Endocrine Abstracts

During the past decade, few topics in medicine have been more controversial or clinically relevant than the effects of hormone replacement therapy (HRT) on risk for cardiovascular disease (CVD) in postmenopausal women. Based on extensive observational, animal model, and in vitro studies, many clinicians and patients were convinced that HRT lowered risk for CVD, a perception that helped make HRT use one of the most well-established treatment paradigms in American medicine. However, recent unexpected negative results from randomized clinical trials, including the Women's Health Initiative announced in July, have completely revised this view, transforming our understanding of the effect of HRT on CVD risk from one of presumed benefit to one of proven harm. This surprising turn of events has made it clear that the effects of HRT on vascular health are far more complex than initially assumed and urgently in need of additional study. Understanding how it is that estrogen, which has such favorable effects on intermediate pathways such as lipid metabolism and endothelial function, could nonetheless increase risk for CHD events would undoubtedly shed new light on the pathogenesis of atherosclerosis and provide fundamentally important additional information concerning estrogen biology. These issues will be discussed in detail.