WASHINGTON - Post-menopausal women taking hormone therapy are at an increased risk of stroke regardless of the age at which they start the treatment, according to the results of a new study.
Women taking the female sex hormone estrogen have a 39 percent higher risk of stroke than those who have never taken it, said the study published Monday in the Archives of Internal Medicine.
It also found a "strong relationship" between the levels of estrogen taken and higher risk, with larger doses increasing the risk.
For women taking a combination of estrogen with progestin, a synthetic form of progesterone, the increased risk was 27 percent, the researchers said.
"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 Francine Grodstein and colleagues at Brigham and Women's Hospital and Harvard Medical School.
However, the researchers noted that younger women are generally at lower risk of stroke than older women, and said the risk might be further minimized by using lower doses and shorter treatment periods.
The researchers found no clear increased risk in women who took hormone therapy for less than five years at younger ages, which could be due to the smaller number of cases involved.
The study involved 121,700 women aged 30 to 55 who took part in the Nurses' Health Study from 1976 to 2004. There were 360 cases of stroke among the women who had never used hormones and 414 among those currently using them.
The study comes amid an ongoing debate about the risks and benefits of hormone therapy for post-menopausal women, but was the first to look at women who began treatment several years before the menopause, the researchers said. - AFP/sh
From ChannelNewsAsia.com; source article is below:Post-menopausal hormone therapy increases stroke risk