Hormone replacement therapy protects against heart disease in younger women

Feb 14 2006

According to a new study hormone replacement therapy using estrogen does not appear to protect postmenopausal women from heart disease.

It does not also appear to reduce the risk of heart attack or coronary death in healthy postmenopausal women.

The study by Judith Hsia, M.D., from George Washington University in Washington, D.C., analyzed data from the Women's Health Initiative (WHI), and included data from two large clinical trials that evaluated whether hormone therapy with estrogen reduces the risk of coronary heart disease in postmenopausal women.

One part of the study was designed to test estrogen therapy alone, as opposed to estrogen in combination with progestin.

Over ten thousand women aged 50 to 79 years who had undergone a hysterectomy were assigned to take either a mix of several estrogens, or a placebo.

The original intention had been to study the women for 8.5 years, but the trial was stopped in March 2004 after only 6.8 years because the hormone treatment appeared to increase the risk of stroke.

As a result millions of women stopped HRT and sought alternatives to what had previously been promoted as a way of preventing heart disease.

During the course of the trial, the women taking hormones experienced 201 coronary events, which included heart attacks and coronary deaths, while those taking placebo had 217 events.

Overall, the risk was similar for women who took hormones compared with those who did not, though there was a suggestion of lower risk in women age 50 to 59 years.

Among the 1,396 women who were aged 50 to 59 years at the start of the study, there was no significant reduction in heart attack or coronary death among those taking estrogen.

However, coronary revascularization (reestablishment of blood supply to the heart) was less frequent among women taking estrogen, as were several combined endpoints, such as myocardial infarction, coronary death and revascularization.

The authors say the trial may have been unable to demonstrate a significant difference in the risk of myocardial infarction or coronary death by age group because of the low event rate in young women.

This suggests that HRT, is safer in younger women just entering menopause than it is in older women well past it.

The study concludes that although HRT does not provide overall protection against heart attacks there may be some benefit against heart disease in younger menopausal women.

It is the second study to suggest that women who start taking replacement drugs as they begin menopause have a 30 percent lower risk of heart disease than women who do not take them.

Following the results of the 2002 WHI study experts cautioned women to only take hormone replacement drugs in the lowest possible doses and for the shortest possible time.

But others were quick to point out that the average age of the women in the WHI study was well above 60, and well past menopause and would have already been suffering the health effects of aging when they started HRT.

The report is published in the Archives of Internal Medicine.