Increased Stroke Risk With Combo HRT
But Estrogen-Only Effect Unclear
Feb. 14, 2003 --The hormone replacement researchers have finished dotting the i's and crossing the t's for the massive estrogen-progestin study that burst the hormone replacement bubble last summer and the news is still discouraging: Postmenopausal taking estrogen and progestin increase their risk for stroke by 33% compared with women who don't take hormones, regardless of whether there's a history of high blood pressure.
The Heart Lung and Blood Institute halted the study when it was discovered that postmenopausal women taking combination therapy -- estrogen plus progestin -- had an increased risk for breast cancer, heart disease, and stroke, which was equivalent to eight, seven, and eight more cases per 10,000 women respectively. But in that study, the average age at which the women were started on therapy was 63, although the optimal age is as close to menopause as possible.
At the time, the "overall increased risk for stroke was reported as 41% greater than postmenopausal women who were taking placebo," says Sylvia Wasserthiel-Smoller, PhD, professor of epidemiology and social medicine at the Albert Einstein College of Medicine, New York. Women who have a history of high blood pressure who took Prempro, the study drug, increased their risk for stroke by 40%, she says. In healthy women the stroke risk increased by 28%. Overall, the increased risk amounts to eight more strokes per year for every 10,000 women.
But Smoller, a principle investigator for the Women's Health Initiative Study, says the findings are still quite clear: Taking combination therapy is hazardous to the brain. She tells WebMD "given the choice between sweating and a stroke, I would recommend that women learn to tolerate the sweating." Nevertheless, HRT is indicated to relieve the symptoms of menopause.
Smoller adds, however, that the Women's Health Initiative is continuing another part of the study that is investigating the effect of estrogen alone on risk for stroke. "That part of the study is continuing so I want to be very clear that we have no final word on estrogen alone," she says. Before the estrogen-progestin arm was stopped last summer, the study investigators had sent out two letters warning participating doctors that there appeared to be excess risk associated with the combination therapy. Asked if similar warning letters have been sent to doctors supervising the estrogen-only arm, Smoller says no such warnings have been sent.