Younger women may be able to take hormone replacement therapy without raising their risk of heart disease, U.S. researchers reported on Monday in a study aimed at reducing some of the confusion surrounding HRT.
Women who started taking the drugs as they began menopause — which typically starts in the mid-40s and lasts through the mid-50s — had a 30 percent lower risk of heart disease than women who did not take them, the researchers found.
The findings contrast with those of a highly publicized 2002 study called the Women's Health Initiative or WHI, which found HRT raised the risk of heart attack, stroke, breast cancer and other serious conditions. After it came out, millions of women stopped HRT and sought alternatives.
"It may help to untangle some of the confusion," said Dr. JoAnn Manson of Harvard Medical School and Brigham and Women's Hospital in Boston, who worked on both studies.
After the 2002 Women's Health Initiative was published, experts cautioned women to only take HRT in the lowest possible doses and for the shortest possible time.
Sales of Wyeth's Premarin and the company's other female hormone replacement drug, Prempro, fell dramatically and the company, the biggest maker of HRT, announced plans to close at least one plant and to lay off sales staff.
But HRT remained popular in part because doctors had observed that women taking the drugs were less likely to have heart disease over the long term. Manson and others who worked on the WHI study noted the women in it were on average 63 — a decade past menopause.
They wondered what would happen with younger women, just entering menopause.
So they used data from the Nurses' Health Study, an ongoing study of 121,700 female nurses, age 30 to 55 when it started in 1976. Every two years these women have filled out detailed questionnaires on their health, habits and medications. When they died, their medical records were carefully added.
Lower risk of heart disease
The nurses' data showed that if women took HRT at younger ages, they had a 30 percent lower risk of heart disease than women the same age who did not take HRT.
"It does suggest that women who are good candidates for hormone therapy because they are recently menopausal and having moderate to severe hot flashes and are at low risk of heart disease may not need to be alarmed about the (earlier) findings," Manson said in a telephone interview.
"The evidence is beginning to converge. But it is certainly not conclusive. We don't want people running out and taking hormone therapy and thinking it was going to protect their heart and that there are no risks involved."
Writing in the Journal of Women's Health, Manson and colleagues stress that more research is needed.
The 2002 findings have caused doctors to take a fresh look at menopause, and many have criticized the idea that it is a medical condition that needs drug treatment.
Some studies suggest many symptoms attributed to menopause may be natural consequences of aging, including reduced libido, higher risk of heart attack and forgetfulness.
Other critics have suggested the formulation of HRT may be a factor. Women in both the 2002 and the 2006 studies mostly took Premarin or Prempro, which are made using pregnant horse urine.