NHS Choices

Caution urged over CT scan radiation doses

NHS Choices - Behind the Headlines - Fri, 15/08/2014 - 11:24

BBC News reports on a sharp rise in the number of CT scans being performed, exposing people to the potential health risks of radiation.

However, as The Daily Telegraph says, it is not possible to calculate the cancer risk due to exposure to CT scans because there is a lack of data.

These media stories follow the publication of a report by the Committee on Medical Aspects of Radiation in the Environment (COMARE). COMARE has reviewed trends in the use of CT scans in the UK. The review weighs up the risk-benefit balance of using CT scans, and considers ways to obtain the best quality scan image while minimising the necessary radiation dose.

The COMARE report sets out good practice guidance, encouraging doctors to take a more “proactive approach” to protecting patients and reducing radiation doses.

The committee recommendations cover equipment and procedures already in place, but also note there are dose reduction features available on some of the newer CT scanning machines that should be considered when new equipment is purchased.

 

What is COMARE and why is it looking at CT scans?

The Committee on Medical Aspects of Radiation in the Environment (COMARE) is an independent expert advisory committee, set up in 1985 to assess the available evidence and advise the government on the health effects of any form of natural or man-made radiation.

This is the committee’s 16th major published report. It follows a request from the Department of Health to assess the data available on radiation exposure during CT scans. The report looked at whether radiation exposures were justified (whether the benefits of the CT scans outweighed the risks). It also looked at ways to optimise the benefits of CT scans while minimising the risk to patients.

 

What does COMARE’s report say about the use of CT scans?

We are exposed to many sources of radiation, with the majority of radiation exposure coming from natural, environmental sources. Figures from the US show that on average, each year in the 1980s, only 15% of radiation exposure came from medical sources (0.54 millisievert [mSv] per person per year) – the rest from natural sources. By 2006, radiation exposure coming from medical sources each year had leapt to almost 50% of total annual radiation exposure (2.98mSv).

By contrast, the UK’s less medically intensive culture means that only 15% of our radiation exposure comes from medical sources. However, it has still increased from 0.33mSv per person per year in 1997, to 0.4mSv in 2008.

CT scans account for much of this exposure. In the 1980s CT scans were only contributing around a quarter of the medical radiation dose in the UK, but this had increased to around two-thirds by 2008. The number of CT scans performed by the NHS in England each year increased from just over 1 million in 1996/97, to almost 5 million by 2012/13, with no sign of reaching a plateau.

The report says there has been wider use of CT scans among younger people and children, whose tissues may have greater sensitivity to radiation. They also, of course, have a longer lifespan ahead of them in which potential harmful effects may be observed.

 

How do the risks and benefits of CT scans compare?

A CT scan is a special type of X-ray that produces very accurate cross-section views of the inside of the body.

The COMARE report highlights how CT scans can:

  • improve diagnosis and staging of cancers
  • reduce need for unnecessary “exploratory surgery” or other invasive examinations
  • demonstrate response to treatments
  • help the treatment of certain conditions, such as guiding biopsies and treatments for stroke or heart disease

However, it says that 70% of indications for CT scans recommended by guidance relate to benign (non-harmful) or potentially benign conditions. It says that CT scans are increasingly being used as a standard investigation, replacing other conventional ways of detecting health problems.

There are potential risks related to radiation. Radiation can cause immediate direct damage to body tissues (such as radiation burns and hair loss), although usually only when given at higher doses. More problematically, radiation is also recognised as a carcinogen. It could potentially be involved in the future development of cancers for the person being scanned, or potentially having genetic effects in any future children.

Overall, there is uncertainty about the level of risk from radiation from CT scans. The risk to anyone is influenced by many factors, including age and size, the part of the body being scanned, number of scans given and radiation dose, and the radiosensitivity and genetic susceptibility of the individual.

Studies to date examining radiation risk are often population-based studies that have not accounted for important factors such as the age or medical prognosis of that person, making it difficult to attribute radiation as the direct cause of any outcomes.

UK law means that medical radiation exposures for patients must be:

  • “Justified” – exposure producing sufficient benefit to the exposed individual to outweigh the potential risk of exposing to radiation
  • “Optimised” – procedures and techniques should be in place to keep radiation exposures as low as reasonably practical

 

What does the COMARE report recommend?

COMARE recommends encouraging a more proactive approach to protecting the patient and reducing radiation dose as part of its good practice advice.

It wants:

  • the UK to be actively involved in further research into the risks of radiation
  • Public Health England to undertake more frequent UK dose surveys to provide data to support regular updating of national diagnostic reference levels, including those specifically regarding children. COMARE advises the Department of Health to require healthcare providers to submit dose data for individual patients
  • hospitals to consider CT scanners that have a full range of dose reduction features when buying new equipment
  • the Department of Health to fund, if necessary, independent evaluation of CT scanners
  • the Royal College of Radiologists to work to ensure that CT scans are optimised, taking into account both image quality and dose. This would mean requests for CT scans needing to include a clear statement regarding the clinical question to be answered by the scan
  • the Royal College of Radiologists and other appropriate organisations to review and produce referral guidelines that give greater emphasis on alternative imaging techniques that use less or no ionising radiation

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

Links To The Headlines

Sharp rise in CT scans on children and adults. BBC News, August 14 2014

Cancers caused by CT scan cannot be calculated due to lack of data: Comare report. The Daily Telegraph, August 15 2014

Cancer fears prompt call to cut hospitals' CT scan radiation levels. The Guardian, August 15 2014

Categories: NHS Choices

Macmillan finds cancer survival 'postcode lottery'

NHS Choices - Behind the Headlines - Fri, 15/08/2014 - 11:24

“Cancer postcode lottery ‘costs 6,000 lives a year’,” reports The Times.

This, and similar headlines, are based on cancer survival figures compiled by Macmillan Cancer Support. The cancer charity’s report suggests that the proportion of people who die within a year of a cancer diagnosis is two-thirds higher in poor-performing areas, compared with high-performing areas.

These are shocking statistics, but it’s important to bear in mind that one-year cancer survival rates don’t give us the whole picture about the state of cancer care in England.

In a press release, MacMillan reports that around 6,000 more people could survive for at least 12 months after their cancer diagnosis if average survival across the whole of England matched the top 10% of local healthcare regions.

It identified areas such as Telford, Medway and Dagenham as having among the lowest cancer survival rates. Leafy Surrey, Dorset and Richmond had among the best cancer survival rates, according to the charity.

MacMillan suggests that the differences in survival could be explained by differences in waiting times for urgent referrals and start of treatment, which should be a set standard across the country. The charity calls for this “looming crisis” in cancer care to be addressed.

 

What does the MacMillan cancer survival report say?

MacMillan used data from the Office for National Statistics (ONS) and London School of Hygiene and Tropical Medicine to find the estimates for one-year survival for all types of cancer combined for all adults (aged 15 to 99) in 2011.

The average one-year survival for the whole of England was 68%. This means that roughly two-thirds of all people in England diagnosed with cancer survived for 12 months after they were diagnosed, and a third of people died by 12 months. In the 10% of regions with the best one-year survival rates in the UK, one-year survival was almost three-quarters, at 71%.

 

What is the reason for the differences in one-year cancer survival?

Links To The Headlines

Cancer patients: best and worst places to live for survival revealed. The Daily Telegraph, August 15 2014

Postcode lottery 'is killing 6,000 cancer patients every year': Proportion who die within year of diagnosis is two-thirds higher in worst-performing areas than the best. Mail Online, August 15 2014

Cancer treatment in England: 'Inexcusable postcode lottery' causes 6,000 'needless' deaths. Daily Express, August 15 2014

Categories: NHS Choices

High-salt diet linked to 1.6 million heart deaths

NHS Choices - Behind the Headlines - Thu, 14/08/2014 - 11:20

"Salty diet 'causes 1.6 million deaths worldwide each year'," reports The Daily Telegraph. It goes on to quote a researcher saying this is "nearly 1 in 10 of all deaths from cardiovascular causes worldwide".

This scary-sounding headline has a grain of truth in it, but the science it's based on doesn't prove that salt is causing these deaths. In fact, the news is based on a modelling study.

To estimate the effect of current sodium intake on cardiovascular mortality worldwide, researchers used available data on:

  • sodium consumption
  • the dose-response effects of sodium consumption on blood pressure
  • the association between blood pressure and cardiovascular mortality
  • data on cause-specific deaths

Globally, 1.65 million deaths from cardiovascular causes in 2010 were attributed to people consuming more than 2g of sodium per day. That's roughly 5g of salt a day. Currently, UK advice is for adults to eat no more than 6g of salt a day.

But this study could not prove that sodium restriction reduces cardiovascular mortality. This means the findings are generally in keeping with current salt recommendations that adults consume no more than 6g of salt a day.

 

Where did the story come from?

The study was carried out by researchers from Tufts University, the Harvard School of Public Health, Brigham and Women's Hospital, Harvard Medical School, and the University of Washington in the US, and the Cambridge Institute of Public Health and Imperial College London in the UK.

It was funded by the Bill and Melinda Gates Foundation.

The study was published in the peer-reviewed New England Journal of Medicine. This article was open access, which means it's free to view online.

The media coverage is generally representative of this research, but it's worth bearing in mind that the study's results are estimates only. Also, the link between sodium and death has only been indirectly assessed by examining sodium's effect upon blood pressure, and then blood pressure's effect upon cardiovascular death.

 

What kind of research was this?

This was a modelling study that aimed to estimate the effects of sodium intake on cardiovascular deaths around the world.

This modelling study can estimate how many deaths from cardiovascular disease can be attributed to a sodium intake over 2g.

However, it does not prove that sodium consumption of more than 2g a day caused any of these deaths, or that sodium restriction reduces cardiovascular mortality.

 

What did the research involve?

The researchers modelled the effects of sodium intake on cardiovascular mortality around the world. They estimated the fraction and numbers of deaths estimated to be attributable to sodium intake above a reference level of 2g of sodium a day.

To do this, the researchers needed estimates of global sodium consumption, the effect of sodium intake on blood pressure, and the effect of blood pressure on cardiovascular deaths.

Estimating global sodium consumption

Previously conducted national or subnational surveys on individual level sodium consumption were systematically traced by the researchers. These surveys were based on measurements of sodium in urine, or estimates of sodium intake in the diet, or both. The researchers quantified consumption according to age, sex and country.

Assessing the effect of sodium intake on blood pressure

The researchers carried out a meta-analysis of all randomised controlled trials identified in two prior systematic reviews that had evaluated the effect of reduced sodium on blood pressure. They looked at the effects according to age, race and the presence or absence of hypertension.

Assessing the effects of blood pressure levels on deaths caused by cardiovascular disease

The effect of blood pressure levels on deaths as a result of cardiovascular disease was assessed by combining results from two large international projects (including 99 cohorts, comprising a total of 1.38 million participants, among whom there were 65,000 cardiovascular events) that pooled individual level data. The researchers looked at the effects according to age.

The number of people who die from cardiovascular disease was estimated from the Global Burden of Disease Study 2010.

 

What were the basic results?

The researchers estimated the average level of consumption of sodium worldwide was 3.95g a day and regional averages ranged from 2.18g to 5.51g a day. From their meta-analysis of randomised controlled trials, they found reducing sodium intake reduced blood pressure.

Each reduction of 2.30g of sodium a day was associated with a reduction of 3.82mmHg in blood pressure, although the effects depended on population characteristics such as age and race.

They also found lower blood pressure was associated with a reduced risk of cardiovascular death.

The researchers calculated nearly 1 of every 10 deaths from cardiovascular causes (1.65 million deaths a year, 9.5% of all cardiovascular deaths) is attributed to a sodium intake of more than 2g a day.

Four of every five deaths (84.3%) occurred in low- and middle-income countries, and two of every five deaths (40.4%) were premature (before 70 years of age).

The rate of death from cardiovascular causes associated with sodium intake above the reference level was highest in Georgia and lowest in Kenya.

 

How did the researchers interpret the results?

The researchers concluded that: "In this modelling study, 1.65 million deaths from cardiovascular causes that occurred in 2010 were attributed to sodium consumption above a reference level of 2.0g per day."

 

Conclusion

Links To The Headlines

Salty diet 'causes 1.6 million deaths worldwide each year'. The Daily Telegraph, August 13 2014

Links To Science

Mozaffarian D, et al. Global Sodium Consumption and Death from Cardiovascular Causes. New England Journal of Medicine. Published August 14 2014

Categories: NHS Choices

Is UK obesity fuelling an increase in 10 cancers?

NHS Choices - Behind the Headlines - Thu, 14/08/2014 - 11:00

“Being overweight and obese puts people at greater risk of developing 10 of the most common cancers,” reports BBC News.

The news is based on research using information in UK GP records for more than 5 million people, to see whether body mass index (BMI) was associated with 22 types of common cancers.

The researchers found that increasing BMI was associated with increased risk of several types of cancer. Some of these associations weren’t linear, meaning that there wasn’t always a steady increase in cancer risk with increased BMI. Additionally, some of the links seemed to be dependent on individual patient characteristics, such as gender and menopausal status.

The researchers estimated that 41% of uterine and 10% or more of gallbladder, kidney, liver and colon cancers could be attributable to excess weight.

However, increasing BMI was also found to decrease the risk of some types of cancer (such as prostate and premenopausal breast cancer).

The researchers suggest that BMI affects cancer risk through a number of different processes. However, the study was not able to demonstrate that being overweight or obese directly increase or decrease risk of these cancers, nor is it able to show the biological reasons for any of the associations found.

It is also not able to account for all possible factors that contribute to cancer risk, such as genetics and lifestyle factors.

Nevertheless, maintaining a healthy weight has proven benefits beyond any reduction in cancer risk. As always, the best way to do this is by eating a balanced diet and exercising regularly.

 

Where did the story come from?

The study was carried out by researchers from the London School of Hygiene and Tropical Medicine, and the Farr Institute of Health Informatics Research. The study was funded by the National Institute for Health Research, the Wellcome Trust and the Medical Research Council.

The study was published in the peer-reviewed medical journal The Lancet. This article is open-access and can be accessed for free on the journal’s website.

The story was widely covered by the media.

 

What kind of research was this?

This was a cohort study that aimed to investigate the link between BMI and the most common site-specific cancers after adjusting for potential confounders.

As this is a cohort study, it cannot prove that obesity causes cancer, as there may be a wide variety of other factors (such as hereditary, sociodemographic and lifestyle factors) that could explain the associations seen.

 

What did the research involve?

The researchers studied primary care (GP) records from 5.24 million people, using data collected between 1987 and 2012.

They calculated BMI from recorded weight and height, both of which are recorded by GPs when patients are registered, during patient care, or because the GP thinks it’s relevant to the patients’ health.

The researchers then looked to see if people had a cancer diagnosis in their records, in particular:

  • female breast cancer
  • prostate cancer
  • mouth, oesophageal, stomach, colon and rectum cancers
  • lung cancer
  • non-Hodgkin lymphoma
  • leukaemia and multiple myeloma (blood cancers)
  • ovary, uterus (womb) and cervix cancers
  • pancreas, brain and central nervous system cancers
  • liver and gallbladder cancer
  • kidney and bladder cancer
  • thyroid cancer
  • malignant melanoma

The researchers looked to see whether BMI was linked with increased risk of cancer. They estimated the average effect of a 5kg/m² increase in BMI on cancer risk.

They controlled for age, smoking status, alcohol use, previous diabetes diagnosis, socioeconomic status, time period and gender in their analyses.

 

What were the basic results?

People were followed for 7.5 years on average, and during the study, 166,995 people (3.2%) developed one of the cancers of interest.

The researchers found that a 5kg/m² increase in BMI was associated with an increased risk of the following types of cancer:

  • uterus (hazard ratio (HR) 1.62, 99% confidence interval (CI) 1.56 to 1.69)
  • gallbladder (HR 1.31, 99% CI 1.12 to 1.52)
  • kidney (HR 1.25, 99% CI 1.17 to 1.33)
  • cervix (HR 1.10, 99% CI 1.03 to 1.17)
  • leukaemia (HR 1.09, 99% CI 1.05 to 1.13)
  • liver (HR 1.19, 99% CI 1.12 to 1.27)
  • colon (HR 1.10, 99% CI 1.07 to 1.13)
  • ovarian (HR 1.09, 99% CI 1.04 to 1.14)
  • postmenopausal breast cancers (HR 1.05, 99% CI 1.03 to 1.07)

There was a borderline statistically significant increase in the risk of thyroid cancer (HR 1.09, 99% CI 1.00 to 1.19), pancreatic cancer (HR 1.05, 95% CI 1.00 to 1.10) and cancer of the rectum (HR 1.04, 95% CI 1.00 to 1.08).

The researchers noted that not all the associations were linear, and that the associations between BMI and both colon and liver cancer were more marked in men than in women. Increases in ovarian cancer risk with BMI were larger in premenopausal than postmenopausal women, and there were differences by menopausal status for breast cancer.

The researchers estimated that 41% of uterine and 10% or more of gallbladder, kidney, liver and colon cancers could be attributable to excess weight.

A 5kg/m² increase in BMI was associated with a reduced risk of the following types of cancer:

  • premenopausal breast cancer risk (HR 0.89, 99% CI 0.86 to 0.92)
  • oral cavity (HR 0.81, 99% CI 0.74 to 0.89)
  • lung (HR 0.82. 99% CI 0.81 to 0.84)

There was a borderline statistically significant reduction in the risk of prostate cancer (HR 0.98, 99% CI 0.95 to 1.00).

The researchers noted that when the analysis was restricted to people who had never smoked, a 5kg/m² increase in BMI did not reduce the risk of oral cavity or lung cancer. They suggest that this inverse association seen when all people were considered was due to residual confounding.

Overall, the researchers estimated that a 1kg/m² population-wide increase in BMI would result in 3,790 additional annual UK patients developing cancer of the uterus, gallbladder, kidney, cervix, thyroid, leukaemia, liver, colon, ovarian or postmenopausal breast cancer.

 

How did the researchers interpret the results?

The researchers concluded that, “BMI is associated with cancer risk, with substantial population-level effects. The heterogeneity in the effects suggests that different mechanisms are associated with different cancer sites and different patient subgroups.”

 

Conclusion

This large UK cohort study of more than 5 million people has found that, although there was variation in the effect of BMI on different cancers, a higher BMI was associated with increased risk of several cancers.

Overall, the researchers estimated that a 1kg/m² population-wide increase in BMI would result in 3,790 additional people in the UK each year developing uterus, gallbladder, kidney, cervix, thyroid, leukaemia, liver, colon, ovarian or postmenopausal breast cancer.

However, not all of the identified links were completely clear, with some showing a clearer linear association between increasing BMI and increasing cancer risk than others. Also, strangely, increased BMI was also found to decrease the risk of some types of cancer, such as lung cancer. Such associations may be explained by other factors: for example, smokers – who are obviously at a much higher risk of lung cancer – tend to have a lower BMI than non-smokers.

However, this study is unable to demonstrate that being overweight or obese definitely directly increase or decrease the risk of these cancers. The researchers suggest that BMI affects cancer risk through a number of different processes. The study is also not able to account for all possible factors that may be entangled in the links (such as various hereditary, sociodemographic and lifestyle factors).

Nevertheless, it is well established that maintaining a healthy weight has many health benefits, including reducing the risk of many common chronic diseases. The best way to do this is by eating a balanced diet and exercising regularly.

 

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

Links To The Headlines

Obesity epidemic fuelling 12,000 cancers a year. The Daily Telegraph, August 14 2014

Obesity is blamed for 12,000 cancer cases every year: Being overweight can increase chance of developing some forms of the disease by 60%. Mail Online, August 14 2014

Being overweight or obese 'linked to 10 common cancers'. BBC News, August 14 2014

Obesity increases risk of 10 common cancers, study finds. The Independent, August 14 2014

12,000 cancer cases a year a linked to obesity. Daily Express, August 14 2014

Links To Science

Bhaskaran K, et al. Body-mass index and risk of 22 specific cancers: a population-based cohort study of 5.24 million UK adults. The Lancet. Published August 14 2014

Categories: NHS Choices

Anti-obesity drugs 'may still work in middle-age'

NHS Choices - Behind the Headlines - Wed, 13/08/2014 - 11:27

“Drug to halt the dreaded spread of middle age,” reports The Daily Telegraph, with similar headlines on the Daily Express and Daily Mail websites.

However, these claims are rather premature given the research they’re based on anti-obesity drugs that aren’t licensed for use in the UK. Also, the study in question involved mice, not people.

Researchers compared middle-aged, obese mice to healthy young mice. They found that existing, but unlicensed, anti-obesity medications (lorcaserin, d-fenfluramine and sibutramine) reduced food intake to a similar extent in both groups of mice.

Our brains change as we get older or more obese, leading to a “rewiring” of the parts involved in energy balance. It was thought that anti-obesity medications that work on this part of the brain might not work in older, fatter people because of the rewiring. But this study suggests that despite the rewiring, the brain machinery needed for these drugs to work still functions – at least in mice.

This research is likely to help in the development of future weight loss drugs. But for now, consuming fewer calories and burning more calories off with regular brisk walking is a better defence against middle-aged spread than holding out for a miracle weight loss pill any time soon.

Where did the story come from?

The study was carried out by researchers from the University of Cambridge and the University of Aberdeen in collaboration with researchers from the University of Michigan Medical School in the US and the Consejo Nacional de Investigaciones Científicas y Técnicas in Argentina. It was funded by Diabetes UK, the Wellcome Trust, the National Institutes of Health, and the MRC Centre for Study of Obesity and Related Disorders.

The study was published in the peer-reviewed journal Endocrinology. The article is open access, meaning it can be accessed and read free of charge.

The media reporting of the story was generally accurate, but the headline claims that there could be a pill to stop middle-aged spread aren’t quite right. Two of the anti-obesity treatments (d-fenfluramine and sibutramine) tested in this study have been withdrawn from clinical use due to off-target effects. The other drug, lorcaserin (brand name Belviq), was approved by the US FDA in 2012, but it is not approved in Europe and appears unlikely to be approved.

What kind of research was this?

This was an animal study.

The researchers report that both obesity and ageing are associated with rewiring of the main brain pathway involved in energy homeostasis. This leads to reduced activity of a group of brain cells called the pro-opiomelanocortin (POMC) neurons, which are found in the hypothalamus. The POMC neurons make hormones that are important in regulating appetite and body weight.

A number of anti-obesity drugs (lorcaserin, d-fenfluramine and sibutramine) work by increasing the activity of the neurotransmitter serotonin, increasing the activity of the POMC neurons.

The researchers were concerned that the anti-obesity drugs may not work in older, obese people due to reduced activity of these neurons. They performed a number of experiments in mice to determine whether the drugs work in older, obese mice.

Animal studies are ideal for this type of basic research, but trials on humans are required before an assessment of the benefits and risks of anti-obesity medications can be made.

What did the research involve?

The researchers initially confirmed that the anti-obesity drugs work by increasing the activity of the POMC neurons. They did this by comparing the food intake of normal mice with that of mice genetically engineered to lack POMC neurons that had been given anti-obesity drugs.

The researchers then tested whether the anti-obesity drugs reduced the appetite of older, obese mice who had the POMC neurons. They tested the effect of lorcaserin, d-fenfluramine and sibutramine on normal mice, young adult mice (three to five months old) and middle-aged mice (12 to 14 months old, the equivalent of a human 40 year old according to the authors). The middle-aged mice were heavier and fatter than the young adult mice.

What were the basic results?

Food intake was significantly reduced (described as an anorectic effect) in normal mice after they were given anti-obesity drugs. However, food intake was not significantly changed in the genetically engineered mice that did not have the POMC neurones.

The researchers found that young adult mice and middle-aged mice reduced food intake to a similar extent after being given the anti-obesity drugs.

The researchers went on to do further brain studies. These found there is similar gene expression in young and middle-aged mice, and that the serotonin signalling machinery in POMC neurons still functions as well in middle-aged mice as in young mice.

How did the researchers interpret the results?

The researchers conclude that serotonin obesity medications require POMC neurons to have an effect on appetite. And while this pathway is remodelled with ageing, the anatomical machinery is preserved and appetite suppressive effects are maintained in older mice. They say that these findings are of clinical significance to the global ageing obese population.

 

Conclusion

This animal study has found that anti-obesity medications that increase serotonin signalling reduce food intake in “middle-aged, obese” mice to a similar extent as in young mice.

There had been concern as both obesity and ageing are associated with rewiring of the main brain pathway involved in energy homeostasis. The “rewiring” leads to reduced activity of POMC neurons, found in the hypothalamus and these POMC neurons make hormones that are important in regulating appetite and body weight.

A number of anti-obesity drugs (lorcaserin, d-fenfluramine and sibutramine) work by increasing the activity of the neurotransmitter serotonin, increasing the activity of the POMC neurons. As a result of the rewiring changes, it was thought these changes might mean that anti-obesity medications wouldn’t work.

From the results of this study, it seems that although POMC neurons may become less active as animals become older and fatter, they can be stimulated to become active by certain drugs – at least in mice.

However, claims there could be a pill to stop middle-aged spread are not strictly true – as we’ve seen, this study simply found that drugs continued to work in older subjects. Further, two of the anti-obesity treatments tested in this study have been withdrawn from clinical use due to off-target effects (d-fenfluramine and sibutramine). The other drug, lorcaserin, was approved by the US FDA in 2012, but it is not approved in Europe and appears unlikely to be approved here.

For now, exercise and eating healthily is the best defence against middle-aged spread.

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

Links To The Headlines

A drug could soon destroy middle-age spread: Pill could stop cells that control appetite becoming lazy with age, causing us to overeat. Mail Online, August 13 2014

Drug to halt the dreaded spread of middle age. The Daily Telegraph, August 13 2014

Scientists discover secret to losing weight in middle-age. Daily Express, August 13 2014

Links To Science

Burke LK, et al. 5-HT obesity medication efficacy via POMC activation is maintained during aging. Endocrinology. Published July 22 2014

Categories: NHS Choices

Salt injections: not a cure for cancer

NHS Choices - Behind the Headlines - Wed, 13/08/2014 - 11:27

“Salt injection ‘kills cancer cells’ by causing them to self-destruct,” reports the Mail Online.

Despite this headline, there is no new treatment for cancer using salt. The Mail Online reports on an early phase of experiments in laboratories that have worked out how increasing the amount of sodium chloride (salt) within a cell causes it to die.

The researchers did not inject cancer with salt, although they did create a way of getting salt inside cells (but not with a needle and syringe, as you may imagine from the headlines). In fact, they made two new molecules that bind to chloride and take it into cells. This increase in chloride also causes sodium to move into the cell, leading to an increase in sodium chloride.

Scientists already knew that increasing the level of salt within a cell would cause the cell to die, but wanted to know why.

The researchers found that increasing the salt level within normal and cancer cells in the laboratory caused cell death through one of the natural mechanisms, called the “caspase-dependent pathway”. This is a different pathway for cell death than the ones currently triggered by cancer drugs. The researchers hope this knowledge can be used to develop new drugs to treat cancer.

 

Where did the story come from?

The study was carried out by researchers from South Korea, the US, UK and Saudi Arabia. It was funded by the National Creative Research Initiative programme in South Korea, the US Department of Energy, the Engineering and Physical Sciences Research Council and a European Union Marie Curie Career Integration grant.

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

Although most of the Mail Online’s coverage of this study was accurate, the headlines implied that cancer can be killed by injecting cells with salt. This is not the case. Researchers have found out how cells (both healthy cells and cancerous cells) die when there are increased levels of salt inside them. It is important to note that they have only done this in cells in a laboratory, not in any humans or other living creatures.

 

What kind of research was this?

This was a series of laboratory experiments designed to test compounds that the researchers designed as chloride transporters. They also wanted to better understand how cell death occurs when there is increased sodium chloride within the cell. Understanding the mechanism means that future research can look at ways of targeting it in cancer cells, but avoiding their healthy counterparts.

 

What did the research involve?

A number of molecular experiments, using cell membranes, were carried out to test compounds that the researchers designed as chloride transporters. After this, they worked out the underlying mechanisms behind cell death by increasing the salt level in cancer cells.

The researchers studied the effect the compounds had on the amount of sodium that then entered the cells through sodium channels, and whether it affected other positive ions, such as potassium and calcium.

The researchers then studied normal human cells from the prostate and lung, as well as rat kidney cells and human cancer cells from the lung, pancreas, colon and cervix, in the lab. These studies aimed to determine how increasing the amount of sodium chloride (salt) within the cells caused them to die.

Further experiments involved reducing the amount of sodium or chloride outside the cells to see what effect this would have on the ability of the cell to increase the level of salt. The drug amiloride (used to treat high blood pressure and heart failure) was used to test the effect of blocking the sodium channels.

 

What were the basic results?

The researchers made two new molecules, which attach to chloride and increase the amount that enters cells. The increased amount of chloride in the cells caused more sodium to enter. This excess sodium chloride triggered cell death through the “caspase-dependent pathway” (a different pathway to the ones usually induced by cancer drugs). Cell death occurred in all types of cells used – both healthy and cancerous cells.

The molecules were found to have no effect on the levels of potassium or calcium in the cells.

Cell death from this pathway did not occur when the concentration of sodium or chloride outside of the cells was low. Nor did it occur when cells were soaked in amiloride, which prevents increased sodium from entering the cells. These experiments indicated that increased levels of both chloride and sodium (in other words, salt) were required inside the cell to trigger cell death from the caspase-dependent pathway.

 

How did the researchers interpret the results?

The researchers conclude that, “synthetic transporters can be used to induce an influx of Cl- [chloride] as well as Na+ [sodium], and that this leads to an increased level of reactive oxygen species (ROS), the release of cytochrome c from the mitochondria and induction of apoptotic cell death via the caspase-dependent pathway”. They go on to say that “ion transporters, therefore, represent an attractive approach for regulating cellular processes that are normally controlled tightly by homeostasis”.

 

Conclusion

This is an early phase in the development of new drugs to combat cancer, and it should be stressed that these experiments did not involve humans or injecting cancer with salt. There is no new treatment for cancer using salt.

This research has, however, shed light on how increasing the salt level in cells can trigger the activation of one of the cell’s pathways for causing cell death.

Two different molecules were developed that transported chloride. The increased amount of chloride within the cells caused more sodium to enter. This caused cell death in a variety of different types of cancer cells in the lab, including healthy cells.

Understanding these underlying mechanisms will help pave the way for new drug developments. However, new drugs based on this science are a long way off, largely because there needs to be a way to use the technology to target only cancer cells, and not damage healthy ones. 

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

Links To The Headlines

Salt injection 'kills cancer cells' by causing them to self destruct...and it could pave the way for new drugs to prevent the disease. Mail Online, August 12 2014

Links To Science

Ko S-Y, et al. Synthetic ion transporters can induce apoptosis by facilitating chloride anion transport into cells. Nature Chemistry. Published August 11 2014

Categories: NHS Choices

Toothbrushing advice 'conflicting'

NHS Choices - Behind the Headlines - Tue, 12/08/2014 - 11:15

"Teeth-brushing advice unacceptably inconsistent," reports The Guardian, while the Mail Online states that a "simple, gentle scrub is best".

These headlines relate to a small literature review that found diversity in the methods of manual toothbrushing recommended by dental associations, toothpaste and toothbrush companies, dental textbooks, and experts in 10 countries. The study authors concluded that this inconsistency "should be of serious concern to the dental profession".

The diversity of advice across the countries was thought to be because of a lack of good evidence about which toothbrushing technique is most effective, which further research could address.

The study has several limitations, but these are unlikely to change its overall message. Despite its small and imperfect nature, this literature review highlights a fundamental issue in dentistry – that the toothbrushing techniques currently recommended are probably not strongly evidence based.

This research may spur dental and other related organisations to provide evidence-based guidance on oral hygiene – and to let the public know which brushing technique works best for kids and grown-ups.

 

Where did the story come from?

The study was carried out by researchers from the Department of Epidemiology and Public Health at University College London (UCL), and was published in the peer-reviewed British Dental Journal.

No funding source was reported.

Generally, the media reported the story accurately, with the Mail Online including an instructional video of a man brushing his teeth circularly. However, given the research's conclusions, there is no guarantee this is the most effective technique.

 

What kind of research was this?

The researchers say dentists, dental associations and government bodies all recommend regular daily toothbrushing because it is so important for preventing periodontal disease and caries.

However, there appears to be no consensus among professional bodies on the best method of toothbrushing for the general population, or for people of different ages or with particular dental conditions.

This study aimed to investigate this by conducting a literature review assessing methods of toothbrushing recommended for both adults and children.

 

What did the research involve?

The research involved examining online material on methods of toothbrushing from:

  • dental associations
  • toothpaste and toothbrush companies
  • associated organisations providing professional advice
  • dental textbooks

The consistency of recommendations from different sources was compared narratively.

The study mainly used simple Google and Google Scholar search strategies to identify relevant material, and focused their search remit on 10 countries they deemed to have the highest dental research and recommendation outputs: Australia, Brazil, Canada, Denmark, Finland, Japan, Norway, Sweden, the United Kingdom and the United States. Google Translate was used to translate non-English websites.

A score sheet was used to record relevant information, and the techniques were categorised based on the angle of the toothbrush bristles and the movement of the toothbrush head.

Supplementary information on toothbrushing frequency, duration and powered toothbrushing recommendation was collected.

Pictures and videos that were sourced were reviewed independently by three dentists, and a consensus view was recorded on the techniques they showed.

 

What were the basic results?

Of 66 sources located, 58 had one or more items of codeable data, while eight sources did not have any useable data. It was not possible to discern a brushing technique from 19 of the sources.

The main finding was evidence of vast diversity between recommendations on toothbrushing techniques, how often people should brush their teeth, and for how long.

Links To The Headlines

Teeth-brushing advice unacceptably inconsistent, study finds. The Guardian, August 8 2014

Revealed, the perfect way to brush your teeth: Forget fancy circular motions – a 'simple, gentle scrub is best'. Mail Online, August 8 2014

Links To Science

Wainwright J and Sheiham A. An analysis of methods of toothbrushing recommended by dental associations, toothpaste and toothbrush companies and in dental texts. British Dental Journal. Published August 8 2014

Categories: NHS Choices

Growth of newborn babies' brains tracked

NHS Choices - Behind the Headlines - Tue, 12/08/2014 - 11:15

"Scans chart how quickly babies' brains grow," reports BBC News Online.

The headline follows a fascinating study that shows newborn babies' brains are about a third the size of an adult's at birth, and rapidly grow to just over half the size of an adult's within three months.

The study involved 87 healthy babies who were given an MRI brain scan within the first week of life. Most then had a second scan after a month, and some had a third scan aged around three months. The researchers measured the size of the different major structures of the brain and calculated the growth rate.

The speed of growth was greatest just after birth, increasing by 1% per day, gradually tailing off to 0.4% per day by 90 days. The baby boys' brains were slightly larger than the baby girls' brains just after birth (347cm3 compared to 335cm3) and had grown slightly faster by 90 days (66% of the size) compared with female brains (63%).

Studies such as this can help our understanding of brain development, which could help unearth abnormal processes and certain developmental conditions. Being able to monitor brain development over time with an investigation that does not appear to have any side effects is also welcome. But this small study can't be used on its own as a reference for what's normal.

 

Where did the story come from?

The study was carried out by researchers from the University of California, the University of Hawaii and the Norwegian University of Science and Technology.

It was funded by the National Institutes of Neurological Disorders and Stroke, the National Institute on Drug Abuse, and the National Institute on Minority Health and Health Disparities.

A clear conflict of interest was reported by one of the study authors, who is a founder and equity holder in CorTechs Labs – a company selling software that analyses brain volumes from MRI scans and compares these volumes to norms.

The study was published in the peer-reviewed medical journal, JAMA Neurology.

The BBC reported the study accurately.

 

What kind of research was this?

This was an observational study aiming to plot the brain development of healthy babies using repeated MRI scans.

The researchers say there are usually problems obtaining a useable MRI image for newborn infants because it is hard to get the baby to stay still, head sizes change rapidly during the first few months, and the shape of the head may have been affected by birth.

To add to the difficulties, all of the neurones are already present but squeezed into a third of the size of an adult brain, making images more difficult to interpret.

The researchers wanted to chart normal development in babies who were not distressed by illness and therefore able to sleep during the scan.

This information could provide a benchmark that could help work out how and when all sorts of disorders start to occur, and therefore potentially lead to new treatments. 

 

What did the research involve?

The researchers gave 87 babies (39 boys and 48 girls) an MRI scan about a week after birth. The scan was conducted while they were asleep, so no sedation was required.

A repeat scan was performed on 57 babies after one month, and 49 of them had a third scan two months later.

The researchers measured the size of the different major structures of the brain and calculated the growth rate.

Data was collected regarding the ethnicity of the child and the mother's medical history and use of medication during the pregnancy.

Babies were excluded from the study if:

  • they had any known neurological disorders or abnormalities 
  • they had any newborn illness requiring more than one week in intensive care
  • there was a brain abnormality
  • they had overt perinatal TORCH infections (toxoplasmosis, other, rubella, cytomegalovirus or herpes simplex) at birth, or a major neurological disorder since birth 
  • there was any chromosomal anomaly
  • there were any other contraindications for MRI studies
  • the mother tested positive for HIV infection 
  • the mother had smoked tobacco cigarettes or had more than three alcoholic drinks a month during the pregnancy

 

What were the basic results?

The baby boys' brains were slightly larger than the baby girls' brains just after birth (347cm3 compared to 335cm3).

The longer the gestational age, the bigger each section of the brain, apart from the pallidum (an area that may be important in reward and motivation) and the third ventricle (a cerebrospinal fluid-filled area involved in communication between different areas of the brain).

By 90 days, the brains had grown by nearly two-thirds, with male brains growing slightly faster (66%) compared with female brains (63%).

The highest area of growth was the cerebellum at the back of the brain, which controls movement, co-ordination and balance. This had grown by 113% in males and 105% in females.

The slowest area was the hippocampus, which is known to be involved in memory formation – on average, this grew by 47%.

On average, the brains grew from 33.5% of the average size of an adult's brain to 54.9% by 90 days.

The speed of growth was greatest just after birth, at 1% per day, gradually reducing to 0.4% per day by 90 days.

Most of the babies were of mixed race (54%), then native Hawaiian/Pacific islander (22%), Asian (13%), white non-hispanic (8%) and black (1%).

 

How did the researchers interpret the results?

The researchers reported that they have "accurately mapped out early postnatal whole-brain growth trajectories for male and female infants", which they believe is the first time this has been done.

They say if the study is repeated on a larger and more diverse group of babies, this information could provide a reference point to measure brain growth in babies who have had a brain injury, and for monitoring the effects of any treatments.

 

Conclusion

This study has mapped out the growth rate of the major structures of the brain in 87 apparently healthy neonates from within a week of birth up to 90 days.

A study of this nature can help our understanding of the growth and development of the brain and our ability to monitor brain development over time. The fact the investigation had no apparent side effects is also welcome.

However, as the authors point out, the relatively small size of the study means the results cannot be used as a reference for normal development. Larger and more ethnically diverse studies would be required.

The goal of establishing data for a reference for normal development ties in with the commercial conflict of interest mentioned earlier, as one of the authors founded a company which sells software that analyses brain volumes from MRI scans and compares these volumes to norms.

Currently, brain growth is estimated using a measuring tape to chart the baby's head circumference over time.

The circumference is compared against established norms, with deviation from the norm a potential indication of problems in development and warranting further investigation.

The MRI technique offers a potentially more accurate way of measuring growth or confirming abnormality of growth.

Assessing every child's brain development through an MRI scan is not practical and is probably not the intended endpoint. So the real use of this developing knowledge and technology appears to be providing some evidence to help establish a reference for what is normal and what is abnormal. This could allow abnormalities to be detected earlier than we can currently.

However, there would still need to be a decision made about which babies should be scanned. This would most likely be those at a higher risk of developmental problems, possibly because of a family history or a traumatic birth or pregnancy.

This study highlights the importance of the first few months of life on brain development. This can be supported, if possible, by breastfeeding a baby.

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

Links To The Headlines

'Scans chart how quickly babies' brains grow'. BBC News, August 12 2014

Links To Science

Holland D, et al. Structural Growth Trajectories and Rates of Change in the First 3 Months of Infant Brain Development. JAMA Neurology. Published August 11 2014

Categories: NHS Choices

Exercise may cut breast cancer risk, study finds

NHS Choices - Behind the Headlines - Mon, 11/08/2014 - 11:34

"Exercise lowers risk of breast cancer after menopause," reports The Independent. This and similar headlines were sparked by a large study of postmenopausal teachers that found increased recreational activity was associated with a 10% decrease in the risk of breast cancer.

The risk reduction eroded among some women who became less active over the years, suggesting keeping up a certain level of activity might be important in maintaining the benefits.

The study used questionnaires to estimate the levels of walking, cycling and sport the women did outside of work.

It found women who did the equivalent of walking at least four hours a week or doing sport for two hours a week had a reduced risk of breast cancer. Factors such as body mass index (BMI) did not change the results.

However, the majority of women in the study had a healthy BMI and were teachers, so the results may not be applicable to all postmenopausal women.

Lack of physical activity and excess body fat have been linked to an increased risk of many cancers, including breast, colon, endometrial (lining of the womb) and prostate cancer, as well as heart disease, stroke and diabetes.

Despite the limitations of this study, taking regular exercise such as walking has been found to have wide-reaching benefits – the 30 minutes a day suggested in much of the news coverage is enough to get your recommended 150 minutes of exercise a week.

 

Where did the story come from?

The study was carried out by researchers from the Nutrition, Hormones and Women's Health team at the CESP Centre for Research in Epidemiology and Population Health, Université Paris Sud, Université Hospital and the Université d’Auvergne in France.

It was funded by the Institut National du Cancer, the Fondation de France and the Institut de Recherche en Santé Publique.

The study was published in the peer-reviewed medical journal Cancer Epidemiology, Biomarkers and Prevention.

The media reported the study accurately, but did not point out that the study only involved teachers, most of whom were a healthy weight.

 

What kind of research was this?

This was a prospective cohort study looking at the association between the amount of exercise postmenopausal women did and their risk of breast cancer.

The researchers wanted to see whether exercise levels reduced the risk of breast cancer, and whether it mattered if the exercise was recent or several years before.

As this is a cohort study, it can only show an association between the two – it cannot prove that regular exercise can prevent or delay breast cancer.

 

What did the research involve?

The researchers used information gathered from a large prospective cohort study of female teachers in France conducted from 1993 to 2005.

The 59,308 postmenopausal women filled in questionnaires in 1993, 1997 and 2002 on their health status and levels of physical activity. The researchers verified the women's self-reported breast cancer by checking pathology reports and the national cause of death registry.

Physical activity level was assessed by asking the women to estimate the amount of time they spent in a typical week in both the summer and winter:

  • walking (including walking to work, shopping and leisure time)
  • cycling (including cycling to work, shopping and leisure time)
  • doing sports

The level of activity was averaged over these two weeks and graded by metabolic equivalent task (MET). One hour walking was equivalent to three MET hours, while one hour cycling or doing any sport was given six MET hours.

Women were excluded if they had:

  • cancer at the beginning of the study
  • cancer before the menopause (other than basal cell carcinoma)
  • never menstruated
  • missing information on physical activity level
  • been in the top 1% of reported physical activity

The researchers analysed the results according to the level of physical activity reported in each of the three questionnaires. These were adjusted to take into account:

  • age
  • BMI
  • energy intake
  • alcohol use
  • family history of breast cancer
  • history of benign breast disease
  • age of starting their periods and the menopause
  • use of HRT
  • the number of children they had given birth to before and after the age of 30

 

What were the basic results?

The average length of follow-up was 8.5 years. During this time, 2,155 women developed breast cancer. Most of the women (73%) had a BMI between 18.5 and 25.

The researchers calculated that women with levels of recreational activity of more than 12 MET hours a week in the previous four years had a 10% lower risk of breast cancer than those with a lower level (hazard ratio [HR] 0.90, 95% confidence interval [CI] 0.82 to 0.99).

This remained the same after taking numerous other factors into account, including BMI, waist circumference, recent change in weight, sports activities from the age of 8 to 15 years, and the use of progestogen or oral contraceptives.

Women who had done more than 12 MET hours of exercise a week five to nine years ago, but who then became less active, had a 16% increased risk of breast cancer than those who remained active (HR 1.16, 95% CI 1.01 to 1.35).

If activity levels remained the same five to nine years earlier and in the last four years, the activity level during those five to nine years was not significantly associated with breast cancer risk (HR 1.04, 95% CI 0.92 to 1.18).

There was quite a high rate of change in reported levels of physical activity, with a fifth (21%) moving from more than 12 MET hours a week to less than 12 MET hours a week in at least two consecutive questionnaires, and a fifth (20%) moving from less than 12 MET hours a week to a higher level.

 

How did the researchers interpret the results?

The researchers concluded that, "Recent recreational physical activity, even at a modest level, was associated with a breast cancer risk reduction in postmenopause; this association seemed to attenuate a few years after activity stops."

 

Conclusion

This large study has shown that increased exercise is associated with a reduced risk of breast cancer for postmenopausal women. Strengths of the study include the large number of women and that self-reports of breast cancer were verified by a pathology report in 94% of cases.

However, as the authors point out, a limitation of this study is that it was conducted on a group of teachers who were mainly of a healthy weight. This means the results may not be applicable to women of a different weight with different occupations, including more or less sedentary jobs.

The study also relied on self-reported exercise levels, which may not be entirely accurate. It also only looked at recreational physical activity, so did not include any physical activity at work (for example, it didn't distinguish PE teachers from teachers of other subjects).

For the women who developed breast cancer, it is not clear whether the diagnosis occurred before or after the levels of physical activity reduced.

Lack of physical activity and excess body fat have been linked to an increased risk of many cancers, including breast, colon, endometrial (lining of the womb) and prostate cancer, as well as heart disease, stroke and diabetes. Regardless of the limitations of this study, it is still advisable to take regular exercise.

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

Links To The Headlines

Breast cancer risk lower in women who walk 30 minutes a day for years. The Daily Telegraph, August 11 2014

Exercise lowers risk of breast cancer after menopause. The Independent, August 11 2014

Women who walk regularly cut risk of breast cancer. Daily Express, August 11 2014

How a daily walk can cut breast cancer risk: Older woman told it's never too late to start exercise. Daily Mail, August 11 2014

Links To Science

Fournier A, et al. Recent Recreational Physical Activity and Breast Cancer Risk in Postmenopausal Women in the E3N Cohort. Cancer Epidemiology, Biomarkers and Prevention. Published August 11 2014

Categories: NHS Choices

'Safe' stem cell therapy may help stroke recovery

NHS Choices - Behind the Headlines - Mon, 11/08/2014 - 11:13

BBC Online today reports that "Stem cells show promise in stroke recovery".

This accurate headline comes from a study showing how a new technique using a patient's own stem cells to aid recovery from severe ischaemic stoke is feasible and appears to be safe.

But the study was tiny – just five people had the treatment. The study was also not designed to test whether the technique was effective, only whether it was feasible and safe.

This means we cannot be sure the improvements seen in the patients were caused by the stem cell treatment itself. They could have occurred anyway as a natural path of recovery post-stroke – a point the study authors explained.

A much larger trial that compares this stem cell treatment with the best available care would be needed to prove effectiveness, and is a logical future step for this treatment in development.

The well-worn path of treatment development is often long and costly, but is designed to protect patients from potentially harmful treatments, and weeds out all the treatments that are not effective.

However, we should not ignore the fact the technique was well tolerated in the five people and did not appear to lead to any side effects in the six months it was evaluated – a promising result.

 

Where did the story come from?

The study was carried out by researchers from Imperial College Healthcare NHS Trust and Imperial College London.

It was funded by Omnicyte Ltd – a British-based biotechnology company specialising in extracting the therapeutic potential and benefits of stem cell technologies.

The study was published in the peer-reviewed science journal, Stem Cells Translational Medicine.

Generally, the media reported the story accurately, with the BBC explaining that the treatment was in its very early stages and that this latest study was designed to test the safety and feasibility of the stem cell treatment, rather than its effectiveness.

 

What kind of research was this?

This was a proof-of-concept, non-randomised, open-label, human trial. It looked at whether a new stem cell infusion technique in development was feasible and safe to treat patients with acute severe stoke within seven days of it occurring.

The study focused on people who'd had an ischaemic stroke – when blood supply to the brain is cut off either because of a narrowing of the vessels supplying the brain, or because there is a blood clot in these vessels. Most strokes happen suddenly, develop quickly and damage the brain within minutes.

The study was a small feasibility study, meaning it was not designed to provide solid proof that the treatment worked. Instead, its main aim was to see if the technique was possible to use and was safe in a small number of people.

 

What did the research involve?

The researchers wanted to recruit people who could start treatment within seven days of stroke onset and if they had a stroke with particularly severe characteristics.

According to Imperial College, this "total anterior circulation stroke" (TACS) usually has a poor outcome in most people. Typically, just 4% of people who have a TACS stroke are alive and living independently six months after the stroke. For this reason, any treatments that can improve outcomes are extremely welcome.

The researchers excluded people if they were over 80, "medically unstable", had a significant narrowing of the carotid artery, or declined or were unable to participate. However, the researchers had trouble recruiting enough people with this subtype, so the inclusion criteria were widened to include the partial anterior circulation stroke (PACS) subtype of ischaemic stroke.

In the end, five patients who had experienced a clinically confirmed severe stroke in the past seven days (four had TACS stroke, one had PACS stroke) were recruited (out of 82 screened). Each had a small amount of bone marrow extracted under local anaesthetic.

This bone marrow was purified to isolate the patient's own CD34+ stem cells, which were injected into the patient's arteries one or two days later. Side effects were documented for six months after treatment.

The researchers also recorded the degree to which the stroke impaired normal daily functioning using validated clinical rating scales (National Institutes of Health Stroke Scale and modified Rankin Scale), and how well their brains recovered by looking at MRI scans.   

The researchers said they used CD34+ stem cells because they had improved functional recovery in non-human models of ischaemic stroke by promoting blood vessel and nerve cell growth.

The study was designed primarily to test safety and was not designed to prove whether the treatment significantly improves the lives of the participants with any rigour. Much larger trials involving treatment randomisation and control groups would be required for this.

 

What were the basic results?

The main results were:

  • All five patients reportedly tolerated the procedure well with no complications. There were no recurrent strokes and no nerve deterioration during the six-month follow-up period.
  • All patients showed improvements in the clinical ratings of how their stroke impaired their day-to-day functioning from the start of the trial and six months later.
  • The size of the areas of damage assessed by MRI scan reduced in all patients over the six months by 10% to 60%. The average change was 28% at six months' follow-up.
  • There were no signs of tumour growth or blood vessel malformation, which is a potential side effect of injecting stem cells.

 

How did the researchers interpret the results?

The researchers state they "have demonstrated in a phase I clinical trial that autologous CD34+ stem/progenitor cells [stem cells originating from a patient's own body], delivered directly into the middle cerebral artery within the first week of stroke symptoms, is both possible and safe."

They noted: "All patients showed improvements in clinical scores and reductions in lesion volume within six months. Although such patterns of recovery are well recognised in the usual natural history of strokes, these findings are nevertheless reassuring for future trials of CD34+ cell therapy. In particular, we found no evidence of post-intervention stroke (ischaemic or haemorrhagic), vascular malformation or tumour."

 

Conclusion

This study provides evidence that a new technique using a patient's own stem cells to aid the recovery from severe ischaemic stoke is feasible and appears to be safe. It was not designed to test whether the technique was better than doing nothing or better than other types of care or treatment.

The authors are perfectly clear that this "proof-of-concept study was not designed with a control group or powered to be able to detect efficacy". This means we cannot be sure that the improvements seen in the five patients were caused by the stem cell treatment. They could have occurred anyway as part of the natural path of recovery after a stroke – a point made by the authors.

A much larger trial that compares this stem cell treatment with the best available current care is needed to prove its effectiveness.

It may surprise some people to learn that a trial of a new treatment did not actually set out to test whether the treatment worked. This is normal in the sequence of treatment development.

When researchers find a new potential treatment, usually through animal research, they then need to demonstrate that the treatment is feasible to carry out in humans and, most importantly, that it is safe.

To do this, they typically recruit a small number of people and monitor them intensely – as happened in this study. If the treatment is deemed feasible and safe in this small group, they can design larger trials, which aim to both optimise the treatment and prove that it works.

This well-worn path of treatment development is often long and costly, but is designed to protect patients from potentially harmful treatments and weeds out ineffective treatments.

In a press release, the research team say they aim to develop a drug based on this technology, rather than performing the time-consuming bone marrow extraction, purification and injection steps.

They hope that giving the treatment quickly, and in drug form, is more likely to improve patients' chances of recovery than slower alternatives. To do this, they hope to isolate the biological factors secreted by the stem cells and harness these into a drug.

This could be stored in a hospital to be given quickly to a person admitted to A&E after a diagnosis of stroke. This could potentially shorten the treatment time from days to hours.

However, we should not ignore the fact this latest technique was well tolerated and did not appear to lead to any side effects in the six months it was evaluated – a promising result for the patients and researchers involved. The next test will be to see if it works, and how it compares to other treatments and standard care.

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

Links To The Headlines

'Stem cells show promise in stroke recovery'. BBC News, August 9 2014

Study may help victims of stroke. Daily Mail, August 9 2014

Links To Science

Banerjee S, et al. Intra-Arterial Immunoselected CD34+ Stem Cells for Acute Ischemic Stroke. Stem Cells Translational Medicine. Published online August 8 2014

Categories: NHS Choices

Restaurant dining 'as calorific as fast food'

NHS Choices - Behind the Headlines - Fri, 08/08/2014 - 13:00

"Eating in restaurants no better than fast food for health," reports The Daily Telegraph after the publication of a study on the calorie intake of eating out.

The US study found people who enjoyed dining at a full-service restaurant consumed just as many calories as those who ate fast food.

Researchers looked at the diets of more than 12,500 Americans and found those who dined out at fast-food restaurants ate 205 calories more than those who ate at home. Those eating out at non-fast-food restaurants were not far behind, at 194 calories extra calories. 

In an interview with The Daily Telegraph, lead study author Dr Binh Nguyen suggested restaurant food was higher in calories than home-cooked food because "they have more energy-dense foods and bigger portions".

However, this seems speculative as the study didn't report  portion size, making it difficult to know what diners were eating and in what quantity. This missing piece of information is important as it has the potential to significantly influence the study's findings.

In the UK, the average person eats one in every six meals outside the home and we consume up to a quarter of our calories when eating out, according to the Food Standards Agency.

Eating out has been linked to a higher risk of being overweight or obese, which increases the risk of weight-related diseases such as cardiovascular disease and diabetes.

For those who want to maintain a healthy weight, being aware of different sources of energy from food and drink may help you achieve your weight-related goals.

This includes awareness of the possible impact of eating away from the home often, where a person has less direct control over their calorie consumption compared with a home-cooked meal.

For more help and advice on healthy living, check out the NHS Choices healthy eating section.

 

Where did the story come from?

The study was carried out by researchers from the American Cancer Society and the School of Public Health at the University of Illinois, and was funded by the US National Heart, Lung and Blood Institute.

It was published in the peer-reviewed journal, Public Health Nutrition.

The media generally reported the story accurately, although few explored the potential limitations of the study.

 

What kind of research was this?

This was a cross-sectional analysis of data collected from a large US cohort study looking at whether eating away from the home influenced the number of calories people consumed in a day.

The research authors highlight that, in line with rising rates of obesity in the US, there has been a marked upward trend in total energy intake derived from food consumed away from home.

Given the large and increasing numbers of people eating away from home, the researchers wanted to assess the effect of fast-food and full-service restaurant consumption on adults' energy intake and dietary indicators.

 

What did the research involve?

The study recruited non-pregnant adults aged from 20 to 64 who were taking part in a large US nationally representative study called the National Health and Nutrition Examination Survey between 2003 and 2010.

Participants completed two dietary interviews on non-consecutive days, where they reported all foods and beverages consumed in the previous 24 hours. Based on this information, calorie consumption – a measure of the energy content of food and drink – was estimated.

The survey participants were also asked about the source of each food and beverage item in terms of where it came from – for example, from a shop, fast-food restaurant or full-service restaurant.

The full sample included 12,528 people, who completed dietary recall interviews on both days. Those with missing data were excluded from the results.

The main analysis compared the calorie intake of people who reported eating out at fast-food restaurants or full-service restaurants with those who reported eating at home. They also analysed sugar, salt and fat intake.

 

What were the basic results?

The main result was that eating at fast-food and full-service restaurants was associated with consuming more calories.

Fast-food and full-service restaurant consumption was associated with an increase in daily total energy intake of 194kcal and 205kcal respectively, and higher intake of saturated fat (3.48g and 2.52g) and salt (296.38mg and 451.06mg).

Black adults consumed more calories from eating out compared with their white and Hispanic counterparts, the study found. The same was true for middle-income compared with high-income adults.

 

How did the researchers interpret the results?

The study authors found that "adults' fast-food and full-service restaurant consumption was associated with higher daily total energy intake and poorer dietary indicators".

They observed that people did not compensate for this calorie surplus by reducing their energy intake over the rest of the day, which meant their overall calorie intake was higher on days when they ate out.

 

Conclusion

This large study of US adults suggests people eating away from home consume around 200 extra calories compared with people eating at home in any single day. The added calories associated with eating out were similar, regardless of whether people went to a full-service restaurant or a fast-food restaurant.

While the broad conclusions of the study are perfectly plausible, there are a number of limitations to be aware of.

The information on diet came from asking people to recall what they ate in the previous 24 hours, which might be prone to error. People can over or underestimate their food intake and portion size, which would influence the calorie consumption calculation and potentially bias the results.

The analysis did not take into account physical activity levels, so in theory people may have been able to burn off some of the added calories associated with eating out. Related to this, people may eat more after being physically active because of an increase in appetite.

The point is that calories consumed are only one side of the weight equation, the other side being calories burned. We therefore cannot tell whether these added calories actually contributed to long-term weight gain or an increase in disease risk.

The study did not report what the people ate or their portion size, as they were eating outside the home. There was also not enough information to glean details about what types of restaurant food might be better or worse for adding calories.

The study was based in the US, and although the UK diet is similar, there may be important differences in terms of the type of restaurant food and portion size, which means the study's results are less applicable to people in the UK.

However, we should not be complacent as many trends and findings in the US are applicable to the UK in many ways.

Overall, this study serves to remind anyone conscious of their weight to be aware of the potential effects of eating out regularly.

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

Links To The Headlines

Eating out IS worse for your waistline than dining at home: Average restaurant meal contains 200 extra calories - regardless of whether it's fast food or fine dining. Mail Online, August 8 2014

Eating in restaurants no better than fast food for health. The Daily Telegraph, August 8 2014 

Links To Science

Nguyen BT and Powell LM. The impact of restaurant consumption among US adults: effects on energy and nutrient intakes. Public Health Nutrition. Published online July 30 2014

Categories: NHS Choices

Dieting leaves some people 'feeling depressed'

NHS Choices - Behind the Headlines - Fri, 08/08/2014 - 12:26

"It's official; dieting does make us depressed," laments the Mail Online, following the publication of a study on how losing weight affects a person’s mood.

A study of 1,979 overweight and obese people found that those who lost 5% of their bodyweight were nearly twice as likely to feel some symptoms of depression, compared with those who stayed a similar weight.

As expected, it found that losing weight reduced the risk of high blood pressure and lowered levels of fats in the blood, thereby benefiting their health.

However, people who lost weight over the course of the four-year study were 78% more likely to report feelings of being in a “depressed mood” compared with participants whose weight remained stable.

Despite the headlines, the study did not prove that weight loss caused a depressed mood, as the weight loss and the change in mood occurred over the same time period.

Further studies will be needed to establish whether weight loss can cause a depressed mood.

How participants lost weight was not reported, so we can’t tell if they followed any particular diet or physical activity regime that lowered their mood. As a result, the Daily Mail’s headline of  “Dieting DOES make us depressed – even though we're healthier” is not justified, based on this study.

Overall, this study suggests that spontaneous weight loss is beneficial for people’s health, but the psychological effects are less clear – and potentially negative. These results may be worthy of further investigation.

 

Where did the story come from?

The study was carried out by researchers from University College London (UCL). It was funded by the National Institute on Aging and a consortium of UK government departments coordinated by the Office for National Statistics (ONS).

The study was published in the peer-reviewed science journal PLOS One, with the full article free to read online.

The assertion that it is “official” that “Dieting DOES make us depressed – even though we're healthier” is not justified based on this study. This is because the study did not assess depression, and we have no evidence that the people went on a diet to lose weight. They could equally have eaten the same foods as they usually do and increased their exercise a little. How the people lost weight was not reported. 

 

What kind of research was this?

This was a cohort study looking into the physical and psychological effects of weight loss in overweight or obese adults aged 50 years or older.

The researchers flag up how weight-related diseases, such as diabetes and cardiovascular disease, are on the rise, with health organisations worldwide advising overweight and obese adults to reduce their body weight. The physical benefits of weight loss are well established, but the psychological benefits are less clear.

Studies on individuals have found positive psychological benefits, but large population studies have not. This, the authors thought, might be due to the inclusion of healthy-weight individuals who have never had to lose weight.

The research group decided to examine changes following weight loss in a cohort of exclusively overweight/obese adults, to see whether there were psychological gains masked in previous studies.

 

What did the research involve?

The team collected information from 1,979 overweight and obese adults (BMI equal to or higher than 25kg/m2; age 50 and above), free of long-standing illness or clinical depression at baseline, recruited from the English Longitudinal Study of Ageing. During a four-year period, researchers monitored their weight, blood pressure and the level of lipids (fatty substances) in their blood, as well as their mood and wellbeing.

The main analysis looked at whether there were any differences in psychological measures between those who lost weight, compared to those who didn’t.

Participants were grouped according to four-year weight change:

  • participants losing 5% or more in weight
  • participants gaining 5% or more
  • participants whose weight didn’t move up or down by more than 5%

The main measures of psychological wellbeing used were:

  • depressed mood (eight-item Center for Epidemiologic Studies Depression score four or more, includes questions like "Over the last week have you felt sad?" with yes/no response options)
  • low wellbeing (scoring less than 20 on the Satisfaction With Life Scale score)

The main measures of physical wellbeing and disease risk used were:

  • hypertension (systolic blood pressure equal or above140 mmHg or taking anti-hypertensives)
  • high triglycerides (equal or above1.7 mmol/l)

The main analysis controlled for the effects of age, sex, wealth, weight loss intention, major life events that might be stressful, and impact on weight and wellbeing, as well as their health at the start of the study.

 

What were the basic results?

Around 15% of people in the overweight and obese group lost 5% or more of their bodyweight over the four-year period, and a similar proportion gained 5% or more. The vast majority, however, remained a similar weight.

Psychological wellbeing deteriorated (increased rates of depressed mood and low wellbeing) between the start of the study and follow-up across all three-weight change groups.

People who lost 5% or more of their body weight were nearly twice (78%) as likely to report feelings of a depressed mood compared to those whose weight remained stable (odds ratio [OR] = 1.78 [95% CI 1.29– 2.47]). When this was adjusted for the effect of life events the odds ratio fell slightly to OR 1.52, 95% CI 1.07 to 2.17).

The proportion of adults with low wellbeing also increased more in the weight loss group, but the difference was not statistically significant (OR = 1.16, 95% CI 0.81–1.66). In some of the subsequent analysis, weight loss was significantly linked to a lower wellbeing.

Hypertension and high triglyceride prevalence decreased in weight losers and increased in weight gainers (OR = 0.61, 95% CI 0.45–0.83; OR = 0.41, 95% CI 0.28–0.60).

The same results were observed when the researchers accounted for illness and life stress during the weight loss period.

 

How did the researchers interpret the results?

The researchers concluded that “weight loss over four years in initially healthy overweight/obese older adults was associated with reduction in cardio-metabolic risk, but no psychological benefit, even when changes in health and life stresses were accounted for. These results highlight the need to investigate the emotional consequences of weight loss.”

 

Conclusion

This study indicates that overweight or obese people aged over 50 who lose more than 5% or their body weight over four years reap physical benefits, but do not appear to reap psychological benefits; in fact they had worse ratings of “depressed mood” than the people who maintained a stable weight.

The study population is broadly representative of the UK population over the age of 50, and the analysis was appropriate. However, there are limitations to consider when interpreting these findings.

Firstly, the reasons behind the weight loss were not documented – e.g. spontaneous increase in exercise or referral from GP to a weight loss programme. Some reports in the media suggested the low mood might be due to the punitive diets some people might be trying in order to lose weight. However, without more information on the nature and cause of the weight loss, this is pure speculation.

The researchers usefully highlighted the three possible explanations of their results – all of which are plausible, and none can be completely confirmed or dismissed based on this study alone.

  1. weight loss causes depressed mood
  2. depressed mood causes weight loss
  3. weight loss and depressed mood share a common cause

In terms of point one, the authors note that long-term maintenance of weight loss is notoriously hard, with many people failing to keep the weight off. They speculate that this may be a sign of personal costs, strains and difficulties in achieving this, which could affect a person’s mood. This suggests a plausible but unproven mechanism by which weight loss could be a psychological challenge influencing mood and wellbeing. 

In terms of point two, depressed mood may cause weight loss directly or indirectly through changes in appetite or level of physical activity. The design of the study means it was not possible to establish which came first: weight loss or depressed mood..

In terms of point three, some of the obvious common causes of weight loss and low mood include major life events, such as separation or divorce from a partner, or developing an illness – both of which were covered in the analysis. Even though these factors were partially ruled out as a common cause, we cannot rule out other factors as a potential explanation for the results.

Like all cohort studies, some factors may not have been accounted for or may not have been properly measured. A potential confounder in the present study, as noted by the authors, was the presence of underlying disease causing both weight loss and depressed mood. The analysis adjusted for limiting long-standing illness, but this was self-reported rather than diagnosed, so may not be a wholly accurate measure of health status.

Overall, this study suggests that spontaneous weight loss is beneficial for people’s health, but the psychological effects are less clear, and potentially negative. These results may be worthy of further investigation.

 

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

Links To The Headlines

It's official: Dieting DOES make us depressed - even though we're healthier. Mail Online, August 6 2014

Weight loss 'no mood boost even with health benefits'. BBC News, August 6 2014

Links To Science

Jackson SE, Steptoe A, Beeken RJ, et al. Psychological Changes following Weight Loss in Overweight and Obese Adults: A Prospective Cohort Study. PLOS One. Published online August 6 2014

Categories: NHS Choices

Lack of vitamin D may 'raise dementia risk'

NHS Choices - Behind the Headlines - Thu, 07/08/2014 - 18:05

People lacking in vitamin D have a higher risk of developing dementia report several media outlets, including BBC News and The Independent.

A study found people severely lacking in the sunshine vitamin were twice as likely to develop dementia and Alzheimer's disease compared with people with healthy levels (50nmol/l or more).

The findings are based on a study of more than 1,650 people aged 65 and above who were followed over a period of about six years to see if they developed dementia.

Researchers found the higher the vitamin D deficiency, the higher the risk of developing dementia and Alzheimer's disease.

They found severe vitamin D deficiency (less than 25nmol/l) is associated with approximately twice the risk of developing dementia or Alzheimer's disease.

Moderately low levels of vitamin D (between 25nmol/l and 50nmol/l) are associated with a 50% increase in risk.

This study was able to show an association between low levels of vitamin D and the risk of developing dementia. But it does not prove that vitamin D deficiency causes the disease.

Other factors that can increase the risk of developing dementia, including a poor diet, lack of activity and general poor health, can also cause a low vitamin D level.

More research is needed to establish whether eating vitamin D-rich foods, such as oily fish, or taking vitamin D supplements could delay or even prevent dementia.

 

Where did the story come from?

The study was carried out by researchers from the University of Exeter Medical School in the UK, Angers University Hospital in France, and Florida International University, Columbia University, the University of Washington, the University of Pittsburgh, the Veteran Affairs Ann Arbor Center for Clinical Management Research, and the University of Michigan in the US.

This study used data on people taking part in the Cardiovascular Health Study, a cohort study that aimed to investigate the underlying causes of cardiovascular disease.

It was funded by the UK National Institute for Health Research (NIHR) Collaboration for Leadership in Applied Health Research and Care (CLAHRC) for the South West Peninsula.

The study was published in the peer-reviewed journal Neurology and is free to read on the journal's website.

The news coverage was broadly accurate, with a number of stories including quotes from the researchers and other experts pointing out these results do not demonstrate low vitamin D levels cause dementia – they only show an association.

 

What kind of research was this?

This was a prospective cohort study that aimed to determine whether low levels of vitamin D are associated with an increased risk of dementia and Alzheimer's disease.

Cohort studies can show an association, but cannot show low vitamin D levels cause dementia or Alzheimer's disease. This is because there could be other factors responsible for the link seen. Large clinical trials are required to prove increasing vitamin D levels reduces the risk of dementia.

 

What did the research involve?

The researchers studied 1,658 people aged 65 or older who were taking part in a US-based cohort study that aimed to investigate the underlying causes of cardiovascular disease. None of the participants had dementia, heart disease or stroke at the start of the study in 1992.

Blood samples were collected at the start of the study. Researchers used the samples to measure vitamin D levels. They divided people into three categories:

  • severely deficient (vitamin D concentration less than 25nmol/l)
  • deficient (vitamin D concentration between 25nmol/l and 50nmol/l)
  • sufficient (vitamin D concentration 50nmol/l or higher)

The participants were followed for an average of 5.6 years. The researchers looked at whether these people developed dementia or Alzheimer's disease.

A committee of neurologists and psychiatrists reviewed annual brain function tests, brain scans, medical records, questionnaires and interviews, and diagnosed dementia or Alzheimer's disease according to international criteria set by the National Institute of Neurological and Communicative Diseases and Stroke/Alzheimer's Disease and Related Disorders Association.

The researchers compared the risk of developing dementia, including Alzheimer's disease, between people with severely deficient or deficient vitamin D levels and people with sufficient vitamin D levels.

The researchers adjusted their analyses for age, the time of year when vitamin D concentration was measured, education level, sex, body mass index (BMI), smoking status, alcohol consumption and depressive symptoms.

 

What were the basic results?

One hundred and seventy one people developed dementia or Alzheimer's disease during the study. This is equivalent to 10% of the cohort studied.

People with severely deficient or deficient vitamin D concentrations were at an increased risk of developing dementia or Alzheimer's disease:

  • severely deficient vitamin D levels were associated with a 125% increased risk of developing dementia or Alzheimer's disease (hazard ratio [HR] 2.25, 95% confidence interval [CI] 1.23 to 4.13)
  • deficient vitamin D levels were associated with a 53% increased risk of developing dementia or Alzheimer's disease (HR 1.53, 95% CI 1.06 to 2.21)

The researchers also looked at the risk of developing Alzheimer's disease in particular, a common type of dementia. People with severely deficient or deficient vitamin D concentrations were also at an increased risk of developing Alzheimer's disease:

  • severely deficient vitamin D levels were associated with a 122% increased risk of developing Alzheimer's disease (HR 2.22, 95% CI 1.02 to 4.83)
  • deficient vitamin D levels were associated with a 69% increased risk of developing Alzheimer's disease (HR 1.69, 95% CI 1.06 to 2.69)

The researchers repeated their analyses after excluding people who developed dementia or Alzheimer's disease within the first year of the study.

They did this because it has been suggested that people who develop these conditions may change their diet or reduce their outdoor activity, and that might be responsible for the association seen between low vitamin D levels and dementia and Alzheimer's disease.

In this study, the researchers found the association between low vitamin D levels and dementia or Alzheimer's disease remained after the exclusion of people who developed these conditions within one year.

 

How did the researchers interpret the results?

The researchers concluded: "Our results confirm that vitamin D deficiency is associated with a substantially increased risk of all-cause dementia and Alzheimer's disease. This adds to the ongoing debate about the role of vitamin D in non-skeletal conditions."

 

Conclusion

This cohort study of more than 1,650 elderly people has found that over 5.6 years, severe vitamin D deficiency is associated with approximately twice the risk of developing dementia or Alzheimer's disease.

It also found moderate deficiency is associated with a 50% increase in risk compared with healthy levels of vitamin D.

With this being a cohort study, it was not able to show that low levels of vitamin D caused dementia or Alzheimer's disease – it was simply able to show an association.

Other factors that can increase the risk of developing dementia, such as a poor diet, lack of activity and general poor health, can also cause a low vitamin D level.

A further limitation of this study is that the blood samples were only tested for vitamin D levels once. It is not known if any of the participants knew they were deficient and therefore took vitamin supplements during the study period, which could have influenced the results.

Severe vitamin D deficiency can lead to symptoms of lethargy, bone pain, headaches and difficulty concentrating, so it is also conceivable the deficiency was picked up in a number of these people and treated.

More research is needed to establish whether eating vitamin D-rich foods, such as oily fish, or taking vitamin D supplements could delay or even prevent dementia.

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

Links To The Headlines

Low vitamin D 'boosts dementia risk'. BBC News, August 7 2014

Lack of vitamin D raises risk of dementia in later life. Mail Online, August 6 2014

Vitamin D: low levels 'can double dementia risk'. The Independent, August 6 2014

Alzheimer's risk doubles with lack of vitamin D - and upping intake could PREVENT disease. Mirror, August 6 2014

Links To Science

Littlejohns TJ, Henley WE, Lang IA, et al. Vitamin D and the risk of dementia and Alzheimer disease. Neurology. Published online August 6 2014

Categories: NHS Choices

Salt content in cheese 'too high', say campaigners

NHS Choices - Behind the Headlines - Thu, 07/08/2014 - 11:20

"Halloumi and blue cheese saltier than seawater,” reports The Daily Telegraph, following the publication of research on the salt content of cheeses sold in the UK.

Researchers looked at 612 supermarket cheeses and found that salt levels were high. They also found a wide variation in salt content within the same types of cheese.

Halloumi and imported blue cheese contained the highest average amount of salt (2.71g/100g), more salty than seawater (2.5g/100g), whereas cottage cheese contained the lowest average amount of salt (0.55g/100g).

Some types of cheddar – Britain’s best-selling cheese – had much higher levels of salt than others, with supermarket own brands having lower average levels than branded counterparts.

Cheese is one of the top 10 sources of salt in our diet and is widely consumed, with the average person eating 9kg of cheese a year.

Eating too much salt can cause high blood pressure, which can lead to heart disease, stroke and chronic kidney disease.

However, salt is an integral part of the cheese-manufacturing process. It controls moisture, texture and functionality, and also controls microbial growth.

The government has issued voluntary salt targets for specific categories of cheese, to encourage manufacturers to lower their salt content.

This study found that 84.5% of the cheeses in these categories have achieved their target. Unsurprisingly, it found that cheeses without a target had a higher salt content.

Researchers say the salt content in cheese is “unnecessarily high” and are calling for “more challenging salt reduction targets to be set”.

 

Where did the story come from?

The study was carried out by researchers from the Centre for Environmental and Preventive Medicine at Barts, and the London School of Medicine and Dentistry. All researchers are employees, members or the chairman of Consensus Action on Salt and Health (CASH), a non-profit organisation set up in 1996. The study reports that it did not receive funding from any funding agency in the public, commercial or not-for-profit sectors.

The study was published in the peer-reviewed medical journal BMJ Open. It is free to read on the journal's website.

The media’s coverage of the study was generally accurate.

 

What kind of research was this?

This was a cross-sectional survey looking at the salt content of different cheeses sold in UK supermarkets. It aimed to assess whether the salt content had fallen since the government set voluntary targets for some types of cheese.

Eating too much salt puts pressure on the kidneys and can cause high blood pressure. This can lead to heart disease, stroke and chronic kidney disease. High salt intake has also been linked to increased risk of stomach cancer and osteoporosis.

Adults should have no more than 6g of salt per day, according to UK recommendations, although the World Health Assembly has agreed that the target should be for people to consume up to just 5g per day. Current UK consumption levels stand at 8.1g per day. Salt content over 1.5g per 100g in any food is considered high, according to government guidance.

Many cheeses are known to have a high salt content, and on average, the report states that people in the UK consume 9kg of cheese per year. It is therefore important to know which cheeses have a high salt content, so they can be eaten sparingly as part of a balanced diet.

 

What did the research involve?

The researchers surveyed all available cheeses from seven main supermarket chains in the UK by each visiting one large shop. The supermarkets were Asda, Marks & Spencer, Sainsbury’s, Tesco, The Co-operative and Waitrose. Due to resource limitations, only cheddar cheese and cheddar-style cheese products were collected from Morrisons.

They recorded the product name, sodium/salt per 100g, serving size and sodium/salt per portion from the label of each cheese. They categorised and analysed them according to 23 types of cheese, their country of origin, their brand and whether they were on the UK Department of Health's cheese salt reduction target list.

They excluded any cheese that did not have a sample size of at least eight products containing nutrient information on the packaging. This included Jarlsberg, mascarpone, Lancashire, Leerdammer, Maasdam, sheep, Appenzeller, Bavarian smoked and ricotta.

 

What were the basic results?

A total of 612 cheeses were included in the analysis. Halloumi and imported blue cheese had the highest average salt level (2.71g/100g) - saltier than seawater (2.5g/100g) according to CASH followed by some processed cheeses (2.48g/100g). Cottage cheese had the lowest (0.55g/100g).

There was a wide variation in salt content within each category of cheese, and this was particularly marked for parmesan, imported blue cheeses and Emmental.

Cheeses with salt targets had lower levels of salt than those without, and of the 394 cheeses that have voluntary cheese targets, 84.5% have already met their 2012 target.

The salt content of supermarket own-brand cheese was compared with branded cheese for 10 categories of cheese, and researchers found that:

  • Six classes of cheese had higher salt content in branded products than the supermarket's own brand.
  • Four classes of cheese had a higher salt content in the supermarket's own brand compared to a branded version.

 

How did the researchers interpret the results?

“Cheese is unnecessarily loaded with salt,” researchers said in an editorial released with the study. They state in their report that “salt content in cheese in the UK is high. There is a wide variation in the salt content of different types of cheeses and even within the same type of cheese”. Even though 84.5% cheeses are within the voluntary salt targets, researchers say their findings “demonstrate that much larger reductions in the amount of salt added to cheese could be made and more challenging targets need to be set, so that the UK can continue to lead the world in salt reduction”.

 

Conclusion

This study highlights the wide variation in salt content that can be found in cheese. Labelling is now making it easier to make an informed choice regarding where you wish your maximum recommended level of 6g of salt per day to come from. This is particularly important when assessing which cheese is the best option for children, who should consume lower levels of salt.

The study showed that there were many types of cheese that have a reasonably low salt content, including cottage cheese, cream cheese, mozzarella and Emmental. However, cheese is generally calorific, and over-consumption can lead to overweight and obesity and their associated health problems. 

A limitation of this study is that the actual salt content was not independently assessed, but relied on the accuracy of the labels. The authors also acknowledge that they did not investigate how the reduction in salt has been achieved, and there is the possibility that it has been replaced by other additives or ingredients.

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

Links To The Headlines

Concern over salt levels in cheese. Mail Online, August 6 2014

Halloumi and blue cheese saltier than seawater. The Daily Telegraph, August 7 2014

Branded blue cheese and halloumi are 'saltier than seawater'. The Independent, August 6 2014

Cheese too salty and a risk to public health, study finds. The Guardian, August 6 2014

Links To Science

Hashem KH, He FJ, Jenner KH, MacGregor GA. Cross-sectional survey of salt content in cheese: a major contributor to salt intake in the UK. BMJ Open. Published online August 7 2014

Categories: NHS Choices

Saturated fat in dairy 'may protect against diabetes'

NHS Choices - Behind the Headlines - Wed, 06/08/2014 - 15:00

Saturated fat in cheese, yoghurt and other dairy products may protect against diabetes, report the Mail Online, The Daily Telegraph and The Independent.

A study has found that people with higher levels of the types of saturated fatty acid found in dairy products were less likely to develop type 2 diabetes.

Saturated fat – found in butter, cheese and red meat – is generally considered unhealthy and linked to high levels of cholesterol and heart disease, as well as type 2 diabetes.

Researchers looked at blood samples that had been taken from 12,132 people before they developed type 2 diabetes, and compared them with samples obtained from 15,164 healthy people who did not go on to develop diabetes. All participants were from across Europe.

Different types of saturated fat can be identified by looking for chain-like saturated fatty acid molecules, which contain either an odd or even number of carbon atoms.

Analysis of the samples revealed that people with higher levels of “even-chain” fatty acids were more likely to develop diabetes.

Even-chain saturated fatty acids were more likely with diets high in alcohol, soft drinks, margarine and potatoes, although the body can also produce this type of fatty acid.

People with higher levels of “odd-chain” fatty acids in their blood samples were less likely to develop the condition.

Odd-chain saturated fatty acids were more likely through diets high in dairy products, cakes and cookies, nuts and seeds, and fruit and vegetables.

Overall, this study can only tell us that there is an association between the levels of these fatty acids and the risk of developing diabetes – it cannot prove they had a role in causing the condition.

This study furthers understanding of the biological processes that may be associated with type 2 diabetes, but it cannot say that eating dairy is going to cut your risk of this getting chronic disease. 

Despite this, the increased risk from a larger waist circumference, being overweight or obese mean that the amount you eat still needs to be balanced to avoid excess weight gain.

 

Where did the story come from?

The study was carried out by researchers from the University of Cambridge, MRC Human Nutrition Research in Cambridge, the University of Oxford and other universities across Europe. It was funded by the European Commission, the Medical Research Council and the Cambridge Lipidomics Biomarker Research Initiative.

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

This study was not accurately reported by most media outlets. Contrary to several  reports, the study did not prove that saturated fat from dairy products are not bad for health or that they “beat” diabetes. It only showed that a people with a one-off reading of a higher proportion of these types of fats compared to other saturated fats had a reduced risk of developing diabetes. It did not look at any other health outcomes related to dietary intake of dairy products.

The study was also not able to say that people with higher levels of the even-chain saturated fatty acids will develop diabetes, it is only able to show an increased risk.

 

What kind of report was this?

This was a prospective case-cohort study, which looked at the blood levels of different types of saturated fat in people who developed diabetes, compared to a control group who did not develop diabetes over the next 16 years.

They aimed to see if there was a link between any of the nine different types of saturated fatty acids that they measured and type 2 diabetes. As this was a cohort study, it can only show an association between with the levels and the risk of developing diabetes during the study's timeframe. It cannot prove causation.

 

What did the research involve?

The researchers used data from a large study called the EPIC cohort, which followed 340,234 people from eight European countries from 1991 to 2007. From this study, they identified all 12,132 people who did not have a diagnosis of diabetes at the beginning of the study, but who developed diabetes at some point during the 16-year follow-up.

They also randomly selected 15,919 people who did not develop type 2 diabetes. All participants had provided a blood sample at the beginning of the study. They worked out which of these people developed diabetes during the study period from at least two of the following sources: self-report, primary care and secondary care registers, drug registers, hospital admissions and mortality data. This gave them a subgroup of 15,164 people who did not develop type 2 diabetes.

The average age of the participants was 52.

From the blood sample, they measured the levels of nine different types of saturated fatty acids and HbA1C, which is an indicator of type 2 diabetes.

Participants’ weight and height were measured by trained professionals to calculate BMI, and most participants also had their waist size measured. The participants filled in questionnaires on medical history, smoking status, educational level, physical activity level and usual diet over the previous 12 months.

They compared the levels of the different types of saturated fatty acids in the group of people who developed diabetes, compared to those who did not.

 

What were the basic results?

Higher proportions of even-chain saturated fatty acids were associated with a 43% increased risk  of type 2 diabetes, hazard ratio (HR) 1.43 (95% confidence interval (CI) 1.29 to 1.58). There was also a higher proportion in older adults, people with higher BMI and men. Higher even-chain saturated fatty acids were more likely with diets higher in alcohol, soft drinks, margarine and potatoes, and less likely with fruit, vegetables, olive oil and vegetable oil.

Higher proportions of odd-chain saturated fatty acids (mainly from dietary dairy fat intake) were associated with a 30% reduced risk of developing type 2 diabetes, HR 0.70 (95% CI 0.66 to 0.74). The proportion was also higher in people with a lower BMI and women. Higher odd-chain saturated fatty acids were more likely with diets higher in dairy products, cakes and cookies, nuts and seeds, and fruit and vegetables.

Higher proportions of longer-chain saturated fatty acids were associated with a 30% reduced risk of type 2 diabetes, HR 0.70 (95% CI 0.59 to 0.85). Little is known about these fatty acids, but they were associated with a lower alcohol intake.

The results remained significant after taking into account multiple potential confounding factors, such as age, BMI and waist size.

 

How did the researchers interpret the results?

The researchers concluded that odd-chain fatty acids, which mainly come from dairy fat in the diet, are associated with a decreased risk of developing type 2 diabetes. However, they point out that they were not able to rule out the possibility that this association was due to other nutrients present in dairy products, such as vitamin D, calcium or the fermentation process of dairy products.

They also found that even-chain fatty acids are associated with an increased risk of developing type 2 diabetes, but this relationship is more complex and not just related to diet. Even-chain fatty acids can come from a variety of places and not just dietary fat, such as carbohydrates and alcohol, and they can also be produced by the body.

Researchers say further research is required to gain a better understanding of the role of diet in this process before they can confidently advise on dietary intake of saturated fats.

Finally, they report that little is known about the origin or production of longer-chain fatty acids, and they suggest that this should be another area for future research.

 

Conclusion

This study has found an association between higher levels of odd-chain and long chain fatty acids, and a reduced risk of developing diabetes. Higher levels of even-chain fatty acids were associated with an increased risk of developing diabetes.

Strengths of the study include:

  • the large number of participants and diversity, coming from eight European countries
  • a wide range of diets
  • prospective nature of the study, capturing blood levels before diabetes onset
  • diabetes status was not determined by self-report only

However, limitations of the study include:

  • The blood measurement of the saturated fatty acids did not measure the overall amount of saturated fatty acids in the blood, it just looked at the proportion of the different types of saturated fatty acids in each individual. This means that some people may have had high overall levels of saturated fatty acids and some could have had low levels.
  • The blood sample was only taken once at the beginning of the study, and this may not have been representative of normal levels, which fluctuate through diet and activity levels.
  • Reliance on dietary questionnaires being completed accurately.

This study suggests that not all saturated fat may be bad and that the type of dietary saturated fats influence the risk of diabetes, but it does not conclusively show that dairy products are protective. Whatever the case, the increased risk from a larger waist circumference, as well as being overweight or obese, mean that the amount you eat still needs to be balanced to avoid excess weight gain.

 

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

Links To The Headlines

Say cheese: saturated fat in dairy may protect against diabetes. The Daily Telegraph, August 6 2014

Saturated fats that actually BEAT diabetes: Molecules found in some dairy items including yoghurts can cut Type 2 risk. Mail Online, August 6 2014

Some saturated fats could help protect against type 2 diabetes, study finds. The Guardian, August 6 2014

Links To Science

Forouhi NG, Koulman A, Sharp SJ, et al. Differences in the prospective association between individual plasma phospholipid saturated fatty acids and incident type 2 diabetes: the EPIC-InterAct case-cohort study. The Lancet Diabetes and Endocrinology. Published online August 6 2014

Categories: NHS Choices

Daily aspirin 'reduces cancer risk,' study finds

NHS Choices - Behind the Headlines - Wed, 06/08/2014 - 10:39

Taking aspirin every day could cut your risk of developing cancer, report BBC News and The Daily Telegraph among other news outlets, after the publication of a large-scale review of the evidence.

People aged between 50 and 65 who take aspirin every day for 10 years could cut their risk of bowel cancer by 30% and cancers of the throat and stomach by 25%, according to the study published in the Annals of Oncology.

Over 20 years, an aspirin a day would reduce people's risk of heart attacks by 7%, stroke by 9%, and dying prematurely by about 4%. 

Aspirin is an antiplatelet, which means it reduces the risk of clots forming in your blood. Platelets may also protect cancer cells in the body, and it has been suggested aspirin's effect on them may hinder this process. However, the exact mechanism is not well understood and more research is needed.

Taking aspirin every day comes with a serious health warning as it can cause serious side effects such as ulcers and bleeding from the stomach, particularly in elderly people.

However, the researchers argue the benefits of taking the drug need to be balanced against the harms. 

While the findings of this study show promise, it is not clear whether the methods used in compiling it were systematic, so the results may not be entirely reliable.

Anyone thinking of taking aspirin for prevention should talk to their GP first.

 

Where did the story come from?

The study was carried out by researchers from a number of institutions across Europe and the US, including Queen Mary University of London.

It was funded by Cancer Research UK, the British Heart Foundation and the American Cancer Society. The study was published in the peer-reviewed medical journal Annals of Oncology.

Several of the study's authors are consultants to or have other connections with pharmaceutical companies with an interest in antiplatelet agents such as aspirin.

As might be expected with cancer-related news, the research was widely covered in the press. Most of the coverage was uncritical, although most stories warned of the side effects of taking aspirin.

 

What kind of research was this?

This was a review of evidence on the association between aspirin and incidence of deaths from cancer and cardiovascular disease, and potential harmful side effects.

It is not clear whether this was a systematic review, where the evidence is rigorously appraised for its quality and risk of bias. The researchers did not carry out a meta-analysis of the results of studies included, but compiled their own estimates.

The authors say regular aspirin is known to reduce the incidence of cardiovascular disease both in the general population and in high-risk groups, although it is currently only recommended for those at high risk.

However, an increasing body of evidence suggests it may also have a role in cancer prevention. Aspirin is also associated with a risk of bleeding and peptic ulcers. The researchers argue the benefits of taking the drug need to be balanced against the harms.

 

What did the research involve?

Researchers gathered evidence on the effects of aspirin on cancer risk and cancer deaths from systematic reviews published between 2009 and 2012, as well as from some individual studies on specific cancers. Further systematic reviews undertaken by some of the researchers were not included, but were discussed at the "evidence review meeting".

It is not clear how these studies were chosen or whether further studies on the topic were excluded and, if so, what criteria were used to decide which studies to include or exclude.

Evidence for aspirin's effect on cardiovascular disease was taken from one large meta-analysis. The authors based their calculations of the effect aspirin would have on cardiovascular disease by using UK rates from 1998 for cardiovascular-related incidents and deaths, which they adjusted to take account of downward trends in recent years in both the UK and the US.

The researchers used a detailed unpublished analysis of the harmful effects of aspirin.

They calculated the overall benefits and harms for taking aspirin for 10 years, starting at ages 50, 55, 60 and 65, separately for men and women. They made several assumptions in their analysis:

  • the cardiovascular benefit and adverse effects only occur during active treatment (the 10-year period)
  • the protection against cancer begins three years after initiating aspirin and continues for an additional five years after stopping aspirin
  • the protection against cancer mortality begins five years after starting aspirin use and lasts for an additional 10 years after treatment is stopped
  • the protective effects are seen only in colorectal, oesophageal, gastric, breast, prostate and lung cancers

 

What were the basic results?

The researchers calculated that for average-risk individuals aged 50 to 65 taking aspirin for 10 years, there would be a relative reduction of between 7% (women) and 9% (men) in the number of cancer, myocardial infarction or stroke events over a 15-year period, and an overall 4% relative reduction in all deaths over a 20-year period.

Below are their calculations of the effect of aspirin in reducing the risk of cancers and cardiovascular events, giving what the researchers say are "conservative" estimates:

  • colorectal (bowel) cancer – 30% reduction in incidence and 35% reduction in deaths
  • oesophageal cancer – 25% reduction in incidence and 45% reduction in deaths
  • gastric cancer – 25% reduction in incidence and 30% reduction in deaths
  • lung cancer – no reduction in incidence, 10% reduction in deaths
  • prostate cancer – 5% reduction in incidence, 10% reduction in deaths
  • breast cancer – 5% reduction in incidence no reduction in deaths
  • heart attack – 18% reduction in incidence, 5% in deaths
  • stroke – 5% reduction in incidence, 21% increase in deaths

Their calculations on the risk of side effects from taking aspirin are:

  • major (extracranial) bleeding – 70% increase in incidence
  • gastric bleeding – 70% increase in deaths
  • peptic ulcer – 70% increase in deaths

They also say the effects are not apparent until at least three years after starting aspirin and some benefits may be sustained for several years after stopping.

They found no difference between low and high doses of aspirin in terms of health benefits, although there were no studies that did direct comparisons.

 

How did the researchers interpret the results?

The researchers say once aspirin's effect on cancer risk and mortality is taken into account, the benefits of taking aspirin outweigh the risks.

They calculate that to get any benefit, people need to start taking a daily dose of between 75 and 325mg for a minimum of five years. Longer use is likely to have greater benefits, they say.

Further research is needed to determine the optimum dose for taking aspirin and duration of use, and to identify those at increased risk of bleeding.

In an accompanying press release, lead author Professor Jack Cuzick of Queen Mary University of London said: "It has long been known that aspirin – one of the cheapest and most common drugs on the market – can protect against certain types of cancer.

"But until our study, where we analysed all the available evidence, it was unclear whether the pros of taking aspirin outweighed the cons.

"Whilst there are some serious side effects that can't be ignored, taking aspirin daily looks to be the most important thing we can do to reduce cancer after stopping smoking and reducing obesity, and will probably be much easier to implement."

 

Conclusion

While the findings on aspirin and cancer show promise, it is not clear that the results are reliable from the methods reportedly used to compile this review.

This is because it included studies of varying design and quality, with much of the evidence coming from observational studies, which, while useful, cannot be totally relied on to test the effectiveness of healthcare interventions.

It's not clear how the studies included in the review were chosen and whether others on the same topic were excluded. It is also not clear whether or not this was a systematic review, where studies are rigorously appraised for their quality and criteria are established for their inclusion.

Aspirin can cause major side effects such as bleeding from the stomach and peptic ulcers, particularly in older people. It's important to consult with your GP before deciding to take it regularly. 

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

Links To The Headlines

Daily aspirin 'cuts bowel and stomach cancer deaths'. BBC News, August 6 2014

Taking Aspirin daily significantly reduces risk of cancer new study finds. Mirror, August 6 2014

Aspirin should be taken by all over 50s to cut thousands of cancer deaths: study. The Daily Telegraph, August 6 2014

Miracle pill aspirin could even ward off major cancers: Long-term use of the drug can cut chance of developing disease by up to a third. Mail Online, August 5 2014

Daily dose of aspirin 'can cut the risk of cancer', says study. The Independent, August 6 2014 

Links To Science

Cuzick J, Thorat MA, Bosetti C, et al. Estimates of benefits and harms of prophylactic use of aspirin in the general population. Annals of Oncology. Published online August 5 2014

Categories: NHS Choices

Steep rise in antibiotic use for coughs and colds

NHS Choices - Behind the Headlines - Tue, 05/08/2014 - 15:00

GPs are still giving out antibiotics to treat coughs and colds, the Mail Online, The Daily Telegraph and BBC News report, as a study reveals efforts to curb antibiotic use has had "mixed success".

The study found the proportion of people with coughs and colds given antibiotics rose from 36% in 1999 to 51% in 2011: an increase of around 40%.

The rise comes amid warnings that the over-prescription of antibiotics could lead to the emergence of drug-resistant bacteria. 

Antibiotics are medications used to treat, and in some cases prevent, bacterial infections. They are ineffective at treating coughs and colds, which are usually viral infections.

Researchers from Public Health England (PHE) and University College London (UCL) looked at trends in the prescription of antibiotics in more than 500 UK GP surgeries between 1995 and 2011.

They focused on coughs and colds, sore throats, urinary tract infections (UTIs) and middle ear infections (otitis media), which are all subject to specific government recommendations to help curb antibiotic use.

Antibiotic use for sore throats fell between 1995 and 2011, although it was still high considering that approximately 90% of sore throats resolve without antibiotics. The recommended antibiotic for acute sore throat was given in the majority of cases.

The proportion of women prescribed antibiotics for UTIs who were prescribed the recommended short course increased, although there was variation between GP practices.

For middle ear infections, the proportion of cases that were prescribed an antibiotic was broadly unchanged over the study period, but the proportion of people who were prescribed the recommended antibiotic increased.

"The implementation of national guidelines in UK primary care has had mixed success," conclude the study's authors.

Prescriptions of antibiotics for coughs and colds are now "greater than before recommendations were made to reduce it".

The study also found significant variation in antibiotic use for these conditions between GP practices, suggesting that further improvements in antibiotic prescriptions could be made.

 

Where did the study come from?

The study was carried out by researchers from PHE, the Royal College of General Practitioners Research and Surveillance Centre, and UCL.

It was funded by the Health Protection Agency (HPA) and published in the peer-reviewed Journal of Antimicrobial Chemotherapy.

Generally, the media reporting of this story was accurate.

 

What kind of research was this?

This was a cross-sectional study that analysed trends in antibiotic prescription at 537 GP practices in the UK between 1995 and 2011.

The aim of this study was to examine and compare antibiotic use over time and see whether it was in line with recommendations.

Antibiotic prescription in line with recommendations is one of the strategies being implemented to try to limit resistance to antibiotics.

 

What did the research involve?

Researchers analysed antibiotic use in 537 UK GP practices over a 16-year period.

They looked at antibiotic use, the type of antibiotic used, and the length of treatment for:

  • coughs and colds
  • sore throats
  • UTIs
  • middle ear infection (otitis media)

These conditions are subject to recommendations made in 1998 by the UK Department of Health's Standing Medical Advisory Committee (SMAC) that clinicians should:

  • not prescribe antibiotics for simple coughs and colds
  • not prescribe antibiotics for viral sore throats
  • limit prescribing for uncomplicated UTIs to three days in otherwise healthy women

This advice has been supplemented with further professional guidance on antibiotic use from the UK Public Health Laboratory Service in 2000, which recommends that:

  • antibiotics should be avoided for acute sore throat unless specific clinical criteria are met, in which phenoxymethylpenicillin may be prescribed (or clarithromycin if the patient is allergic to penicillin)
  • amoxicillin may be prescribed (or erythromycin if the patient is allergic to penicillin) for acute otitis media if specific clinical criteria are met
  • short-course trimethoprim or nitrofurantoin should be prescribed for UTIs in women if specific clinical criteria are met

The researchers looked at changes over time, as well as variation in antibiotic prescription between practices.

 

What were the basic results?

Coughs and colds
The proportion of cases of coughs and colds where antibiotics were used decreased from 47% in 1995 to 36% in 1999, before increasing to 51% in 2011.

There was marked variation by primary care practice in 2011, with 10% of practices prescribing antibiotics for less than 32% of cases and 10% of practices prescribing antibiotics for more than 65% of cases.

Sore throats
Antibiotic prescribing for sore throats fell from 77% in 1995 to 62% in 1999, and then stayed broadly stable.

Again, there was variation by primary care practice seen in 2011, with 10% of practices prescribing antibiotics for less than 45% of cases, and 10% of practices prescribing antibiotics for more than 78% of cases.

Where antibiotics were prescribed for a sore throat, the appropriate type of antibiotic was used in 69% of cases in 2011, representing a slight increase from 64% in 1995.

Urinary tract infections in women
Trimethoprim or nitrofurantoin are the recommended antibiotics for UTIs, which includes conditions such as cystitis.

The proportion of women aged 16-74 years with a UTI who were prescribed trimethoprim fell from 62% in 1995 to 54% in 2011, and the proportion who were prescribed nitrofurantoin rose from 5% in 1995 to 24% in 2011.

The researchers calculated the length of antibiotic dose from the amount of antibiotic prescribed. When trimethoprim was prescribed, the use of a recommended short course rose from 8% in 1995 to 50% in 2011. When nitrofurantoin was prescribed, the use of a recommended short course rose from 6% in 1995 to 20% in 2011.

Again, there was variation between practices, with a quarter of practices prescribing short courses in fewer than 16% of episodes that were prescribed trimethoprim in 2011.

Otitis media
The proportion of otitis media cases that were prescribed an antibiotic was broadly unchanged over the study period.

Again, there was variation between practices, with 10% of practices prescribing antibiotics for less than 63% of cases and 10% of practices prescribing antibiotics for more than 97% of cases.

Where antibiotics were prescribed, prescriptions for recommended antibiotics rose from 77% in 1995 to 85% in 2011.

 

How did the researchers interpret the results?

The researchers conclude that, "The implementation of national guidelines in UK primary care has had mixed success, with prescribing for coughs/colds, both in total and as a proportion of consultations, now being greater than before recommendations were made to reduce it. Extensive variation by practice suggests that there is significant scope to improve prescribing, particularly for coughs/colds and for UTIs."

 

Conclusion

This cross-sectional study has found the proportion of people with coughs and colds that are prescribed antibiotics rose from 36% in 1999 to 51% in 2011 – an increase of approximately 40%. This is despite the publication of guidance recommending that GPs do not prescribe antibiotics for coughs and colds.

It also found substantial variation between different GP practices, with 10% of practices prescribing antibiotics for less than 32% of cases and 10% of practices prescribing antibiotics for more than 65% of cases, suggesting that substantially lower rates of prescribing could be achieved.

The study also looked at antibiotic prescription for sore throats, UTIs and otitis media. Antibiotic prescription for sore throats fell, and prescription of recommended antibiotics increased.

Over the study period, more women with UTIs were prescribed the recommended short course of antibiotics. For otitis media, the proportion of cases that were prescribed an antibiotic was broadly unchanged, and prescriptions for recommended antibiotics rose.

There was variation between GP practices in antibiotic prescription for these conditions, suggesting that further improvements in antibiotic prescription could be made.

In conclusion, this study suggests there is a need to improve the way antibiotics are prescribed.

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

Links To The Headlines

New figures reveal soaring use of antibiotics despite warnings. The Telegraph, August 5 2014

Antibiotics use for colds 'rises 40%'. BBC News, August 5 2014

GPs dishing out MORE antibiotics just to treat colds: Number given treatment by doctors rose by 40 per cent between 1999 and 2011. Mail Online, August 5 2014

Links To Science

Hawker JI, Smith S, Smith GE et al. Trends in antibiotic prescribing in primary care for clinical syndromes subject to national recommendations to reduce antibiotic resistance, UK 1995-2011. Journal of Antimicrobial Chemotherapy. Published online August 4 2014

Categories: NHS Choices

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