using a test called ModBent. ModBent has a matching element that involves showing complex images and asking people to "Click on the figure that looks exactly like the one you just saw as quickly as possible".

It also has a recognition element, which also shows complex images and asks people, "Is this one of the figures you saw earlier?"

The test scores are built up using both the speed of the answer (reaction time) and how many were recalled correctly (delayed retention). ModBent score was used in this study because it has previously been shown to deteriorate with age.

 

What were the basic results?

The study was completed by 37 people.

The main finding was that people given high-flavanol supplements had a significantly faster ModBent reaction times, but showed no improvement in retention tests. People who were given high flavanols were, on average, 630ms faster than the low-flavanol group after the intervention.

This was mirrored by a higher dentate gyrus function in the high-flavanol group compared with the low-flavanol group, as assessed in the brain scans.

Interestingly, this effect was unrelated to the exercise component. This was a surprise to the researchers, as previous research suggested regular exercise could reduce cognitive decline.

They investigated this further and found the exercise had not led to any physiological changes in VO2 max, one of many measures of cardiovascular fitness, which measures the amount of oxygen you use while exercising at maximum capacity.

From this, the researchers concluded people had not stuck to the exercise component of the intervention, so the results related to this were not valid. 

 

How did the researchers interpret the results?

The researchers stated that, "Our results indicate that dietary cocoa flavanol consumption enhanced DG [dentate gyrus] function," and the cognitive test and brain scan results "provide evidence that age-related changes in the DG observed in aging humans underlie and drive a hippocampal-dependent component of cognitive aging."

 

Conclusion

This small randomised control trial found giving people a supplement high in cocoa flavanols for three months appeared to improve the function of a brain area – the dentate gyrus.

Decreased activity in the dentate gyrus is thought to be involved in age-related memory decline. People who had high-flavanol supplements performed tests assessing cognitive ability more quickly than those who had low-flavanol supplements.

The prospect of halting or reversing age-related cognitive decline through simple changes in your diet is very appealing, and this study suggests one way it might be possible. However, this study alone does not prove this as it has a number of limitations, including:

  • The group sizes were small. Only 37 people took part and they were further subdivided into groups of less than 10 for most comparisons.
  • There were tiny differences in caffeine and theobromine levels in the high- and low-flavanol cocoa packets, making it possible that substances other than flavanols mediated the effects seen.
  • Only reaction times, and not accuracy of performance, improved. Memory improvements weren't shown directly – participants may have improved their reaction times by simply paying more attention to the task. It is not known whether the observed changes in reaction times would have had any meaningful difference in terms of the person's daily life and functioning.
  • Participants who exercised regularly or took regular herbal or vitamin supplements were excluded from the study, meaning results in this group might be different.
  • None of the participants in this trial were reported to have any cognitive impairment, and longer-term diagnoses of cognitive impairment or dementia were not assessed, so it is not known whether high flavanol intake is of any benefit in preventing these outcomes.

It is also important to point out that the cocoa supplement used was specially formulated for the trial. You shouldn't be led to believe that drinking lots of hot chocolate bought in a supermarket, which can be very high in sugar, will necessarily boost your brain power: it may just boost your waistline. In fact, lots of hot chocolate could raise your blood pressure and increase your risk of tooth decay.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Cup of cocoa could give the elderly the memory of a 'typical 30 or 40-year-old'. The Independent, October 27 2014

Cocoa could be the secret to good memory in old age. The Daily Telegraph, October 26 2014

How a cup of cocoa before bed 'can help improve your memory': Chemical found in the beans could help fight against dementia. Mail Online, October 27 2014

Beat memory loss with a cup of cocoa! Change of diet BOOSTS brain. Daily Express, October 27 2014

Links To Science

Brickman AM, Khan UA, Provenzano FA, et al. Enhancing dentate gyrus function with dietary flavanols improves cognition in older adults. Nature Neuroscience. Published online October 26 2014

Categories: NHS Choices

'Running helps manage my high blood pressure'

NHS Choices - Live Well - Fri, 24/10/2014 - 12:46
'Running helps manage my high blood pressure'

Andrew Watson took up running after a routine medical check-up revealed he had high blood pressure.

Overweight and with a family history of hypertension, the 49-year-old knew he needed to be more active.

With a mainly deskbound job and a busy family life, the father-of-three from Devon was leading a largely sedentary lifestyle. 

However, the unexpected blood pressure readings were a wake-up call for Andrew and prompted him to take up running.

Since graduating from Couch to 5K and progressing on to parkrun, free timed 5km runs, he has lost two stone and says running has given him a “new lease of life”.  

With his father being a seasoned parkrunner and his three teenage sons getting a taste for the timed 5km runs, Andrew says running is turning into a family affair.

Why did you start Couch to 5K?

I have a history of raised blood pressure, which is being managed by my GP surgery. I went for a routine check-up just before Easter [2014] and my reading was up again. I was advised to lose a bit of weight, which was a wake-up call. I'd started cycling and watching my portion sizes, but felt I needed to do more. 

How active were you before starting Couch to 5K?

I wasn't a complete couch potato and I'd recently started cycling to work, but my job is mainly desk-based and I found it hard to incorporate exercise into my lifestyle. I knew I needed to increase my physical activity, but I never seemed to get round to it.

How has Couch to 5K changed you?

I feel fitter now than I have done for years, and regular exercise is now part of my lifestyle. The exercise and better diet also help me manage my blood pressure. I've lost over two stone since I started Couch to 5K in April. I also feel better in myself, less stressed and in a better mood. I think it’s down to the sense of achievement I get from running.

What do you like about the Couch to 5K plan?

I'm the sort of person who needs a bit of structure, so I found the podcasts and the commentary and encouragement really helpful. Knowing I had to fit three runs in each week really helped me get into a routine.

How did you hear about parkrun?

I first heard about parkrun’s timed 5km runs from my dad, who is a keen runner and a proud wearer of his 50 parkruns t-shirt! A parkrun was recently set up in Parke Estate, near Bovey Tracey, about a mile or so from my home.

Did you start parkrun after completing Couch to 5K?

I didn't feel confident tackling a 5km run from scratch, as I had tried running in the past and never enjoyed it. I tended to go too fast too soon, and ended up feeling defeated. Parkrun gave me a goal to aim for while doing Couch to 5K. Once I reached Week 7 of the programme, and was running continuously for 20 minutes, I felt ready to give parkrun a go.

How often do you do parkrun?

I've now completed 15 parkruns since starting in June, and I try to go as much as possible. According to other runners, Parke is quite a hard course compared to other parkruns, with plenty of ups and downs.

What do you like about parkrun?

Lots of things! Anyone can give it a go, no matter what level of fitness they are. It's free and convenient for me, being close to home, and as it starts at 9am you still have the rest of the day to do other things. I have a busy job and family life too, so fitting in exercise has been a challenge in the past.

Have your running times improved?

Yes. With my first parkrun, I was hoping just to get round, but secretly hoping it would be in less than 40 minutes. I was thrilled to achieve 34:25 for my first attempt. The following week I shaved about two-and-a-half minutes off that, and my personal best (PB) now stands at 28:50.

Do you do parkrun alone?

My son has run with me a couple of times, but he usually finds friends from school on the start line to run with. I tend to run on my own, but will see quite a few familiar faces, including work mates and neighbours, along the course. My other two sons are showing an interest in parkrun, so it's turning into a family affair.

Have you made new friends doing parkrun?

Yes, parkrun is quite sociable and friendly. The course volunteers give you encouragement on the way round, and a few people head up to the cafe afterwards for a coffee and a chat. I've started volunteering on some days, which is another way of getting involved in the whole social aspect.

How does parkrun keep you motivated?

Couch to 5K got me into the habit of running three times a week, so doing a parkrun on Saturdays and a couple of mid-week runs help to me maintain that routine. The fact that parkrun is a timed run is also great motivation. It drives you to improve your times. Since achieving my initial goal of getting a PB under 30 minutes, I am now considering joining a local running club, and might enter a 10k event in 2015. 

Categories: NHS Choices

'Putting clocks forward boosts kids' exercise'

NHS Choices - Behind the Headlines - Fri, 24/10/2014 - 11:52

“Moving the clocks forward by one extra hour all year in the UK could lead to children getting more exercise every day, say researchers,” reports BBC News.

In the UK, the clocks move forward one hour during the summer months so that there are more daylight hours in the evening (daylight saving time).

A new study has found that children are more active in daylight saving time, regardless of the weather conditions. Its findings suggest that if the clocks were moved forward by one additional hour all year round it could lead to each child in England spending an average of 1.7 extra minutes in moderate to vigorous physical activity per day.

While small, the extra exercise isn’t trivial because children only engaged in this level of activity for 33 minutes a day. Also, spread across the whole population, the impact could be considerable.

However, the study couldn’t eliminate the possibility that there are other things responsible for the associations seen.

The estimates of how much children’s activity would increase would only hold true if the only reason they aren’t more active normally is daylight. Although the researchers took into account the weather in their analyses, it is difficult to adjust for expected (rather than actual) weather conditions. For example, school sports days tend to occur in the summer, in the hope that it will be warm and dry.

 

Where did the story come from?

The study was carried out by researchers from the London School of Hygiene and Tropical Medicine, the University of Bristol and Bristol Biomedical Research Unit, and the International Children’s Accelerometry Database Collaborators. The International Children’s Accelerometry Database is funded by the UK National Prevention Research Initiative. The researchers were funded by the National Institute of Health Research.

The study was published in the peer-reviewed International Journal of Behavioural Nutrition and Physical Activity. This article was open access, meaning it can be accessed for free.

The results of the research were well reported by the BBC and The Daily Telegraph.

 

What kind of research was this?

This was an observational study looking at the relationship between daylight in the evenings and the amount of activity children undertook. Researchers used information from the International Children’s Accelerometry Database, which contains activity data from children participating in studies worldwide, collected using motion sensors called accelerometers. These sensors are worn on the waist, and objectively measure physical activity levels without needing to rely on people remembering and reporting how active they were.

The researchers wanted to assess whether:

  • more evening daylight is associated with higher total physical activity, even after taking into account the weather conditions
  • the overall differences in physical activity in different times of the year are greatest in the late afternoon and early evening
  • changing the clocks affects activity levels

As with all observational studies, it is not possible to prove without a doubt that changing the clocks is directly responsible for the differences in activity levels seen, as other factors could be contributing. However, given that it would not be feasible to test the effect of changing the hours of daylight in a randomised controlled trial, this is the only way of assessing the potential link.

 

What did the research involve?

The researchers examined accelerometer data from 23,188 children aged between five and 16 in nine different countries. They looked to see whether physical activity varied according to time of sunset.

They then examined accelerometer data from the 439 children who had data from a school day just before and just after a clock change (within a week).

The researchers adjusted their analyses to take into account differences in weather (amount of rain or snow, humidity, wind speed and temperature), and differences in the characteristics of the children (such as age, sex and weight).

 

What were the basic results?

Longer evening daylight was associated with a small increase in children’s daily physical activity, even after taking into account other factors. When sunset was at 9pm or later, children spent approximately six minutes longer in moderate to vigorous physical activity than when sunset was at 5pm or earlier. The average time spent performing moderate to vigorous physical activity was 33 minutes per day, so a six-minute difference is not as trivial as it may seem.

The differences in physical activity were greatest in the late afternoon and early evening. The researchers found no association between activity levels in the morning and hour of sunset, and generally no association for activity in the early afternoon. This supported the argument that the extra hours of evening daylight were directly causing the increase in activity seen.

These associations were also seen when comparing the same child just before and just after the clocks changed.

The associations between hour of sunset and more physical activity were only consistently observed in children from five mainland European, four English and two Australian samples. The link was not consistently seen in American, Madeiran and Brazilian samples.

In the English studies, each additional hour of evening daylight was associated with 1.7 extra minutes of moderate to vigorous physical activity per day.

 

How did the researchers interpret the results?

The researchers concluded that in Europe and Australia, more evening daylight appears to increase children’s physical activity. They say that although the average increase is small in terms of minutes per extra hour per child, these small increases would add up when applied across all children in a population.

Also, the increase “compares relatively favourably” with the typical increases in physical activity that can be achieved with intensive programmes aimed at getting children and adolescents to be more active. They conclude that “the introduction of additional daylight saving measures could yield worthwhile public health benefits”.

 

Conclusion

The current study has found that more evening daylight is associated with increased physical activity in children, even after taking into account the weather. The results suggest that if the clocks were moved forward by one additional hour all year round, it could lead to children in England getting an estimated 1.7 extra minutes of moderate to vigorous physical activity per day.

Although this seems like a small amount, it is not trivial in relation to the average amount of activity children were found to have in a day (33 minutes). If every child in the country has a small increase in activity, this adds up to a considerable total increase.

The study’s strengths include the large total number of children assessed, the fact that they used an objective measure of activity, and that the children came from a range of countries.

There are some limitations to the findings of this study. The data was mainly cross-sectional, and it is difficult to eliminate the possibility that there are other things responsible for the associations seen. The estimates of how much activity could increase with a clock change assumes that the differences seen in activity were completely due to the extra hour of daylight. The researchers also note that although they adjusted for the actual weather, it is difficult to adjust for expected weather conditions. For example, school sports days tend to occur in the summer in the hope that it will be warm and dry.

Given that a randomised controlled trial to assess the impact of a clock change would not be feasible, this type of study is likely to be the only way to look at how daylight hours affect activity. The rising levels of sedentary lifestyles and obesity worldwide mean that finding ways to increase physical activity is an important policy area. While this study will contribute to the debate about whether the clocks should go forward an extra hour, there are likely to be a range of other factors the government will consider in making a decision – such as potential business and economic impacts.

 

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Time for change? Moving clocks forward would boost children's health through increased exercise. The Mirror, October 23 2014

Clock change 'good for child health'. The Guardian, October 23 2014

Later sunsets 'increase children's activity levels'. BBC News, October 23 2014

Change clocks to tackle childhood obesity: Shifting time forward by an hour would increase amount of time young can spend playing outside. Mail Online, October 23 2014

Links To Science

Goodman A, et al. Daylight saving time as a potential public health intervention: an observational study of evening daylight and objectively-measured physical activity among 23,000 children from 9 countries. International Journal of Behavioural Nutrition and Physical Activity. Published 23 October 2014

Categories: NHS Choices

Sunshine isn't slimming and can't halt diabetes

NHS Choices - Behind the Headlines - Fri, 24/10/2014 - 11:29

"Sunshine can make you thin," claims the Daily Mirror, while the Daily Express splashed on its front page that, "Sunlight is key to fighting diabetes". Both are strong contenders for the title of the day's most inaccurate health headline.

The news – reported more circumspectly by The Times and BBC News – is based on highly artificial laboratory experiments on mice.

The study found that long-term ultraviolet (UV) light exposure stopped male mice fed a high-fat diet gaining weight. UV also reduced glucose intolerance and insulin resistance and levels of insulin in the blood after fasting, as well as glucose and cholesterol.

In humans, these are signs associated with metabolic syndrome – a combination of diabetes, high blood pressure and obesity that puts you at greater risk of heart disease.

Human skin produces vitamin D when it is exposed to UV light, so the researchers tested whether the same benefits were seen if the mice were given a vitamin D supplement in their food.

But this did not produce the same effects. The researchers instead think nitric oxide, which is also produced when skin is exposed to UV light, may be responsible for the effects of UV.

Mice are nocturnal animals covered in fur, so their skin is not usually exposed to much sunlight. This means this research has no immediate implications for people.

 

Where did the story come from?

The study was carried out by researchers from the University of Western Australia, the University of Southampton and the University of Edinburgh.

It was funded by the BrightSpark Foundation and the Telethon Kids Institute.

The study was published in the peer-reviewed medical journal Diabetes.

The results of this study were well reported by BBC News and The Times, but the same cannot be said for the Mirror and Express.

An extremely kind critic might put the Mirror's claim that "Sunshine can make you thin" and the Express' claim that "Sunlight is key to fighting diabetes" down to wishful thinking and youthful high spirits.

Despite the headline, the Express did manage to rustle up comment from an independent expert from Diabetes UK, something the Mirror failed to do.

 

What kind of research was this?

This was an animal study. It looked at whether UV radiation and taking vitamin D affected the development of obesity and type 2 diabetes in mice eating a high-fat diet.

As the BBC reports, further research is required to see if sunshine has the same effect in people. Mice are nocturnal animals covered in fur, so their skin is not usually exposed to much sunlight.

 

What did the research involve?

The researchers fed 432 male mice either a low-fat diet containing added vitamin D, or a low-fat diet without added vitamin D, for four weeks.

This was done so the mice who had vitamin D supplementation would definitely have enough vitamin D and the mice on the standard diet would have a vitamin D deficiency.

The mice were continued on these diets, and some were switched from a diet low in fat to a diet high in fat. This meant there were four groups of mice:

  • low-fat diet 
  • low-fat diet plus vitamin D
  • high-fat diet
  • high-fat diet plus vitamin D

In each group, mice further split into three groups, which either received no UV radiation or UV radiation at two different doses on a shaved patch on their backs.

One was a low dose that wasn't enough to make the skin go red and was given twice a week. The other dose was enough to make the skin go red and was given once a fortnight.

The mice were fed these diets and irradiated with these UV radiation doses for 12 weeks.

The researchers monitored:

  • the mice's weight
  • their glucose and insulin tolerance 
  • their blood levels of vitamin D, cholesterol, triglycerides (fats), glucose and insulin, and certain hormones (leptin and adiponectin) and signalling molecules

 

What were the basic results?

A high-fat diet significantly increased vitamin D levels in mice fed diets not specifically supplemented with vitamin D.

Mice fed either diet that was further supplemented with vitamin D had significantly higher vitamin D levels than those mice fed a diet that was not supplemented with vitamin D, although the effect of a high-fat diet and vitamin D supplementation was not additive.

UV exposure significantly increased vitamin D levels in mice fed the low-fat diet without vitamin D supplementation, but had no effect on vitamin D levels in mice fed the other diets.

Weight gain 

Mice put on weight during the study. Long-term UV radiation at both doses significantly reduced weight gain in mice fed the high-fat diet without vitamin D supplementation.

Weight gain was similar between the mice that hadn't been irradiated and were fed the high-fat diet without supplementation, and mice fed the high-fat diet with vitamin D supplementation.

Similar results were seen for mice fed the low-fat diet.

Glucose intolerance and insulin resistance

Mice fed the high-fat diet developed glucose intolerance and insulin resistance. However, if mice were also given long-term UV irradiation, they showed reduced glucose intolerance and insulin resistance.

Glucose intolerance and insulin resistance were similar between un-irradiated mice fed the high-fat diet without supplementation and mice fed the high-fat diet with vitamin D supplementation.

Glucose intolerance was also significantly suppressed by long-term, low-dose UV radiation in mice fed the high-fat diet with added vitamin D.

Fasting glucose and insulin levels were also reduced by UV treatment in mice fed the high-fat diet without extra vitamin D.

Cholesterol

Levels of high-density lipoproteins, low-density lipoproteins and total cholesterol were also suppressed by the higher dose of UV irradiation in mice fed the high-fat diet that was not supplemented with vitamin D.

The researchers found vitamin D supplementation reduces the effect UV had on weight gain and markers of metabolic syndrome.

They did further experiments to determine how UV radiation might be having its effect. Their results suggest UV radiation of the skin causes the production of nitric oxide, and this might cause the effects seen.

 

How did the researchers interpret the results?

The researchers conclude that, "Long-term skin exposure to low-dose (suberythemal) and high-dose (erythemal) [UV radiation] suppresses the development of obesity and measures of [metabolic syndrome] in mice fed a high-fat diet. Vitamin D supplementation alone did not reproduce these effects.

"In addition, the suppressive effects of [UV radiation] on obesity and [metabolic syndrome] development were not observed to the same degree in mice that were further supplemented with vitamin D."

 

Conclusion

This study on mice has found long-term ultraviolet (UV) irradiation significantly suppressed weight gain and markers of metabolic syndrome, including glucose intolerance and insulin resistance, and blood levels of fasting insulin, glucose and cholesterol, in male mice fed a high-fat diet.

Many of the benefits of UV radiation were not reproduced by vitamin D supplementation alone. The researchers instead think that another chemical called nitric oxide, which is also produced when skin is exposed to UV light, may be responsible for the differences seen.

Mice are nocturnal animals covered in fur whose skin is not usually exposed to much sunlight. As the BBC reports, further research is required to see if sunshine has the same effect in people.

We can pretty confidently sat that the Express' front page splash saying, "Sunlight is key to fighting diabetes", and the Mirror's claim that "Sunshine can make you thin", are both nonsense. 

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

'Sunshine can slow weight gain and diabetes symptoms'. BBC News, 24 October 2014

Sunlight is key to fighting childhood obesity and diabetes, Scots scientists reveal. Daily Express, 24 October 2014

Sunbathing can stop you gaining weight (well, it works for mice). The Times, 24 October 2014

Links To Science

Geldenhuys S, et al. Ultraviolet Radiation Suppresses Obesity and Symptoms of Metabolic Syndrome Independently of Vitamin D in Mice Fed a High-Fat Diet. Diabetes. 2014;63:3759-3769

Categories: NHS Choices

No need for nightshift workers to avoid steak

NHS Choices - Behind the Headlines - Thu, 23/10/2014 - 12:30

"Shift workers should avoid tucking into steak, brown rice or green veg at night," because these foods "disrupt the body clock," the Mail Online reports.

But the research in question involved lab mice who were fed different amounts of dietary iron for six weeks to see what effect this had on the daily regulation of glucose production in their livers.

The research found mice fed lower-iron diets tended to have better regulated glucose production pathways than those on the higher iron diets. The mice did not have disturbed sleep patterns.

In a press release, the researchers raised the possibility their findings could have "broad implications" for people who do shift work, which could increase their risk of type 2 diabetes. This speculation has been mistakenly highlighted by the media.

The results suggest sustained high iron intakes may compromise our glucose regulation in the liver, but we should interpret these results with caution. The results do not prove that high iron intake has any effect on the risk of type 2 diabetes, as diabetes outcomes were not examined.

If you are concerned about diabetes, there are steps you can take to reduce your risk, such as maintaining a healthy weight (which is recommended whatever hours you work).

 

Where did the story come from?

The study was carried out by researchers from the University of Utah in the US and was funded by the Research Service of the Department of Veterans Affairs and the National Institutes of Health.

It was published in the peer-reviewed medical journal, Diabetes.

By taking the press release at face value, the Mail Online has overextrapolated the implications of this research, which has looked at how different dietary iron intakes in mice influence the daily regulation of glucose production in the liver.

This study is not related to shift work – subheadings such as, "for people who work night shifts, it puts the liver's clock out of sync", are not supported by the evidence.

The press department of the University of Utah appears to have misrepresented and overinterpreted the study in the hopes of hitting the headlines. While they have been successful in getting in the papers, they have perhaps done the science a disservice.

In this study, all mice were kept on a 12-hour light/dark cycle. All that was altering was their iron intake, not their sleep/wake patterns.

 

What kind of research was this?

This was an animal study investigating the role that dietary iron has on the circadian (daily) rhythm of glucose metabolism in the liver.

The researchers describe how the liver maintains a daily balance in regulating glucose, and point out that disruption of this rhythm is associated with type 2 diabetes.

Dietary intake is one of the factors that influence the biological clock in our bodies, but little is said to be known about the role of specific dietary components.

This research focused on dietary iron, as iron is an essential component of several proteins in the body concerned with electron transport and metabolism. Also, haem, the chemical compound containing iron, is necessary for the formation of several proteins involved in regulatory pathways.

 

What did the research involve?

In this study, researchers fed mice chow with different iron concentrations. They did this to create iron levels in the body tissues that would be within the range produced by a normal human diet.

Three-month-old male mice were fed on diets containing low (35mg/kg), medium (500mg/kg) or high (2g/kg) amounts of iron. The upper 2g/kg level is said to be within the fourfold range of iron seen in human livers. The mice were fed on these diets for six weeks while they were maintained in a 12-hour light/dark cycle.

After between six and eight weeks on these diets, the researchers also tested the effect of giving the mice three different chemicals in their daily drinking water.

These chemicals either increased haem synthesis, inhibited haem synthesis, or acted as an antioxidant. They gave the mice these chemicals so they could work out how dietary iron was affecting glucose production in the liver.

The mice were then given various tests, including glucose tolerance tests (GTT) and a variation on the GTT: the pyruvate tolerance test (pyruvate is one of the molecules involved in the production of glucose).

The mice also had their blood levels of haemoglobin, red blood cell volume, insulin and glucagon (the hormone produced when blood glucose levels are low) measured. After death, the mouse liver was analysed in the laboratory.

 

What were the basic results?

The researchers found dietary intake influences the daily rhythm of glucose production in the liver.

Mice fed the lower-iron diet had higher blood glucose levels in response to pyruvate injection than mice on the higher iron diets. This result suggests their livers had better regulated glucose production pathways than those who had been on the higher iron diets.

The researchers found haem production varied with dietary iron intake, and haem influences the activity of an enzyme (Rev-Erbα) key to regulating the liver's daily rhythm. This Rev-Erbα enzyme regulates many aspects of glucose metabolism.

To confirm that dietary iron was affecting haem production, the researchers looked at the effect of chemicals that either increased haem levels or blocked haem production. Treatment with either chemical caused the differences in blood glucose regulation seen to disappear.

The researchers thought dietary iron may cause changes in haem synthesis through reactive oxygen species. This is because the protein that regulates the production of one of the enzymes involved in haem synthesis is regulated by reactive oxygen species, and iron creates reactive oxygen species.

Reactive oxygen species are molecules containing oxygen. Depending on the specific context in which they are formed, reactive oxygen species can be both helpful and harmful to the cells of the body.

To test the above hypothesis, mice were fed an antioxidant to mop up reactive oxygen species. This resulted in many of the differences seen between mice fed different diets to disappear.

Iron intake had no effect on haemoglobin concentration or red blood cell volume.

 

How did the researchers interpret the results?

The researchers say their findings demonstrate that dietary iron affects the circadian rhythm and glucose production in the liver by modifying haem levels in the liver.

 

Conclusion

This animal research demonstrates how dietary iron intake affects the daily regulation of glucose production in the liver. Mice fed lower-iron diets tended to have better regulated glucose production pathways than those who had been on the higher iron diets.

This happens because iron intake influences the production of the iron compound haem, which in turn influences the activity of an enzyme involved in regulating glucose production in the liver.

Overall, it is difficult to draw any meaningful conclusions from these findings. The researchers suggest sustained high iron intakes may compromise our glucose regulation in the liver, but interpretations from this research should be made with caution. The results from this mouse study do not prove that a high iron intake increases the risk of type 2 diabetes.

The results certainly do not have any immediate implications for shift workers. This leap seems to have been made because the study looked at daily rhythms of glucose production, but all mice in this study were maintained on the same light/dark cycle – only their iron intake was altered.

The most effective method of reducing your diabetes risk is to achieve and then maintain a healthy weight. If you are struggling to get the weight off, why not try the NHS weight loss plan, a free evidence-based diet and exercise plan designed to deliver sustainable weight loss. 

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Why shift workers should avoid tucking into steak, brown rice or green veg at night: Iron-rich foods 'disrupt the body clock'. Mail Online, October 22 2014

Links To Science

Simcox JA, Mitchell TC, Gao Y, et al. Dietary Iron Controls Circadian Hepatic Glucose Metabolism through Heme Synthesis. Diabetes. Published online October 14 2014

Categories: NHS Choices

Do dopamine drugs lead to compulsive shopping?

NHS Choices - Behind the Headlines - Thu, 23/10/2014 - 12:10

“Drugs for restless leg syndrome cause gambling, hypersexuality and compulsive shopping,” Metro reports.

Researchers in the US have looked at serious drug side effects reported to the FDA over a 10-year period. In particular, they were interested to see how often reports of impulsive behaviours such as gambling were linked to a group of drugs called dopamine receptor agonists.

These drugs (such as pramipexole) mimic the effect of dopamine on the brain. They are most commonly used to treat Parkinson’s disease and other conditions such as restless legs syndrome.

The drugs have sometimes been known to trigger extremely severe patterns of compulsive behaviours, so the researchers wanted to estimate exactly how common this side effect was.

The study found that 710 events – just under half of all impulse control disorders reported during this 10-year period – were attributed to dopamine receptor agonists. Given the number of prescriptions of these drugs that are likely to be prescribed every year in the US, this would suggest that the compulsive side effect – or at least the reporting of it – is quite rare. We would expect to see a similar pattern in the UK.

The risk of mental health-related adverse effects with these drugs, including impulse control disorders, is already recognised by the UK's medical profession. You or your carer should seek medical advice if there are any changes to your behaviour after taking a dopamine receptor agonist. 

 

Where did the story come from?

The study was carried out by researchers from The George Washington University and Harvard Medical School in the US, and University of Ottawa and Risk Sciences International in Ottawa, Canada. No sources of funding are reported. Two of the authors declare being consultant or expert witnesses in civil and criminal litigation involving many psychiatric drugs, though none involving the drugs that are at the centre of this research. This article is also reported to be based in part on data obtained under license from the National Prescription Audit.

The study was published in the peer-reviewed medical journal  JAMA International Medicine.

The Mail Online’s headline that, “Drugs for Parkinson’s disease can turn patients into gamblers, sex addicts and compulsive shoppers” is not justified by this study alone because – as the study authors acknowledge – the results did “not prove a causal relationship, only that such a relationship was suspected”. The study also only looked at one group of drugs, so the study results do not apply to all Parkinson’s treatments.

 

What kind of research was this?

This was an analysis of adverse drugs events (more commonly known as side effects) reported to the US Food and Drug Administration (FDA) involving six FDA-approved dopamine receptor agonist drugs.

These drugs are used in the initial treatment of Parkinson’s disease – a neurological condition with an unknown cause, where not enough of the chemical dopamine is produced in the brain. This causes the three classic symptoms of tremor, with stiff, rigid muscles and slow movements, as well as a range of other effects, including dementia and depression. While there is no cure, treatments that aim to control this dopamine imbalance are used to try and control symptoms.

Dopamine receptor agonists act directly on dopamine receptors, effectively taking the place of dopamine and stimulating the receptor in the same way. There are a group of these drugs licensed in the UK, including drugs called pramipexole, ropinirole and rotigotine. Dopamine receptor agonists are a different group of treatments from the well-known Parkinson’s treatment Levodopa, which works in a different way.

Dopamine receptor agonists are also sometimes used in restless legs syndrome if a person is having very frequent symptoms.

The drugs are already known to be associated with a risk of adverse mental health issues. This study reports that severe impulse control disorders such as gambling, hypersexuality and compulsive shopping have been reported following the use of these drugs, in both case series and patient surveys. This study aimed to further investigate the potential link between these drugs and this side effect.

 

What did the research involve?

The researchers looked at all domestic and foreign serious adverse drug events concerning impulse control disorders reported to the FDA between 2003 and 2012. They looked at the number of impulse control disorder events that were associated with the use of dopamine receptor agonists, and with all other drugs, to look for differences.

They specifically looked for 10 impulse control disorders as listed in the Medical Dictionary for Regulatory Activities:

  • pathological gambling
  • hypersexuality (experiencing extremely frequent sexual urges)
  • compulsive shopping
  • gambling
  • poriomania (wandering impulses)
  • binge eating
  • excessive masturbation
  • compulsive sexual behaviour
  • kleptomania (impulses to steal)
  • excessive sexual fantasies

For the individual dopamine receptor agonists, they calculated the proportional reporting ratio (PRR).

This involves calculating the frequency of impulse control adverse events for each dopamine receptor agonist drug, as a proportion of all adverse events reported for that drug.

 

What were the basic results?

Overall, the researchers identified 1,580 reports of impulse control disorders associated with any drug over the 10-year period. Gambling was the term mentioned in around half of these reports: pathological gambling in 628 (39.7%) and gambling in 186 (11.8%). This was followed by hypersexuality, which accounted for just under a third of impulse control events (465, 29.4%), and then compulsive shopping, which accounted for around an eighth (202, 12.8%).

Just under half of all the impulse control events were related to dopamine receptor agonists (710, 44.9%) and the remainder to other drugs. The reports related to dopamine receptor agonists occurred in people with an average age of 55 years, and over half of whom were male. Most of these prescriptions had been for Parkinson’s disease (61.7%), with most of the remainder prescribed for restless legs syndrome.

The six specific dopamine receptor agonists examined were pramipexole, ropinirole, rotigotine, bromocriptine, cabergoline and apomorphine – all of which are used in the UK.

The PRR was significant for dopamine receptor agonists, meaning that the proportion of impulse control events was significantly higher than all other events with these drugs. For all dopamine receptor agonists, the PRR was 277.6. Most of the impulse control events associated with these drugs had occurred with pramipexole (410 events; PRR 455.9) followed by ropinirole (188 events; PRR 152.5). The number of reported impulse control events with the other four drugs was between 56 for cabergoline and 12 for apomorphine.

 

How did the researchers interpret the results?

The researchers say that their findings, “confirm and extend the evidence that dopamine receptor agonist drugs are associated with these specific impulse control disorders. At present, none of the dopamine receptor agonist drugs approved by the FDA have boxed warnings as part of their prescribing information. Our data, and data from prior studies, show the need for more prominent warnings”.

 

Conclusion

This study analysed serious adverse drug events reported to the US FDA over a 10-year period, and found that 710 events (just under half of all impulse control disorders reported during this period) were attributed to dopamine receptor agonists. Most of these disorders involved gambling, followed by hypersexuality and compulsive shopping.

This group of six drugs are used in Parkinson’s disease (and a small number of other conditions) where there is a lack of the chemical dopamine. The drugs act directly on dopamine receptors, effectively taking the place of dopamine and stimulating the receptor in the same way.

Dopamine receptor agonists are known to have mental health-related adverse effects; impulse control disorders are already recognised.

This study further highlights this risk, demonstrating that impulse control disorders account for more serious adverse events than all other events associated with these drugs that have been reported to the FDA.

The study is based on US FDA data only, but it could give a good indication of the data reported to UK medicines regulatory authorities. The study also only covers adverse events that are formally reported, and it is unclear how many impulse control disorders may occur, but are not reported.

As the researchers acknowledge, this study still cannot prove that it is the dopamine receptor agonist that has directly caused the adverse events reported.

UK prescribing information for dopamine receptor agonists advises patients and prescribers of the risk of impulse control disorders. If symptoms develop, doctors are advised to reduce the dose or stop prescribing the drug until symptoms resolve.

People in the grip of a compulsive pattern of behaviour are often unaware that their behaviour has changed and that they are acting strangely, so do not seek medical advice. Therefore friends, family members or carers can help by being vigilant for any strange changes in the behaviour of a person taking these drugs.

Analysis by Bazian. Edited by NHS ChoicesFollow Behind the Headlines on TwitterJoin the Healthy Evidence forum.

Links To The Headlines

Drugs for restless leg syndrome cause gambling, hypersexuality, and compulsive shopping. Metro, October 21 2014

Drugs for Parkinson's disease can turn patients into gamblers, sex addicts and compulsive shoppers. Mail Online, October 22 2014

Links To Science

Moore TJ, Glenmullen J, Mattison DR. Reports of Pathological Gambling, Hypersexuality, and Compulsive Shopping Associated With Dopamine Receptor Agonist Drugs. JAMA Internal Medicine. Published online October 20 2014

Categories: NHS Choices

Help if you're feeling under the weather

NHS Choices - Live Well - Wed, 22/10/2014 - 15:55
Help if you're feeling under the weather

Minor illnesses like sore throats, coughs and colds are more common during the winter months. 

A minor health problem can sometimes get worse quickly if you’re over 60. If you or someone you care for is feeling under the weather it’s best to get early advice from your pharmacist.

Why early advice is the best advice

It's best to get advice on your illness as soon as you can, because, being older, if a winter ailment becomes serious you're more likely to need treatment in hospital.

It’s not always easy to ask for help. You may feel that you’re wasting your pharmacist’s time if you go to see them with a minor illness, like a cold or a sore throat. But it's minor health problems like these that your pharmacist is there to help with.

Getting help early means you're likely to recover more quickly and be able to get your life back to normal.  

How your pharmacist can help

Pharmacists are a highly trained and trusted source of health advice for minor health problems. Your local pharmacist can:

  • give you expert advice to help with symptoms of coughs, wheeziness, colds or sore throats
  • see you without an appointment, and often when your GP practice is closed
  • advise you on whether you need to see your GP
  • speak to you privately in a consultation area where other people can’t hear about your health problems
  • help you manage a long-term condition (if you have one), such as diabetes or COPD

Find your nearest pharmacy or learn more about pharmacies and the services they offer

Categories: NHS Choices

Changes in 'Parkinson's walk' predict dementia

NHS Choices - Behind the Headlines - Wed, 22/10/2014 - 12:15

"Subtle changes in the walking pattern of Parkinson's patients could predict their rate of cognitive decline," The Times reports after new research compared the gait of people with Parkinson's disease with those of healthy volunteers.

Parkinson's disease is a condition with three classic features: a tremor, stiff rigid muscles and slow movements, notably a slow, shuffling walk. It also has other symptoms, including Parkinson's dementia, though it can be difficult to predict who will go on to develop dementia.

Researchers wanted to see if comparing the differences in gait (walking pattern) and cognition (thinking) between 121 people newly diagnosed with Parkinson's disease and 184 healthy adults would provide any clues.

As may be expected, the study found measures of both gait and cognition were poorer in people with Parkinson's compared with healthy adults.

They then compared people with Parkinson's who mainly had gait problems with those who mainly had tremor problems.

Though there was no difference in cognitive abilities between the two groups, in those who mainly had gait problems there was a link between this and their cognitive function. That is, if a person had more problems with gait, they tended to have more cognitive problems.

This study will help doctors further understand how gait may be associated with cognition in people with Parkinson's. It suggests that progression in gait problems may be associated with cognitive decline.

While there is currently no cure for dementia, knowing that someone is at a higher risk could help explain often upsetting changes in mood and behaviour, and enable early access to treatment.

 

Where did the story come from?

The study was carried out by researchers from Newcastle University and was funded by the National Institute for Health Research.

It was published in the peer-reviewed open-access journal, Frontiers in Aging Neuroscience, so the article is free to access online.

The Times' reporting is accurate. But the Daily Mail's coverage is misleading and confusing, as its headline asks, "Could your walk signal dementia?"

This study is specific to Parkinson's disease and people with this condition who go on to develop dementia. It is not relevant to the population at large or to other types of dementia, such as Alzheimer's.

 

What kind of research was this?

This was a case-control study examining the differences in gait (walking pattern) and cognition (mental abilities) between people newly diagnosed with Parkinson's disease (the cases) and a comparison group of healthy older adults (the controls).

Parkinson's disease is a neurological condition with an unknown cause, where not enough of the chemical dopamine is produced in the brain. This causes characteristic symptoms of:

  • a resting tremor – shaking when the person is relaxed
  • rigidity – stiff and inflexible muscles
  • slow movements – someone with Parkinson's classically walks with slow shuffling steps, and they are generally slower in all movements

As well as these classic symptoms, there are a variety of others, and usually Parkinson's has some mental health effects, including dementia and depression.

While treatments such as Levodopa can help improve symptoms, there is no cure for Parkinson's and the condition usually progresses.

It has been observed that in people who have a predominant tremor (TD), symptoms progress more slowly than those with predominant postural instability and gait disorder (PIGD).

These people who predominantly have problems with walking and balance tend to demonstrate greater decline, not only in terms of movement, but also cognition.

This study aimed to quantitatively measure the differences in movement and cognition between cases and controls. The researchers expected to see a specific association between movement and cognition in people with the different predominant type of Parkinson's.

 

What did the research involve?

The researchers included 121 people (average age 67) who had been diagnosed with Parkinson's disease in the past four months. They were matched by age and sex to 184 healthy controls, who were able to walk independently and had no specific cognitive or mental health problem.

The Movement Disorder Society (MDS)-revised Unified Parkinson's Disease Rating Scale, which is a well-validated scale, was used to measure disease severity. It was also used to determine which features were predominant – TD (53 people) or PIGD (55 people).

Gait was measured by asking people to walk at their comfortable walking pace for two minutes around a 25m oval walkway. Researchers observed five variables: pace, rhythm, variability in step, asymmetry and posture.

Separately, a range of validated assessment scales were used to measure six domains of cognitive function: global cognition, attention, visual memory, executive function, visuospatial function and working memory.

A range of other tests were performed, including a timed chair stand to assess slow movements and muscle strength. This involved participants being asked to stand up from a seated position with their arms folded across their chest and sit down five times, as quickly as possible.

Balance was measured using the activities balance self-confidence scale, and physical fatigue and depression were also measured.

 

What were the basic results?

All gait variables were significantly different between healthy controls and people with Parkinson's.

People with Parkinson's walked more slowly, walked less symmetrically, made shorter steps, and overall had a more variable gait.

The only measures that were not different were step velocity variability, swing time and step width. As expected, gait measures were poorer for those with Parkinson's characterised as PIGD compared with TD.

When looking at cognition, cognitive outcomes were significantly poorer for people with Parkinson's compared with controls, with the exception of a measure of attention (choice reaction time).

Cognition was no different between the TD and PIGD types of Parkinson's, with the exception of one measure of executive function (semantic fluency), which was poorer in people with PIGD.

The researchers found some association between gait and cognition in both people with Parkinson's and controls. In the group with Parkinson's, four measures of gait (pace, rhythm, variability and postural control) were correlated with measures of cognition, such as poorer measure of gait and poorer cognition.

Two of these measures (pace and postural control) were also associated with cognition in controls. In both people with Parkinson's and the controls, the strongest association was between pace and attention.

Looking at the different types of Parkinson's, associations between measures of gait and cognition were evident in people with PIGD, but not TD.

 

How did the researchers interpret the results?

The researchers say their observations provide a basis for understanding the complex role of cognition in Parkinson's gait.

 

Conclusion

Parkinson's is a neurological disease with characteristic features of tremor, rigidity and slow movements, as well as a variety of other classic symptoms, including Parkinson's dementia.

This case-control study demonstrates how measures of both gait (walking) and cognition are, as would be expected, poorer in people newly diagnosed with Parkinson's disease compared with healthy controls.

The study also demonstrates that in Parkinson's disease, people with a predominant postural instability and gait disorder (PIGD) unsurprisingly have poorer measures of gait than people with predominant tremor disorder (TD).

Though there was little difference in cognitive measures between people with PIGD and TD, in those with PIGD there was a correlation between measures of their gait and cognitive function.

This suggests that progressive gait problems may be associated with progressive cognitive decline in people with Parkinson's disease, though the specific biological mechanisms behind this link were not investigated by this study. The researchers now plan to investigate this link further.

The researchers also acknowledge several limitations with their study, including the relatively small sample size – involving only around 50 people with each subtype of Parkinson's. This means these are small numbers on which to base firm conclusions about the differences between the two subtypes.

There are also other measures the study may not have been able to take into account, including the influence of medication (some had started Levodopa, some not) and depression.

Overall, this study helps doctors to further understand how gait may be associated with cognition in people with Parkinson's, and that predominant gait problems may also be an indicator of more cognitive problems.

While there are no current preventative or treatment implications of these findings in terms of Parkinson's, early recognition of people who may be at risk of dementia is likely to be beneficial.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Walking pattern offers clues to speed of brain decline. The Times, October 22 2014

Could your walk signal dementia? Scientists find link between subtle changes to a person's gait and their brain function. Daily Mail, October 22 2014

Links To Science

Lord S, Galna B, Coleman S, et al. Cognition and gait show a selective pattern of association dominated by phenotype in incident Parkinson's disease. Frontiers in Aging Neuroscience. Published online October 21 2014

Categories: NHS Choices

NICE wants tooth brushing to be taught in schools

NHS Choices - Behind the Headlines - Wed, 22/10/2014 - 11:15

“Children should get their teeth brushed at school, says NHS watchdog,” The Daily Telegraph reports.

The headline follows the publication of guidance by the National Institute for Health and Care Excellence (NICE) on ways for local authorities to improve the oral health of their communities. The new guidelines have been welcomed in some parts of the media, but others have accused NICE of creating a “supernanny state”.

The guidance follows a recent Public Health England survey that demonstrated the wide disparity in oral health across the country, particularly among younger children and vulnerable socioeconomic groups.

Overall, across the country, 12% of young children were found to have tooth decay, but this varied – from more than a third of children in Leicester, to just 2% in other parts of the country.

As NICE says, dental problems such as tooth decay and gum disease can have a wide range of effects, not only causing pain and the need to remove decayed teeth, but affecting a person’s ability to speak, eat, smile and socialise.

The recommendations aim to help authorities commission health, social care and educational services that promote and protect oral health. This includes advice on ways to improve oral hygiene, such as reducing the consumption of sugary food and drinks, alcohol and tobacco, increasing the availability of fluoride, and encouraging people to get regular dental check-ups.

Among these recommendations are those focused towards improving oral health among young and school-age children, including considerations for nurseries and primary schools to supervise tooth brushing in children at high risk of tooth decay.

 

What does NICE recommend?

Essentially, NICE wants action to promote and protect oral health by:

  • improving diet and reducing consumption of sugary food and drinks, alcohol and tobacco
  • improve oral hygiene
  • increase the availability of fluoride
  • encourage people to go to the dentist regularly
  • increase access to dental services
Public services

Among the recommendations targeted towards public action, they advise that:

  • Public services (including leisure centres, community or drop-in centres, nurseries and schools) make plain drinking water freely available and provide a choice of sugar-free food and drinks, including vending machines on site.
  • All health and wellbeing policies and services for adults, children and young people should include advice and information on nutrition and wellbeing, and how tooth decay and gum disease are preventable; this includes educating people on the importance of regular tooth brushing and tooth brushing techniques, the importance of fluoride toothpaste and regular dental check-ups, and the links between high-sugar diets, alcohol and tobacco, and poor oral health.
Advice for parents

Specific to younger children, NICE recommends that all early years services (including midwives and health visitors, children’s centres, nurseries and childminding services) should have a requirement to train staff in giving oral health advice.

This advice should include:

  • promoting breastfeeding and healthy weaning
  • promoting food, snacks (such as fresh fruit) and drinks (water and milk) that are part of a healthier diet
  • explaining that tooth decay is a preventable disease and how fluoride can help prevent it
  • promoting the use of fluoride toothpaste as soon as teeth come through
  • encouraging people to regularly visit the dentist from when a child gets their first tooth
  • giving a practical demonstration of how to achieve and maintain good oral hygiene and encouraging tooth brushing from an early age
  • advising on alternatives to sugary foods, drinks and snacks as pacifiers and treats
  • using sugar-free medicine
  • giving details of how to access routine and emergency dental services
  • explaining who is entitled to free dental treatment
  • encouraging and supporting families to register with a dentist
Schools and nurseries

A recommendation that has stimulated the most comment and debate in the newspapers is that nurseries and primary schools in areas where children are at risk of poor oral health should consider supervising children in tooth brushing.

Such schemes would include having a requirement to get consent from parents or carers, and provide free toothbrushes and fluoride toothpaste – one set for the premises and one to take home.

In high-risk nurseries and primary schools, where supervised tooth brushing is not possible, a fluoride varnish programme should be considered. This involves coating the teeth with a film of the chemical fluoride, which has a protective effect against decay. At least two applications of fluoride varnish a year would be needed.

NICE also includes recommendations to raise awareness of the importance of oral health during a child’s school years. This includes similar policies to above, of having healthy food and drink choices available, ensuring that opportunities are found in the curriculum to teach the importance of maintaining good oral health and highlighting how it links with appearance and self-esteem.

 

What has been the response to the recommendations?

Some newspapers have accused NICE of promoting a nanny state agenda, such as the Mail Online stating that: “Now nanny state wants lessons in brushing teeth! Schools told they must help halt decay caused by children's sugary diets.”

Just a few weeks before, the same newspaper was reporting that: “One in 8 three-year-olds has rotting teeth… and [sugary] fruit juice is to blame.”

Early intervention at a young age, through education on effective dental care both at home, and reinforced at school, could make a lifetime’s worth of difference.

As Elizabeth Kay, foundation Dean for the Peninsula Dental School, Plymouth, says: “Around 25,000 young children every year are admitted to hospital to have teeth taken out. Given that we know how to prevent dental disease, this really should not be happening.

“If there were a preventable medical condition which caused thousands of young children (mostly around five years old) to end up in hospital to have body parts removed, there would be an outcry.

“These guidelines offer local authorities an opportunity and evidence as to how they can stop the most vulnerable children and adults in their areas from suffering from the pain, trauma and lifetime negative effects of tooth decay.”

The director of the centre for public health at NICE, Professor Mike Kelly, further explains: “Children as young as three are being condemned to a life with rotten teeth, gum disease and poor health going into adulthood. Many children have poor diets and poor mouth hygiene because there is misunderstanding about the importance of looking after children’s early milk teeth and gums. They eat too much sugar and don’t clean their teeth with fluoride toothpaste. As a society, we should help parents and carers give their children the best start in life and act now to stop the rot, before it starts.”


Analysis by
Bazian. Edited by NHS Choices. Follow Behind the Headlines on TwitterJoin the Healthy Evidence forum.

Links To The Headlines

Children should get their teeth brushed at school, says NHS watchdog. The Daily Telegraph, October 22 2014

Schools should check kids brush teeth, says NICE. BBC News, October 22 2014

Now nanny state wants lessons in brushing teeth! Schools told they must help halt decay caused by children's sugary diets. Mail Online, October 22 2014

Schools Urged To Supervise Brushing Of Teeth. Sky News, October 22 2014

Nursery-age children ‘should get tooth-brushing lessons’. The Independent, October 22 2014

Stop the rot with lessons on brushing teeth, schools told. The Times, October 22 2014

Categories: NHS Choices

Paralysed man walks again after pioneering surgery

NHS Choices - Behind the Headlines - Tue, 21/10/2014 - 12:30

"World first as man whose spinal cord was severed WALKS," the Mail Online reports. In pioneering research, transplanted cells have been used to stimulate the repair of a man's spinal cord.

The headlines are based on a scientific report describing a 38-year-old man whose spinal cord was almost completely severed in a knife attack. The man had completely lost feeling and movement below the injury and was paralysed from the chest down.

Researchers injected the man's damaged spinal cord with cells taken from parts of the brain involved in interpreting smell signals from the nose to the brain. This treatment was combined with a graft from one of the nerves in his lower leg to reconnect the stumps of spinal cord severed by the injury. 

After surgery, the man had improved trunk stability, partial recovery of the voluntary movements of the lower extremities, and an increase of muscle in one thigh, as well as improvements in sensation. According to an accompanying press release, the man is now able to walk using a frame.

While previous techniques have managed to "re-route" nerve signals around a damaged section of the spinal cord, this is the first time that damage to the cord has been directly repaired.

These results are very encouraging, but, as the researchers note, the findings will need to be confirmed in other patients with similar types of spinal cord injury.

 

Where did the story come from?

The study was carried out by researchers from Wroclaw Medical University, the Polish Academy of Sciences, Karol Marcinkowski Medical University, the Neurorehabilitation Center for Treatment of Spinal Cord Injuries AKSON in Poland, the Medical University of Warsaw, the University Clinical Hospital and the UCL Institute of Neurology in the UK.

It was funded by the Wroclaw Medical University, the Nicholls Spinal Injury Foundation and the UK Stem Cell Foundation.

The study was published in the peer-reviewed journal Cell Transplantation and has been made available on an open access basis, so it is free to read online.

The news was widely reported by both the UK and international media. Coverage was accurate, if uncritical. The lead author's claim that this research was "more impressive than man walking on the moon" seems to have been accepted without question by the media.

However, other experts are less impressed. For example, Dr Simone Di Giovanni, Chair in Restorative Neuroscience at Imperial College London, is reported by the Science Media Centre as saying, "One case of a patient improving neurological impairment after spinal cord knife injury following nerve and olfactory cell transplantation is simply anecdotal.

"Extreme caution should be used when communicating these findings to the public, in order not to elicit false expectations on people who already suffer because of their highly invalidating medical condition."

 

What kind of research was this?

This was a case report, which often report unusual medical findings in a single person. They often describe rare diseases, strange symptoms or untypical responses to treatment.

The results of this case report will need to be confirmed in a larger group of patients with similar types of spinal cord injury before such stem cell transplants can be said to be an effective treatment for spinal cord injuries.

Even if the treatment proves effective, it may not be safe in all cases. Because of its complexity, neurological surgery has a higher rate of complications than most other types of surgery.

 

What did the research involve?

The case report describes a 38-year-old man whose spinal cord was damaged in a knife attack, leading to his spinal cord being almost completely severed. The man had completely lost sensory (feeling) and motor (movement) function below the injury, resulting in paraplegic paralysis (where both legs and the lower body are paralysed).

The researchers removed one of his olfactory bulbs, the parts of the nervous system that normally transmit information on smell from the nose to the brain.

They then grew cells from the man's olfactory bulbs in the laboratory. They were interested in two cell types: olfactory ensheathing cells and olfactory nerve fibroblasts. Both of these cell types have been shown to mediate regeneration and the reconnection of severed axons (nerve cells).

The researchers transplanted the cultured cells by injection into the man's spine above and below the injury. 

To fully bridge the gap and reconnect the stumps of spinal cord severed by the injury, they also combined this treatment with a graft of small strips of nerve taken from one of the nerves in the man's lower leg (the sural nerve).

The man received intense neurorehabilitation through exercises and other interventions designed to help recovery from a nervous system injury or compensate for its effects.

 

What were the basic results?

The man seemed to have no adverse effects in the 19 months following the operation.

From five months after the operation, the man had improved neurological function. By 19 months after surgery, he had improved trunk stability (sometimes known as core stability), partial recovery of the voluntary movements of the lower extremities, and an increase in the muscle of one thigh, as well as improvements in sensation (feeling).

According to accompanying media reports, the man is now able to walk using a walking frame.

Interestingly, removal of one of the olfactory bulbs did not cause the man to permanently lose his sense of smell on one side, as might have been expected.

 

How did the researchers interpret the results?

The researchers conclude that to their knowledge, "This is the first clinical indication of beneficial effects of transplanted autologous bulbar cells."

 

Conclusion

Overall, these results demonstrate the first person with a severed spinal cord to have regained movement and sensation in his lower limbs following a cell transplant. Specifically, this involved a combination of cells taken from the olfactory bulb and a graft from nerve cells in the leg, which were used to reconnect the severed sections of spinal cord.

These results are very encouraging, but, as the researchers note, these will need to be confirmed in a larger group of patients with similar types of spinal cord injury.

Further research is also required into how best to access the olfactory bulb. In this study, it was accessed by craniotomy – a surgical operation where a bone flap is temporarily removed from the skull to access the brain. As the researchers also state, there remains a possibility that sources of other, more readily obtainable reparative cells may be discovered.

Though this treatment has given good recovery of movement and sensation, there has not yet been a full recovery in terms of bowel, bladder and sexual function. These functional effects of spinal cord injury can of course have an equally devastating effect on a person as loss of movement or sensation.

The results will undoubtedly give hope to many people affected by paralysis as a result of spinal cord injury. However, while very promising, there are still many steps to go until a new treatment is found that gives complete functional recovery from severe spinal cord injury.

Analysis by Bazian. Edited by NHS Choices
Follow Behind the Headlines on TwitterJoin the Healthy Evidence forum.

Links To The Headlines

World first as man whose spinal cord was severed WALKS: Fireman paralysed by knife attack recovers after UK scientists use nose cells to re-grow nerve cells in his spine. Mail Online, October 21 2014

Paralysed man walks again after cell transplant. BBC News, October 21 2014

Paralysed man Darek Fidyka walks again after treatment by British doctors on brink of 'cure'. The Independent, October 21 2014

Paralysed man Darek Fidyka walks again after pioneering surgery. The Guardian, October 21 2014

Paralysed man helped to walk again. The Daily Telegraph, October 21 2014

Paralysed man walks again: ‘It’s incredible — like being reborn’. The Times, October 21 2014

Links To Science

Tabakow P, Raisman G, Fortuna W, et al. Functional regeneration of supraspinal connections in a patient with transected spinal cord following transplantation of bulbar olfactory ensheathing cells with peripheral nerve bridging. Cell Transplantation. Published online October 21 2014

Categories: NHS Choices

Smokers' homes 'as polluted as Beijing'

NHS Choices - Behind the Headlines - Tue, 21/10/2014 - 11:29

"Living with smoker 'as bad as living in polluted city'," BBC News reports. Scottish researchers have estimated that the level of fine particulate matter (PM2.5) in smokers' households is similar to those found in a heavily polluted city such as Beijing.

PM2.5 are tiny particles less than two and a half microns wide that are components of air pollution. Because of their size, they are able to penetrate the lungs' defences against external foreign bodies, potentially causing damage. They have been linked to chronic respiratory conditions such as asthma and even lung cancer.

Researchers found, on average, PM2.5 concentrations from smokers' homes were about 10 times higher than those found in non-smoking homes. If smoking households became non-smoking, most non-smokers would have their PM2.5 intake cut by more than 70%.

Over a lifetime, the researchers calculated that PM2.5 intake from living with a smoker could be equivalent to living in a heavily polluted city, and could have the health problems associated with such an environment. For example, there has been a dramatic rise in reported asthma cases in urban areas of China.

Ideally, if you smoke, you should quit now for the benefit of your health and the health of others. If you are unable or unwilling to do so, smoke outdoors, especially if you are sharing the house with children. Simply blowing the smoke out of a window will still lead to an increase in PM2.5. 

 

Where did the story come from?

The study was carried out by researchers from the University of Aberdeen and the Institute of Occupational Medicine in Edinburgh.

No funding was reported, but the study used data from other studies that had been funded by the Big Lottery Fund, the Irish Environmental Protection Agency and the Scottish School of Public Health Research.

It was published in the peer-reviewed public health journal Tobacco Control. This article was open-access, meaning it can be accessed and read for free.

The research was well reported by BBC News.

 

What kind of research was this?

This study brought together data from four previous cross-sectional studies that had measured PM2.5 concentrations in smoking and non-smoking households in Scotland. These concentrations were then used to model daily and lifetime PM2.5 intake.

Cross-sectional studies take data at one point in time, so they cannot prove cause and effect.

However, homes where there was likely to be a significant additional source of PM2.5 (for example, a coal or solid-fuel fire) were excluded from the analysis.

It is therefore probable that the tenfold difference seen between PM2.5 concentrations in smokers' and non-smokers' houses was a result of smoking.

 

What did the research involve?

The researchers used data from four studies conducted between 2009 and 2013, which had measured PM2.5 concentrations in a total of 93 smoking and 17 non-smoking households in Scotland. They combined this information with data on typical breathing rates and activity patterns.

Using this information, the researchers estimated:

  • daily PM2.5 intake
  • the percentage of total PM2.5 inhaled within the home environment
  • the percentage reduction in daily intake that could be achieved by switching to a smoke-free home

 

What were the basic results?

The researchers found:

  • the average PM2.5 concentration was 31 micrograms per cubic metre (µg/m3) in smoking homes
  • the average PM2.5 concentration was 3µg/m3 in non-smoking homes

From the modelling study, they estimated:

  • PM2.5 intake for a two-year-old child would be 34µg/day in a non-smoking home and 298µg/day in a smoking home. If a smoking home became a non-smoking home, PM2.5 intake would reduce by 79%.
  • PM2.5 intake for an 11-year-old child would be 45µg/day in a non-smoking home and 291µg/day in a smoking home. If a smoking home became a non-smoking home, PM2.5 intake would reduce by 76%.
  • PM2.5 intake for a 40-year-old would be 59µg/day in a non-smoking home and 334µg/day in a smoking home. If a smoking home became a non-smoking home, PM2.5 intake would reduce by 74%.
  • PM2.5 intake for a 70-year-old housebound adult would be 27µg/day in a non-smoking home and 479µg/day in a smoking home. If a smoking home became a non-smoking home, PM2.5 intake would reduce by 86%.

The researchers then estimated lifetime intake. They calculated the average lifetime intake of PM2.5 for people living in non-smoking households in Scotland is 0.76g, while the average lifetime intake for those living in a smoking household (but not smoking themselves) is more than seven times that amount, at 5.82g.

They calculated that some non-smokers living with a smoker will actually inhale more PM2.5 than non-smokers living in heavily polluted urban settings.

 

How did the researchers interpret the results?

The researchers concluded that, "Fine particulate pollution in Scottish homes where smoking is permitted is approximately 10 times higher than in non-smoking homes. Taken over a lifetime, many non-smokers living with a smoker inhale a similar mass of PM2.5 as a non-smoker living in a heavily polluted city such as Beijing.

"Most non-smokers living in smoking households would experience reductions of over 70% in their daily inhaled PM2.5 intake if their home became smoke-free. The reduction is likely to be greatest for the very young and for older members of the population because they typically spend more time at home."

 

Conclusion

This study has found that, on average, fine particulate pollution (PM2.5) concentrations from smoking households were about 10 times those found in non-smoking homes.

The combined results of the modelling studies suggested most non-smokers would have their PM2.5 intake cut by more than 70% if smoking households quit the habit.

Over a lifetime, the researchers calculated PM2.5 intake from living with a smoker could be the equivalent of living in a heavily polluted city.

The generalisability of these results depends on how representative the smoking and non-smoking homes were of the general population.

The researchers note there were wide differences in the PM2.5 concentrations measured in different studies, which they state is probably a result of differences in the populations the samples were drawn from.

They say it is possible smokers living with children restrict their children's exposure to secondhand smoke, so these results may not be generalisable.

In any case, there are many benefits to stopping smoking and there is no justification to subjecting children to the risks of smoke exposure, even if steps are taken to mitigate this.

Read more about how Cecelia Elliott, a young mother, managed to successfully quit smoking for the sake of her son.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Living with smoker 'as bad as living in polluted city'. BBC News, October 21 2014

Links To Science

Semple S, Apsley A, Ibrahim TA, et al. Fine particulate matter concentrations in smoking households: just how much secondhand smoke do you breathe in if you live with a smoker who smokes indoors? Tobacco Control. Published online October 20 2014

Categories: NHS Choices

BMI tests 'miss' over a quarter of obese children

NHS Choices - Behind the Headlines - Mon, 20/10/2014 - 13:00

"Quarter of obese children missed by BMI tests," the Mail Online reports.

The headline was prompted by a review that combined the results of 37 studies in more than 50,000 children and found body mass index (BMI) is an imperfect way of detecting excess body fat.

The study estimated more than a quarter of children (27%) with excess body fat might not be classified as obese when using BMI measurements alone.

This may mean the missed children don't get the same support to achieve a healthy weight as those correctly identified as obese, and so remain at a higher risk of developing a range of weight-related diseases, such as type 2 diabetes.

BMI has long been known to be a relatively blunt tool in terms of accurately assessing body fat, as demonstrated in a similar study in 2012. However, this latest study puts a specific figure on the imperfection.

That said, BMI remains a very useful tool. It provides a reasonably accurate method to estimate obesity rates at a population level, taking just minutes to complete.

Other methods can be more resource and time consuming (hydrostatic weighing), or can have large margins of error if not done correctly (skin callipers).

Overall, this study adds to the evidence of BMI's "bluntness" by quantifying the possible impact of the inaccuracy.

If you are worried about your child's weight, contact your GP. They should be able to make a more detailed assessment.

 

Where did the story come from?

The study was carried out by researchers from the US and Czech Republic. No funding source was reported.

It was published in the peer-reviewed medical journal, Pediatric Obesity.

The Mail Online's coverage was broadly accurate, though if we were being really pedantic we would point out to the headline writers that 27% is not the same as 25%.

 

What kind of research was this?

This was a systematic review and meta-analysis of studies assessing the diagnostic performance of BMI to detect excess fat in children up to the age of 18.

systematic review seeks to identify and pool the results of all published material on a specific topic, and is an effective way of summarising lots of research evidence. A meta-analysis is a related statistical exercise, where the results of studies are pooled. 

Excess fat in people raises the risk of many weight-related diseases, such as diabetes and heart disease. Detecting excess fat in children helps identify those most at risk of damaging their health.

The researchers point out the ideal way of identifying obesity in children and adolescents has not been determined, although BMI is the most widely used screening tool.

This involves weighing and measuring the height of a young person to estimate their BMI. The BMI is then compared against standard cut-offs, which categorises the person as either underweight, a healthy weight, overweight or obese.

In England, this is the approach adopted by the NHS National Child Measurement Programme.

 

What did the research involve?

The researchers searched electronic medical databases for studies assessing the performance of BMI measurement compared with other measures of body fat in people less than 18 years of age.

They then pooled the individual study findings using a meta-analysis to give an overall estimate of how well BMI identified people with excess body fat.

All of the studies included had to compare measuring body fat using BMI with a different reference method, such as DEXA.

Study authors of relevant articles published on the topic were contacted to source additional relevant literature and supplement the electronic database searches.

The main analysis reported the sensitivity and specificity of using BMI to detect excess fat in males and females.

The analysis explored variation between the studies with regard to differences as a result of race, BMI cut-off, BMI reference criteria, and the reference standard for assessing fatness.

 

What were the basic results?

The analysis included 37 studies involving 53,521 patients. The average age in the studies ranged from 4 to 18 years.

The main finding was that commonly used BMI cut-offs showed a pooled sensitivity to detect high fatness of 0.73 (95% confidence interval [CI] 0.67 to 0.79) and a specificity of 0.93 (95% CI 0.88 to 0.96).

This means that BMI correctly identified children with high fat levels 73% of the time, and correctly identified children without high fat levels 93% of the time.

On the flip side, this means up to 27% (100% minus 73%) of children with high fat levels were not correctly identified using BMI, so 27% was the false positive rate.

There was moderate variation in the pooled results as a result of the confounders mentioned above.

 

How did the researchers interpret the results?

These results led the researchers to conclude that, "BMI has high specificity but low sensitivity to detect excess adiposity [body fatness] and fails to identify over a quarter of children with excess body fat percentage."

 

Conclusion

This systematic review and meta-analysis showed using BMI to detect excess body fat in children up to the age of 18 was not perfect. It estimated more than a quarter of children with excess body fat might not be classed as obese using BMI measurements alone.

This may mean they don't get the same help and support to achieve a healthy weight as those correctly identified, and so remain at a higher risk of developing a range of weight-related diseases.

BMI is known to be a far from perfect measure of body fatness, but is often a useful start, so the main conclusion of the research will be nothing new to many health professionals.

However, this study has put a specific figure on the imperfection: more than 25% are incorrectly given the all-clear when their weight may be harming their health.

England's current screening of children for excess body fat, the National Child Measurement Programme, uses BMI as its main measure, so this is very relevant to England's youth.

The way excess body fatness is assessed in this programme is regularly assessed, and this study may contribute to the evidence base considered at the next review of the methodology.

Measuring body fat in children on a large scale is a challenge, and the best way to do this is likely to be balancing accuracy with pragmatism. Some measures of body fat are time consuming to perform and, in the context of a busy school environment, this may be influential.

Overall, this study raises a known issue with using BMI to assess body fat in children, but adds to the evidence by quantifying the possible impact of the inaccuracy.

If you have any concerns about your child's weight, your GP will be able to assess whether their weight may be affecting their health and can offer help and support.

Analysis by Bazian. Edited by NHS ChoicesFollow Behind the Headlines on TwitterJoin the Healthy Evidence forum.

Links To The Headlines

Quarter of obese children missed by BMI tests could be at risk of diabetes and heart disease, scientists warn. Mail Online, October 17 2014

Links To Science

Javed A, Jumean M, Murad MH, et al. Diagnostic performance of body mass index to identify obesity as defined by body adiposity in children and adolescents: a systematic review and meta-analysis. Pediatric Obesity. Published online June 24 2014

Categories: NHS Choices

Viagra could double up as heart failure drug

NHS Choices - Behind the Headlines - Mon, 20/10/2014 - 11:30

"Sex pill Viagra could help men suffering from heart disease," reports the Mirror. This headline follows a new review into the potential heart benefits of the active ingredient in erectile dysfunction drugs such as sildenafil (Viagra), called phosphodiesterase type-5 inhibitors (PDE5is).

PDE5is work by helping blood vessels dilate, which in the case of erectile dysfunction increases blood flow to the penis.

Researchers were interested in whether this dilation effect could have benefits for certain heart conditions, such as heart failure, where the heart struggles to pump blood because of previous damage to heart muscles.

They pooled the findings of 24 randomised controlled trials (RCTs), which suggested PDE5is were better than placebos at improving some measures of heart function in men with early signs of heart disease. 

Commonly reported side effects included flushing, skin rashes and headaches.

Importantly, the study did not assess the drugs' effects on the heart versus treatments currently available to treat or prevent heart conditions.

This means we that cannot say whether they are safer or more effective than existing drugs. PDE5is are currently unlicensed for the treatment of heart failure.

 

Where did the story come from?

The study was carried out by researchers from Sapienza University of Rome and was funded by a Ministry of Research Grant.

It was published in the peer-reviewed medical journal BioMed Central. This is an open access journal, so the study is free to read online.

Generally, the media reported the story accurately. The Mirror, for example, chose its words carefully in saying that, "The sex pill could help men suffering from heart disease". Using the word "could", rather than "does" or "would", adds a necessary element of uncertainty.

The Mirror's reporting of the study was of a reasonable quality, and included relevant quotes from the study's lead author and a useful explanation of a subtype of heart disease known as left ventricular hypertrophy. In many ways, the paper has put its "posher" broadsheet rivals to shame with its reporting.

 

What kind of research was this?

This was a systematic review and meta-analysis of RCTs to assess the effects of the group of drugs known as PDE5i on heart health and function.

These drugs are currently licensed to treat erectile dysfunction, and include sildenafil, which carries the widely known brand name Viagra.

PDE5is work by helping blood vessels relax and dilate, increasing blood flow through the vessels.

This effect also lowers blood pressure, so these drugs are currently contraindicated or used with caution in people with heart disease, including those who have had recent strokes or heart attacks, as the effects are unknown.

However, various research studies have continued to investigate the possibility these drugs could have a beneficial effect on heart function. This review has looked into their effect on cardiovascular outcomes further.

A systematic review of RCTs is one of the most robust study designs aimed at proving whether something works or does not work. It can also tell us whether there is simply not enough evidence to tell one way or the other.

 

What did the research involve?

The research team searched online medical research databases for placebo-controlled RCTs evaluating the effectiveness and safety of PDE5i for a range of heart-related measures.

They then pooled the results of a number of RCTs to create combined estimates of the effects of PDE5is in different people with different heart characteristics.

Some of the main measures they looked at to test if PDE5is improve heart health were:

  • cardiac mass and structure – abnormally high mass can impair the function of the heart
  • cardiac performance
  • afterload – the force developed in the wall of the left ventricle (the large heart chamber that pumps blood to the rest of the body) during blood ejection
  • endothelial function – the endothelium is the inner lining of blood vessels
  • heart rate and blood pressure

RCT results were divided into a number of subgroups to compare:

  • people with moderate-severe left ventricular hypertrophy (LVH) versus those without – LVH is where the wall of the left ventricle is enlarged and thickened, meaning it is under strain and can't pump as effectively; this is often an early sign of heart disease caused by high blood pressure
  • left versus right heart disease (damage to the left or right ventricles of the heart)
  • cardiac disease versus non-cardiac disease (conditions not directly related to the heart that can impact on heart functions, such as anaemia or kidney disease)
  • age – 60 and under, versus over 60

All studies were RCTs, double-blind and placebo-controlled. Four studies were crossovers with variable washout periods (a period during a clinical trial where no treatment is given, allowing the effects of previously administered drugs to be "washed out" of the body).

14 trials received funding from the pharmaceutical companies Pfizer and Eli Lilly or foundations.

The main analysis compared the results of PDE5i with a placebo across the different subgroups and combined overall.

 

What were the basic results?

The searches returned 24 relevant RCTs containing 1,622 participants – 954 randomised to PDE5i and 772 to placebo.

The main results favoured PDE5i compared with placebo across a range of heart outcomes. Sustained PDE5 inhibition produced:

  • an anti-remodelling effect by reducing cardiac mass (−12.21 g/m2, 95% confidence interval [CI] −18.85, −5.57) in people with left ventricular hypertrophy, and by increasing end-diastolic volume (volume after heart filling: 5.00 mL/m2, 95% CI 3.29, 6.71) in people without LVH
  • an improvement in cardiac performance by increasing cardiac index (0.30 L/min/m2, 95% CI 0.202, 0.406) and ejection fraction (3.56%, 95% CI 1.79, 5.33) – both measures related to how much blood is ejected into the body's circulation
  • no changes in afterload
  • an improvement in flow-mediated vasodilation (3.31%, 95% CI 0.53, 6.08)

The commonest side effects were those known to be associated with PDE5i, such as flushing, headache, nosebleeds and gastric symptoms.

 

How did the researchers interpret the results?

The researchers concluded that, "PDE5i could be reasonably offered to men with cardiac hypertrophy [enlarged heart muscle] and early-stage heart failure.

"Given the limited gender data, a larger trial on the sex-specific response to long-term PDE5i treatment is required."

 

Conclusion

This systematic review of 24 RCTs indicated PDE5is were more effective than placebos at improving specific measures of heart health and were broadly safe.

PDE5is lower blood pressure, so these drugs are currently contraindicated or used with caution in people with cardiovascular disease, including those with low blood pressure and a history of stroke or heart attack, as the effects are unknown.

However, various research studies have continued to investigate the possibility that these drugs could have a beneficial effect on heart function.

This review has looked into their effect on cardiovascular outcomes further and found some promising results, including that they could be beneficial in people with left ventricular enlargement and high blood pressure.

But the study has only compared PDE5is with placebos, and has not assessed their effects against heart treatments currently available to treat or prevent heart conditions.

Similarly, the studies included varied in terms of:

  • daily dosage of PDE5i
  • length of treatment – from 4-week to 12-month study periods
  • endpoint assessment method
  • age
  • baseline cardiovascular status
  • gender – 8 trials enrolled only males and 16 trials had a mixed population of 540 females and 459 males

Pooling such diverse studies may have papered over some of the cracks and nuances in treatment efficacy and safety. For example, these drugs may work much better in some groups than others, or be less safe in some groups compared with others.

The studies provided a range of clinical data, such as changes in cardiac mass and flow-mediated vasodilation. But it is not clear what impact these measurements would actually have in terms of developing lower levels of heart disease, improving quality of life or extending disease-free life.

Most of the research was in men, so the knowledge about the effects of PDE5i in women are less clear.

Overall, the review suggests PDE5is are better than placebo for improving some measures of heart function, but the clinical implications of these findings are currently unclear.

Despite the review's conclusions that these drugs could have a good safety profile for use in people with certain heart conditions, more research looking at this specific issue is needed.

These interesting findings prompt the need for further research and, for the time being, the current prescribing information, which advises the cautious prescribing of PDE5i in people with existing cardiovascular conditions, is likely to remain in place.   

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Forget sex, Viagra could be used for heart disease. The Times, October 20 2014

How Viagra could help halt heart attacks and strokes, with some doctors saying it should be routinely prescribed. Mail Online, October 20 2014

Sex pill Viagra could help men suffering from heart disease, a study has revealed. Daily Mirror, October 20 2014

Viagra could soon be used for heart disease patients: researchers. The Daily Telegraph, October 20 2014

Links To Science

Giannetta E, Feola T, Gianfrilli D, et al. Is chronic inhibition of phosphodiesterase type 5 cardioprotective and safe? A meta-analysis of randomized controlled trials. BMC Medicine. Published online October 20 2014

Categories: NHS Choices

Exercise data signs could cut sugary drink intake

NHS Choices - Behind the Headlines - Fri, 17/10/2014 - 12:00

“Signs warning shoppers how much exercise they need to do to burn off calories in sugary drinks can encourage healthier choices,” BBC News reports. Signs in shops in an area of Baltimore seemed to have led to a change in shopping habits amongst Afro-American teenagers.

Researchers first studied beverage purchases by black teens at six corner stores in Baltimore.

They then tested the effect on purchasing habits of displaying different types of calorie information, such as the number of calories in a sugary drink, or how much walking or running you’d need to do to burn off the calories.

Overall, they found that displaying the information changed beverage purchases, with fewer sugary drinks purchased and fewer large drinks purchased, leading to fewer overall calories.

Environmental interventions, including product information and advertising, are known to have some effect on purchasing intentions, so may be a way to target the obesity epidemic. However, it would be premature to generalise these results to other environments and populations at this stage.

There has been a significant amount of research suggesting that that people habitually underestimate the amount of calories they eat, as well as the amount of exercise required to burn off these calories. Therefore, a case could be made that manufacturers could consider adding information such as exercise data to their products.

 

Where did the story come from?

The study was carried out by researchers from Johns Hopkins Bloomberg School of Public Health, Baltimore, in the US, and was funded by the Robert Wood Johnson Foundation through its Healthy Eating Research programme.

The study was published in the peer-reviewed American Journal of Public Health.

Both the BBC News and the Mail Online's reporting of the study was accurate.

 

What kind of research was this?

This was a type of case-crossover study, which aimed to look at the effect that displaying calorific information in different ways in a small sample of corner stores in the US had on the purchase of sugar sweetened beverages (SSBs) by US teenagers from black minority ethnic groups. 

SSBs that were assessed by the study included “soda”, fruit drinks, sport drinks, vitamin water and “Hug” (a US product similar to Fruit Shoot).

A traditional case-crossover study is one where each individual is being used as their own control. In one circumstance, they will be exposed to the risk exposure (the “case”), and in another they will be exposed to the “control” exposure. In this study, the exposure being altered is calorie information. Though described by the researchers as a case-crossover study, this wasn’t a traditional example of this study type, as they weren’t ensuring that it was the same individuals being exposed to each scenario. Rather, they were looking at the same environment (an area of inner-city Baltimore) after an exposure.

It could also be considered to be a type of “before and after” study, where they are just looking at the differences before and after an intervention.

The researchers say that consumption of SSBs is believed to be an important contributor to adolescent obesity, particularly among minority ethnic groups. The researchers report that SSB consumption makes up 15% of the daily calorie intake of minority adolescents, with black adolescents drinking at least twice the daily maximum of SSBs advised by American guidelines (eight to 12 ounces a day). Understanding the potential for environmental interventions is said to be essential for curbing the obesity epidemic.

 

What did the research involve?

This study was conducted in six corner stores in low-income black neighborhoods in Baltimore over a 10-month period, between 2012 and 2013. The target population was black adolescents aged between 12 and 18.

They investigated the effect of displaying four different types of calorific information on SSBs:

  • absolute number of calories in the drink
  • number of teaspoons of sugar
  • minutes of running required to burn off the calories
  • miles of walking required to burn off the calories

Each of these different pieces of information was displayed on a brightly coloured sign in a prominent location on the fridge containing drinks saying, respectively:

  • “Did you know that a bottle of soda or fruit juice has about 250 calories?”
  • “Did you know that a bottle of soda or fruit juice has about 16 teaspoons of sugar?”
  • “Did you know that working off a bottle of soda or fruit juice takes about 50 minutes of running?”
  • “Did you know that working off a bottle of soda or fruit juice takes about 5 miles of walking?”

The signs were based on the estimate that the average 15-year-old would weigh around 50kg (110lbs).

Information was collected of purchases by black adolescents who appeared to be aged 12 to 18 years. A random sample of 35 adolescent purchases per store per week was collected, with information recorded on whether or not the adolescent purchased a beverage and, if so, what type and size of drink.

Over a four-week period, they collected baseline information of SSB purchases when no calorie information was available. Then the six stores displayed each of the different types of information for two weeks, during which time the information on adolescent purchases continued. There was a one week “washout” period between the different signs, where no sign was displayed. For a final six-week post-interventional period, all calorie information was removed.

They also conducted a sample of interviews, where adolescents were stopped and asked whether they had noticed the signs, understood the information, and whether this had influenced their purchases.

The main outcomes described in the study were:

  • whether an SSB was purchased
  • total number of calories
  • whether a large volume was purchased (above 16 ounces, as there had been recent local efforts to ban these sizes in food establishments)

 

What were the basic results?

Over the course of the study, information was collected on 4,516 purchases by black adolescents, 3,098 of which were for beverages of any type. This included 601 beverage purchases during the baseline weeks, 2,311 beverage purchases spread across all four calorie information interventions, and 186 beverage purchases in the post-intervention period.

During the baseline week, just under three-quarters of purchases included a beverage, 97% of which were for SSBs, just over half of which were large volume SSBs, and mean calories of all beverages was 207kcal (206 for SSB beverages).

During each of the interventions there was a change in beverage purchases, with fewer SSBs purchased, fewer large volume SSBs and fewer beverage calories. For example, across all four interventions, the calorie content of any beverage fell from 207 to 184kcal (206 to 196 for SSBs). The proportion of all beverage purchases that included an SSB fell to 89% and the proportion of SSB purchases that were large volume fell from 55% to 37%.

Even in the post-intervention period, after removing the signs, SSB purchases, volume and total calories remained lower than at baseline.

In the interviews, just over a third of adolescents reported seeing the calorie information displayed, 95% of whom reported understanding them, and 40% said they changed their purchase as a result.

 

How did the researchers interpret the results?

The researchers conclude that, “Providing caloric information was associated with purchasing a smaller SSB, switching to a beverage with no calories, or opting to not purchase a beverage; there was a persistent effect on reducing SSB purchases after signs were removed”.

 

Conclusion

This is an interesting study exploring how displaying different types of calorie information in corner stores may change SSB purchases among minority ethnic groups in the US.

Environmental interventions, including product information and advertising, are known to have some effect on purchasing intentions, so may be a way to target the obesity epidemic.

Many experts argue that we are now living in an "obesogenic environment", where the everyday world around us encourages unhealthy food. For example, a study we covered in March 2014 found an association between the number of fast food outlets in a given area and body mass index.

However, little can be firmly concluded from this study. It has focused on studying only black adolescents in one specific region of the US, and has only looked at the effect of the interventions in six corner stores. We don’t know the effect of displaying such information in the wider population, or in different locations (for example fast food outlets, rather than just corner stores).

It is also difficult in such a study to definitely know how much the intervention is having a direct impact on people’s purchasing habits. In this study, the sample of interviews helped to inform this, which suggested that around a third had noticed the signs, and it had influenced the subsequent purchases of 40% of people.

The overall changes in beverage calories during and after the interventions was also fairly small (around 10-20kcal) so it is difficult to say whether or not this would have any meaningful effect on targeting overweight and obesity.

Though environmental interventions are likely to be of some effect in targeting the obesity epidemic, the overall change needs to be towards a healthier, balanced diet in general, combined with regular exercise, rather than change in just one specific area, such as whether or not you purchase an SSB.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on TwitterJoin the Healthy Evidence forum.

Links To The Headlines

Sugary drinks warning signs change habits of US teens. BBC News, October 17, 2014

Run FOUR miles to burn off just one bottle of coke: Scientists call for exercise data to be printed on packaging instead of calories. Mail Online, October 17 2014

Links To Science

Bleich SN, Barry CL, Gary-Webb TL, Herring  BJ. Reducing Sugar-Sweetened Beverage Consumption by Providing Caloric Information: How Black Adolescents Alter Their Purchases and Whether the Effects Persist. American Journal of Public Health. Published online October 16 2014

Categories: NHS Choices

Vegetative patients show awareness during scans

NHS Choices - Behind the Headlines - Fri, 17/10/2014 - 12:00

"Vegetative patients may be more conscious of the world than we think," The Independent reports. Electrodes have detected what has been described as "well-preserved" networks of brain activity in patients in a vegetative state.

A vegetative state is when a person is awake and may have some basic motor reflexes, but no signs of awareness. It is one of a group of conditions known as disorders of consciousness and often develops after a severe head injury.

This study performed electroencephalogram (EEG) examinations to study the electrical signals and connections in the brains of 32 people with disorders of consciousness, comparing them with 26 healthy adults.

The researchers demonstrated that the networks of electrical connections thought to support awareness are impaired in people with disorders of consciousness. They also found the quality of people's brain connections correlates with their level of awareness.

Most interestingly, they also found a small number of people in a vegetative state may have more conscious awareness than it seems.

Four people in this state were found to show some signs of "hidden awareness" – they demonstrated brain activity on functional MRI scans when asked to imagine playing tennis (in neurological circles, this is known as the tennis test).

When looking at the EEG results, the researchers found some of the brain connections that support consciousness in healthy adults were also well preserved in these people.

The researchers suggest these results may help improve clinical assessments in the future, as well as help identify people who may still have some level of conscious awareness, despite not being able to demonstrate this.

 

Where did the story come from?

The study was carried out by researchers from the University of Cambridge, the University of California, the University of Western Ontario, and the Universidad Diego Portales, Chile.

Funding was provided by various sources, including the Wellcome Trust, the UK Medical Research Council, and the National Institute for Health Research.

It was published in the peer-reviewed journal, PLOS Computational Biology, which is open access, so the study is available to read online for free.

The Independent and BBC News reported the study accurately. However, while the sentiment of the Daily Express' headline, "Talking to vegetative state patients can help recovery", may be well intentioned, it does not have a strong foundation.

Although the study found a small number of people in a vegetative state did seem to have some conscious awareness, despite this not being apparent, it did not look at their brain activity in response to friends and family talking to them. And it certainly has not examined whether this may or may not help them recover.

 

What kind of research was this?

This was a case control study that looked at electrical signals coming from the brains of people with disorders of consciousness, and compared them with normal healthy controls.

There are three conditions that generally fall into what are termed disorders of consciousness, which usually occur after a severe brain injury.

A minimally conscious state is where the person has very little consciousness, but demonstrates some variable response or awareness of their surroundings.

A vegetative state is the middle condition, where the person has no environmental awareness at all, but they still demonstrate a sleep-wake cycle and reflexive responses (such as to pain or sound).

A person in a coma is unconscious, with no awareness at all, does not respond to their environment, and has no sleep-wake cycle and no normal reflex responses.

This study aimed to further understand the distinctive brain networks that characterise the different disorders of consciousness.

 

What did the research involve?

This study took bedside EEG recordings of the electrical signals coming from the brains of 32 people with disorders of consciousness, as well as 26 healthy controls.

They looked at the amplitude of oscillations and then looked at the structure of brain networks connected by these oscillations.

The researchers then compared the electrical patterns and connections between the people with disorders of consciousness and the healthy controls.

They also examined what signalling abnormalities are present in people with disorders of consciousness, to what extent these patterns are consistent across patients, and how the patterns correlate with the level of behavioural response present.

 

What were the basic results?

The results of this study are quite complex, reporting the intricate differences in brain networks and connectivity between people with disorders of consciousness and healthy controls.

In general, the researchers found distinct differences in people with disorders of consciousness compared with the healthy controls.

They also found the quality of signalling networks in people with disorders of consciousness correlated with the degree of behavioural response they demonstrated.

Of the people in a vegetative state – who by definition have no behavioural responses – four out of 13 were surprisingly found to demonstrate some signs of brain activity when asked to imagine playing tennis while having their brain scanned by functional MRI scan.

When looking at the EEGs of this small number of vegetative patients with some signs of "hidden awareness", the researchers found they had well-preserved signalling networks similar to those of healthy adults.

 

How did the researchers interpret the results?

The researchers concluded that their findings "inform current understanding of disorders of consciousness by highlighting the distinctive brain networks that characterise them".

They say tests in a minority of people in a vegetative state indicate signalling pathways that could support mental function and consciousness, although these people have profound behavioural impairment.

 

Conclusion

This study performed EEG examinations to study the electrical signals and connections in the brains of 32 people with disorders of consciousness, comparing them with 26 healthy adults.

The researchers demonstrated the network of electrical connections that support awareness, and how these connections are impaired in people with disorders of consciousness. They also found the quality of people's brain connections correlates with their level of awareness.

Of most interest, they found a small number of people in a vegetative state may have more conscious awareness than it seems.

A vegetative state is characterised by a person maintaining spontaneous reflexes, such as to pain or sound, and having a normal sleep-wake cycle, but they cannot demonstrate behavioural responses or conscious awareness of their surroundings.

But in this study, four people in this state were found to show some signs of hidden awareness – they demonstrated brain activity on a functional MRI scan when asked to imagine playing tennis.

When looking at their EEGs, the researchers found some of the brain connections that support consciousness in healthy adults were also well preserved in these people, too.

The researchers suggest the distinct brain network connections seen in people with disorders of consciousness that they have identified in this study may help improve clinical assessments in the future.

This information may also help identify people who may still have some level of conscious awareness, despite not being able to demonstrate this.

Further research building on these findings is awaited. Despite one newspaper's report to the contrary, the results of this study are not suddenly going to lead to new treatments for disorders of consciousness – at least in the short term. But learning more about the relationship between brain activities and levels of awareness is always valuable.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Vegetative patients may be more conscious of the world than we think. The Independent, October 16 2014

Vegetative patients show glimmers of consciousness. BBC News, 17 October 2014

Talking to vegetative state patients can help recovery. Daily Express, 16 October 2014

Links To Science

Chennu S, Finoia P, Kamau E, et al. Spectral Signatures of Reorganised Brain Networks in Disorders of Consciousness. PLOS Computational Biology. Published 16 October 2014

Categories: NHS Choices

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