Bone fracture risk overstated, say experts
Friday January 18th, 2008
Drug companies are exploiting a risk factor for osteoporosis in order to boost their profits, believe experts.
Dr Ray Moynihan of the University of Newcastle, Australia, and colleagues write in the British Medical Journal that women with slightly lowered bone mineral density, labelled pre-osteoporosis or "osteopenia" are being targeted.
They say that the benefits of drug treatment for the condition have been overstated and the side-effects underplayed.
"Osteoporosis is a controversial condition," they write. Groups with a vested interest portray osteoporosis as "a silent but deadly epidemic bringing misery to tens of millions of postmenopausal women".
But the authors believe this amounts to disease mongering, in order to sell tests and drugs to relatively healthy women.
"Now the size of the osteoporosis market seems set to greatly expand, as the push begins to treat women with pre-osteoporosis," they warn. This condition is claimed to affect more than half of all white postmenopausal women.
Drug treatments seem to be cost-effective for women with moderate or high risk, but this is not necessarily the case in osteopenic women, the authors write.
Following their analysis, they state: "The evidence is weak". One study boasted a 75 per cent reduction in relative risk, but this translates into only a 0.9 per cent reduction in absolute risk.
They suggest that "up to 270 women with pre-osteoporosis might need to be treated with drugs for three years so that one of them could avoid a single vertebral fracture".
They add: "The flip side of exaggerating benefits is playing down harms." The drug strontium ranelate is known to cause diarrhoea, and there is concern over an increased risk of vascular, neurological, and other abnormalities.
Alonso-Coello, P. et al. Drugs for pre-osteoporosis: prevention or disease mongering? The British Medical Journal, Vol. 336, January 19, 2008, pp. 126-29.
Heart risk for patients who don't respond to aspirin
Friday January 18th, 2008
People who are "aspirin resistant" are at higher risk of death from heart disease, researchers warned today.
These individuals have blood plasma cells which are not affected by aspirin in the same way as normal people (called "aspirin sensitive"). The condition is difficult to identify, with different methods used in different studies.
Its links to clinical outcome are not clear, so Professor Michael Buchanan of McMaster University Health Sciences Centre, Canada, and colleagues set out to analyse the link to heart disease.
They looked at 20 studies of aspirin resistance including 2,930 patients with cardiovascular disease. These patients were given aspirin at between 75 and 325 mg daily as a preventative measure against blood clots.
Reporting on-line in the British Medical Journal, the researchers report that 28 per cent of the patients were classified as aspirin resistant. These patients had nearly four times the risk of a cardiovascular-related event (such as a heart attack or stroke), and nearly six times the risk of death.
The team conclude: "Patients who are resistant to aspirin are at a greater risk of clinically important cardiovascular morbidity long-term than patients who are sensitive to aspirin."
Other blood-thinning drugs, such as Clopidogrel or Tirofiban, did not seem to provide a benefit to these patients.
The authors add that aspirin resistance can be measured by a variety of tests, all of which are associated with clinically important adverse events. They say the condition should be taken into account when prescribing aspirin, and call for further research to determine the best method of diagnosis.
Krasopoulos, G. et al. Aspirin "resistance" and risk of cardiovascular morbidity: systematic review and meta-analysis. The British Medical Journal, published online January 18, 2008.
Young age of black breast patients
Thursday January 17th, 2008
Black British women who contract breast cancer are likely to develop the disease as much as 20 years earlier than white women, according to research published yesterday.
A study in east London, UK, found that black women are diagnosed with the disease at an average age of 46 - compared with 67 for white women.
Fewer black women than white women develop breast cancer so the finding, reported in the British Journal of Cancer, raises several issues.
Researchers found that black women who developed the disease tended to be diagnosed at an advanced stage and to suffer from fast-developing disease.
The findings come from a study of nearly 300 women diagnosed with breast cancer at Homerton Hospital, Hackney.
Researcher Dr Rebecca Bowen, said: "Twenty five per cent of all breast cancer cases diagnosed in London during the period studied were in women aged 45 or younger - but this figure rose to 45 per cent among the black population in Hackney.
"We think the differences in the way tumours of black and white women behave can be put down to the biological differences between the two ethnic groups.
"We're now trying to find out why the tumours are so different so that we can develop new treatments to target the aggressive forms of breast cancer seen in young black women."
Early onset of breast cancer in a group of British black women. RL Bowen et al. 2008. British Journal of Cancer.
Probiotics have genuine effect, say researchers
Wednesday January 16th, 2008
Scientists investigating probiotics, or "friendly" bacteria, have found that they can have noticeable effects when taken orally.
Products such as tablets and yoghurt drinks containing live bacteria are widely available. But some argue that probiotics cannot change the gut microflora.
"Whilst there are at least a billion bacteria in a pot of yoghurt, there are a hundred trillion in the gut, so you're just whistling in the wind," says Professor Jeremy Nicholson of Imperial College London, UK.
His team and colleagues from the Nestle Research Centre in Lausanne, Switzerland, looked in detail at how probiotics may change the biochemistry of the intestine by affecting gut microbes, which play a role in metabolism.
They gave two types of probiotic drink to mice that had been transplanted with human gut microbes. The drinks had "a whole range of biochemical effects", the team report in the journal Molecular Systems Biology.
These effects were noticeably different between the two probiotic strains used - Lactobacillus paracasei and Lactobacillus rhamnosus.
Professor Nicholson said: "Our study shows that probiotics can have an effect and they interact with the local ecology and talk to other bacteria. We're still trying to understand what the changes they bring about might mean, in terms of overall health, but we have established that introducing 'friendly' bacteria can change the dynamics of the whole population of microbes in the gut."
In the future it may be possible to develop probiotic products which are tailored for people with particular conditions and different types of metabolism, the team believe.
"The results of this study are highly promising to address personalised nutrition," commented researcher Dr Sunil Kochhar of the Nestle Research Centre.
Martin, F. P. J. et al. Probiotic modulation of symbiotic gut microbial-host metabolic interactions in a humanized microbiome mouse model. Molecular Systems Biology, published online January 15, 2008.
Possible heart risk from calcium pills
Wednesday January 16th, 2008
Women who take calcium supplements may be risking heart problems, researchers warned today.
Previous evidence indicates that high calcium intake may protect against heart disease, so Professor Ian Reid of the University of Auckland, New Zealand, and colleagues looked into the effects of calcium supplementation in women focusing on risk for heart attack, stroke, and sudden death.
The researchers carried out a randomised trial of 1,471 healthy postmenopausal women with an average age of 74. Half took a calcium supplement and half took a placebo, and they were all followed for five years.
Heart attack was significantly more common in the calcium group - with an estimated doubling in risk - as was the combined endpoint of heart attack, stroke, and sudden death, with an estimated risk increase of 50 per cent.
Results are published on-line by the British Medical Journal today (January 16). However, the authors add that when they included unreported events, which they took from national hospital records, the increase in risk was smaller and only "borderline significant".
They write: "Because of the high incidence of vascular disease in postmenopausal women any effects of calcium supplements on vascular health could be as important in terms of their effects on morbidity and mortality as their effects on bone."
Following their study, the authors conclude: "Calcium supplementation in healthy postmenopausal women is associated with upward trends in cardiovascular event rates."
This is worrying, they add, because "the morbidity and mortality that would follow from even a small adverse effect on vascular event rates is such that the beneficial effects of calcium supplementation on bone loss would be rapidly counterbalanced".
Bolland, M. J. et al. Vascular events in healthy older women receiving calcium supplementation: randomised controlled trial. The British Medical Journal, published online January 16, 2008.
Shifts force women out of work
Tuesday January 15th, 2008
Women who work shifts may find themselves forced into early retirement, according to new findings.
A major study in Denmark suggests women suffer more from shift-work based careers than men.
Researchers said that in general women were more likely than men to need a disability pension. But if their career had involved shift work, the risk of early retirement was increased by 34 per cent.
The study of 8,000 workers found no impact of shift work on men, according to the report published on-line by Occupational and Environmental Medicine.
Some 253 women retired early on grounds of ill health while 173 men had to take the same course.
Researcher Dr Finn Tuchsen, of the National Research Centre for the Working Environment, Copenhagen, writes: "This study did not look at the reasons for enforced early retirement. But shift work has been associated with an increased risk of heart disease, breast cancer, peptic ulcer, sleep disturbance, complications of pregnancy and accidents.
"But it is not clear why women should be more vulnerable."
Occup Environ Med 2007; doi: 10.1136/oem.2007.036525
Mums' Med diet beats allergy
Tuesday January 15th, 2008
The healthy Mediterranean diet of olive oil, fish and salads could offer a major benefit to pregnant women, according to a new study.
Researchers found the diet can "significantly" cut the risk of a child developing allergies and symptoms of asthma.
The findings come from a study conducted in Crete, in the heart of the Mediterranean sea, and reported today on-line by the journal Thorax.
Researchers studied some 468 families from pregnancy until when children were over the age of six.
They used questionnaires to establish whether women were eating a "traditional" diet of vegetables, fruit, nuts, fish, dairy products and olive oil.
In the years after birth, some 17 per cent of the children showed signs of allergy, as measured by skin tests. Some 13 per cent had persistent wheezing and six per cent had asthma-like symptoms as well as positive skin tests.
The researchers, led by Dr Leda Chatzi, of the University of Crete, said the children's own diet seemed to bear little relationship to their chances of suffering from allergy - but their mother's diet during pregnancy did.
They said women who ate vegetables more than eight times a week, fish more than three times and legumes at least twice a week seemed to offer their children especially strong protection.
Women who ate red meat more than three times a week seemed to increase the risk.
Thorax 2008; doi: 10.1136/thx.2007.081745
Bio-artificial heart breakthrough
Monday January 14th, 2008
Scientists have taken a major step in creating a biological artificial heart, it was announced last night.
In animal studies, researchers stripped an adult heart of all its cells and filled it with cells taken from a baby.
The adult heart provided blood vessels and valves, they report in the journal Nature Medicine.
The artificial heart was maintained in a device called a bioreactor to simulate natural conditions and allow the new cells to take root.
The researchers, from the University of Minnesota, USA, said they saw contractions of the artificial heart after four days and after another four days there was limited pumping.
Led by Professor Doris Taylor, they say: "This approach may hold promise for its use in transplant surgery."
She told the Sunday Telegraph that routine use of the treatment was "years away".
One possibility is that for humans, the replacement cells might be generated from a patient's own stem cells.
She said: "We could begin with human cells and pig or human scaffold now but creating the larger bioreactors and generating the reagents and growing enough cells would cost tens of thousands of dollars for each heart at this point.
"That is just too expensive to answer basic questions. We of course want to move in that direction, but funding is limited. As we can we will go forward - perhaps one heart at a time."
Nature Medicine DOI: 10.1038/nm1684
Gain without pain in diet trial
Monday January 14th, 2008
An Atkins-style diet is effective at helping people lose weight without pain, British researchers have reported.
A high protein, low carbohydrate diet proved successful at reducing hunger and helping weight loss in a study at the Rowett Research Institute, Aberdeen, Scotland.
The project, conducted in 2004, was high profile as one of the volunteers was a recent Big Brother winner, Cameron Stout.
Researchers compared two high protein diets. One was very low in carbohydrates, which represented just four per cent of the diet. The second was 30 per cent carbohydrate.
Volunteers on the low-carb diet lost nearly a full stone - 6.3kg - during two months of the diet.
The high-carb volunteers lost two thirds of this amount in weight, some 4.3 kg or 9 lbs.
The findings have now been published in the American Journal of Clinical Nutrition.
Mr Stout, who lost 12 kg during the study, had reported surprise at not feeling hungry during the project.
He said last night that it was a "great experience".
He said: "The food was excellent and the staff looked after us very well. Because I have such an irregular lifestyle I don’t find it easy to stick rigidly to all that I learnt while I was at the Institute, but I try to make an effort most of the time.
"For me it was mainly about breaking bad habits."
Researcher Dr Alex Johnstone said the only note of caution was a finding from the same study that a low-carb diet had an impact on the health of the gut - as it could reduce the numbers of some types of bacteria that live in the organ.
She said: "Our volunteers found both diets to be equally palatable, but they felt less hungry on the high-protein low-carbohydrate diet compared with the diet which contained high-protein but moderate amounts of carbohydrate."
She added: "We will be looking in more detail at the complex way in which we respond to changes in our diet before we can say whether low-carbohydrate ketogenic diets are a suitable tool for everyone who wants to lose weight."
The American Journal of Clinical Nutrition, volume 87(1), pages 44-55.
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