Abstract 9204: High Plasma Estradiol Level as an Independent Risk Factor for Ischemic Arterial Disease Among Postmenopausal Women. A Population-Based Study (the Three-City Cohort Study)

Abstract

Background : Hormone therapy may increase the risk of coronary heart disease and stroke among postmenopausal women. However, the impact of endogenous steroid sex hormones (SSH) on ischemic arterial disease (IAD) has been poorly investigated. Objectives. To investigate the association of SSH with the risk of IAD among postmenopausal women. Methods : In the French prospective Three-City cohort study including subjects over 65 years, we investigated the association of bioavailable 17β-estradiol and total Testosterone with the 4-year incidence of IAD (coronary heart disease and ischemic stroke) among postmenopausal women who did not use any hormone therapy. Biological measurements were performed for all cases (n=106) and a random sample of controls (n=522) using a case/cohort study design. Hazards ratios (HR) and 95% Confidence Interval (95% CI) were estimated by weighted Cox proportional models. Results. In univariate analysis, subjects in the third tertile of bioavailable 17β-estradiol had an increased risk of IAD as compared with those in the first tertile (HR=1.80; 95%CI: 1.05-3.08, p for linear trend=0.03). Adjustment for traditional cardiovascular risk factors including obesity and diabetes did not substantially change the strength of this association (comparison of third tertile versus first tertile: HR=1.73; 95%CI: 1.01-3.05, p for linear trend=0.04). With respect to total testosterone, both univariate and multivariate analysis showed no significant association with the risk of IAD. Conclusion. Elevated plasma levels of bioavailable 17β-estradiol emerge as a significant and independent risk factor for IAD among postmenopausal women. These data are consistent with the findings of Women's Health Initiative trials and suggest deleterious effects of estradiol on cardiovascular disease in elderly women.