Press releases Monday 11 January to Friday 15 January 2010

Please remember to credit the BMJ as the source when publicising an article and to tell your readers that they can read its full text on the journal's website (http://www.bmj.com).

(1) Blood pressure drugs may help ward off Alzheimer's disease and dementia
(2) Early physiotherapy could help prevent complications after breast cancer surgery
(3) Daily calcium and vitamin D supplements prevent fractures
(4) Social inequality gap still exists for common cancers
(5) Study adds weight to link between radiation exposure and circulatory disease

(1) Blood pressure drugs may help ward off Alzheimer's disease and dementia
(Research: Use of angiotensin receptor blockers and risk of dementia in a predominantly male population: prospective cohort analysis)
http://www.bmj.com/cgi/doi/10.1136/bmj.b5465
(Editorial: Antihypertensive agents and prevention of dementia)
http://www.bmj.com/cgi/doi/10.1136/bmj.b5409

Angiotensin receptor blockers, drugs that are commonly used to treat high blood pressure and heart disease, are associated with a reduced risk of Alzheimer's disease and dementia, according to research published on bmj.com today.

The study also concludes that angiotensin receptor blockers seem to offer greater protection against Alzheimer's disease and dementia than other high blood pressure and heart disease medication.

Dementia, including Alzheimer's disease, threatens an increasing number of people as they get older. It also has major economic implications as individuals who suffer from either disease can spend long periods of time in nursing homes.

While dementia and Alzheimer's disease are complex diseases, there is increasing evidence of three main risk factors: age, genetics and heart disease. In particular, mid-life diseases like diabetes and high blood pressure seem to be linked to a higher chance of developing dementia.

This is the first large scale study to investigate whether angiotensin receptor blockers reduce the risk of developing dementia and Alzheimer's disease, say the researchers.

The authors, led by Professor Benjamin Wolozin from Boston University School of Medicine, investigated the incidence of dementia in over 800,000 mostly (98%) male subjects in the US from 2002 to 2006. The participants had cardiovascular disease and were 65 years of age or older.

One group of research subjects were using angiotensin receptor blockers, another the blood pressure lowering drug lisinopril and the third, other comparative drugs used for heart disease.

The results show that the group on angiotensin receptor blockers were significantly less likely to develop Alzheimer's disease or dementia. They also demonstrate that angiotensin receptor blockers have an additive effect when used in combination with another type of high blood pressure drug (ACE inhibitors) - individuals with existing Alzheimer's disease or dementia who took both medicines were less likely to die early or be admitted to nursing homes.

Wolozin concludes that the research is important because it is the "first to compare both risk of dementia and progression of dementia in users of angiotensin receptor blockers compared with users of a drug from the same class (lisinopril) or users of other drugs prescribed for cardiovascular disease."

The public health implications of finding an effective way of preventing dementia are immense, say two senior doctors from the University of Calgary, in an accompanying editorial. However, further work is needed to verify the usefulness of antihypertensives in general and angiotensin receptor blockers in particular, they conclude.

Contacts:

Research: Professor Benjamin Wolozin, Department of Pharmacology and Department of Neurology, Boston University School of Medicine, Boston, MA, USA
Email: Gina.Digravio@bmc.org

Editorial: Colleen Maxwell, Associate Professor, Departments of Community Health Sciences and Medicine, Faculty of Medicine, University of Calgary, Alberta, Canada
Email: maxwell@ucalgary.ca

Early physiotherapy, including massage and shoulder exercises, could help to prevent and reduce one of the most common complications of breast cancer surgery, finds a study published on bmj.com today.

Secondary lymphoedema is the most significant chronic complication after breast cancer surgery or radiation therapy. It is caused by damage to the lymphatic system during treatment, leading to fluid retention and arm swelling. It affects 71% of women within 12 months of surgery and can also cause cosmetic disfigurement, anxiety, depression and emotional distress.

Currently, women with breast cancer have a 77% probability of surviving at least 10 years, so effective prevention and management of complications that can impair function and affect quality of life after treatment are important.

So a research team in Madrid set out to investigate the effectiveness of early physiotherapy in reducing the risk of secondary lymphedema after breast cancer surgery.

They identified 120 women who had undergone breast cancer surgery involving removal of lymph nodes between May 2005 and June 2007.

Sixty patients were assigned to early physiotherapy and an educational strategy (intervention group) and 60 to the educational strategy only (control group). Both programmes lasted three weeks and patients were followed up four weeks after surgery, and again at three, six and 12 months after surgery.

Physiotherapy included manual lymph drainage, massage of scar tissue, and shoulder exercises by a physiotherapist. The educational strategy included materials about the lymphatic system and advice on how to avoid injury and prevent infection.

One year follow-up was completed by 116 women. Of these, 18 (16%) developed secondary lymphoedema: 14 in the control group (25%) and four in the intervention group (7%). This difference was statistically significant.

A survival analysis also showed a significant difference, with secondary lymphoedema being diagnosed four times earlier in the control group than in the intervention group.

Early physiotherapy could help to prevent and reduce secondary lymphoedema in women for at least one year after breast cancer surgery, conclude the authors. Further studies are needed to clarify whether early physiotherapy after breast cancer surgery can remain effective in preventing secondary lymphoedema in the longer term.

An accompanying editorial says that physiotherapy shows promise in a selected group of women and suggests that clinicians should consider referring patients to physiotherapists who are trained in treating lymphoedema.

Contact:

Maria Torres Lacomba, Professor of Physiotherapy, Physiotherapy Department, School of Physiotherapy, Alcala de Henares University, Madrid, Spain
Email: maria.torres@uah.es

Daily supplements of calcium and vitamin D significantly reduce the risk of fracture, irrespective of age, sex, or previous fractures, concludes a study published on bmj.com today.

However, for vitamin D supplements alone, no significant effects were found.

Fragility fractures are a major cause of illness in older people and a considerable burden to health services, yet conflicting evidence exists on the role of vitamin D, either alone or in combination with calcium, in reducing fractures. Some studies have shown a reduction in the risk of fractures, others have shown no effect, and one recent study found an increased risk of hip fracture.

The best dose to use, which patients benefit most, and which fractures are most amenable to such treatment remain a clinical dilemma.

So a team of researchers based at Gentofte Hospital in Copenhagen and the University of Southern Denmark analysed data from seven large trials to assess the effectiveness of vitamin D or vitamin D plus calcium in reducing fractures among 68,517 older people (average age 70 years). The study also involved collaborators in the UK, Norway and the Women's Health Initiative in the US.

They found that vitamin D given alone in doses of 10-20 ±g/day is not effective in preventing fractures.

By contrast, calcium and vitamin D given together reduce hip fractures and total fractures, and probably vertebral fractures, irrespective of age, sex, or previous fractures.

The authors emphasise that their analysis does not allow for a direct comparison of vitamin D against vitamin D given with calcium, but only comparisons between each intervention and no treatment. Additional studies of vitamin D are also needed, especially trials of vitamin D given daily at higher doses without calcium, they conclude.

Although the evidence is still confusing, there is growing consensus that combined calcium and vitamin D is more effective than vitamin D alone in reducing non-vertebral fractures, says Professor Opinder Sahota from Queen's Medical Centre, Nottingham in an accompanying editorial. Further studies are needed to define the optimal dose, duration, route of administration, and dose of the calcium combination.

Contacts:

Research: Bo Abrahamsen, Department of Internal Medicine and Endocrinology, Copenhagen University Hospital Gentofte, Hellerup, Denmark
Email: b.abrahamsen@physician.dk

Editorial: Opinder Sahota, Professor Orthogeriatric Medicine, Department of Health Care of Older People, Queen's Medical Centre, Nottingham, UK
Email: opinder.sahota@nuh.nhs.uk

Despite the implementation of the NHS Cancer Plan, social factors still strongly influence access to and the provision of care delivered by NHS hospitals in England, concludes a study published on bmj.com today.

The NHS Cancer Plan was published in 2000 to improve outcomes overall and to reduce health inequalities, in part through greater equity of access to and provision of health care for all social groups. But the extent to which access to health care has improved for all those in need regardless of their socioeconomic circumstances, age, or sex has not been examined.

So a team of researchers at University College London set out to determine the extent to which type of hospital admission (emergency compared with elective) and surgical procedure varied by socioeconomic circumstances, age, sex, and year of admission for the three most common cancers: colorectal, breast, and lung cancer.

Together these accounted for 64% of new cases diagnosed in 2006 and 40% of deaths from cancer in 2007.

Using hospital episode statistics, they identified 564,821 patients aged 50 and over admitted to an NHS hospital in England with a diagnosis of colorectal, breast, or lung cancer. They then analysed the proportion of patients admitted as emergencies and receiving the recommended surgical treatment from 1999 to 2006 according to their socioeconomic circumstances, age, sex, and year of admission.

During the study period, nearly a third of patients with colorectal cancer were admitted as emergencies, and this proportion did not improve over time. Over half of patients with lung cancer were also admitted as emergencies, and this proportion increased over time.

In contrast, there was a downward trend in the proportion of patients with breast cancer admitted as emergencies.

Patients from deprived areas, older people, and women were more likely to be admitted as emergencies. Patients from deprived areas were also less likely to receive preferred procedures for rectal, breast, and lung cancer. These findings did not improve over time.

In terms of preferred surgical treatment, men were slightly less likely to undergo the preferred surgical procedure for rectal cancer (anterior resection) and resection for lung cancer.

Although older people were more likely to receive anterior resection for rectal cancer, they were less likely to receive breast conserving surgery and lung cancer resection

The authors conclude that reducing inequalities in survival depends on improving timely presentation, early referral, and the application of evidence based clinical guidelines among socially disadvantaged groups.

They also recommend audit of local surgical practice and monitoring of sociodemographic variations in procedure use "to raise standards and ensure best practice."

Contacts:

Rosalind Raine, Professor of Health Care Evaluation, Department of Epidemiology and Public Health, University College London, UK
Email: r.raine@ucl.ac.uk

(5) Study adds weight to link between radiation exposure and circulatory disease
(Research: Radiation exposure and circulatory disease risk: Hiroshima and Nagasaki atomic bomb survivor data, 1950-2003)
http://www.bmj.com/cgi/doi/10.1136/bmj.b5349
(Editorial: Exposure to radiation and higher risk of circulatory disease)
http://www.bmj.com/cgi/doi/10.1136/bmj.b4326

Exposure to moderate levels of radiation may increase the rates of heart disease and stroke, but the degree of risk at lower doses is unclear, finds a large study of atomic bomb survivors published on bmj.com today.

Although the authors cannot be certain that this is a direct (causal) link, their study provides the strongest evidence available to date of an association between circulatory disease and moderate radiation exposure.

Several studies have shown that high doses of radiation to the heart or head and neck from radiotherapy cause an excess of deaths from heart disease or stroke in later years. But it is uncertain whether radiation exposures at relatively low dose levels (under 1 Gy) also increase the risk.

This is an important public health issue because of the increasing use of multiple computed tomography (CT) scans and other relatively high dose diagnostic medical procedures.

Medical use of radiation is typically measured in milligray (mGy). The average radiation dose from an abdominal x-ray is 1.4 mGy (0.0014 Gy), that from an abdominal CT scan is 8.0 mGy (0.008 Gy), and that from a pelvic CT scan is 25 mGy (0.025 Gy).

To investigate this further, Dr Yukiko Shimizu and colleagues from the Radiation Effects Research Foundation in Japan examined the risk of heart disease and stroke in 86,611 atomic bomb survivors from Hiroshima and Nagasaki who have been followed up for 53 years, from 1950 to 2003, as part of the Japanese atomic bomb survivor Life Span Study.

Each member of the group had received an estimated radiation dose from 0-4 Gy (86% received less than 0.2 Gy) at the time of the bomb. Other risk factors for circulatory disease that could have affected the results, such as smoking, alcohol intake, education, occupation, obesity and diabetes were also taken into account.

The researchers found an elevated risk of both stroke and heart disease at doses above 0.5 Gy, but the degree of risk at lower doses was unclear.

Together, this represents about 210 excess deaths from circulatory disease associated with radiation exposure - about a third as many as the total excess number of cancer deaths (about 625) among atomic bomb survivors in the Life Span Study.

Adjusting for other factors made little difference to these risks.

This study provides the strongest evidence available to date that radiation may increase the rates of stroke and heart disease at moderate dose levels (mainly 0.5-2 Gy), though the results below 0.5 Gy are not statistically significant, say the authors. Further studies should provide more precise estimates of the risk at low doses, they conclude.

This study adds to a growing body of moderate and low dose data suggesting an association between cardiovascular disease and exposure to low-moderate levels of radiation, as well as the well understood association at high doses, says Mark Little from Imperial College London, in an accompanying editorial.

However, it is unclear whether the biological mechanisms operating at high doses of radiation apply to low doses, and this should be the focus of future research, he concludes.

Contacts:

Research: Dr Kazunori Kodama, Chief scientist, Radiation Effects Research Foundation, Hiroshima, Japan
Email: kodama@rerf.or.jp

Editorial: Mark Little, Reader in Statistics, Department of Epidemiology and Public Health, Imperial College Faculty of Medicine, London, UK
Email: mark.little@imperial.ac.uk

FOR ACCREDITED JOURNALISTS

For more information please contact:

Emma Dickinson
Tel: +44 (0)20 7383 6529
Email: edickinson@bma.org.uk

Press Office telephone : 020 7383 6254 (Weekdays : 0900hrs - 1800hrs)
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BMA House, Tavistock Square, London WC1H 9JP

and from:

the EurekAlert website, run by the American Association for the Advancement of Science (http://www.eurekalert.org)
http://intranet.bmj.com/departments/dept-bmj/bmj-team-resources/web-team-resources/General_blogging_principles.doc