NHS Choices

Is frequent mouthwash use linked to oral cancer?

NHS Choices - Behind the Headlines - Fri, 04/04/2014 - 12:55

"Experts warn using mouthwash more than twice a day can give you cancer," the Daily Mirror reports. The news comes from a European study that examined the oral health and dental hygiene of people diagnosed with cancers of the mouth, throat, vocal chords or oesophagus (collectively called "upper aerodigestive cancers").

The researchers found that people with the poorest oral health (including wearing dentures and bleeding gums) had a more than doubled risk of these cancers compared with those with the best oral health.

Similarly, they found that those with the poorest dental care (including frequency of tooth brushing and visiting the dentist) had a more than double risk compared with those with the best dental care.

Importantly, these associations remained after adjustment for smoking and alcohol consumption – established risk factors for these cancers – and for other factors that may influence risk, such as socioeconomic status.

But despite the Mirror's headline, the link between oral cancer and mouthwash is less clear. The association was only significant when looking at very frequent use (three times a day).

Very few people used mouthwash this frequently, which decreases the reliability of this risk estimate. There is certainly no credible evidence that mouthwash "can give you cancer". 

Even if there is a true link, it is unclear whether it is mouthwash itself (the alcohol content) or the reasons it is being used, such as poor oral hygiene, that are responsible for the association.

The results do suggest a link between poor dental hygiene and oral cancers, however, and reinforce the importance of maintaining good dental health.

 

Where did the story come from?

This was multicentre research conducted by numerous academic institutions across Europe and the US.

The study was supported by the European Community Fifth Framework Programme, the University of Athens Medical School, the Bureau of Epidemiologic Research Academy of Athens, Padova University, Compagnia di San Paolo, Associazione Italiana per la Ricerca sul Cancro (AIRC), the Piedmont Region, targeted financing from the Estonian government through the European Regional Development Fund in the frame of Centre of Excellence in Genomics, and the 7FP Project ECOGENE.

It was published in the peer-reviewed Journal of Clinical Oncology.

The quality of the UK's media reporting on the study was mixed. BBC News rightly focused on the link between poor dental hygiene and oral cancer.

But the Daily Mirror incorrectly states in its headline that, "Experts warn using mouthwash more than twice a day can give you cancer". In fact, the researchers specifically go out of the way in their conclusion to state that their data does not provide proof that excessive mouthwash increases cancer risk.

 

What kind of research was this?

This was a case-control study that included a group of people diagnosed with cancer of the mouth, throat, vocal chords or food pipe (oesophagus). They were then matched with a group of people without these cancers (the controls) and were interviewed about their oral health, dental care and lifestyle.

The researchers aimed to see whether oral health and dental care – in particular, the use of mouthwash – may be associated with these cancers. As a group, these cancers are sometimes called "upper aerodigestive cancers" as they involve the upper parts of the respiratory and digestive system.

These cancers are said to account for around 129,000 new cancer cases in the European Union, making them the fourth most common cancers for men and the tenth for women.

Alcohol and smoking are widely known to be risk factors for these cancers. Other research has also associated the cancers with lower fruit and vegetable consumption, and found that they are more common among lower socioeconomic status groups.

Additional research has also suggested that poorer dental and oral health may be associated with increased risk, independent of alcohol and smoking behaviour.

It is also speculated that frequent use of mouthwash could be a risk factor as a result of the ethanol (alcohol) it contains. However, there is limited evidence proving that there is an increased risk associated with mouthwash containing alcohol.

This study aimed to examine whether mouthwash and wider oral health and dental care are associated with the risk of upper aerodigestive cancers, importantly adjusting for the potential confounders of smoking and alcohol.

 

What did the research involve?

This study used information from the multicentre alcohol-related cancers and genetic susceptibility in Europe (ARCAGE) case-control study, which was conducted across 13 centres in nine European countries.

The study included 1,963 people newly diagnosed with cancers of the mouth, throat, vocal chords or oesophagus between 2002 and 2005 (cases). They were matched by age and sex to 1,993 people without cancer, who were randomly selected from people attending the same medical centres or hospitals as the cases for other health reasons.

All participants were interviewed about a range of health and lifestyle measures:

  • sociodemographic characteristics (number of years of full-time education was used as the main indicator of socioeconomic status)
  • smoking history (lifetime smoking history was used to calculate "pack years")
  • alcohol consumption (lifetime consumption of number of drinks per day was assessed for all categories of alcoholic drinks)
  • weekly consumption of fruits and vegetables (recorded by food frequency questionnaire)
  • employment history
  • body measurements
  • medical and dental history, including oral hygiene habits

Oral health was assessed using the following scoring system, where a maximum total score of 7 would indicate poorest oral health:

  • wearing of dentures (none = 0; partial denture in upper or lower jaw = 1; partial denture in both jaws = 2; complete denture in one jaw = 3; complete denture in both jaws = 4)
  • age at starting to wear dentures (no denture = 0; denture at age 55 years or older = 1; denture at age 35-54 years = 2; denture at age below 35 years = 3)
  • frequency of gum bleeding from brushing teeth (sometimes or never = 0; always or almost always = 1; 0 in subjects wearing complete dentures in both jaws)

Similarly, dental care was assessed as follows, where a maximum total score of 8 would indicate poorest dental care:

  • frequency of tooth cleaning (at least twice per day = 0; once per day = 1; 1-4 times per week = 2; less often or never = 3)
  • use of toothbrush, toothpaste or dental floss (two or three of these = 0; only one of these three = 1; none of these = 2)
  • frequency of visiting a dentist (at least once per year = 0; every 2-5 years = 1; less than every 5 years = 2; never = 3)

Participants were asked about their use of mouthwash in a separate question, but this was not included in these scores.

The researchers also took blood samples to look at whether people had four variations in genes that code for proteins involved in breaking down alcohol (ethanol).

The researchers previously found these variations to be associated with risk of upper aerodigestive cancers, with one particularly associated among heavy drinkers.

As many brands of mouthwash contain alcohol, the researchers wanted to test whether a person who had these variants influenced the potential link between mouthwash and upper aerodigestive cancers.

 

What were the basic results?

Participants were aged 60 years on average. Almost half of cases had mouth cancer (48%), followed by cancer of the lower throat or vocal chords as the next most common cancer (36%).

After adjustment for all other measured health and lifestyle factors, the risk of upper aerodigestive cancers increased with poorer dental care. People with the worst dental care (scores of 5-8) had the highest risk, more than double the cancer risk for people with the best dental care (a score of 0; odds ratio [OR] 2.36, 95% confidence interval [CI] 1.51 to 3.67).

Looking at oral health, people with the poorest oral health (score of 5, 6 or 7) had an increased risk compared with those with the best oral health (score of 0). People with the highest oral health score of 7 had a more than doubled risk compared with those with a score of 0 (OR 2.22, 95% CI 1.45 to 3.41). Those with moderate oral health – a score of 1-4 – were not at increased risk compared with those with the best oral health.

Reported use of mouthwash of more than three times per day was associated with tripled risk of upper aerodigestive cancers (OR 3.23, 95% CI 1.68 to 6.19). Importantly, the researchers say that although this effect was strong, only 1.8% of cases and 0.8% of controls reported such frequent use.

These relatively small numbers reduce confidence that these estimates of risk are correct. There was also no link between less frequent use of mouthwash (less than three times a day) and risk.

Looking at the four gene variants, certain variants associated with faster ethanol metabolism were associated with a decreased risk of these cancers, while a variant associated with slower ethanol metabolism was associated with increased risk.

One particular variant associated with faster ethanol metabolism was found to be less common in mouthwash users compared with "never users".

 

How did the researchers interpret the results?

The researchers concluded that poor oral health and dental care seem to be independent risk factors for upper aerodigestive cancers, even after adjusting for potential confounders such as smoking and alcohol use.

They say that, "Whether mouthwash use may entail some risk through the alcohol content in most formulations on the market remains to be fully clarified."

 

Conclusion

This multicentre study conducted across nine European countries has many strengths, including its large sample size. Most importantly, it adjusted for smoking and alcohol consumption, which are well-established risk factors for these cancers and could otherwise influence the association between oral health and dental hygiene and these cancers.

The researchers also adjusted for other potential risk factors, such as socioeconomic status and how much fruit and vegetables people ate.

However, there are some potential limitations. Although the researchers have made every effort to adjust for these confounders, as the researchers themselves acknowledge, the questions asked about these lifestyle factors may not fully capture a person's smoking habits, alcohol use and diet, so there is still the possibility that they have some effect.

Also, the questions asked around oral health and dental hygiene may not have given a full representation of the person's mouth care. These self-reported measures were not checked against dental records.

The study asked people to rate their current oral health and dental hygiene, and in the people with cancer this was after their diagnosis. This may not reflect their lifelong oral health or care before their diagnosis. An independent assessment provided by a dentist, or examination of dental records, may have been more reliable.

Nevertheless, the study does support an independent link between oral health and dental hygiene and aerodigestive cancers. The link seems biologically plausible and further study could also assess why these links might exist. Previous studies have suggested similar links, and ideally a systematic review would be able to look at this new study alongside the other available evidence. Such a review may provide new insights into potential risk factors.

Despite reports to the contrary, the link between mouthwash and cancer is less clear. Although using mouthwash more than three times a day was more common among cases than controls, very few people used mouthwash this frequently – only 1.8% of cases and 0.8% of controls. Risk calculations involving such small numbers of people are less reliable than those including larger samples.

The possible link between mouthwash and mouth and throat cancers needs to be clarified. If there is a link, it is currently unclear whether it could be related to the alcohol contained in mouthwash, or whether the link is caused by poor oral health and not a direct effect of mouthwash at all. It could be that poor oral health or dental hygiene increases the risk, and people with poorer health are also more likely to use mouthwash.

However, in the meantime, if you are concerned, there are plenty of alcohol-free mouthwash brands available. Your local pharmacist should be able to advise you.

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

Links To The Headlines

Experts warn using mouthwash more than twice a day can give you cancer. Daily Mirror, April 4 2014

Mouthwash use 'linked to oral cancer': People who use products more than three times a day increase risk. Daily Mail, April 4 2014

Study identifies 'new risks' for mouth and throat cancers. BBC News, April 4 2014

Mouthwash overuse has possible link to mouth and throat cancer. Daily Express, April 4 2014

Links To Science

Ahrens W, Pohlabeln H, Foraita R, et al. Oral health, dental care and mouthwash associated with upper aerodigestive tract cancer risk in Europe: The ARCAGE study. Oral Oncology. Published online March 28 2014

Categories: NHS Choices

Vegetarians have 'poorer quality of life' study claims

NHS Choices - Behind the Headlines - Fri, 04/04/2014 - 11:30

“Vegetarians are 'less healthy and have a lower quality of life than meat-eaters’,'' The Independent reports. A study from Austria suggests there is an association between a vegetarian diet and an increased risk of certain chronic diseases.

But before any meat eating readers start feeling smug, the study provides no proof that vegetarians are in poorer health than meat eaters.

This was an Austrian survey which simply took a group of 330 people put into a general “vegetarian” category (some in this category were not exclusively vegetarian). They were matched with groups of people from three “carnivorous” categories; ranked in terms of total meat consumption.

The groups were then compared on a range of different health and lifestyle measures to see if any differences were observed.

The researchers found various differences; both good and bad.

The “vegetarians” had lower body mass index (BMI) and alcohol intake, but they also had increased prevalence of three chronic diseases: “allergies”, “cancer” and “mental illness”.

The study has numerous limitations, including the cross sectional survey design, where data is taken at a single point in time, so it cannot prove cause and effect.

It could be the case, for example, that people with certain cancers could chose to adopt a vegetarian diet to try and improve their health, rather than a vegetarian diet increasing the risk of developing cancer.

However, as the research included a relatively small sample of only 330 vegetarians, the prevalence of the 18 diseases questioned in this group could differ from another group, meaning these associations with the three diseases could purely be due to chance. 

Overall the decision to follow a vegetarian diet or one containing meat remains a personal lifestyle choice, often based on ethical as well as health reasons.

 

Where did the story come from?

The study was carried out by researchers from Medical University Graz, Graz, Austria. No sources of funding were reported.

The study was published in the peer reviewedopen access medical journal PLOS one and can be read online for free (PDF, 158kb).

Most of the UK media’s reporting on the study does not mention its numerous limitations and that it cannot prove cause and effect.

There were also inaccuracies in reports that vegetarians were 50% more likely to have a heart attack. There was no significant difference between the vegetarian and three carnivorous groups for any cardiovascular diseases questioned – history of heart attack, high blood pressurestroke or diabetes.

 

What kind of research was this?

This was a cross sectional study using Austrian survey data collected in 2006/7. It aimed to see whether there was any difference in various health-related variables between people following different dietary habits.

The researchers say that previous research has associated vegetarian and Mediterranean diets with various health benefits and reduced risk of certain diseases.

Meanwhile increased red meat consumption has often been associated with detrimental health effects.

Therefore the researchers aimed to investigate health differences between different dietary habit groups among Austrian adults. The main limitation with this study is that it is only cross sectional and looking at a specific population. It can note associations, but it can’t prove cause and effect. It is possible that the associations seen might be in fact be due to ‘reverse causality’.

Any associations seen could be due to people with health problems switching to diets that are perceived to be healthier, rather than their diet causing health problems.

 

What did the research involve?

The researchers analysed the diet, health and lifestyle of 15,474 Austrian people aged over 15 years (55% female) who took part in the Austrian Health Interview Survey (AT-HIS) which ran from March 2006 to February 2007. The surveys are carried out every eight years and include a representative sample of the Austrian population (response rate for this survey 63%).

In face-to-face interviews people were asked about socio-demographic characteristics, health related behaviours (including smoking, alcohol and physical activity), BMI, diseases and medical treatments, and also psychological health.

Without a clear definition of the categories being given, people were asked whether they considered their diet to be:

  • vegan
  • vegetarian including milk and/or eggs
  • vegetarian including fish and/or milk/eggs
  • carnivorous but rich in fruits and vegetables
  • carnivorous but less rich in meat
  • carnivorous rich in meat.

Few people reported that their diet corresponded to one of the vegetarian diets, and therefore all three of these were grouped together. The 330 “vegetarians” were then age- sex- and socioeconomically-matched to one individual from each of three “carnivorous” groups, resulting in a total sample size of 1,320 people.

Assessments of health and diseases included questioning self-perceived health (ranging from 1 very good, to 5, very bad) and functional impairment (1 very to 3 not impaired). They assessed 18 specific diseases (including heart attack, high blood pressure, stroke, cancer, arthritis and mental illness), which were classed as being “present” or “absent”. “Medical treatments” was classed as having consulted a GP or one of seven different specialists in the past 12 months (“consulted” or “not consulted”).

The number of vaccinations was also coded, in addition to looking at preventative care measures such as attending for “preventive check-ups”, “prostate gland check-up”, mammography and smear tests.

They also measured quality of life using the short version of an established questionnaire assessing four domains of physical, psychological health, social relationships and environment.

They then looked at differences between the “vegetarians” and the matched individuals in the three different “carnivorous” groups and their various lifestyle habits and diseases.

In some of the analyses the researchers adjusted for BMI, physical activity, smoking behaviour and alcohol consumption.

 

What were the basic results?

The researchers found that the “vegetarians” had lower BMI (22.9kg/m2) compared to the three other carnivore groups (23.4 in those with less rich meat, 23.5 in those rich in fruit and veg, and 24.9 in those rich in meat). Looking at lifestyle behaviour, vegetarians drank less alcohol, drinking on 2.6 days of the week in the past month than those in the three carnivore groups who drank on 3 to 4.8 days. They didn’t differ on smoking or physical activity.

Looking at health and disease they found that “vegetarians” tended to self-report poorer health and higher levels of functional impairment. They also reported more chronic diseases overall. Looking at specific diseases, those significantly more common among the vegetarians were:

  • “allergies” (31% prevalence compared to between 17 and 20% in the different carnivorous groups)
  • “cancer” (5% prevalence compared to 1 to 3%)
  • “mental illness” (anxiety and depression only: 9% prevalence compared to 4 to 5%)

“Urinary incontinence” was significantly less common in “vegetarians” (2% vs. 3 to 6% in the different carnivorous groups). 

Vegetarians consulted doctors more than those eating a carnivorous diet less rich in meat, but were vaccinated less than all the other carnivore groups. They also made less use of preventative check-ups than those eating a carnivorous diet rich in fruit and vegetables.

They also found that “vegetarians” had a lower quality of life in the domains of “physical health” and “environment” than those consuming a carnivorous diet less rich in meat.

Lower quality of life regarding “social relationships” were also reported in “vegetarians”.

 

How did the researchers interpret the results?

The researchers conclude that their results show that “a vegetarian diet is associated with poorer health (higher incidences of cancer, allergies, and mental health disorders), a higher need for health care, and poorer quality of life.” They suggest that “public health programs are needed in order to reduce the health risk due to nutritional factors”.

 

Conclusion

Despite the media headlines, the results from this Austrian cross sectional survey provide no proof that vegetarians are in poorer health than meat eaters.

The study has simply compared a group of people with a “vegetarian” diet with three different groups of people following “carnivorous” diets on a range of different health and lifestyle measures to see if any differences are observed.

The study has numerous limitations:

  • The cross sectional study cannot prove cause and effect and that the dietary pattern is responsible for any of these self-reported differences. In fact it is possible the associations seen could be due to ‘reverse causality’: people with existing health problems might have switched to a vegetarian diet that may be perceived to be more healthy.
  • Very general categories of “vegetarian” and three “carnivorous” groups were used. As the person’s dietary pattern was self-reported, and the categories were not defined, people grouped into these categories could in reality have had widely different dietary intake patterns, and some people could be incorrectly categorised. 
  • Very general categories of diseases were used. The researchers questioned the presence of 18 specific diseases, but these do not appear to have been medically verified and seem to have just been classed as being “present” or “absent” without having any idea of what this means (for example whether the person actually met diagnostic criteria for this condition, how long they’d had it, how severe it was, whether it was being treated). They found links with three of these 18 diseases, but considering this study includes a relatively small sample of only 330 vegetarians; it is possible these may be chance observations. A sample of another 330 could have found different disease prevalence.
  • Similar to diseases and dietary groups, very crude measures of all health habits and health variables were also used.
  • The study includes only an Austrian sample who may have different dietary, health and lifestyle habits from other countries.

Of note, the study found associations between a vegetarian diet and increased risk of “allergies”, “cancer” and “mental illness”, but not cardiovascular diseases.

Overall the decision to follow a vegetarian diet or one containing meat remains a personal lifestyle choice.

For a healthy lifestyle, all people should aim to eat a diet high in fruit and vegetables and low in saturated fats, salt and sugars, moderate alcohol intake, avoid smoking and take exercise in line with current recommendations.

Read more about healthy eating.

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

Links To The Headlines

Vegetarians are 'less healthy and have a lower quality of life than meat-eaters', scientists say. The Independent, April 3 2014

Vegetarians are 'less healthy' and have a poorer quality of life than meat-eaters. Mail Online, April 3 2014

Links To Science

Burkert NT, Muckenhuber J, Großschadl F, et al. Nutrition and Health – The Association between Eating Behavior and Various Health Parameters: A Matched Sample Study (PDF: 158kb). PLOS One. Published online February 7 2014

Categories: NHS Choices

Can warm-water exercise help high blood pressure?

NHS Choices - Behind the Headlines - Thu, 03/04/2014 - 12:30

"Working out in warm water could be a radical new cure for high blood pressure," the Mail Online reports. Results of a small study suggest that "hot aquarobics" may benefit people who had failed to respond to conventional treatment for high blood pressure.

The study was a small randomised trial that included 32 people with high blood pressure that had not responded to at least three previous blood pressure medications. Those involved did not exercise regularly.

They were randomly selected to do either 12 weeks of three hours of exercise a week in a swimming pool filled with warm water, or to carry on as normal.

The blood pressure of people doing the warm-water exercises did fall to levels that are usually considered healthy. If this effect could be sustained on a long-term basis, this would reduce the risk of cardiovascular diseases such as heart attacks or stroke.

At the moment we don't know which aspect of the exercise programme had the effect, as the programme was compared with doing no regular exercise at all.

We do not know if it was the water, the exercise, the temperature, a combination of all three or another feature of the exercise programme that caused the effect.

There is also the possibility that a placebo effect may have influenced the results.

Further long-term studies in a larger group of people comparing water-based and land-based exercise programmes and pool water at different temperatures are now required.

Read about other lifestyle changes you can make to lower your blood pressure.

 

Where did the story come from?

The study was carried out by researchers from the University of São Paulo, Brazil. It was funded by Fundação de Amparo à Pesquisa do Estado de São Paulo and Conselho Nacional de Desenvolvimento Científico e Tecnologico (Foundation for Research Support of the State of São Paulo and the National Council for Scientific and Technological Development).

It was published in the peer-reviewed International Journal of Cardiology.

The majority of the Mail Online's reporting was accurate, but it should be noted that the importance of the different elements of the exercise programme can't be determined by this study.

We don't know if it was the exercise, the fact it took place it water, the temperature of the water, or another feature of the exercise programme was key. We also don't know how warm water exercise might be having an effect.

The Mail Online's explanation that, "the temperature of the water dilates blood vessels, improving flow of blood" is plausible but as yet unproven. The reporting does conclude with a useful and appropriate quote from a cardiac nurse, reminding readers that, "getting a minimum of 150 minutes of moderate intensity physical activity throughout the week will help keep your heart healthy".

 

What kind of research was this?

This was a randomised controlled trial (RCT) that examined the effects of heated water-based exercise on blood pressure in people with high blood pressure that had not responded to at least three previous blood pressure medications (resistant hypertension).

The study states that around an estimated 10-30% of people with high blood pressure have resistant hypertension and these people are at risk of cardiovascular disease.

Randomised controlled trials are the ideal way to answer this question. However, this was a short-term study with only 32 participants. As the researchers themselves note, further long-term studies involving a larger group of people comparing water-based and land-based exercise programmes and pool water at different temperatures are required in the future.

 

What did the research involve?

The trial involved 32 people between the ages of 40 and 65 years old who had high blood pressure that had not responded to at least three previous blood pressure medications (resistant hypertension). None of the participants had coronary heart disease and none of these people performed regular physical activity.

They were randomly divided into two groups of 16 people. One group performed hour-long exercise sessions in a swimming pool heated to 32ºC three times a week for 12 weeks.

The exercise sessions consisted of walking and callisthenic exercises (callisthenics includes exercises such as star jumps). The other group maintained their normal routine.

Both groups were instructed not to perform any additional leisure time activity and participants continued taking their normal blood pressure medications during the trial.

Before and after the trial, the researchers measured the participants' blood pressure over a 24-hour period during which participants performed normal daily activities.

Participants wore a blood pressure cuff that measured their blood pressure every 15 minutes during the day and every 20 minutes during the night.

Measuring blood pressure in this way avoids the "white coat" effect – the effect that being at the doctor's can have on blood pressure because many people are nervous about visiting a doctor.

The researchers looked at whether there was a change in blood pressure after the trial and whether there was a difference in the change for people who had performed the exercise sessions, compared with people who maintained their normal routine.

 

What were the basic results?

After 12 weeks, blood pressure fell significantly in people who performed the warm-water exercise sessions. Average systolic (the upper blood pressure figure, which relates to the pressure in the arteries when the heart contracts) and diastolic (the lower blood pressure figure, which relates to the pressure in the arteries when the heart relaxes and fills with blood) blood pressure fell over the 24-hour period, and during daytime and night-time periods:

  • average 24-hour systolic: decrease from 137 to 120 mm Hg
  • average 24-hour diastolic: decrease from 81 to 72 mm Hg
  • average daytime systolic: decrease from 141 to 120 mm Hg
  • average daytime diastolic: decrease from 84 to 73 mm Hg
  • average night-time systolic: decrease from 129 to 114 mm Hg
  • average night-time diastolic: decrease from 74 to 66 mm Hg

In contrast, in the control group, average systolic and diastolic blood pressure significantly increased over the 24-hour period and during the daytime period. Diastolic blood pressure increased during the night-time period in people in the control group.

The researchers also found that the amount of time blood pressure readings exceeded the threshold for defining high blood pressure (blood pressure load) significantly decreased in the exercise group in all time periods. There was no significant change in blood pressure load during any of these periods in the control group.

The researchers also looked at heart and lung function by performing a fitness test on a treadmill. They looked at blood pressure, heart rate, peak oxygen consumption and respiratory exchange rate.

Before the trial, both groups had similar values. After the trial, people who had performed the warm-water exercise had significantly improved peak oxygen consumption and respiratory exchange rate. There was no significant change in these measurements in the control group.

 

How did the researchers interpret the results?

The researchers conclude that, "Heated water-based exercise training leads to a significant reduction on 24-hour, daytime and night-time blood pressures in [patients with resistant hypertension]."

They go on to say that, "Studies comparing exercise training in heated water with that on land will be needed to better understand the mechanisms of the [blood pressure] lowering in resistant hypertension. Research involving a large number of patients, long-term training and pool water at different temperatures would be required in the future."

 

Conclusion

This small randomised trial has found that 12 weeks of three hours a week of exercise in a swimming pool filled with warm water reduced blood pressure in a specific group of people with high blood pressure that had not responded to at least three previous blood pressure medications.

A limitation of the study was that the people taking regular exercise sessions in warm water were being compared with a control group who were continuing to take no exercise.

It is therefore unclear whether it was the fact that they actually exercised, rather than the type of exercise, was the key factor. It is possible that a similar effect on blood pressure would have occurred if they had been encouraged to go for a regular brisk walk or a cycle ride.

A better comparison perhaps would have been to compare two groups where the only difference was either the exercise (with both groups in warm water, one exercising, one not) or the change in water temperature (with both groups exercising, one in warmer water, one in cooler).

The small size of the trial – only 16 people in each group – is also an important limitation.

As the researchers themselves note, further long-term studies in a larger group of people, comparing water-based and land-based exercise programmes and pool water at different temperatures, would be required in the future.

Exercise and an active lifestyle are already recommended as a way of lowering high blood pressure. Other recommended lifestyle changes you can make include reducing your salt intake, eating a healthy, balanced diet, reducing the amount of alcohol you drink, stopping smoking, losing weight if you are overweight, reducing the amount of caffeinated drinks you drink, and trying relaxation therapies such as yoga.

Read more about lifestyle changes you can make to lower your blood pressure.

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

Links To The Headlines

Could exercising in warm water cure high blood pressure? Research suggests it could even help those who don't respond to drugs. Mail Online, April 2 2014

Links To Science

Guimaraes GV, Galvani de Barros Cruz L, Morita Fernandes-Silva M, et al. Heated water-based exercise training reduces 24-hour ambulatory blood pressure levels in resistant hypertensive patients: A randomized controlled trial (HEx trial). International Journal of Cardiology. Published online March 15 2014

Categories: NHS Choices

Ketamine tested as severe depression treatment

NHS Choices - Behind the Headlines - Thu, 03/04/2014 - 01:00

“The illegal party drug ketamine is an ‘exciting’ and ‘dramatic’ new treatment for depression,” BBC News reports. A small study found that some people with severe depression responded well to the drug.

The study involved people with severe depression (including people with depression as part of bipolar disorder) who had failed to respond to conventional treatments.

They were treated with intravenous infusions of ketamine either once or twice a week for three weeks.

Some people responded well to treatment; eight people (almost a third) experienced a significant improvement in depression symptoms.

Though another seven people withdrew from the study – two because of side effects during the infusion; and five because they were getting no benefit and were becoming more anxious. 

This may suggest ketamine may only be effective and tolerable for a minority of patients.

Researchers were concerned that ketamine may have a detrimental effect on memory (as has been reported among heavy recreational users) but this does not seem to have been the case.

This was an early stage study and not a randomised controlled trial, which is the most reliable way to measure a drug’s effectiveness. Much more research is needed into its safety and effectiveness before it is known whether it could one day be licensed for treatment of depression. And if it is, it is likely to be for very specific groups of people receiving hospital care for their condition who have not responded to all other treatment options. 

 

Where did the story come from?

The study was carried out by researchers from Oxford Health NHS Foundation Trust and the University of Oxford. It was funded by the National Institute for Health Research. 

The study was published in the peer-reviewed Journal of Psychopharmacology.

It was widely covered in the media, sometimes misleadingly. For example, BBC News reported that depression is common, affecting one in 10 people at some point in their lives (which is correct). However, in this study ketamine was only used for people with severe depression that had not responded to other treatments. This type of depression only affects a small number of people with the condition.

Even for this group of people, this is early stage research into the use of ketamine, carried out in highly controlled conditions.  

 

What kind of research was this?

This was an open label study which investigated the use of two different doses of ketamine in a group of people with depression that had not responded to previous antidepressant treatment (this included people with resistant depression as part of bipolar disorder).

The study took place in a hospital clinic where electroconvulsive therapy (ECT) is normally performed. ECT is a treatment sometimes used in people with severe depression that has not responded to previous treatment. Although it can be effective, the benefits of ECT have to be balanced against the risk of memory loss, a side effect of ECT. Other side effects include short-term headaches, nausea and muscle aches. So there is a need for further treatment options for such people with treatment-resistant depression.

In this open label study two groups of people were treated with one of the two different dose schedules. It was not a randomised controlled trial (RCT), which would randomise people to either the treatment being investigated or a comparison treatment. And being open label meant that both researchers and participants knew the treatment that was being given.

A study such as this is an early stage study, which primarily aims to give an indication of the possible safety and effectiveness of a treatment, and so see whether further testing in an RCT would be indicated as the next stage. 

The researchers say that several RCTs have shown that a single dose of ketamine can have a rapid antidepressant effect in some people with treatment resistant depression, who have been taken off other treatments.

The response, they say, has been seen in both people with resistant depression and people with resistant depression as part of bipolar disorder.

However these patients have relapsed within a short time – typically a week.

In this study the researchers aimed to explore the safety and effectiveness of giving repeated ketamine infusions to people who continued using other antidepressant medication.

In particular they wanted to find out of ketamine had any adverse effects on memory and cognitive function.

 

What did the research involve?

Researchers recruited 28 patients with diagnosed, treatment-resistant depression or bipolar disorder. They identified people who had been referred to psychiatry, or those who self-referred to advertisements for the study. All potential participants had their diagnosis confirmed by a specialist using standard diagnostic criteria. Treatment resistant was defined as a failure to respond to two separate ‘trials’ of antidepressant treatment.

The participants were injected intravenously with ketamine over three weeks, in the ECT clinic of a local hospital. One group of 15 people had one infusion a week, while a second of 13 people had two infusions a week. Each infusion lasted 40 minutes. The dose administered was 0.5mg per kg of body weight. (This is a much lower dosage that people typically take for recreational use – some heavy users can take several grams at a time).

Before each infusion researchers measured the participants’ mood, using a number of established psychological scales. Vital signs such as blood pressure and heart rate were monitored before and during each infusion, and participants were monitored for any immediate side effects.

The main outcome the researchers were interested in was response at the end of the three weeks of treatment which was defined as a 50% or more reduction in depression score on a widely used depression scale (the Beck Depression Inventory). Participants completed other established mood and depression scales over the three weeks, and also took a number of established tests to measure their memory function.

Participants were followed up for six months where possible, with the severity of depression and possible side effects monitored throughout.

 

What were the basic results?

Below are the study’s main findings:

  • Eight people (29%) responded to the treatment.
  • Of those who responded, only three (11%) had responded within six hours after a single infusion. However, all of those who responded did so before the third infusion.
  • How long the response lasted varied – from 25 days to 24 weeks.
  • Eight people (29%) did not complete their infusions, two because of acute adverse reactions during the infusion and five because of failure to benefit and increasing anxiety. 
  • Common side effects experienced by most people included nausea, anxiety, confusion and altered perception. Participants commonly reported short lived “dissociative” effects – such as feeling disconnected from their body – but they did not feel any euphoria with the treatment.
  • Ketamine was not associated with memory impairment.

 

How did the researchers interpret the results?

The researchers say their study suggests that repeated ketamine infusions for treatment resistant depression can be safely given to patients while still taking their usual medication, although they can occasionally cause problems such as anxiety and vomiting. There were no problems with cognitive function.

“Intravenous ketamine is an inexpensive drug which has a dramatic, but often short-term, effect in some patients whose lives are blighted by chronic severe depression”, says principal investigator Dr Rupert McShane, a consultant psychiatrist at Oxford Health and a researcher in Oxford University's Department of Psychiatry.

He adds: “We now need to build up clinical experience with ketamine in a small number of carefully monitored patients. By trying different infusion regimes and adding other licensed drugs, we hope to find simple ways to prolong its dramatic effect”.

 

Conclusion

This small open label trial aimed to further investigate the safety and possible effectiveness of giving repeated ketamine infusions over a three week period to a small group of people with depression that had not responded to previous treatments. Almost a third responded to treatment. The treatment also had no detrimental effect on participants in terms of memory, though there were some side effects and seven people withdrew from the study. Two because of side effects during the infusion; and five because they were getting no benefit and were becoming more anxious. 

This was an early stage study and not a randomised controlled trial, which is the most reliable way to measure a drug’s effectiveness and reduce the possibility of bias. The study cannot show definitively that ketamine is safe and effective for treatment resistant depression. Taken with previous research it suggests that repeated injections of ketamine can be given safely under carefully controlled conditions in the hospital setting, and could be of some benefit to specific groups of people with treatment resistant depression.

However, much further research in larger randomised controlled trials will now be needed to look further into the safety of ketamine and see how it compares to other treatments for this group of people.

It is not currently licensed for use in depression, and it is not yet known whether it could one day be licensed for use in depression. Though if it is, it is likely to be for very specific groups of people receiving hospital care of their condition who have not responded to all other treatment options (much in the same way as ECT services are currently provided). 

It is highly unlikely that ketamine will ever be prescribed in the same way as antidepressants.

Using ketamine without medical supervision is both illegal and dangerous. Regular users often develop what is known as ‘ketamine bladder’, caused by the drug’s inflammatory effects.

Symptoms of ketamine bladder include:

  • a sudden intense need to urinate which can result in urinary incontinence (wetting yourself)
  • urinating more frequently
  • severe pain when passing urine
  • blood in the urine

If you think you have developed a dependency on ketamine contact your GP for advice. You can also use the NHS Choices service finder to find your nearest NHS drug misuse service.

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

Links To The Headlines

Ketamine 'exciting' depression therapy. BBC News, April 3 2014

Horse tranquilliser Ketamine could cure severe depression. The Daily Telegraph, April 3 2014

Could ketamine be used to treat depression? Illegal drug has a rapid effect on patients not responding to medication. Mail Online, April 3 2014

Horse drug ketamine is ‘remarkable’ treatment for depression. Metro, April 3 2014

Ketamine has ‘remarkable’ effect in treating severe depression where orthodox treatments have failed, Oxford trial finds. The Independent, April 3 2014

Ketamine may help treat depression, UK study finds. The Guardian, April 3 2014

Links To Science

Diamond PR, Farmery AD, Atkinson S, et al. Ketamine infusions for treatment resistant depression: a series of 28 patients treated weekly or twice weekly in an ECT clinic. Journal of Psychopharmacology. Published online April 3 2014

Categories: NHS Choices

New genetic clues about skin cancer

NHS Choices - Behind the Headlines - Wed, 02/04/2014 - 18:00

“Skin cancer: Genetic mutations 'warn of risk',” reports BBC News today.

The science behind the headline involved sequencing the genetic material of 184 people with a strong family history of malignant melanoma, the most serious type of skin cancer.

The aim was to identify previously unknown genetic variations that may increase the risk of melanoma; information that could possibly have a future role in the early detection of people with a high genetic risk.

The genetic profiling narrowed in on variations in the POT1 gene, a gene involved in the protection of the ends of chromosomes, large bundles of densely packed DNA in cells.

The people involved mostly came from families where:

  • numerous people had been affected by melanoma
  • were individuals that presented with multiple separate melanomas, or
  • had developed melanoma at a very early age, suggesting there could be a genetic link for their cancer

As such the research was a step forward in understanding the genetics of melanomas in people with a strong family history, but the results cannot be applied to all people with melanoma.

It is too early to accurately assess whether there could be implications for treatments or whether screening tests for people with a family history would be a viable option.

This research does not change the most important fact about melanomas. While not all cases of melanomas are preventable, you can reduce your risk by avoiding overexposure to sunlight and artificial sources of UV lights such as sunbeds.

 

Where did the story come from?

The study was led by researchers from the Wellcome Trust Sanger Institute in collaboration with numerous other internationally based medical and academic research institutions. The first author and many colleagues were funded by the Wellcome Trust or Cancer Research UK.

The study was published in the peer-reviewed science journal Nature Genetics.

BBC News reported the study accurately, and discussed the potential implications of the discovery for screening for the disease in people with a family history of melanoma.

 

What kind of research was this?

This was a genetic study looking to identify new genetic origins of melanoma.

Melanoma is the most serious type of skin cancer. Some of the risk of developing it may be influenced by the genes that you inherit, or your family history.

The researchers estimate that around 10% of people with melanoma have one first-degree relative previously diagnosed. And that 1% of people with melanoma have two or more first-degree relatives previously diagnosed. A number of gene variations have been identified as increasing the risk of melanoma, but others remain unknown. The current study sought to identify new genetic variants that might influence the risk of melanoma in people with a strong family history.

 

What did the research involve?

The study looked at 184 cases of melanoma from 105 family lines and sequenced parts of their genetic material looking for genetic similarities that may indicate risk of developing the disease.

The people involved mostly came from families where numerous people had been affected by melanoma, or were individuals that presented with multiple separate melanomas or had developed melanoma at a very early age, suggesting there could be a genetic link for their cancer. 

Some people (16 samples) had their entire genomes sequenced, but most just sequenced the parts that made proteins (called the exome).

Importantly these people did not have any of the genetic variants that are already known to increase the risk of melanoma (mutations in CDKN2A and CDK4). So, from a genetic point of view, it was not clear how these people developed melanoma.

By sequencing their genetic material, the research team wanted to find if they had any variations in common. This might point to undiscovered risk factors or causes of the disease.

Including people from the same family line allowed the team to investigate whether the genetic variations were passed from parent to child, or whether the DNA damage had happened spontaneously within the individual and not passed on.

Participants were recruited from the UK, The Netherlands and Australia.

 

What were the basic results?

The study identified a handful of new genetic variants passed through some families affected with melanoma.

From this long list, the researchers found some of genetic variations affected a similar genetic area. These affected the protection of telomeres 1 gene (POT1), in some cases causing the loss of function in the protein it coded. Telomeres are sections of DNA at the end of chromosomes (highly organised bundles of DNA) that help protect chromosomes against genetic deterioration.

POT1 variations affected four of the 105 families (almost 4%), and was the clearest genetic variant identified during the research. They tested people without melanoma and found they did not carry the same POT1 genetic variants as those with melanoma.

The implication of this was that disruption in the regulation of telomeres, through these specific genetic variations, could lead to cancer.

The researchers subsequently characterised the nature of the genetic variation in detail, including the different variations on the POT1 gene and the resultant effects on the POT1 protein.

 

How did the researchers interpret the results?

The researchers state that “as the dysregulation of telomere protection by POT1 has recently been identified as a target for potential therapeutic intervention [in other research], it may be possible that the early identification of families with POT1 variants might facilitate better management of their disease in the future”.

 

Conclusion

This genetic sequencing study identified rare variations in the POT1 gene affecting 4% of families with melanoma of previously unknown genetic origins. The implication was that this variant increased the risk of developing melanoma. Similarly, early identification of families with POT1 variants might facilitate better management and hopefully prevention of any potential disease in the future. For example the families could be given advice about the importance of limiting UV exposure.

However, the current study has only investigated 184 people and found that POT1 gene variants were present in only 4% of people with melanoma. Study in another sample of people with a family history of melanoma may give a totally different prevalence of this variant. Also, previous research has already shown that other genetic mutations are associated with increased risk of melanoma, and there may be others associated that have yet to be discovered. There is not a single gene variant that gives increased risk of melanoma. So although this research is undoubtedly valuable in furthering our understanding of the possible genetics of melanoma in people with a strong family history, there is still more work to be done.  

The findings by themselves are not of any immediate value to patients. However, as Dr Safia Danovi of Cancer Research UK said on the BBC website: “This is a step forward for people with a strong family history of melanoma, the most dangerous form of skin cancer.”

Dr Danovi also provided a useful reminder that genetics is only part of the equation when considering risk of melanoma; sun exposure is a second and much more easily controlled risk factor, “it's important to remember that, for most of us, avoiding sunburn and sunbeds is the best way to reduce the risk of this disease".

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

Links To The Headlines

Skin cancer: Genetic mutations 'warn of risk'. BBC News, March 30 2014

Links To Science

Robles-Espinoza CD, Harland M, Ramsay AJ, et al. POT1 loss-of-function variants predispose to familial melanoma. Nature Genetics. Published online March 30 2014

Categories: NHS Choices

Probiotics 'no good' at treating infant colic

NHS Choices - Behind the Headlines - Wed, 02/04/2014 - 17:55

“Probiotics 'don't ease' baby colic,” the Mail Online reports. A small, though well-conducted, study suggests that probiotics – commonly touted as “friendly bacteria” – could actually make symptoms worse.

Colic is a poorly understood condition in which otherwise healthy babies cry excessively and frequently. While not a serious threat to a baby’s health, colic can be extremely distressing for parents – especially those of the sleep deprived variety (is there any other kind?).

The study included 167 young babies with colic and looked at whether giving them daily drops of the probiotic Lactobacillus reuteri (L. reuteri) improved symptoms, in comparison to giving them inactive placebo drops. The researchers found the treatment did not help.

In fact, after a month of treatment, formula-fed babies in the probiotic group actually cried or fussed for almost an hour longer than those in the placebo group. The treatment did not have any side effects.

This may be bad news for parents struggling to comfort their crying baby. The good news, however, is that all babies grow out of colic within a few months.

 

Where did the story come from?

The study was carried out by researchers from the Royal Children’s Hospital, Murdoch Childrens Research Institute and the University of Melbourne (all in Australia), and the Child and Family Research Institute (Canada). It was funded by the Georgina Menzies Maconachie Charitable Trust.

The study was published in the peer-reviewed British Medical Journal on an open-access basis, meaning the study is free to read online.

The Mail Online’s coverage of the study was accurate.

 

Links To The Headlines

Probiotics 'don't ease' baby colic: Study finds drops have no effect on reducing periods of crying among children aged under three months. Mail Online, April 2 2014

Links To Science

Sung V, Hiscock H, Tang MLK, et al. Treating infant colic with the probiotic Lactobacillus reuteri: double blind, placebo controlled randomised trial. BMJ. Published online April 1 2014

Categories: NHS Choices

Single men risk ignoring melanoma symptoms

NHS Choices - Behind the Headlines - Wed, 02/04/2014 - 10:00

“Men who live alone at greater skin cancer risk,” The Daily Telegraph reports.

The headlines are based on a population study from Sweden, which followed almost 30,000 people diagnosed with malignant melanoma – the most serious form of skin cancer.

Despite the headline, the study did not find that men who live alone were at greater risk of developing melanoma.

Rather, it found that in men who did develop melanoma, those living by themselves were 40% more likely to have had a more advanced stage of disease at the time of diagnosis. Men living alone were also less likely to survive the disease.

These links were significant even after adjusting for age, sociodemographics and melanoma characteristics.

There are some limitations, including that that the study has examined only a Swedish population, which may have both genetic as well as climate-related implications.

Nevertheless, a link between living alone and delayed diagnosis seems plausible. If someone lives with a partner they may be more likely to discuss a suspect mole with them; the partner may encourage them to see a doctor; or the partner may notice a mole that the person would not otherwise have done.

Overall the study highlights the need for us all to be vigilant about any suspicious moles or marks on the skin. Melanoma can be an aggressive cancer, and a good outcome relies on early diagnosis and treatment.

 

Where did the story come from?

The study was carried out by researchers from the Karolinska Institutet and other academic institutions in Sweden, and was funded by the Swedish Cancer Society, the Radiumhemmet Research Funds, the Sigurd and Elsa Goljes Memorial Foundation and that Stockholm County Council.

The study was published in the peer reviewed Journal of Clinical Oncology.

The Telegraph article gives accurate coverage of this study, though it is important that the headline – “Men who live alone at greater skin cancer risk” – is not misinterpreted.

It is not that men who live alone had a greater risk of actually developing melanoma. Instead it is that if they had developed melanoma, they were more likely to be diagnosed at a later stage than if they lived with someone. 

 

What kind of research was this?

This was a Swedish population study which aimed to see whether in people with malignant melanoma, disease stage at the time of diagnosis and disease survival were associated with whether the person lived alone or with someone else. As the researchers say, previous studies suggest that social support and marital status have an influence on survival from a range of cancers.

Melanoma is the most serious type of skin cancer. It can be very aggressive and spread rapidly to the lymph nodes and elsewhere in the body. A good outcome relies on diagnosis and treatment as early as possible.    

 

What did the research involve?

This research used the Swedish Melanoma Register to identify 27,235 people diagnosed with malignant melanoma between 1990 and 2007. They only included people with melanoma on the skin (cutaneous malignant melanoma), excluding the people with the rarer types of melanoma that develop elsewhere in the body (for example in the pigment cells in the eye). These people were followed up to death, emigration, development of a new melanoma, or the end of follow-up in December 2012, whichever came first.

The researchers collected information from the registry on each person’s tumour characteristics and treatment. They also documented whether each person lived with a partner or lived alone at the time they were diagnosed (marriage status was not considered). Single people who lived with children were classed as living alone, as it was thought that children could not help contribute to early cancer diagnosis.

The researchers looked at melanoma survival rates according to cohabitation status.

They adjusted their analyses for possible confounding factors such as:

  • age
  • educational level (used as the main indicator of socioeconomic status)
  • living area (metropolitan, urban or rural)
  • year of diagnosis
  • various tumour characteristics (including tumour site, staging information and laboratory findings)

 

What were the basic results?

People in the study were diagnosed with melanoma at average age of 62 years and the average follow-up period was eight years. Overall the five-year cancer survival rate for all people in the study was 92% for women and 85% for men.

Among people with a partner the average age at diagnosis was lower for women (55 years) than men (64 years). Among single people average age at diagnosis was higher for women (68 years) than men (63 years).

Across all age groups, a higher proportion of single men had more advanced melanoma at the time of diagnosis than cohabitating men. In women, a difference in melanoma stage at diagnosis according to whether they were single or cohabitating was only seen in women above the age of 70.

After adjusting for confounding factors, single men were around 40% more likely to be diagnosed with a more advanced tumour stage than men living with a partner.

The difference in risk was similar when comparing diagnoses in the earlier stages of diseases (odds ratio [OR] 1.42 95% confidence interval [CI] 1.29 to 1.57 for being diagnosed with stage II rather than stage I), and when comparing the later stages of disease with early stage disease (OR 1.43 [95% CI 1.14 to 1.79] for being diagnosed with stage III or stage IV rather than stage I).

Single women were 15% more likely than women living with a partner to be diagnosed with stage II than stage I cancer (OR 1.15, 95% CI 1.04 to 1.28). But no associations with cohabitation status were seen for more later disease stages.

When looking at survival, after adjustment for all measured confounders including the characteristics of the melanoma at diagnosis, single men were 31% more likely to die from the disease than men living with a partner (hazard ratio 1.31, 95% CI 1.18 to 1.46).

Cohabitation status had no significant effect on survival in women.

 

How did the researchers interpret the results?

The researchers conclude that across men of all ages, living alone is associated with reduced survival from malignant melanoma, which can be partially attributed to being diagnosed at a more advanced disease stage. They say “this emphasizes the need for improved prevention and early detection strategies for this group”.

 

Conclusion

This Swedish research benefits from including a very large population sample of people with malignant melanoma – almost 30,000 people diagnosed over a 17 year period.

It also benefits from using a registry, which would be expected to contain reliable information on patient and cancer characteristics, and it has adjusted their analyses for these various confounders.

It finds a clear link that men who lived alone were consistently more likely than men who lived with a partner to have melanoma that was at a more advanced stage at the time of diagnosis and to have poorer survival outlook. The poorer survival outlook may be expected to be a result of the later stage at diagnosis, although interestingly single men were still at increased risk of dying from melanoma even after disease characteristics at the time of diagnosis had been adjusted for.

Women living alone were more likely to be diagnosed with stage II rather than stage I cancer, but no association was found with later stage cancer. Cohabitation status had no significant effect on survival in women with melanoma.

The link does seem plausible. For example, if someone lives with a partner they may be more likely to discuss a suspect mole with them; the partner may encourage them to see a doctor; or the partner may notice a mole that the person would not otherwise have done. All of these things are possible explanations for why men living alone may be diagnosed at a later stage.

However, there are limitations to bear in mind. The study has only assessed whether the person lived alone or with a partner at the time of diagnosis. It is not known how long they had lived with this person, and the nature of this relationship is not known. Also, though the researchers have taken into account as many confounders as possible, there may be a range of unmeasured health and lifestyle factors that may be involved in the relationship. For example, we don’t know how much UV exposure people were getting, and whether there was any difference between single and cohabiting people in their level of exposure, or how much care they took to protect their skin in sunlight.

Also, importantly the study was conducted in Sweden where people, as a broad generalisation, can be fair skinned. They may also get less intense sun exposure in the far Northern hemisphere than people born in hotter climes – though nothing is of course known about travel abroad (which could again differ between single and cohabiting people). These factors may mean that the results may not be the same in people living in other countries.  

Overall the study highlights the need for us all to be vigilant about any suspicious moles or marks on the skin. Melanoma can be an aggressive cancer, and a good outcome relies on diagnosis and treatment as early as possible.

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

Links To The Headlines

Men who live alone at greater skin cancer risk. The Daily Telegraph, April 1 2014

Links To Science

Erikssoon H, Lyth J, Månsson-Brahme E, et al. Later Stage at Diagnosis and Worse Survival in Cutaneous Malignant Melanoma Among Men Living Alone: A Nationwide Population-Based Study From Sweden. Journal of Clinical Oncology. Published online March 31 2014

Categories: NHS Choices

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NHS Choices - Live Well - Tue, 01/04/2014 - 12:38
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Categories: NHS Choices

No proof Earl Grey can fight heart disease

NHS Choices - Behind the Headlines - Tue, 01/04/2014 - 12:00

“A cup of Earl Grey 'as good as statins' at fighting heart disease,” reports The Daily Telegraph, entirely without proof.

The science behind this headline did not show Earl Grey was as good as statins (a class of drugs used to lower high cholesterol) in people.

The study was early stage research on a small group of rats in a laboratory. None of the research involved humans, tea, or any assessment of heart disease.

The research involved an extract called HGMF, taken from the bergamot fruit; a citrus fruit used to flavour teas such as Earl Grey.

Rats with high cholesterol levels were fed a high cholesterol diet for three weeks and given either the bergamot extract (HMGF) or the commonly used statin, simvastatin.

The researchers found that HMGF had cholesterol-lowering effects similar to that of simvastatin. Though importantly, as the research was in rats, it is not possible to say that HGMF would work the same way in humans, unless directly tested.

Furthermore, this study tested a pure extract rather than tea containing the extract, the effects of which may be different. For instance it is unclear how much Earl Grey you would need to be exposed to a comparable level of HGMF; it may take gallons of the stuff.

This study is absolutely not a reason to stop taking prescribed statins to replace them by drinking Earl Grey tea as this could be dangerous.

 

Where did the story come from?

The study was carried out by researchers from the University of Calabria (Italy) and was funded by the Italian National Project.

The study was published in the peer-reviewed Journal of Functional Foods.

The Daily Telegraph and the Mail Online reporting was potentially misleading and arguably irresponsible.

While the main body of the article was factually accurate, the headlines (one of which was on the front page of the Telegraph) implied that drinking Earl Grey tea had been proven to be as effective as statins.

Statins are known to be effective and have a large weight of evidence from human research proving this. By contrast, the effects of Earl Grey tea, as far as we are aware, have barely been researched, so they are not on an equal playing field. So suggestions that Earl Grey is “just as effective” are unfounded.

This could have encouraged people who had been prescribed statins, some of which are at high risk of experiencing a cardiovascular disease such as a heart attack or stroke, to stop taking their medication.

 

What kind of research was this?

This was an animal study looking at the effect of bergamot extract on the cholesterol profile of rats with high cholesterol and comparing it with a commonly used statin called simvastatin.

Statins are a class of related drugs currently used to lower cholesterol levels in people at risk of cardiovascular disease, the main cause of death in many westernised countries. The drugs lower cholesterol levels by acting on an enzyme called 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) in the body.

The researchers were looking to see if other compounds might work in a similar way to statins and affect the same enzyme. They decided to investigate bergamot (Citrus bergamia Risso), a citrus fruit widespread in the Mediterranean area.

The fruit has anecdotal cholesterol-lowering properties and the study authors said it was only toxic at very high levels, implying it might be relatively safe. The researchers state bergamot essence is used in teas, jams and sherbet, but there was no special mention of Earl Grey in the underlying research. It appears the media has made a link with this specific tea as it apparently contains high levels of the extract and is well known to a UK readership.

 

What did the research involve?

The study used 48 rats with high cholesterol to compare the cholesterol-lowering effects of bergamot extract 3-hydroxy-3-methyl-glutaryl flavanones (HMGF) with the commonly-used statin, simvastatin. The rats’ diets were carefully controlled so all that differed was their cholesterol treatment – bergamot or statin.

Body weight, blood cholesterol levels, cellular protein levels, liver enzyme activity and genetic regulatory mechanisms were all monitored and recoded for evidence of cholesterol-lowering properties in the different treatment groups.

Contrary to the headlines, the experiments involved a dry extract from bergamot fruit peel. Unfortunately for the rats they did not get to sample any tea, Earl Grey or otherwise. 

The important measures were total cholesterol, another type of blood fat (triglycerides), and specific subtypes of cholesterol called very low density lipoproteins (VLDL), low-density lipoproteins (LDL) and high-density lipoproteins (HDL). HDLs are the so called “good” cholesterol, whereas LDLs are the “bad” cholesterol. This is a simplistic account of their roles within the body, but is sometimes useful.

Before the experiment all rats were stabilised on regular rodent food before being randomly divided into four groups of 12 animals each:

  • control group: received a regular diet for three weeks
  • high cholesterol control group: received a high cholesterol diet for three weeks (regular diet +2% cholesterol +0.2% cholic acid; a bile acid that has a role in fat absorption and moderating cholesterol levels)
  • high cholesterol group treated with statin: received the high cholesterol diet for three weeks (regular diet +2% cholesterol +0.2% cholic acid); from the 2nd to the 3rd week each rat was given simvastatin (20 mg/kg bodyweight/day) 
  • high cholesterol group treated with bergamot extract HMGF: received the high cholesterol diet (regular diet +2% cholesterol +0.2% cholic acid) for three weeks; from the 2nd to the 3rd week each rat was given HMGF (60 mg/kg bodyweight/day)

The main analysis compared the cholesterol lowering effects of simvastatin with the bergamot extract HMGF.

 

What were the basic results?

Both the bergamot extract and simvastatin reduced total cholesterol (in blood and in the liver), triglyceride levels, and VLDL and LDL levels – the bad cholesterol. However, an increase in HDL content – the good cholesterol – was observed exclusively in the HMGF-treated rats.

Both bergamot extract and simvastatin regulated enzymes were involved in cholesterol metabolism in a similar way at a protein and gene regulation level. This implied the changes observed were not coming from some other secondary effects of the extract and were direct result of changes to how cholesterol was metabolised in the rats’ livers.

The study investigated the safety of the extract to some degree. It found the extract had a low toxicity to cells in the body, and did not cause DNA damage at doses lower than 90 micrograms per millilitre.

 

How did the researchers interpret the results?

The researchers stated that their study “demonstrated that the three statin-like flavanones, extracted from bergamot peel and contained in HMGF, exert a similar behaviour [in] respect to commercial simvastatin on a model of hypercholesterolaemic rats [rats with high cholesterol levels]” and that “the daily supplementation of HMGF in the diet could be very effective for the treatment of hypercholesterolaemia”.

 

Conclusion

This animal experiment indicated that the bergamot extract HMGF may have cholesterol-lowering effects similar to that of the commonly used statin, simvastatin, when given to mice with high cholesterol levels that were fed high cholesterol diets for three weeks.

The main limitation of the study was that none of the research involved humans. Therefore, it is not possible to say the bergamot extract would work the same way in humans, unless directly tested. Furthermore, this rat study tested a pure extract rather than tea containing the extract, the effects of which may be different. For instance, taking milk in tea could potentially affect how the extract is metabolised in the body compared to a pure extract.

The headlines indicated Earl Grey tea could help fight heart disease, but based on the underlying research study only, there is little evidence for that. Also the study made no assessment of the long-term health benefits of the reductions in cholesterol in the rats. For example, the effects may have been temporary.

There needs to be more robust research in humans to find out if bergamot extract holds any real promise in lowering cholesterol levels and so fighting cardiovascular diseases such as heart disease and strokes in the future.

We would not want anyone to think this research is a reason to stop taking statins and replace them with drinking tea containing bergamot extract; this could potentially be dangerous. If you have any concerns about your cholesterol levels, or any cholesterol-lowering treatments that you are currently prescribed, consult your doctor.

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

Links To The Headlines

A cup of Earl Grey 'as good as statins' at fighting heart disease, study finds. The Daily Telegraph, March 30 2014

Earl Grey, the brew that could tackle heart disease: Scientists say bergamot found in the tea could be as effective as statins in controlling cholesterol. Mail Online, March 31 2014

Links To Science

Di Donna L, Iacopetta D, Cappello AR, et al. Hypocholesterolaemic activity of 3-hydroxy-3-methyl-glutaryl flavanones enriched fraction from bergamot fruit (Citrus bergamia): “In vivo” studies. Journal of Functional Foods. Published online February 1 2014

Categories: NHS Choices

Call to make 5 a day fruit and veg into '7 a day'

NHS Choices - Behind the Headlines - Tue, 01/04/2014 - 01:00

“7 a day fruit and veg 'saves lives’” reports BBC News, while The Daily Telegraph states that “10 portions of fruit and vegetables per day” is best.

The headlines have been prompted by the results of a UK-based study that used information on more than 65,000 randomly selected adults who were participating in the Health Survey for England.

This is an ongoing health survey that looks at health and lifestyle factors such as fruit and vegetable consumption. The researchers followed up participants for an average of 7.7 years after their initial participation.

The researchers found that eating fruit and vegetables was associated with a lower risk of death from any cause, looking especially at deaths as a result of cardiovascular disease and cancer. The higher a person's intake of fruit and vegetables, the greater the protective effects seemed to be.

People who ate seven or more portions a day had a 33% reduced risk of death compared with people who ate less than one portion.

This study provides further evidence of the benefits of eating fruit and vegetables. However, the study does carry limitations, with the most pertinent being that there could have been other factors (confounders) responsible for the associations seen. These could include smoking history, exercise levels and income.

Much of the media’s reporting implies that this study contradicts the official Department of Health advice about eating five portions of fruit and vegetables a day. It should be stressed that the advice in full was to eat at least five portions a day. The “5 a day” target was always meant to be a minimum target to hit, rather than the maximum.

 

Where did the story come from?

The study was carried out by researchers from University College London. This study was unfunded, but used information for the Health Survey for England, which was funded by the Department of Health and the Health and Social Care Information Centre. In the interests of transparency, it should be made clear that the Behind the Headlines team are employed by the Health and Social Care Information Centre.

The study was published in the peer-reviewed Journal of Epidemiology and Community Health. This article is open-access, meaning that it can be accessed for free from the journal’s website.

The results of this study were reported accurately by the UK media. However, they all reported figures for all causes of mortality, excluding any deaths that occurred in the first year of the study.

This meant that the risk of death they reported (42%) was reduced by a greater extent than when these people were included in the analysis (33%).

 

What kind of research was this?

This was a cohort study that aimed to assess if fruit and vegetable consumption in a group of people representative of the UK population was linked to:

  • death from any cause
  • death due to cancer
  • death due to cardiovascular disease 

A cohort study is the ideal study design to answer this question. However, this study design is limited by the fact that other confounders could have been responsible for the associations seen.

In the study, people who consumed more fruit and vegetables were generally older, less likely to smoke, more likely to be women, be of a higher social class and have a higher standard of education.

In addition, the proportion of people who were vigorously active increased as more portions of fruit and vegetables were consumed.

Although the researchers tried to adjust for these factors in their analyses, these differences may influence the association seen.

 

What did the research involve?

The researchers used information on 65,226 adults who were aged 35 years or older, who responded to the Health Survey for England.

Participants were visited by an interviewer who asked about fruit and vegetable consumption on the previous day. They were asked about their consumption of:

  • vegetables
  • fresh, canned and frozen fruit
  • salad
  • pulses
  • dried fruit
  • fruit juices/smoothies
  • dishes made mainly from fruit or vegetables

Responses were coded into portion sizes. A maximum of one portion of pulses, one of fruit juice or a smoothie and one of dried fruit contributed to total daily portions of fruit and vegetables.

The researchers looked at mortality (death) records over 7.7 years (on average), to see if participants had died – and if they had, what they had died of.

The researchers compared the risk of death for people eating less than one portion to people eating more than one portion.

The researchers adjusted their analysis for the following confounders:

  • age
  • sex
  • smoking status
  • social class
  • education
  • body mass index (BMI)
  • level of physical activity
  • alcohol consumption

 

What were the basic results?

During the 7.7 years (on average) follow-up period, 6.7% of participants died (equivalent to 4,399 deaths).

Eating one or more portion of fruit and vegetables was associated with a significantly reduced risk of death from any cause compared to eating less than one portion. The risk of death from any cause decreased as portions of fruit and vegetables increased.

People consuming seven or more portions a day had the lowest risk of death from any cause, with a 33% reduced risk (hazard ratio [HR] 0.67, 95% confidence interval [CI] 0.58 to 0.78), compared to those who ate less than one portion a day (a portion was defined as 80g).

Eating three or more portions of fruit and vegetables was associated with a significantly reduced risk of death from cancer and death from cardiovascular disease. Risk of death from cancer was 25% lower in participants eating between five and seven portions, and seven portions or more (HR 0.75, 95% CI 0.62 to 0.91 for 5 to <7 portions; HR 0.75, 95% CI 0.59 to 0.96 for 7 or more portions). Risk of death from cardiovascular disease was lowest in people eating seven or more portions, with a 31% reduced risk (HR 0.69, 95% CI 0.53 to 0.88).

When fruit and vegetable consumption was analysed separately, the risk of death from any cause was lowest in people eating three to less than four portions of fruit per day (HR 0.84, 95% CI 0.76 to 0.93) and three or more portions of vegetables per day (HR 0.68, 95% CI 0.58 to 0.79).

Eating vegetables was associated with greater reductions in risk of death than eating the same number of fruit portions. 

The researchers also looked at the type of fruit and vegetable consumption and found that consumption of vegetables, salad, fresh fruit and dried fruit were associated with decreased risk of death from any cause. However, consumption of frozen or canned fruit was associated with an increased risk of death.

 

How did the researchers interpret the results?

The researchers conclude that they found “a strong inverse association between fruit and vegetable consumption and all-cause mortality”. They go on to say that “fruit and vegetable consumption was significantly associated with reductions in cancer and [cardiovascular disease] mortality, with increasing benefits being seen with up to more than seven portions of fruit and vegetables daily for the latter [vegetables]. Consuming vegetables appeared to be significantly better than consuming similar quantities of fruit. When different types of fruit and vegetables were examined separately, increased consumption of vegetables, salad, fresh and dried fruit showed significant associations with lower mortality. However, frozen/canned fruit consumption was associated with a higher risk of mortality”.

 

Conclusion

This UK-based study found that eating fruit and vegetables was associated with a lower risk of death from any cause, and deaths from cardiovascular disease and cancer. The higher the intake of fruit and vegetables, the greater the protective effects seemed to be.

People who ate seven or more portions a day had a 33% reduced risk of death from any cause, a 25% reduced risk of death from cancer and a 31% reduced risk of death from cardiovascular disease, compared with people who ate less than one portion per day.

The researchers found that vegetables may lower risk more so than fruit. Consumption of vegetables, salad, fresh fruit and dried fruit were associated with decreased risk of death from any cause, although consumption of frozen or canned fruit was associated with an increased risk of death.

This study provides further evidence of the benefits of eating fruit and vegetables; however, it is based on only one diet measurement over 24 hours, which may not be representative of a person's usual diet and does not take into account changes in diet over time.

This study is limited by the possibility that other factors (confounders) could have been responsible for the associations seen. In the study, people who consumed more fruit and vegetables were generally older, less likely to smoke, more likely to be women, be of a higher social class and have a higher standard of education.

Despite reporting to the contrary, the results of this study do not go against the current “5 a day” message. This is a minimum recommended level. When it comes to fruit and vegetables, as long as you watch your calorie and sugar intake it is very much the case of “the more the merrier”.

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

Links To The Headlines

Seven-a-day fruit and veg 'saves lives'. BBC News, April 1 2014

Healthy diet means 10 portions of fruit and vegetables per day, not five. The Daily Telegraph, April 1 2014

Forget five a day: You need SEVEN portions of fresh fruit and veg per day to live longer, says new research. The Independent, April 1 2014

Are you getting your seven-a-day? Experts say we need more helpings of fruit and veg. Daily Mirror, April 1 2014

Fruit and vegetable intake: five a day may not be enough, scientists say. The Guardian, April 1 2014

Forget five a day, we should eat SEVEN a day for a long life: Eating more portions of fruit and veg can cut risk of dying prematurely by 42%. Daily Mail, April 1 2014

Diet that adds years to life: Seven fruit and veg a day halves risk of an early death. Daily Express, April 1 2014

Have you had your ten-a-day? Five-a-day ‘not enough’ – and doubts over canned fruit too. Metro, March 31 2014

Links To Science

Oyebode O, Gordon-Dseagu, Walker A, Mindell JS. Fruit and vegetable consumption and all-cause, cancer and CVD mortality: analysis of Health Survey for England data. Journal of Epidemiology and Community Health. Published online March 31 2014

 

Categories: NHS Choices

Statins 'improve erectile dysfunction symptoms'

NHS Choices - Behind the Headlines - Tue, 01/04/2014 - 01:00

“How statins could boost your love life: Cholesterol lowering drugs ‘reduce erectile dysfunction’,” reports the Daily Mail.

The paper reports on a small but well-conducted analysis of existing data into statin use and symptoms of erectile dysfunction (inability to obtain or maintain an erection).

Statins are widely used to reduce cholesterol levels in an attempt to prevent cardiovascular diseases such as heart attacks.

The researchers’ analysis found that statins did improve scores on the International Inventory of Erectile Dysfunction – a well-validated “scorecard” for erectile dysfunction.

The researchers state that the increase seen was equivalent to about one-third of the improvement seen with drugs specifically designed to treat erectile dysfunction, such as the class of drugs known as phosphodiesterase 5 (the most famous of which is Viagra aka sildenafil).

It is unclear how statins may improve erectile dysfunction, but the researchers speculate that it may be due to decreased levels of LDL cholesterol and improved endothelial function – which includes the ability of blood vessels to dilate and constrict. This could then increase the flow of blood to the penis.

Although the methods used by the researchers were sound, the 11 randomised controlled trials included in the analysis only included a total 713 men.

Statins are unlikely to be prescribed for erectile dysfunction in men without cardiovascular risk factors.

 

Where did the story come from?

The study was carried out by researchers from Rutgers Robert Wood Johnson Medical School in the US.

No source of funding was reported, but the researchers state that they have no conflicts of interest. 

The study was published in the peer-reviewed Journal of Sexual Medicine.

The results of the study were well reported in the Daily Mail.

 

What kind of research was this?

This was a systematic review and meta-analysis of studies assessing the effects of statin therapy on erectile dysfunction.

A systematic review is an overview of primary studies. Systematic reviews use explicit and reproducible methods to search for and assess studies for inclusion in the review. A meta-analysis is a mathematical synthesis of the results of the included studies.

This is an appropriate way of pooling and studying the body of available evidence on a specific topic. 

 

What did the research involve?

The researchers studied databases of published literature to identify studies that had assessed the effects of statin therapy on erectile dysfunction. They excluded studies in animals, basic science or nutrition studies, reviews, editorials, case reports and studies which did not assess the effect of statin therapy on erectile dysfunction.

Once the studies had been identified, the researchers assessed study quality to see if there were any biases, and extracted data about the study characteristics and results.

The researchers extracted five-item International Inventory of Erectile Function (IIEF) scores. The five-item IIEF is a widely used, multi-dimensional self-report instrument for the evaluation of male sexual function. Possible scores range from 5 to 25. Lower scores represent poorer sexual function.

The researchers then performed a meta-analysis to combine the results of the included studies.

 

What were the basic results?

The researchers identified 11 randomised controlled trials (RCTs) and three observational studies.

The researchers initially performed a meta-analysis of the RCTs (which included 713 people).

The IIEF score increased significantly by 3.4 points with statins compared to control. The researchers state that this increase is about one-third of the improvement seen with phosphodiesterase 5 inhibitors (which include Viagra). These are a class of drugs designed to temporarily boost the flow of blood to the penis during sexual stimulation.

The three observational before and after studies did not show a significant difference in IIEF score before and after statin administration. However, when these were combined with the RCTs, statins were still associated with a significant 3.2 point improvement in IIEF score.

 

How did the researchers interpret the results?

The researchers conclude that “statins cause a clinically relevant improvement of erectile function as measured by the five-item version of the IIEF.”

 

Conclusion

This systematic review and meta-analysis found that statins improved scores on the International Inventory of Erectile Dysfunction. The researchers state that the increase seen was equivalent to about one-third of the improvement seen with phosphodiesterase 5 inhibitors (which include Viagra). 

It is unclear how statins may improve erectile dysfunction but the researchers speculate that it may be due to decreased levels of LDL cholesterol and improved endothelial function – which includes the ability of blood vessels to dilate and constrict.

Although systematic reviews and meta-analyses are the appropriate way of pooling and studying the body of available evidence on a specific topic, it only included 11 RCTs featuring 713 people. As the researchers point out, the studies used different statins at different doses, had different follow-ups and were on different populations.

Statins are unlikely to be prescribed for erectile dysfunction in men without cardiovascular risk factors; at least in the near future.

If you are having problems with erectile dysfunction, and the lifestyle factors discussed above fail to help, then contact your GP for advice. The causes of erectile dysfunction can also be psychological as well as physical, so drug treatment may not be the best option for you.

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

Links To The Headlines

How statins could boost your love life: Cholesterol lowering drugs 'reduce erectile dysfunction'. Daily Mail, April 1 2014

Statins the wonder drug can boost your sex life. The Times, April 1 2014

Links To Science

Kostis JB, Dobrzynski JM. The Effect of Statins on Erectile Dysfunction: A Meta-Analysis of Randomized Trials. The Journal of Sexual Medicine. Published online March 29 2014

Categories: NHS Choices

First cat-to-human TB infections reported

NHS Choices - Behind the Headlines - Fri, 28/03/2014 - 10:00

“Cats have passed TB to humans for the first time,” the Daily Mail reports. Authorities are closely monitoring the situation and the risk of further transmission has been described as “very low”.

The headline is based on the news that two people in England have developed tuberculosis (TB) after contact with a domestic cat infected with Mycobacterium bovis (M. bovis). This bacterium is a leading cause of TB in cattle and a less common cause, in other species.

This is newsworthy as these are the first documented cases of cat-to-human transmission anywhere in the world.

Between December 2012 and March 2013, a veterinary practice in Newbury, Berkshire, diagnosed nine cases of M. bovis infection in domestic cats. Two people who had contact with these cats were found to have an active TB infection.

Cat owners are advised to not be anxious. Though TB can be spread from animals to humans, the risk of cat owners or their families becoming infected is thought to be very low. If owners have a pet that is unwell they should consult a vet.

When cases of M.bovis in animals are diagnosed, current animal health legislation in England requires vets to notify the Animal Health and Veterinary Laboratories Agency (AHVLA) who then inform Public Health England (PHE).

The local AHVLA, Health Protection Team and veterinary surgery will provide support based on the individual circumstances.

 

What is the risk to people?

PHE, the agency responsible for public health in England, offered screening to 39 people who were identified to have had contact with the infected cats as a precautionary measure. Two cases of active TB were identified, both of whom were confirmed to have been infected with M. bovis and are responding to treatment.

A further two cases of “latent TB" were also identified. Latent TB means that the people had been exposed to TB at some point but they did not have active disease. PHE said it was not possible to confirm whether the two cases of latent disease were caused by M. bovis or something else.

 

What is TB?

Tuberculosis (TB) is a chronic infectious disease. It is caused by a group of bacteria within the Mycobacterium tuberculosis complex (a related “family” of species). TB can affect nearly all warm-blooded mammals, including farm animals, wildlife, pets and humans.

TB can infect any part of the body, but most commonly occurs in the lungs (pulmonary tuberculosis).   

Most cases of TB in humans are due to a mycobacterium called Mycobacterium tuberculosis. Another mycobacterium that causes TB is M. bovis, which most commonly causes TB in cows. However, M. bovis can infect other mammals, including humans. M. bovis accounts for less than 1% of the total of human TB cases diagnosed in the UK every year. People working closely with livestock or regularly drinking unpasteurised milk have a greater risk of exposure.

A small number of M. bovis infections in pets, mostly cats, have been recorded. M. bovis infection is rarely recorded in dogs. In 2013, there were 16 cases in domestic cats (of 60 examined) and one case in a domestic dog (of nine examined).

 

How do pets catch TB?

Pets can become infected in a number of ways, including:

  • by mouth – for example, by drinking unpasteurised infected cows’ milk or eating carcasses of infected animals
  • breathing in respiratory droplets from other infected animals
  • bite wounds – either from being bitten by an infected animal or if a wound gets infected by bacteria present in the environment

 

What are signs of TB in pets?

TB infection in pets can cause a serious long-standing disease. Signs of TB in pets include coughing, wheezing and weight loss. Lumps, abscesses or bite wounds that fail to heal, especially those around the head and neck, can also be caused by TB and are most frequently seen in infected cats.

The nine cats that were diagnosed with M. bovis between December 2012 and March 2013 in Newbury had a lack of appetite, non-healing or discharging infected wounds, evidence of pneumonia and different degrees of lymphadenopathy (lymph nodes of abnormal size).

The clinical signs of TB infection in pets are not unique and can be similar to other infections.

 

How can TB be spread from pets to humans?

The most likely routes of transmission would be:

  • via respiratory droplets from infectious pets with signs of respiratory infection, such as coughing
  • from contaminated environment
  • via ingestion (by mouth) following handling of pets with cutaneous (skin) tuberculous lesions
  • via contamination of unprotected cuts in the skin

PHE has assessed the risk of transmission of M. bovis from cats to humans as being very low.

 

How is TB treated in pets?

The choice of treatment of your pet – if it has TB – is a decision for you to make in consultation with your vet. However, the AHVLA and PHE caution that:

  • there are no drugs licensed in the UK for the treatment of mycobacterial infections in animals, meaning that the “recommended” regimens for cats are based on limited clinical experience rather than randomised controlled trials. This means that they may not work or may have other health risks
  • treatment involves prolonged courses of multiple drugs, which can be difficult to administer to pets
  • a high rate of treated pets become unwell again

If pets remain infected despite treatment it can increase the risk of developing antibiotic-resistant strains of M. bovis, and the infection risk continues. This means that for public health reasons if a pet is diagnosed with culture-confirmed M. bovis infection, the most sensible course of action is usually to have the animal “put to sleep” (euthanised).

 

How is TB treated in humans?

Treatment for TB depends on which type you have, although a long course of antibiotics is most often used.

While TB is a serious condition that can be fatal if left untreated, deaths are rare if treatment is completed.

 

What happens next?

The relevant authorities will continue to monitor the situation carefully. While the spread of TB from cats to humans is certainly unusual, and perhaps unique, it is certainly not something to panic about.

There are an estimated 8,500 cases of TB every year, so this new impact of cat to human transmission on the public health burden is tiny.

The most effective methods of reducing your risk of catching any sort of disease from a pet is to always wash your hands after handling them, make sure their immunisations are up to date, and keep their fur clear. Read more about pet hygiene.

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

Links To The Headlines

Could you catch TB from YOUR tabby? Fear as four British people catch disease from CATS in Home Counties in first-ever known cases of feline-human transmission. Daily Mail, March 28 2014

First cases alert: pet cats spread TB to four people. The Independent, March 28 2014

Mewberculosis: Medical first as cats are found to pass TB on to their owners. Metro, March 27 2014

Pet cats infect two people with TB. BBC News, March 27 2014

Pet cats infect humans with TB for first time. Pet cats infect humans with TB for first time. The Daily Telegraph, March 27 2014

First documented cat-to-human TB infection revealed. The Guardian, March 27 2014

Links To Science

Categories: NHS Choices

Smoke-free laws linked to improved child health

NHS Choices - Behind the Headlines - Fri, 28/03/2014 - 00:00

"Laws banning smoking in public places have had a positive impact on child health," BBC News reports. Researchers found lower rates of preterm births and childhood severe asthma cases after the introduction of smoke-free laws.

11 studies published between 2008 and 2013 were reviewed, in a bid to examine the effect smoking bans around the world have had on child health. In particular, the effects on preterm birth, low birth weight and childhood hospital attendances for asthma were noted.

They found there was a 10% drop in preterm births and childhood asthma after the introduction of smoking bans, but that smoking bans had not had a significant effect on low birth weight.

These results are biologically plausible. However, all 11 studies only looked at changes in the rates of childhood health outcomes before and after smoking bans were introduced, meaning that it is difficult to pinpoint smoking bans as the single, direct cause of any differences. Numerous other changes could have been responsible for the differences seen.

Despite this limitation, this research provides further support for smoke-free environments.

As well as the risks mentioned above, smoking around children can increase their risk of coughs and colds, ear infections and even fatal conditions, such as meningitis and cot death. Read more about the dangers of exposing children to passive smoking.

If you are a smoker who lives in a home with children, you should try to stop smoking, or at least do it in an outside area, away from sight.

 

Where did the story come from?

The study was carried out by researchers from Maastricht University (Netherlands); The University of Edinburgh (UK); Hasselt University and the University of Leuven (Belgium); and Brigham and Women’s Hospital/Harvard Medical School (US).

It was funded by the Thrasher Fund, Lung Foundation Netherlands, International Paediatric Research Foundation, Maastricht University and the Commonwealth Fund, which is a private philanthropic institute.

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

The results of the study were well reported by BBC News and The Guardian.

 

What kind of research was this?

This was a systematic review and meta-analysis of studies that had examined the effect of smoke-free legislation on children’s health.

systematic review is an overview of primary studies. They use explicit and reproducible methods to search for and assess studies for inclusion in the review.

meta-analysis is a mathematical synthesis of the results of the included studies, and is an appropriate way of pooling and studying the body of available evidence on a specific topic. 

The researchers performed this study to help inform national and international policy decision on the implementation of smoke-free legislation.

Most developed countries now have some type of smoke-free legislation.

 

What did the research involve?

The researchers searched databases of published literature and the WHO International Clinical Trials Registry Platform. They also consulted with an expert panel to identify:

The primary health outcomes they were interested in were preterm birth and low birth weight, as well as hospital attendances for asthma.

Once the studies had been identified, the researchers assessed the quality of the studies, to see if there were any biases, and extracted data about their characteristics and results.

The researchers then performed a meta-analysis to combine the results of the included studies.                             

 

What were the basic results?

The researchers identified 11 studies, which were all interrupted time series. In this type of study, information is collected at multiple time points before and after an intervention – in this case, the introduction of a smoking ban. Interrupted time series aim to determine if the intervention has an effect significantly greater than the underlying trend. For example, a particular health outcome might have been falling before the intervention. If a before-and-after study had been performed, it might have incorrectly concluded that the intervention had an effect. By taking observations at multiple time points before and after the intervention, this trend would have been seen in an interrupted time series.  

After the results of the studies were pooled in a meta-analysis, smoke free legislation was associated with:

  • a 10% reduction in the relative risk of preterm birth (-10.4%, 95% Confidence Interval [CI]  -18.8 to -2.0). This was based on the results of four studies, with a total of 1,366,862 people.
  • a 10% reduction in the relative risk of hospital attendances for asthma (-10.1%, 95% CI -15.2 to -5.0). This was based on the results of three studies, with a total of 225,753 people.
  • no change in the relative risk of low birth weight (-1.7%, 95% CI -5.1 to 1.6). This was based on the results of six studies, with more than 1.9 million people.

 

How did the researchers interpret the results?

The researchers concluded that “smoke-free legislation is associated with substantial reductions in preterm births and hospital attendance for asthma. Together with the health benefits in adults, this study provides strong support for WHO recommendations to create smoke-free environments”.

 

Conclusion

This systematic review and meta-analysis found there was a 10% drop in preterm births and childhood asthma after the introduction of a smoking ban. However, smoking bans were found not to have a significant effect on low birth weight.

These results are biologically plausible. Previous research suggests that exposure to smoke in pregnancy may have a negative impact on pregnancy outcomes. Similarly, exposure to smoke in early childhood may increase the risk of a child of developing a respiratory condition such as asthma.

However, as all of the studies only examined changes in the rates of childhood health outcomes before and after smoking bans were introduced, it is difficult to pinpoint smoking bans as the single direct cause of any differences. Numerous other changes could have been responsible for the differences seen.

If smoking bans have had a direct influence on the changes seen, it is difficult to know why this is the case. For example, both preterm birth and childhood asthma are known to be associated with smoking; it is possible that the decline in the rates of both since the introduction of a smoking ban could be the result of pregnant women or children having less secondhand smoke exposure in public places.

However, it could also be due to increased public awareness of the detrimental health effects of smoking around the time of ban, which could have influenced smokers’ behaviour. For example, pregnant women may have been more likely to give up smoking themselves, or make sure that they were not exposed to smoke.

Similarly, parents/carers who smoked could have become more aware of the effects it could have on their child(ren). As a result, they could consciously make sure not to smoke in the house or car when children were present. 

Overall, although time trend studies can suggest that a particular factor is associated with particular outcomes, it is difficult to know exactly how or why this change has occurred. 

All of the included studies were carried out in Europe or North America – this means that the results cannot necessarily be extrapolated and generalised on a global scale.

Despite these limitations, this study does provide further support for smoke-free environments and the importance of not exposing children to passive smoking.

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

Links To The Headlines

Smoking bans cut asthma and premature births by 10%, study says. BBC News, March 28 2014

Smoking bans cut premature births. The Guardian, March 28 2014

Links To Science

Been JV, Nurmatov UB, Cox B, et al. Effect of smoke-free legislation on perinatal and child health: a systematic review and meta-analysis. The Lancet. Published online March 28 2014

Categories: NHS Choices

Doctors launch new tool to measure your 'heart age'

NHS Choices - Behind the Headlines - Thu, 27/03/2014 - 11:00

“People are being urged to find out their "true" heart age in order to cut the risk of heart attacks and strokes,” BBC News reports. Doctors have put together a new risk calculator called JBS3 that can tell you the real “age” of your heart.

Risk calculators for cardiovascular diseases or CVDs (conditions that affect the heart and blood vessels) are nothing new. The “granddaddy” of risk calculators – the Framingham risk calculator – has been available for years.

But this new JBS3 calculator has the benefits of:

  • being easily accessible online
  • providing what is thought to be an accurate risk estimate of experiencing a serious CVD such as a heart attack or stroke
  • unlike previous risk calculators it is of use to younger adults who, while possibly not having a short-term risk of CVD, could be on the route to a stroke or heart attack due to unhealthy lifestyle choices

This new JBS3 calculator was specifically designed to help healthcare practitioners identify and communicate risk of CVDs to the “sizeable number” of people whose risk in the next 10 years is low, but who may be at high risk over their lifetime.

The calculator includes estimates of someone’s “heart age” and the years they can be expected to enjoy without developing cardiovascular disease.

It also shows the benefits that people would experience if they made changes in their lifestyle such as stopping smoking, or reducing blood pressure or cholesterol levels. It also shows the effects of delaying making these changes.

The ultimate aim of the calculator is to empower people to reduce their risk of cardiovascular disease.

It is expected that the JBS3 calculator will become an important component of the NHS Health Check plan – an ongoing programme for adults aged 40 or over.

 

Who has produced the risk calculator?

The risk calculator has been produced by experts from 11 UK professional societies (the Joint British Societies or JBS) and charities involved with cardiovascular disease (CVD) prevention.

The tool is based on the available scientific evidence and on assumptions where evidence is not available.

It is part of newly updated JBS guidelines on the prevention of cardiovascular disease, called JBS3.

The guidelines have been written for GPs and practitioners to help guide their work with patients, in preventing CVD.

 

Why is a new calculator needed?

The JBS notes that although CVD deaths have almost halved in the last 40-50 years, cardiovascular disease is still the leading cause of deaths worldwide. This is especially the case as levels of risk factors for CVD, such as obesity and diabetes, are increasing.

They say that currently, prevention strategies target only those at high short term risk (within the next 10 years) of a heart attack or stroke.

They point out that this ignores many individuals – often younger people and women – who may not be at short term risk, but whose family history and lifestyle factors mean they may be at high risk of developing CVD in their lifetime.

There is a growing body of evidence, they say, that CVD develops over a long term with most heart attacks and strokes occurring in people in the “intermediate risk” category.

The new calculator assesses the risk of heart disease and stroke throughout someone’s lifetime, as well as in the short term.

 

What sort of people is the risk calculator recommended for?

The JBS recommends that the new calculator is used by healthcare professionals for estimating CVD risk for all individuals except those already known to have CVD or specific conditions that put them at high risk, such as diabetes, chronic kidney disease, or a specific genetic condition that leads to high cholesterol.

One of its main aims is to identify the “sizeable” number of people who are at low short term risk but high lifetime risk, of CVD. It aims to help both patients and health professionals better understand cumulative lifetime risk and what can be done to lower it.

 

What factors does the risk calculator assess and what results does it give?

The calculator assesses established risk factors for cardiovascular disease such as blood pressure, cholesterol levels, smoking status, family history, age and gender. It uses these to calculate not only the risk of CVD within the next 10 years, but over a lifetime. These are displayed in a number of ways that a healthcare professional can use to discuss these figures with their patient:

  • A person’s “Heart age”, compared to someone of the same age, gender and ethnicity with optimal risk factors (for example, not smoking and not overweight or obese).
  • “Healthy years” – a thermometer image showing how many years an individual can be expected to survive without having a heart attack or stroke.
  • An “Outlook screen” showing a graph with the chance of survival without a CVD event.

The tool also enables the healthcare professional to show the patient the potential effect on CVD risk of various lifestyle changes or interventions such as lowering blood pressure, or stopping smoking.

 

Can you give an example of the figures the calculator might produce?

The press release accompanying the release of the guideline and calculator gives an example of a 35 year old female smoker, with:

  • a high systolic blood pressure (the first number in a blood pressure reading) of 160 mm Hg
  • a high total cholesterol of 7mmol/l (the recommended level for healthy individuals is 5mmol/l)
  • plus a family history of premature CVD

The calculator estimates that the woman would have a “true heart age” of 47 (above her actual age). She could expect to survive to the age of 71 without having a heart attack/stroke. Her 10 year risk would be less than 2%.

The calculator estimates that if this woman stopped smoking, cut her total cholesterol to 4mmol/l and her systolic blood pressure to 130 mm Hg, her heart age would fall to 30 (below her actual age). She could expect to live to the age of 85 before having a heart attack/stroke and more than halve her 10 year risk to less than 0.25%.

 

How will the risk calculator be used in the NHS?

The JBS3 risk calculator is going to form a key component of the NHS Health Check programme in England aimed at 40-74 year olds. The authors note it is not intended to prompt blanket prescribing of the cholesterol lowering drugs statins and other heart health drugs.

In a related press release the Joint British Societies are quoted as saying “It is important to emphasise that, for the majority, the strong message will be the potential gains from an early and sustained change to a healthier lifestyle rather than prescription of drugs,”.

Lifestyle changes include quitting smoking, achieving a healthy weight through adopting a healthy diet and boosting the amount of regular exercise while curbing sedentary activity.

 

Can I use the risk calculator?

The JBS3 risk calculator is openly available online. However it has been designed for use by doctors and other healthcare practitioners with their patients. To work, the calculator requires values you may not have access to yourself (such as your cholesterol levels and blood pressure).

While the calculator can give you a relatively accurate risk assessment it is recommended that the results it provides are also assessed by a health professional.

If you are aged 40 or above you can have a free NHS Health Check which will assess your risk of heart disease as well as other chronic diseases such as dementia, stroke and kidney disease.

The JBS3 risk calculator is not appropriate for people who have existing CVD and should only be used with caution in patients with certain high risk conditions such as high blood pressure, diabetes and chronic kidney disease.

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

Links To The Headlines

Check if your heart is 'older' than you, say doctors. BBC News, March 26 2014

Links To Science

JBS3 Board. Joint British Societies’ consensus recommendations for the prevention of cardiovascular disease (PDF, 1.7Mb). March 2014

Categories: NHS Choices

Could a DNA test predict obesity risk in children?

NHS Choices - Behind the Headlines - Thu, 27/03/2014 - 00:00

"A DNA blood test can predict obesity levels in children as they grow up, scientists claim," the Metro reports. The test, which is based on measuring "switches" in DNA, may help identify children who would benefit from early intervention.

This was a small study of 40 children who had their DNA analysed during early childhood. The test is based on a process called methylation. This is a chemical process that can influence the effects of genes on the body (gene expression), essentially "turning off" certain genes. Methylation can have both positive and negative effects.

The analysis did find an association between methylation at four sites in the DNA and increased body fat between the ages of nine and 14. But this study does not prove that the modifications directly caused the increased body fat.

It took into account the children's age, sex, time of reaching puberty and an estimate of physical activity, but other important factors were not accounted for, including the children's diets.

Read more advice about helping your child keep to a healthy weight.

 

Where did the story come from?

The study was carried out by researchers from the universities of Southampton, Plymouth and Exeter, and was funded by Bright Future Trust, BUPA Foundation, Kirby Laing Foundation, Peninsula Medical Foundation, the EarlyBird Diabetes Trust and the National Institute for Health Research.

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

The media has largely focused on the possibility that a blood test in young children could predict obesity in adolescence.

The study did find an association between certain genetic modifications and later obesity in a small sample of children.

However, it has not yet been determined how well any such test would perform in a larger sample of children. It is also not clear whether it would help prevent obesity in the children identified.

 

What kind of research was this?

This was a cohort study of children, following them from the age of five to 14 to see if certain genetic modifications could predict later levels of obesity.

The modifications being studied were not changes to the DNA sequence, but the presence of certain chemical modifications to the DNA (called methylation) that affect whether a gene is active or not. These chemical changes are part of the normal way that genes are controlled in the body.

This type of study design is appropriate for this type of question, as it followed the children over a long period of time and can show if there is a link.

In this type of study, researchers try to isolate the effect of one factor among the many that might be having an effect. But it is very difficult to account for all of these factors, especially for a condition as complex as obesity, which can be influenced by genetic, environmental and sociodemographic factors.

 

What did the research involve?

The researchers annually assessed 40 children over nine years to see if they could identify whether the status of a gene that is important for energy metabolism was associated with obesity.

They looked at the chemical modification (methylation) of various sites in the DNA before the children reached the age of five, then seeing whether this changed during childhood and if it could predict levels of obesity in later childhood.

The researchers looked at the methylation of part of peroxisomal proliferator-γ-co-activator-Iα (PCGIα), a gene that codes for a protein involved in energy metabolism. They examined seven specific sites in the DNA within this gene.

Previous studies have found that these seven sites have mostly been methylated in overweight adults with type 2 diabetes mellitus compared with adults of a normal weight. Methylation suppresses the activity of the gene.

The researchers recruited a random sample of 40 children (20 girls and 20 boys) in 2000-01 from a larger study called the EarlyBird study. Between the ages of five and 14, each year the children:

  • had a blood test to measure insulin resistance and methylation at the seven sites in PCGIα
  • had height and weight measurements taken to calculate body mass index (BMI)
  • had a measurement of body composition (such as the amount of fat) using a technique called dual X-ray absorptiometry from the age of nine
  • wore a motion monitor (accelerometer) for seven days so physical activity levels could be measured
  • had height measurements taken to determine the age of reaching puberty

The researchers also measured the percentage of the sites that were methylated at each age. They then looked at whether there was an association between the percentage that were turned off at five years old and the child's level of fat between the ages of nine and 14.

 

What were the basic results?

Results were available for 34 of the 40 children.

The level of methylation of the seven sites in PCGIα was relatively stable over the nine years of the study. At one site, for each 10% increase in the level of methylation at age five to seven years, body fat increased by 12.5% (95% confidence interval [CI] 4.7 to 20.3) between the ages of nine and 14.

Similar, but lower, levels of increased body fat (6.3 to 7.6%) were also found to be associated with methylation at three other sites.

There was no association between methylation of these four sites and sex, level of physical activity or time of reaching puberty. Age was only associated with methylation at one site.

There were no associations between the level of body fat and the level of methylation of the other three sites.

 

How did the researchers interpret the results?

The researchers concluded that measuring methylation of these sites in PCGIα in childhood may be useful in predicting cardio-metabolic disease risk (obesity-related diseases such as type 2 diabetes and heart disease).

 

Conclusion

This small cohort showed an association between chemical modification (methylation) of four sites in a gene (PCGIα) that codes for a protein involved in energy metabolism in young children, and increased body fat between the ages of nine and 14.

This study has found an association, but it cannot prove that methylation was directly responsible for increased body fat. For example, while the association was still there despite accounting for sex, age, estimated physical activity levels and puberty, other factors such as diet were not assessed.

A further limitation is that physical activity levels were measured for only seven days each year. This will give a rough indication of activity levels, but may not be an accurate representation of physical activity over the entire year.

The researchers themselves point out that the findings cannot rule out the possibility that the difference in the levels of fat in the children was because of calorie intake, another environmental factor or other genetic factors.

The study's findings do not tell us how well a test based on these genetic modifications would perform at predicting body fat in a large sample of young children, not least because multiple genetic and environmental factors are likely to contribute to a child's weight.

Even if a child is born with an increased vulnerability to obesity, it certainly does not mean that this is a fate set in stone.

The benefits of children staying active and eating a healthy diet have been well documented, and this study does not change the current advice.

If you are worried about your child's weight, it is best to act now rather than ignore the problem. The longer this type of a problem is ignored, the more difficult it can become to treat.

Read more advice for parents with overweight or very overweight children.

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

Links To The Headlines

Heading off the obesity epidemic: DNA tests at five can tell if a child will be fat at 14. Metro, March 26 2014

The new blood test for children that can tell if they are going to be obese - by the time they are teenagers. Mail Online, March 25 2014

New test could identify children at risk of obesity - and help parents take action to prevent it happening. Daily Mirror, March 26 2014

Links To Science

Clarke-Harris R, Wilkin TJ, Hosking J, et al. Peroxisomal proliferator activated receptor-γ-co-activator-1α promoter methylation in blood at 5–7 years predicts adiposity from 9 to 14 years (EarlyBird 50). Diabetes. Published online March 12 2014

Categories: NHS Choices

Adding fluoride to water does prevent tooth decay

NHS Choices - Behind the Headlines - Wed, 26/03/2014 - 12:00

“Consider mass fluoridation of water, says health body," BBC News reports.

The news follows study by Public Health England providing compelling evidence that fluoridation of mains water is a safe and effective way of preventing tooth decay.

Fluoridation has been morally and ethically controversial in some quarters and has raised health concerns because it affects the water supply distributed to every home in an area and so is “unavoidable”.

Public Health England carried out the research into the impact of adding fluoride to the water supply to assess the benefits and address some of the health concerns.

The research found benefits for children’s dental health, which could in turn take pressure off NHS services.

 

What is fluoride?

Fluoride is a naturally occurring mineral found in water in varying amounts, depending on which area of the UK you live in. It's also found in certain foods and drinks, including tea and fish.

Fluoride’s can help reduce the risk of tooth decay (where the outer layers of teeth become damaged by acids), which is why it's added to many brands of toothpaste.

 

What did the report involve?

England provides a unique “test-bed” to study the effects of fluoride. This is because unlike many other developed nations, there has been no mass fluoridation of water at a national level.
Instead, individual local authorities have chosen whether they want to add fluoride to the water supply.

For example, people in Birmingham have received a fluoridated water supply for many years, while Greater Manchester’s water supply is unfluoridated.

In its report, Public Health England compared a series of health outcomes between “fluoridated” and “unfluoridated” local authorities.

 

What were the key findings?

The key findings of the report (PDF, 1.5Mb) were:

  • there were 15% fewer five-year olds with tooth decay in fluoridated areas than non-fluoridated areas
  • there were 11% fewer 12-year olds with tooth decay
  • there were 45% fewer hospital admissions of children aged one to four for tooth decay (mostly for extraction of decayed teeth under a general anaesthetic) in fluoridated areas than non-fluoridated areas

 

Does fluoridation of water pose any risks?

No significant health risks have been detected over many years in large populations who have been provided with a fluoridated water supply.

One of the most compelling pieces of evidence about the safety of fluoridation comes from the US. Around 200 million people have been exposed to a fluoridated water supply for decades and there have been no credible reports of harm.

There is a potential risk that a condition called dental fluorosis can occur, particularly if a child’s teeth are exposed to too much fluoride when they're developing.

Mild dental fluorosis can be seen as very fine pearly white lines or flecking on the surface of the teeth. Though, aside from changes in appearance, mild dental fluorosis does not cause damage to the teeth.

The report found that around one in 100 children in Newcastle (which has a fluoridated water supply) had a moderate degree of dental fluorosis.

The report concludes “water fluoridation is a safe and effective public health measure.”

 

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

Links To The Headlines

Consider mass fluoridation of water, says health body. BBC News, March 25 2014

Government study backs fluoride in water. The Daily Telegraph, March 25 2014

Add fluoride to water to improve British teeth, say Government's health advisers. The Independent, March 25 2014

Smile! Fluoride in tap water IS safe after all and can even IMPROVE dental health claim scientists. Mail Online, March 25 2014

Links To Science

Public Health England. Water fluoridation - Health monitoring report for England 2014 (PDF 1.53MB). March 2014

Categories: NHS Choices

Plain cigarette packaging doesn't work, says industry funded study

NHS Choices - Behind the Headlines - Wed, 26/03/2014 - 11:00

“Unbranded cigarettes could mean people smoke more, experts warn,” The Daily Telegraph reports.

However, the evidence provided by experts and reported on by the media has not been peer reviewed, and their work has been funded by a major cigarette manufacturer.

The news story is based partly on an analysis of smoking trends in Australia and partly on new industry data on tobacco shipped to retailers in the same country. We have only appraised the former of the two.

In 2012, Australia introduced a plain tobacco packaging law. The country's law makers believed that stripping branding from cigarettes packs and including graphic images of the health risks smokers face may stop youngsters from taking up the habit.

The study indicated that smoking rates in Australians aged 14-17 have been steadily declining over the past decade. However, there is tentative evidence to suggest this long-term trend didn’t dramatically alter in the year after the plain packaging law was introduced (from December 2012 to December 2013).

Importantly, there was only a year’s worth of data after the law came into effect on which to assess whether it had had the desired reduction in smoking uptake among the young. This is a relatively short period to assess such an impact.

Because of this, it is difficult to make any firm conclusions on whether plain packaging affected smoking prevalence.

It is also worth noting that the tobacco industry is estimated to kill five million people a year worldwide, according to the US Centers for Disease Control and Prevention.

 

Where did the story come from?

The study was carried out by researchers from The Department of Economics at the University of Zurich (Switzerland) and Saarland University (Germany), and was funded by Philip Morris International (PMI). PMI describes itself as “the leading international tobacco company”. The authors stated that “at no time did we provide Philip Morris International with access to the underlying data”. However, the researchers do not say whether PMI had any control over the study design and other factors that could influence the results.

The study was published as part of a “working paper series” for the Department of Economics at the University of Zurich. The research does not appear to have been peer reviewed, meaning it has not been scrutinised by independent experts in the field for methodological rigor, or to check if the conclusions are reliable. This increases the risk of misleading findings, which can reach the public and mainstream media before they have been properly scrutinised.

There is a clear potential conflict of interest in receiving funding from a leading tobacco company when attempting to carry out impartial research assessing smoking data. The risk of misleading information being presented is further increased when the research is not peer reviewed. Given that both these factors are present in this particular study, the results should be interpreted with caution.

Generally, the media reported the story accurately. However, few mentioned the potential conflict of interest surrounding the funding or how the study was conducted, and none mentioned the lack of peer reviewing.

 

What kind of research was this?

This was a cross-sectional study using data to estimate the impact of plain packaging on smoking prevalence in 14-17-year-olds in Australia.

In December 2012, the Australian Plain Packaging Act 2011 came into force, with the aim of reducing smoking prevalence. However, the law was particularly intended to prevent young people taking up smoking. Australia was the first country to enforce a law of this nature, and other governments are eager to see if it works before deciding whether to do something similar.

 

What did the research involve?

The study used market research data from the Roy Morgan Single Source (Australia).

Roy Morgan is a major Australian market research firm, and the Single Source data set has been drawn from surveys. The data is reported to be weekly surveys completed through computer-assisted personal interviews (CAPI), which were administered door-to-door and sampled about 50,000 Australians a year.

The participants were Australians aged 14-17, and were assessed between January 2001 and December 2013. The surveys aimed to see whether the plain packaging law introduced in December 2012 was achieving a reduction in smoking prevalence.

The researchers used yearly prevalence data to plot a long-term trend of smoking from 2001 to 2013. Their main analysis then looked at month-on-month prevalence variations, to see if there was any obvious acceleration of the downward trend after the packaging ban was introduced.

Smoking prevalence was based on a binary variable on whether the person smoked. There was no further description of how this was arrived at, or what participants were asked as part of the CAPI assessing their smoking.

 

What were the basic results?

There was a decline in the annual long-term trend for smoking prevalence in Australians aged 14-17 years. Smoking prevalence reduced from nearly 12% in 2001 to almost 6% in 2013 – an annual average decline of 0.44%.

The month-on-month estimates were based on samples of between 350 and 200 people – some months saw slightly less people taking part. Because of this, there was a large variation surrounding the longer-term downward trend.

The month-on-month estimates since the introduction of the packaging ban saw a similarly large variation in smoking prevalence. There was no obvious acceleration of the long-term downward trend based on the data.

In a related press statement, new figures on tobacco sales were released from Philip Morris International. This statement says the information “shows that legal tobacco sales actually rose incrementally, by 59 million cigarettes in the first year plain packaging was introduced. This increase reversed the long-term decline of legal sales volumes in the country since before 2009”. 

How did the researchers interpret the results?

Based on the trend analyses, the researchers said they failed to find any evidence for an actual plain packaging effect on reducing smoking in young people.

Conclusions in the press release based on the trend analysis and tobacco sales figures indicated that “plain packaging in Australia has not reduced smoking rates and has had no impact on youth smoking prevalence. Consumers aren’t smoking less, they are just buying cheaper alternatives like roll-your-own cigarettes, or turning to branded packs available on the black market”.

 

Conclusion

This study indicates that smoking rates in Australians aged 14-17 have been experiencing a steady decline over the last decade. The evidence tentatively suggests this long-term trend didn’t dramatically alter in the year after the plain packaging law was introduced (between December 2012 and December 2013).

Importantly, there was only a year’s worth of data after the law was introduced on which to assess its impact. This is a relatively short period to assess such an impact, and it may be too narrow a timescale to identify a movement in the long-term trend. Furthermore, the month-on-month prevalence estimates are highly volatile, so cannot be relied upon to give an accurate picture either.

It was also not clear how smoking prevalence was assessed, so the exact estimates of smoking rates may be erroneous. It was also not clear if the same method was used over the entire decade, allowing prevalence estimates to be accurately compared year-on-year. Changes in how smoking was assessed during the questionnaire and categorised into smokers and non-smokers could distort the results.

The separate data released containing tobacco sales data was not critically appraised as part of this article, so we cannot comment on whether this data is reliable or informative.

The smoking data for this trend study was obtained from a market research company. Census data containing information smoking prevalence may also be available, and it would be useful to see if this alternative data source matches the information presented in this study. If this were possible, we would at least be able to cross-validate the longer-term trend findings from this study.

The research does not appear to have been peer reviewed, meaning it has not been scrutinised by experts in the field for methodological rigor, or to check if the conclusions are reliable. This significantly increases the risk that misleading findings can reach the mainstream media and public before it has been properly scrutinised.

Based on this data alone, it is difficult to make any firm conclusions on whether the plain packaging affected prevalence rates.

While the researchers stated that there was no access to the analysis of the data by the tobacco company, it raises questions – and eyebrows – that this research has been released to the press without being peer reviewed by independent experts.

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

Links To The Headlines

People smoke more in countries where cigarette packets show NO branding: Smokers buy cheaper cigarettes in plain packaging. Mail Online, March 25 2014

Unbranded cigarettes could mean people smoke more, experts warn. The Daily Telegraph, March 24 2014

Links To Science

Kaul A, Wolf M. The (Possible) Effect of Plain Packaging on the Smoking Prevalence of Minors in Australia: A Trend Analysis (PDF, 156kb) University of Zurich – Department of Economics. March 2014

Categories: NHS Choices

NICE: 'schools should provide morning-after pill'

NHS Choices - Behind the Headlines - Wed, 26/03/2014 - 11:00

New guidelines on contraceptive services for young people issued by the National Institute for Health and Care Excellence (NICE) have prompted widespread coverage.

The headlines have focused on a number of elements, with The Daily Telegraph reporting that, "Schools are told to give free morning-after pills and condoms to teenage girls to cut unwanted pregnancies", while The Daily Express claims that there is "Outrage as NHS says 'give pupils the morning-after pill'."

The media coverage largely focuses on recommendations to:

  • provide free emergency contraception such as the morning-after pill (which includes provision by suitably qualified nurses, including school nurses, and pharmacists)
  • provide school and education-based contraceptive services
  • provide condoms in addition to other methods of contraception

NICE is the body that advises on best practice for healthcare in England. These new guidelines aim to improve access to high-quality contraceptive services for young people.

The guidance is targeted at professionals who may have a role in contraceptive services. The wide-ranging recommendations advise on how to assess local need for contraceptive services, and offer culturally appropriate and non-judgemental services to young people.

 

How did the media report the news?

The publication of the new NICE guidelines was covered very reasonably by the Mail Online website.

The Daily Telegraph also took an initially balanced view. However, it chose to cite only two independent comments, both in opposition to the advice.

Patient Concern described the guidance as "like a way of promoting promiscuity", while a spokesperson for Comment on Reproductive Ethics, known for its links to religious groups, said: "Having a stockpile of the morning-after pill on hand is a licence for unprotected sex". Neither of these statements is backed by the evidence.

 

What are the NICE recommendations on contraceptive services?

The new young people's contraceptive guidance advises those in charge of health-related services in England to give all young people access to contraception. Advice should also be provided at convenient locations so that everyone can get contraceptive services, regardless of where they live.

The recommendations emphasise the need to offer additional tailored support to meet the particular needs and choices of those who are socially disadvantaged or who may find it difficult to use contraceptive services.

There are 12 recommendations set out in the guidelines. The recommendations that have been the main focus of the media attention include:

  • providing contraceptive services for young people – doctors, nurses and pharmacists should provide information about the full range of contraceptives available
  • providing contraceptive services after a pregnancy
  • providing contraceptive services after an abortion – the guidelines point out that it is important to dispel the myth that there is no need for contraception after an abortion and to explain that women are fertile immediately after an abortion
  • providing school and education-based contraceptive services – information on the location and hours of local services should be available
  • providing emergency contraception – suitably qualified nurses (including school nurses) should be given the ability through "patient group directions" (PDGs) to give free oral emergency contraception to young women and ensure that young people know where to obtain free emergency contraception
  • young women should be informed that an intrauterine device is a more effective form of emergency contraception than the oral method and can be used on an ongoing basis
  • providing condoms as well as other methods of contraception – condoms should always be made accessible along with other contraception, as they help prevent the transmission of sexually transmitted infections (STIs)

PDGs are a legal framework established in 2000 that allows some registered health professionals to provide a specified treatment to a predefined group of people without them having to see a doctor.

Treatment provided under PDGs should be reserved for situations in which this offers an advantage for patient care without compromising patient safety.

 

How do contraceptive pills work?

There are quite a lot of contraceptive methods to choose from. One of the most popular forms of contraception is the combined oral contraceptive pill – usually just called "the Pill" – which contains synthetic versions of the hormones oestrogen and progesterone. When taken correctly, it is more than 99% effective at preventing pregnancy.

Women need to follow the guidance of healthcare professionals on how to use the Pill prescribed for them, including advice on what to do if a combined pill is missed.

The combined pill is not suitable for everyone – there are various groups of women who cannot take it or should take it with caution. Other kinds of contraceptive pill or devices are available.

Read more about the 15 methods of contraception.

 

What are the methods of emergency contraception?

A woman can use emergency contraception to prevent pregnancy after having unprotected sex or if a method of contraception has failed. There are two methods of emergency contraception:

  • the emergency contraceptive pill (the morning-after pill) – either Levonelle or ellaOne
  • the copper intrauterine device (IUD) – a small plastic and copper device that can be fitted into your womb by a doctor or nurse within five days of having unprotected sex or up to five days after ovulation

Both of these methods are effective at preventing pregnancy if they are used soon after unprotected sex. However, the IUD is always 99.9% effective, whereas Levonelle is very slightly less effective.

The emergency contraceptive pill should not be used as a regular method of contraception. However, if the copper IUD is fitted, this can be used as an ongoing form of contraception.

 

Are there any side effects or risks of complications of contraceptive pills? The combined pill (the Pill)

There are some risks associated with using the combined contraceptive pill. However, these risks are small, and the benefits outweigh the risks for most women.

Oestrogen in the pill may cause your blood to clot more readily. If a blood clot develops, it could cause a deep vein thrombosis (clot in your leg), pulmonary embolus (clot in your lung), stroke or heart attack.

The risk of getting a blood clot is very small, but your doctor will check if you have certain risk factors that make you more vulnerable before they will prescribe the Pill. These risk factors include being a smoker, being overweight, having high blood pressure, or having a personal or close family history of blood clots.

Research is ongoing into the link between breast cancer and the Pill. Research suggests that users of all types of hormonal contraception have a slightly higher chance of being diagnosed with breast cancer compared with women who do not use them. However, your risk of breast cancer returns to normal 10 years after you stop taking the Pill.

Research has also suggested a link between the Pill and the risk of developing cervical cancer and a rare form of liver cancer. However, the Pill does offer some protection against developing endometrium (lining of the womb) cancer, ovarian cancer and colon cancer.

The emergency pill

Taking the emergency contraceptive pill has not been shown to cause any serious or long-term health problems. However, it can sometimes have side effects. Common side effects include:

  • abdominal (tummy) pain
  • headache
  • irregular menstrual bleeding (spotting or heavy bleeding) before your next period 
  • nausea (feeling sick)
  • tiredness

Less common side effects include:

  • breast tenderness
  • dizziness
  • headache
  • vomiting – seek medical advice if you vomit within two hours of taking Levonelle or three hours of taking ellaOne, as you will need to take another dose or have an IUD fitted

When the copper IUD is inserted, it needs to be ensured that there is no current sexually transmitted infection, as an existing infection can be worsened by inserting the IUD.

Pain or discomfort is the most common side effect immediately after inserting the copper IUD. In the longer term, side effects include the possibility of heavier or more painful periods.

 

Conclusion

Everyone makes mistakes, but if you find yourself relying on the morning-after pill as a regular method of contraception, you may want to speak to a healthcare professional about what would be the most suitable form of ongoing contraception for you to use. This could include methods that do not involve needing to take a daily pill, such as contraceptive patchesinjections or an implant.

However, none of these methods will protect you against sexually transmitted infections (STIs). Condoms are cheap, free of side effects and they will protect you against STIs such as chlamydia.

For more information about your contraception options, visit the Contraception guide. If you have any health questions and want to speak to someone in confidence, call:

  • the Sexual Health Line on 0300 123 7123
  • Brook on 0808 802 1234
  • the fpa on 0845 122 8690
  • NHS 111

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

Links To The Headlines

Now schools are told to give free morning-after pills and condoms to teenage girls to cut unwanted pregnancies. Mail Online, March 26 2014

Teenage girls will be able to stock up on morning-after pill under new NHS guidance. The Daily Telegraph, March 25 2014

Teenage girls need better access to morning-after pill – Nice. The Guardian, March 26 2014

Outrage as NHS says 'give pupils the morning-after pill'. Daily Express, March 26 2014

Morning-after pill 'should be available in schools'. ITV News, March 26 2014

Links To Science

National Institute for Health and Care Excellence (NICE). Contraceptive services with a focus on young people up to the age of 25. March 2014

Categories: NHS Choices

Back pain 'leading cause of disability,' study finds

NHS Choices - Behind the Headlines - Tue, 25/03/2014 - 11:30

"Back pain behind 'more disability than any other condition'," ITV News reports after a new study found that the condition may now be the leading cause of disability worldwide.

The study looked at how much disability is caused by lower back pain globally. It found that lower back pain caused more disability than any other condition, affecting nearly 1 in 10 people and becoming more common with increasing age.

The condition was most common in Western Europe, followed by North Africa and the Middle East, and was lowest in the Caribbean and Latin America.

The results of this research – which used data from a large study undertaken in 2010 on the global burden of disease – are likely to be reliable, and its findings will be of concern to health officials.

The study does a good job at highlighting a common but often overlooked condition. Lower back pain is not usually linked to any serious disease, but can be debilitating and emotionally distressing. It can be triggered by bad posture while sitting or standing, bending awkwardly, or lifting incorrectly.

Find out more about how to prevent back pain.

 

Where did the story come from?

The study was carried out by researchers from a number of academic institutions in Australia, the University of Washington in the US, and the Royal Cornwall Hospital in the UK.

It was funded by the Bill and Melinda Gates Foundation, the Australian Commonwealth Department of Health and Ageing, the Australian National Health and Medical Research Council, and the Ageing and Alzheimer's Research Foundation.

The study was published in the peer-reviewed medical journal, Annals of Rheumatic Diseases.

ITV News, the Daily Express and the Mail Online coverage of the study is fair, although the Express was wrong to class the growing number of people suffering from lower back pain as an "epidemic". Strictly speaking, an epidemic refers to the spread of infectious disease. 

But, as the authors point out, back pain is on the rise because of the world's ageing population, a trend that is likely to continue.

 

What kind of research was this?

This research was a collection of systematic reviews that set out to assess the "global burden" of lower back pain. The reviews were part of the Global Burden of Disease Study 2010, research that assessed the degree of ill health and disability in 187 countries, divided into 21 regions, for the years 1990, 2005 and 2010.

The authors point out that lower back pain is an extremely common health problem, and the leading cause of disability and work absence throughout much of the world.

Their paper describes in detail the methods and results for estimating the global burden of lower back pain in the 2010 study.

 

What did the research involve?

The researchers defined lower back pain as pain "from the lower margin of the twelfth ribs to the lower gluteal folds", with or without pain referred down one or both legs, that lasts for at least one day.

They classified the condition into four categories, depending on the level of severity, whether the pain was chronic (long term) or acute, and whether it involved referred pain in the leg. Each category was given a weighting for the degree of disability caused.

They then undertook systematic reviews of the:

  • prevalence – how many people are affected by lower back pain overall
  • incidence – how many people are diagnosed with lower back pain in a specific time period
  • remission – data on if and when the lower back pain went away
  • duration – how long it lasted
  • risk of death associated with the condition

The researchers found no relevant studies on duration and remission, and no evidence that lower back pain is associated with a higher risk of death.

They identified 170 studies on prevalence, of which 117 met the criteria to be included in the systematic review, with data available from 47 countries and 16 of the 21 world regions. Prevalence was broken down by age, sex and region.

They also looked at surveys from five countries about the impact of acute and severe chronic lower back pain, with and without leg pain. They also considered additional information on the condition from national health surveys carried out in more than 50 countries, although this data was not included in the systematic reviews.

The researchers used the disability weighting, together with the data on prevalence, to calculate the overall level of disability caused by lower back pain for the years 1990, 2005 and 2010. The measure they used to express this is called years lived with disability (YLDs).

The authors also assessed the toll taken by lower back pain using a measure called disability adjusted life years (DALYs). These are worked out by combining the number of years of life lost as a result of early death (YLL) and the number of years lived with disability (YLD). As there is no risk of mortality from lower back pain, in this study YLDs and DALY estimates are the same.

 

What were the basic results?

Researchers found that out of all 291 conditions studied in the Global Burden of Disease 2010 Study, lower back pain ranked highest in terms of disability (YLDs) than any other condition.

It ranked sixth in terms of the overall burden, measured as DALYs. The number of DALYs increased from 58.2 million (95% confidence interval [CI] 39.9 million to 78.1 million) in 1990, to 83 million (95% CI 56.6 million to 111.9 million) in 2010.

Globally, almost 1 in 10 (9.4%) people had lower back pain (95% CI 9.0 to 9.8), with slightly more men (10.1%) suffering the condition than women (8.7%). Both prevalence and burden increased with age. Prevalence was highest in Western Europe, with 15% suffering back pain. 

 

How did the researchers interpret the results?

The researchers say that lower back pain causes more global disability than any other condition. With the ageing world population, this burden can be expected to increase.

There is an urgent need for further research to better understand the condition and attempt to mitigate its growing burden.

 

Conclusion

This systematic review used a disability rating to quantify the severity of lower back pain in combination with data on prevalence throughout the world.

As the authors point out, this study had some limitations, however. Some of the information it used came from questionnaires asking people to recall their back pain, which could make the results prone to bias.

Also, the categories of disability used referred to the effect of back pain on bodily functions such as washing and dressing, rather than broader aspects of life, such as wellbeing or economic impact. This means it cannot estimate the full impact of back pain in a population.

However, with this in mind, it could be the case that the study actually underestimates, rather than overestimates, the burden of lower back pain.

Back pain is not usually linked to any life-threatening conditions, but its effect can be debilitating and distressing.

It's a cliché that doctors know nothing about the back, but, as with most clichés, it has a kernel of truth: lower back pain is a poorly understood condition. Further research is urgently needed into the ways in which back pain can better be prevented and managed.

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

Links To The Headlines

Back pain behind 'more disability than any other condition'. ITV News, March 25 2014

Epidemic of back pain is set to get worse as population ages. Daily Express, March 25 2014

How slouching when sitting and driving for long periods without breaks is causing eight in ten Britons to get severe lower back pain. Mail Online, March 25 2014

Links To Science

Hoy D, March L, Brooks P, et al. The global burden of low back pain: estimates from the Global Burden of Disease 2010 study. Annals of the Rheumatic Diseases. Published online March 24 2014

Categories: NHS Choices

Could Botox be used to treat severe asthma?

NHS Choices - Behind the Headlines - Tue, 25/03/2014 - 10:30

“Botox is commonly used to smooth out wrinkles, but new research suggests it could be used to help asthma sufferers,” the Mail Online report.

While early results seem encouraging, the research being reported on is still at proof of concept stage.

For most people, asthma can be controlled using conventional treatments such as inhalers. However, some people's asthma symptoms are resistant to treatment (intractable).

The researchers make the case that abnormal vocal cord movement, caused by muscle spasms, may be responsible for some of these intractable asthma cases.

So they tested Botox (botulinum toxin) – a powerful neurotoxin that can cause temporary partial paralysis – on 11 people with severe intractable asthma who had abnormal vocal cord movements that had failed to respond to speech therapy.

After injecting a course of Botox into their vocal cords, participants reported better asthma control, and airway size at the level of the vocal cords was increased. However, there were no changes in measures of lung function.

While the results seem promising it is important to point out that there was no control group in this small study. So any improvement in symptoms could be due to the placebo effect.

As the treatment appears to be relatively safe it should lead to further randomised controlled trials, which will help assess whether a placebo effect influenced the results.

 

Where did the story come from?

The study was carried out by researchers from Monash University in Australia. It was funded by Monash Medical Centre. 

The study was published in the peer-reviewed journal Respirology.

The results of this study were poorly reported by the Mail Online. The story headline read “injections into the vocal cords proven to help patients breathe”. Although the study did find that people reported better asthma control, there were no improvements in lung function after the treatment.

In addition, as the study was not a randomised controlled trial, it cannot prove that the improvements in asthma control were due to the injections.

Finally, the article appears to have been “cut in half” as it has no proper ending and just peters out.

 

What kind of research was this?

This study was a case-series of 11 people who still had severe asthma symptoms despite optimised treatment and who had abnormal vocal cord movement which was not improved by speech therapy.

All 11 were treated with vocal cord injections of Botox. The researchers wanted to see whether Botox is an effective treatment that improves asthma control.

A small study like this, often referred to as a phase I trial, can provide some indication of whether Botox may be a safe and effective treatment. However a randomised controlled trial is required to determine whether any improvements seen are actually due to the treatment and are not just due to people reporting improved symptoms because they have been treated (the placebo effect).

 

What did the research involve?

The study involved 11 people who had severe asthma symptoms despite optimised treatment and who had abnormal vocal cord movement which was not improved by speech therapy. They were treated with Botox injections into one of their vocal cords. If people didn’t have improved symptoms they were given additional injections.

After treatment, response was assessed using the following:

  • asthma control test scores – a self-reported “scorecard” that is based on the severity and frequency of symptoms (minimum five points for poor control, maximum 25 points for good control)
  • spirometry (where the amount and/or speed of air that can be inhaled or exhaled is measured)
  • measuring vocal cord narrowing using computerised tomography (CT) scans, where a series of X-rays are taken to create a detailed image of the larynx

The researchers also collected information on any side-effects that were experienced by the participants.

 

What were the basic results?

Four people had a single Botox injection, and the other seven received repeat injections, with two people receiving four injections. In total, 24 injections were given.

Asthma control test scores one month after each injection were significantly improved, from an average of 9.1 before treatment to 13.5 after treatment. The researchers state that changes of three or more on this score are clinically important.

Airway size was measured by computerised tomography in 10 patients. Some patients had received multiple injections when it was measured. Compared to before treatment, the amount of time the airway was narrowed below the lower limit of normal significantly improved from 39.4% to 17.6%.

There was no change in lung function as assessed by spirometry.

Side effects were noted after 17 of the 24 injections. Dysphonia (voice disorder) occurred after 16 injections and lasted for up to six weeks in five of the cases, though they were still able to have normal conversations. Dysphagia (difficulty swallowing) was reported after six of the 24 injections. All cases were categorised as ‘mild’.

One person with severe asthma required hospital admission and steroids after having the injection under general anaesthetic. The study fails to make clear whether this was due to an adverse reaction to the Botox or to the general anaesthetic (or to something else entirely).

 

How did the researchers interpret the results?

The researchers conclude that “although a placebo effect cannot be ruled out, local injection of botulinum toxin may be an effective treatment for intractable asthma associated with abnormal vocal cord movement. Further mechanistic studies and a double-blind randomised controlled trial of botulinum toxin treatment are merited.”

 

Conclusion

This small study involved 11 people who had severe asthma symptoms despite optimised treatment and who had abnormal vocal cord movement which was not improved by speech therapy. The results suggest that Botox injections into one of the vocal cords improved asthma control and the airway size at the level of the vocal cords was increased. However, there were no changes in measures of lung function.

As the researchers point out, this study was not controlled or blinded and a placebo effect cannot be excluded.

It is also not known how long any effect would last, as participants were only assessed for one to three months after treatment.

It is also currently unclear how common the problem of abnormal vocal cord movements is in people with poorly controlled asthma.

In conclusion, although Botox could be a promising treatment for people with asthma who also have abnormal vocal cord movement, further randomised controlled trials are needed.

If you do feel that your asthma symptoms are poorly controlled then speak to your GP or the doctor in charge of your care. There are a range of treatments that may be of benefit.

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

Links To The Headlines

Could BOTOX be used to treat asthma? Injections into the vocal cords proven to help patients breathe. Mail Online, March 24 2014

Links To Science

Baxter M, Uddin N, Raghav S, et al. Abnormal vocal cord movement treated with botulinum toxin in patients with asthma resistant to optimised management. Respirology. Published online March 23 2014

Categories: NHS Choices

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