Is Hormone Therapy Dangerous for Women with Existing Heart Risk?

Researchers from the University of Michigan School of Public Health reported last month in the Archives of Internal Medicine that hormone therapy may produce adverse heart health effects even in women who begin treatment within the recommended timeframe post-menopause.

In a University of Michigan news release, epidemiologist MaryFran R. Sowers, PhD, lead researcher and John G. Searle Professor of Public Health at the University of Michigan School of Public Health, said hormone therapy could “accentuate certain pre-existing heart disease risk factors,” and noted that the research “also showed that in women without existing atherosclerosis, hormone therapy use included some positive effects on lipids but also some negative effects related to heart health.” She recommended that women considering estrogen replacement should also have their cardiac health evaluated.

The study on estrogen therapy’s effects on heart disease risk was created in part to explain the “timing hypothesis,” which “suggests that if a woman implements a hormone therapy program within six years of her final menstrual period, this narrow window is enough to deter heart disease from developing with the onset of menopause.” The six-year timing hypothesis was first proposed to explain findings from the Women’s Health Initiative study, a 15-year clinical trial launched in 1991 to study “the effects of postmenopausal hormone therapy [estrogen plus progestin and estrogen alone], diet modification, and calcium and vitamin D supplements on heart disease, fractures, and breast and colorectal cancer.”

That explanation may be inadequate, however, because Sowers said that even “within the six-year window, there were negative aspects [of estrogen therapy] related to heart disease.” She said that researchers “also saw negative outcomes in terms of the inflammation process,” which can be related to heart disease. Thus, she recommended that women considering hormone therapy should have their risk for heart disease measured not only through the standard lipid panels, but also by measuring inflammation markers.

Additional Information

Women’s Health Initiative Scientific Resources Site

Mixed Findings Cast Doubt on HRT Timing Hypothesis

Study of Women’s Health Across the Nation