A new study has revealed that postmenopausal women taking hormone therapy to overcome the symptoms of menopause have an increased risk of stroke.
The study, led by Francine Grodstein, Sc.D, from Brigham and Women's Hospital (BWH), evaluated stroke risk linked to hormone therapy in 121,700 women (age 30 to 55 at the beginning of the study) who participated in the Nurses' Health Study from 1976 to 2004.
There were 360 cases of stroke among women who had never used hormones and 414 cases of stroke among women who were currently using hormones.
Grodstein and colleagues at Harvard Medical School, Boston, found that 39 percent for women taking estrogen and 27 percent for hose taking estrogen with progestin had an increased risk for stroke.
"This increased risk was observed for women initiating hormone therapy at young ages or near menopause and at older ages or more than 10 years after menopause," wrote the authors.
"The incidence of stroke was relatively low in younger women, and the attributable risk in women aged 50 through 54 years indicated approximately an additional two cases of stroke per 10,000 women per year taking hormones.
"There was also a strong relationship found between dose of estrogen and stroke, with larger doses increasing the risk," they added.
The findings in the Nurses' Health Study indicate that hormone therapy is associated with an increased risk of stroke, regardless of the hormone regime or the timing of hormone therapy initiation.
The report appears in April 28 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.