Weighing hormone therapy's benefits.

Physicians often recommend that older women take estrogen to counter many of the uncomfortable or potentially debilitating changes that may accompany menopause. A study now finds that, in terms of longevity, women at high risk of heart disease derive the greatest initial gain from these hormone-replacement drugs, now among the most widely prescribed in the United States.

Though postmenopausal hormones can be prescribed indefinitely, there has been "a poor understanding of what they do over the long term," observes epidemiologist Francine Grodstein of the Harvard School of Public Health in Boston. That's why her team has been probing their effects as part of a lengthy, ongoing study of 121,700 nurses.

The researchers focused on 3,600 nurses who were healthy in 1976 but have since died. For each woman, they found 10 other nurses who had the same initial health status, year of birth, and age at menopause but were alive at the time of the woman's death. Women not taking hormones were almost 40 percent more likely to have died--usually from chronic disease--than women who had never used supplements.

The greatest benefit accrued to women at high risk of heart disease. Hormone therapy cut their risk of premature death by 50 percent--five times the reduction seen among estrogen users without heart disease risks, Grodstein's team reports in the June 19 New England Journal of Medicine.

A partial explanation comes from a study in the June 9 Archives of Internal Medicine. Its authors, at the Chicago Institute for Clinical Research, found that among women with elevated cholesterol, estrogen supplements provide effects similar to those of a potent cholesterol-lowering drug.

Indeed, "there is a sizable number of women for whom estrogen replacement alone may be sufficient to bring cholesterol levels down to their treatment goal," says Kevin C. Maki, an author of the report.

Any longevity benefit from estrogen, however, begins dropping off within 10 years of taking the hormones and disappears within 5 years of stopping the therapy, the Harvard study finds. Because breast cancer incidence begins climbing among hormone users after 5 to 10 years, women will have to factor all these observations into whether, when, and for how long they may want to take the drugs, she says.

A third new study further complicates such analysis by lending support to estrogen's apparent role in the brain (SN: 9/7/96, p, 154). In an ongoing study of 472 aging women, researchers at Johns Hopkins University in Baltimore compared rates of Alzheimer's disease among postmenopausal women who did and did not take hormones. Over the 16-year study, estrogen supplements appeared to have halved the incidence of Alzheimer's in these women, they report in the June Neurology. Only 9 of the 34 Alzheimer's patients had taken estrogen.

"This carefully done study is suggestive of a protective effect on Alzheimer's disease," says neurologist David A. Drachman of the University of Massachusetts Medical Center in Worcester. However, further work will be needed, he adds.

Zaven Khachaturian, head of the Chicago-based Alzheimer's Disease Association's Ronald and Nancy Reagan Research Institute, agrees. He notes, however, that the design of the Hopkins study is stronger than that of many earlier ones, so its findings could play "an important role in encouraging others to conduct clinical trials" that prescribe postmenopausal hormones explicitly to head off Alzheimer's dementia.