Hormone Replacement Therapy: Patch Less Risky for Stroke than Pill?

The risk for stroke associated with hormone replacement therapy (HRT) in postmenopausal women seems lower among those on low-dose transdermal regimens, according to a nested case-control study in BMJ.

From a cohort of almost 900,000 women over age 50, researchers age-matched 16,000 women who had a stroke over a follow-up period averaging 7 years with some 60,000 controls. Current users of oral estrogens, alone or in combination, had a higher stroke rate than nonusers of HRT.

When comparing oral and transdermal HRT directly, researchers found a lower stroke risk among transdermal users. However, high-dose patch users (>50 μg of estrogen) actually had a higher risk relative to nonusers (rate ratio, 1.88).

The authors warn that although their results suggest that the low-dose transdermal route may be safer, they do not represent definitive evidence.

BMJ article (Free)