By Amanda Dunn –Health Reporter
May 28 2003
A landmark study has linked hormone replacement therapy to increased rates of dementia in women over 65, casting further doubt over the safety of HRT.
The study of more than 4500 American women found those taking a particular combination of hormones were twice as likely to develop dementia as those who were not.
The findings are from the same trial in which researchers last year reported an increased risk of breast cancer and heart disease in women taking the hormones.
Further questions about hormone therapy were raised this month in the New England Journal of Medicine, which reported research showing that HRT – while helping to diminish menopausal symptoms such as hot flushes and night sweats – did not improve quality of life for women who did not have symptoms.
The latest findings were based on a study involving 4532 American women aged 65 or older, half of whom were taking a combination of oestrogen and progestin, and half of whom were given a placebo.
Over the four years of the trial, 61 women were diagnosed with dementia – most commonly, Alzheimer’s disease – with 40 of those in the oestrogen and progestin group, and 21 in the placebo group.
But the risk of developing dementia remained small, at 2 per cent compared with 1 per cent overall.
The trial was abandoned last year when the findings on breast cancer and heart disease came to light.
The latest findings have led the study’s researchers to conclude that, for this particular group of women, “the risks of oestrogen plus progestin outweigh the benefits.” The study, conducted by the Women’s Health Initiative, is published in today’s Journal of the American Medical Association.
Hundreds of thousands of Australian women taking HRT were yesterday urged not to panic, with doctors stressing that only a small number of them would be taking the particular combined therapy used in the trial.
Emeritus director of Prince Henry’s Institute, Henry Burger, said the study was the first large randomised trial looking at the link between hormone therapy and dementia. Previous studies had suggested that treatment with oestrogen alone may have a protective effect on brain function.
Professor Burger said that women over 60 who were significantly post-menopausal and did not have symptoms should probably not be on hormone therapy.
He also stressed that younger women who were taking this combination should not be unduly concerned.
Susan Davis, director of research at the Jean Hailes Foundation, a women’s health group, said many women were unnecessarily frightened about HRT after last year’s trial cancellation. Since then, she said use of the combined oestrogen and progestin had significantly waned, and she suspected that the progestin in the study may have been the reason behind the findings.
Head of the menopause clinic at the Royal Women’s Hospital, Di Palmer, said that most hormone therapy prescribed in Australia was at or around the time of menopause. She said the only known risks associated with the treatment were an increased risk of blood clots, a small increase in the risk of breast cancer if taken over more than five years and a small increase in the risk of cardio-vascular disease. But she said the benefits included the alleviation of symptoms, and a reduced risk of broken bones.
An endocrinologist at Austin Health, Ego Seeman, agreed that hormone therapy was beneficial to women with debilitating symptoms. But he said too many were taking the hormones without a compelling reason, and the therapy should not be taken for prevention of chronic diseases such as osteoporosis, heart disease and dementia