Testosterone is not associated with mortality in older African-American males

Abstract

Introduction. Although testosterone and its association with disease progression and mortality is a widely studied topic, no studies have evaluated mortality risks related to testosterone levels in an older African-American population. The mechanisms for known racial differences in mortality risk for certain cancers and cardiovascular risk factors are largely unknown. Elucidating a mortality risk associated with testosterone levels may give insight into the elevated risk for certain diseases in African-Americans.Methods and results. Study data were derived from a cohort 622 African-Americans (age 80.05 ± 6.4, range 68–102) from Saint Louis, Missouri that includes 190 males (age 79.38 ± 6.2, range 70–102). The eligible sample for this report includes 56 of the 190 males (age 78.89 ± 6.9, range 70–102) who donated blood at baseline in 1992–1994 and subsequently tested for total testosterone and bioavailable testosterone. Covariates for adjusted analyses were lower body functional limitations, physician visits and comorbidities, also collected at baseline. Males' mean bioavailable testosterone levels (ng/dl) were 33.33 ± 24.4 (n above 70 ng/dl = 5) and mean total testosterone levels (ng/dl) were 246.63 ± 118.7 (n above 300 ng/dl = 20). Vital status was determined through 2002; 41 males (73%) were deceased and 15 were alive. Mortality did not differ among males with testosterone levels <300 versus 300+ (p = 0.42) or with bioavailable testosterone levels <70 versus > 70 (p = 0.34). Total testosterone levels did not predict mortality when adjusted for age (Adjusted Hazard Ratio [AHR] = 0.998; 95% confidence interval [CI] 0.995–1.001; p = 0.28) or adjusted for age and other covariates (AHR = 0.099; 95% CI 0.996, 1.002; p = 0.35). Bioavailable testosterone levels did not predict mortality when adjusted for age (AHR = 0.992; 95% CI .977–1.007; p = 0.30) or when adjusted for age and other covariates (AHR 0.991; 95% CI .976–1.006; p = 0.261).Conclusion. In older African-American males, total and bioavailable testosterone levels, with and without adjustment for covariates, are not independently associated with mortality risk.