Risks and benefits of hormone replacement therapy: the evidence speaks

Abstract

Until recently, observational studies suggested a decreased risk of cardiovascular disease, osteoporotic fractures, cognitive decline and colon cancer with the use of hormone replacement therapy (HRT). Recent randomized controlled trials have failed to show a protective effect of HRT in reducing the risk of coronary artery disease and instead have revealed an increased risk of heart disease, stroke, invasive breast cancer and venous thromboembolism, but a decreased risk of colorectal cancer and osteoporotic fractures. In this article we review the current evidence of the risks and benefits of HRT.

Fig. 1: Meta-analysis of observational studies of the risk of coronary artery disease in postmenopausal women taking estrogen and those not taking estrogen, published up to mid-1997. Reprinted, with permission, from reference 3. Copyright 1998, Annual Reviews.

Fig. 2: Effect of hormone replacement therapy (HRT) on cardiovascular and noncardiovascular outcomes among postmenopausal women with coronary artery disease (CAD) in the Heart and Estrogen/progestin Replacement Study (HERS) and HERS II (longer follow-up)., Venous thromboembolism (VTE) was the only outcome on which HRT had a significant effect compared with placebo.

Fig. 3: Effect of HRT on cardiovascular and noncardiovascular outcomes among healthy postmenopausal women in the Women's Health Initiative trial. Outcomes are grouped according to whether HRT had a negative or positive effect, or no effect, compared with placebo. [Source: WHI HRT Update — 2002, National Heart, Lung, and Blood Institute (National Institutes of Health, US Department of Health and Human Services), Bethesda, Md. (available www.nhlbi.nih.gov/health/women/upd2002.htm [accessed 2003 Mar 19]).