Major study of oestrogen abandoned

The US government is ending the last major study of oestrogen, saying taking oestrogen alone is not as bad as taking it together with the hormone progestin, but it is still too risky for long-term use.

Women who took oestrogen alone after menopause had a significantly increased risk of stroke, and possibly a higher risk of dementia, too, the National Institutes of Health said in Washington.

Doctors long thought that using oestrogen, alone or together with progestin, would keep women healthier after menopause, in such ways as reducing heart attacks and keeping the brain sharp.

Millions of women have stopped using the oestrogen-progestin combination since 2002, when federal scientists warned that those pills raised the risk of breast cancer, strokes and heart attacks.

Scientists were not sure whether oestrogen alone was as risky. Only women who have undergone a hysterectomy can even consider taking oestrogen alone in other women, progestin use with oestrogen is crucial to protect against uterine cancer.

Now, the NIH is shutting down its study of oestrogen-only use, too, telling the 11,000 women enrolled to stop using their pills.

The women, who were healthy 50- to 79-year-olds, took either oestrogen or a dummy pill for nearly seven years.

Among the findings released today:

:: Oestrogen alone increased the risk of a stroke as much as oestrogen-progestin does. For every 10,000 women, those taking hormones suffer eight more strokes per year than nonhormone users.

:: Oestrogen alone had no effect, good or bad, on heart disease. In contrast, the oestrogen-progestin combination increases heart attack risk by 29%.

:: Oestrogen alone did not increase the risk of breast cancer. Again in contrast, the oestrogen-progestin combination had increased that risk, by 26%.

:: Either type of hormone therapy seems good for women’s brains. Preliminary data from a related study of women 65 and older suggest those taking oestrogen alone were more likely to suffer some degree of dementia than those taking a placebo, the NIH said.

Likewise, scientists announced last May that the oestrogen-progestin combination doubled the risk of Alzheimer’s and other forms of dementia.

Both oestrogen alone and with progestin have some benefits. Both types decrease the risk of a hip fracture from bone-thinning osteoporosis, and are the more effective treatment for such symptoms of menopause as hot flashes.

But the NIH said considering the pills’ other risks, only women who cannot take one of the nation’s many other osteoporosis treatments should consider oestrogen for that use.

The Food and Drug Administration stresses that women who use any form of oestrogen to relieve menopausal symptoms should use the lowest dose for the shortest duration.