HRT may cause 39% higher risk of stroke

Women taking hormone replacement therapy have up to a 39% higher risk of suffering a stroke, according to a study by the Harvard Medical School in Boston, USA.

The study, published in the Archives of Internal Medicine, included 121,700 women aged between 30 and 55 who participated in the Nurses' Health Study. It found 360 cases of stroke amongst women who had never taken HRT versus 414 among current HRT patients.

According to the study, there is a 39% higher risk of stroke for women taking estrogen, and a 27% higher risk for those taking combination therapy of estrogen and progestin. The risk was equal for women initiating treatment at any age, before or after menopause, with the exception of those taking hormone therapy for less than five years at younger ages, although this may be related to the smaller number of cases representing that segment of the trial.