Women sweating out menopausal symptoms got a splash of good news this week with the release of a new study showing that estrogen supplements can improve heart health in some middle-aged women. Earlier studies had raised concern that all types of hormone therapy increased menopausal women's risk of heart disease, in addition to increasing the risk of stroke, blood clots and, sometimes, breast cancer.
Specifically, the new study, appearing in the New England Journal of Medicine, found that recently menopausal women who started taking estrogen-only pills in their 40s or 50s, soon after they had their ovaries and uteruses surgically removed for medical reasons, and who continued taking them for an average of seven years, had about 30 to 40 percent less of the gummy arterial plaque that's associated with clogged arteries than similar women who took placebo pills. The women who were the most faithful about taking their daily pills had about a 60 percent reduction in the measurable plaque in their blood vessels.
Taking estrogen pills is not completely without risk--even young women face an increased chance of venous thrombo-embolism (potentially fatal blood clots). But the lead author of the new study, Dr. JoAnn Manson, Harvard professor and chief of prevention medicine at Brigham and Women's Hospital in Boston, said these results should be reassuring to women without ovaries and uteruses who want to use low-dose hormone therapy during their 40s and 50s to treat hot flashes and other symptoms. The news is particularly heartening because this is the group of menopausal women most likely to experience severe symptoms, and hormone therapy is the most effective treatment. It also has the added plus of preventing (at least in the short term) the accelerated bone loss associated with menopause.
Manson added that this study, like several other new analyses of data related to the huge federal Women's Health Inititative, clarifies the point that the risks of taking hormone therapy are not the same for everyone. Key determinants, like age, medical history and elapsed time since menopause, must be considered by clinicians before writing out prescriptions.
The authors also said that these new results have limited application to the much larger group of postmenopausal women who use combined hormone therapy (estrogen plus progesterone). While the addition of progesterone is necessary to protect women with intact uteruses from developing endometrial cancer, progesterone blunts estrogen's positive ability to reduce bad cholesterol. That partly explains why a a number of studies have indicated that over time, the use of combined hormone therapy increases the risk of heart disease, in addition to stroke, blood clots and breast cancer. However, for some younger postmenopausal women with moderate to severe symptoms, combined hormone therapy can be used with relatively little risk for less than five years.
Some heart experts, like Dr. Howard Hodis, director of the Artherosclerosis Research Center at the University of Southern California, hailed the new findings as strong evidence that women without uteruses should start taking estrogen-only pills right after menopause as part of a long-term strategy to prevent heart disease. He said he would urge such patients to stay on estrogen for the next several decades, advice that is similar to that given women 10 years ago. "All drugs are double-edged swords," he said. "but the bottom line is that these women are living longer."
Other experts were quick to disagree with that conclusion. They said the current recommendation that hormones should only be used short term to treat symptoms and not to protect against heart disease should not be changed. "Estrogen has not been proven to be the elixir of life," said Dr. Jacques Rossouw, the project officer of National Institutes of Health's Women's Health Initiative and a coauthor of the study. He said there is still "no rigorous evidence" that estrogen can be used safely long term to prevent heart disease, especially since it is believed to cause more serious side effects over time.
Rossouw and Manson believe the prevailing theory: that as women age their plaque levels inevitably increase within blood vessels, whether they are using hormone therapy or not. At some point after 60, estrogen seems to switch from its good-girl role to become a cardiovascular troublemaker, they said. Or as an accompanying editorial in NEJM put it, estrogen appears to "destabilize a vessel with more advanced disease by promoting erosion, or even rupture, of the atherosclerotic plaque," which could prompt a range of circulation or cardiovascular problems.
Manson, the author of "Hot Flashes, Hormones and Your Health" (McGraw-Hill), said the latest hormone studies reinforce the consensus that "estrogen is complex and has many biological effects, and some risks increase with duration. We need to be cautious about long-term treatment with hormone therapy." She added that these new results should not be used to justify new use or continued use of hormones after the age of 60, when heart disease generally becomes more common. She said younger menopausal women with a history of heart problems, stroke, diabetes and blood clots in the legs should also be discouraged from using estrogen to treat their symptoms.