Oral and Transdermal Estrogen Therapy and Risk for Stroke

In the Women's Health Initiative randomized trials, postmenopausal oral estrogen therapy raised risk for stroke. However, whether this risk is elevated among transdermal estrogen users is unknown. In this population-based nested case-control study, investigators used a large U.K. database to assess risk for stroke associated with use of oral and transdermal hormone therapy among 870,000 women (age range, 50–79) during the 20-year study period.

Researchers identified 16,000 women who received diagnoses of first stroke and matched them with 60,000 randomly selected controls. After adjustment for multiple confounders, current use of any dose of oral estrogen or oral estrogen–progestogen was associated with elevated risk for stroke, compared wit…