Endogenous sex hormones and cardiovascular disease incidence in men

Background: Data suggest that endogenous sex hormones (testosterone, dehydroepiandrosterone sulfate [DHEA-S], and estradiol) influence cardiovascular disease (CVD) risk factors and vascular function. Yet, prospective studies relating sex hormones to CVD incidence in men have yielded inconsistent results. Objective: To examine the association of circulating sex hormone levels and CVD risk in men. Design: Prospective cohort study. Setting: Community-based study in Framingham, Massachusetts. Participants: 2084 middle-aged white men without CVD at baseline. Measurements: The authors used multivariable Cox regression to relate baseline levels of testosterone, DHEA-S, and estradiol to the incidence of CVD (coronary, cerebrovascular, or peripheral vascular disease or heart failure) during 10 years of follow-up. Results: During follow-up, 386 men (18.5%) experienced a first CVD event. After adjustment for baseline standard CVD risk factors, higher estradiol level was associated with lower risk for CVD (hazard ratio per SD increment in log estradiol, 0.90 [95% Cl, 0.82 to 0.99]; P = 0.035). The authors observed effect modification by age: Higher estradiol levels were associated with lower CVD risk in older (median age > 56 years) men (hazard ratio per SD increment, 0.86 [Cl, 0.78 to 0.96]; P = 0.005) but not in younger (median age <= 56 years) men (hazard ratio per SD increment, 1.11 [Cl, 0.89 to 1.38]; P = 0.36). The association of higher estradiol level with lower CVD incidence remained robust in time-dependent Cox models (updating standard CVD risk factors during follow-up). Serum testosterone and DHEA-S levels were not statistically significantly associated with incident CVD. Limitations: Sex hormone levels were measured only at baseline, and the findings may not be generalizable to women and nonwhite people. Conclusions: In the community-based sample, a higher serum estradiol level was associated with lower risk for CVD events in older men. The findings are consistent with the hypothesis that endogenous estrogen has vasculoprotective influences in men.