Study Sheds New Light on Hormone Safety
A secondary analysis of the 2002 landmark Women’s Health Initiative (WHI) study, which led millions of women to stop hormone therapy during menopause, has found that the risk of heart disease may now vary by age and years since menopause. What does this finding mean for women in menopause?
The new information, reported in the Journal of the American Medical Association (April 4, 2007), may have some women and physicians taking another look at hormone therapy to alleviate menopause symptoms.
The results suggest that women who begin hormone therapy within 10 years of menopause may face less risk of coronary heart disease (CHD) due to hormone therapy, compared with women farther from menopause. Overall, hormone therapy does not lower the risk of CHD. Yet, the farther a woman is from the onset of menopause when she begins hormone therapy, the higher the risk of CHD due to hormone therapy appears to be. The researchers noted, however, that, because there were so few deaths and heart attacks in that group, the difference was not statistically significant.
In the latest analysis, the researchers reexamined previously collected data from the women who had not had hysterectomies and took conjugated estrogens/medroxyprogesterone acetate tablets (Prempro; Wyeth) and women who had a hysterectomy and took only estrogen. The pooled data included 27,347 participants.
The investigators wanted a more in-depth look at earlier observed trends in hormone effects by distance from menopause. They broke down the data into 3 age categories (50 to 59, 60 to 69, and 70 to 79) and by years since the onset of menopause (<10, 10 to 19, and =20).
In terms of age, the biggest disparity in CHD risk and overall deaths between the hormone-therapy and the placebo groups was in women 70 to 79. The difference was greatest in women≥60 who were still experiencing hot flashes and night sweats. These participants were likely to have risk factors for CHD (eg, high blood pressure or high cholesterol). It was unclear, however, whether this finding explained their higher risk on hormone therapy.
The 50-to-59 age group showed more promising results. The fact that hormone therapy did not raise the chance of heart disease or death among this group “offers some reassurance that hormones remain a reasonable option for the short-term treatment of menopausal symptoms,” but prolonged use could still be dangerous, according to the researchers. Other results from the data include the following:
- Confirmation that hormone therapy raises the risk of stroke and that this risk does not appear to be influenced by age or time since menopause
- An apparent increased risk of breast cancer in women taking estrogen with progestin, even in women within 10 years of menopause
Clinicians also urge menopausal women—whether they elect to take hormones, take another prescription drug, or seek no treatment—to make lifestyle changes that include exercise and healthy eating.
The new results are a reversal of the findings that halted the WHI study in 2002.
Those findings had indicated that conjugated estrogens/medroxyproges-terone acetate increased postmeno-pausal women’s risk of breast cancer, and that overall risks—including heart attack, stroke, and blood clots—outnumbered benefits.
The trial was stopped after 5.6 years. The results caused anxiety among women taking the hormone therapy and caused a major decline in hormone use.
More bad news came 2 years later when a parallel study found that estrogen alone increased the risk of stroke and produced no reduction in the risk of CHD. The estrogen-alone study, which was halted after 6.8 years, also found an increased risk of blood clots.