Monday, February 23, 2009

Blood pressure drugs can curb Alzheimer's

This seems a rather striking finding and certainly warrants follow-up with a better sample and more controls

Blood-pressure drugs taken by thousands could reduce the risk of Alzheimer's disease. Patients on medication for hypertension - the medical term for high blood pressure - are less likely to develop dementia than those who are healthy and do not use the drugs, scientists found. Doctors had previously found lowering blood pressure can reduce the risk of dementia later in life. But this study suggests hypertension drugs may have a protective effect because of something they contain rather than because of their effect on blood pressure. Further research is set to establish whether they could help reverse the symptoms of Alzheimer's or even prevent it.

Around 400,000 people in Britain suffer from Alzheimer's with a further one million diagnoses expected over the next ten years. Doctors at the Mount Sinai School of Medicine, New York, carried out post-mortem examinations on 300 patients for the study, published in Neurology magazine. They identified which patients had been diagnosed with high blood pressure and which were taking drugs to ease their condition. Analysis found `substantially' fewer symptoms of Alzheimer's in those who had been taking medication for their hypertension than among normal, healthy people.

Neil Hunt, of the Alzheimer's Society, said: `We know high blood pressure doubles the risk of developing Alzheimer's so treating hypertension is vital. It is becoming increasingly important to investigate whether anti-hypertensive medication may also be a potential treatment for Alzheimer's.'


Journal abstract:

Less Alzheimer disease neuropathology in medicated hypertensive than nonhypertensive persons

By L. B. Hoffman et al.

Objective: To test the hypothesis that use of antihypertensive medication is associated with lower Alzheimer disease (AD) neuropathology.

Methods: This was a postmortem study of 291 brains limited to those with normal neuropathology or with uncomplicated AD neuropathology (i.e., without other dementia-associated neuropathology) in persons with or without hypertension (HTN) who were and were not treated with antihypertensive medications. Neuritic plaque (NP) and neurofibrillary tangle (NFT) densities, quantified in selected brain regions according to the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) neuropathologic criteria, with additional cortical NP counts, yielded 24 neuropathologic regional measures or summaries. Medicated hypertension (HTN-med; n = 77), nonmedicated HTN (HTN-nomed; n = 42), and non-HTN (no-HTN; n = 172) groups were compared by analyses of variance.

Results: The HTN-med group had significantly less neuropathology than the no-HTN group. The no-HTN group averaged over 50% higher mean NP and NFT ratings, and double the mean NP count, of the HTN-med group. The HTN-nomed group had significantly more neuropathology than the HTN-med group, but not significantly less than the no-HTN group.

Conclusions: There was substantially less Alzheimer disease (AD) neuropathology in the medicated hypertension group than the nonhypertensive group, which may reflect a salutary effect of antihypertensive medication against AD-associated neuropathology.

Neurology 2009. Published online February 18

Frozen human egg system improved

THE first "frozen egg" baby born in Australia through a revolutionary technique will give single women and couples greater choice for having children later in life. Lucy was born last October to a Sydney couple, and the success is expected to spark huge interest in the technique.

Freezing has been relatively unsuccessful until now because human eggs are so fragile. It has grown out of a demand from mainly single women in their 30s who want to delay childbirth. The $10,000 process is also suitable for cancer patients who store eggs before radiation or chemotherapy, which often damage the reproductive system. The technique would also be used by women who have a family history of early menopause. Because of low success rates in the traditional method of slow egg freezing, women have had to take their chances by relying on IVF, sometimes leaving it too late.

Since July 2006, Sydney IVF has been testing the process, which boasts almost a 100 per cent success rate in freezing and thawing eggs. The IVF breakthrough works by snap-freezing the egg, which avoids ice crystals forming in the cell and damaging genetic material. Vitrification is used around the world to freeze embryos, but has never been successfully used in Australia for eggs.

Dr Kylie de Boer, general manager of Sydney IVF, said she expected numbers of women and couples wanting to freeze their eggs to soar. "Women want to have their eggs frozen for social reasons, such as they are not ready to have children, or for medical reasons," she said. "We get about 5-10 inquiries a month now for egg freezing for social reasons." Only 25 couples so far have used the process, which involves up to 10 eggs being collected and stored in liquid nitrogen vapour. The pregnancy rate is about 63 per cent.

Lucy's parents, who do not wish to be identified, used the process as part of their IVF treatment. Her mother was 37 when she had her eggs frozen. They were stored for six months before being fertilised and the embryo implanted. Now with a healthy girl, the 38-year-old mother said she would recommend it to other women. "My husband and I are so happy with our beautiful little girl," she said. "My pregnancy was textbook and the birth was a natural one, and occurred at full term. "We would love to have more children and will opt for IVF treatment once again."


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