Hormone replacement therapy: cardiovascular benefits for aging women.

Observational studies suggest that hormone replacement therapy (HRT) reduces the risk of coronary artery disease by approximately 50%. This review focuses on possible mechanisms for this reduction in disease risk. HRT reverses many of the lipid and lipoprotein change associated with menopause, and the route of hormone delivery influences these changes. Oral HRT improves serum markers of clotting, although it may increase the risk of deep vein thrombosis. Endothelial function, particularly endothelium-dependent vasodilation, improves with estrogen. Central body fat appears to be reduced with oral HRT, possibly reducing the risk of coronary artery disease. Insulin sensitivity, which worsens after menopause, may be improved with HRT. Global systolic function, as measured by ejection fraction, may improve with oral HRT. Understanding how HRT regimens influence cardiovascular risk may allow physicians to make intelligent choices about HRT for particular patients.