-Endogenous sex hormones have been related to cardiovascular outcomes and mortality. We hypothesized that sex hormones are related to atrial fibrillation (AF) in a community-based cohort of middle-aged to older men.
METHODS AND RESULTS:
-We examined testosterone, estradiol, and dehydroepiandrosterone sulfate [DHEA-S]) in relation to incident AF in men participating in the Framingham Heart Study. We assessed the 10-year risk of AF in multivariable-adjusted hazard models. The cohort consisted of 1251 men (age 68.0±8.2), of whom 275 developed incident AF. We identified a significant interaction between age and testosterone, and therefore stratified men into age 55-69 (n=786), 70-79 (n=351), and ≥80 (n=114). In men 55-69 each 1-standard deviation (SD) decrease in testosterone was associated with hazard ratio (HR) 1.30 (95% confidence interval [CI], 1.07 to 1.59) for incident AF. The association between testosterone and 10-year incident AF in men 70-79 did not reach statistical significance. In men ≥80 years a 1-SD decrease in testosterone was associated with HR 3.53 (95% CI, 1.96 to 6.37) for AF risk. Estradiol was associated with incident AF (HR, 1.12; 95% CI, 1.01 to 1.26). DHEA-S had a borderline association with risk of AF that was not statistically significant (HR, 1.12; 95% CI, 0.99 to 1.28).
-Testosterone and estradiol are associated with incident AF in a cohort of older men. Testosterone deficiency in men ≥80 is strongly associated with AF risk. The clinical and electrophysiologic mechanisms underlying the associations between sex hormones and AF in older men merit continued investigation.
Alex's notes: Not much to say here other than to remind you that this is correlation, not causation. One review on the subject acknowledges that older men have lower circulating testosterone compared with younger men, and exhibit poorer health. Whether age-associated differences in hormone levels are causally related to cardiovascular disease, or are biomarkers reflecting accumulated ill-health remains under debate. Lower testosterone levels are associated with aortic, peripheral vascular, and cardiovascular disease in middle-aged and older men. In some but not all studies, lower levels of testosterone predict increased incidence of cardiovascular events and mortality. Small scale randomized clinical trials (RCTs) testosterone supplementation suggest a protective effect against myocardial ischemia in men with coronary artery disease, but there have been no RCTs with the prespecified outcomes of cardiovascular events or mortality. Observational studies of testosterone supplementation have reported contrasting results.
All that said, it's probably best to keep your testosterone in youthful levels. Want to know how? Train hard and eat smart.