Context:Higher testosterone in black compared with white men has been postulated to explain their higher prostate cancer incidence. Previous studies comparing hormone levels by race might have been limited by size, restricted age variation, or lack of representation of the general population.Objective: Our objective was to compare serum testosterone, estradiol, and SHBG concentrations among non-Hispanic black, non-Hispanic white, and Mexican-American men.Participants, Design, and Setting: A total of 1413 men aged 20ϩ yr and who attended the morning examination session of the Third National Health and Nutrition Examination Survey (NHANES III) in 1988 -1991 were included in this cross-sectional study.Measurement: Serum hormone concentrations were measured by electrochemiluminescence immunoassays.Results: After applying sampling weights and adjusting for age, percent body fat, alcohol, smoking, and activity, testosterone concentrations were not different between non-Hispanic blacks (n ϭ 363; geometric mean, 5.29 ng/ml) and non-Hispanic whites (n ϭ 674; 5.11 ng/ml; P Ͼ 0.05) but were higher in Mexican-Americans (n ϭ 376; 5.48 ng/ml; P Ͻ 0.05). Non-Hispanic blacks (40.80 pg/ml) had a higher estradiol concentration than non-Hispanic whites (35.46 pg/ml; P Ͻ 0.01) and Mexican-Americans (34.11 pg/ml; P Ͻ 0.01). Non-Hispanic blacks (36.49 nmol/liter) had a higher SHBG concentration than nonHispanic whites (34.91 nmol/liter; P Ͻ 0.05) and Mexican-Americans (35.04 nmol/liter; P Ͻ 0.05). Conclusions:Contrary to the postulated racial difference, testosterone concentrations did not differ notably between black and white men. However, blacks had higher estradiol levels. Mexican-Americans had higher testosterone than whites but similar estradiol and SHBG concentrations. Given these findings, it may be equally if not more important to investigate estradiol as testosterone in relation to diseases with racial disparity. (J Clin Endocrinol Metab 92: 2519 -2525, 2007)

The association of sex hormone levels with mortality over a median of 16 years of follow-up was evaluated in a prospective cohort study. The study included 1,114 US men who participated in phase 1 (1988-1991) of the Third National Health and Nutrition Examination Survey Mortality Study and had no history of cardiovascular disease or cancer at baseline. Multivariable adjusted hazard ratios for all-cause mortality associated with a decrease in hormone concentration equal to the difference between the 90th and 10th percentiles of the sex hormone distributions were estimated by using proportional hazards regression. The hazard ratios associated with low free testosterone and low bioavailable testosterone levels were 1.43 (95% confidence interval (CI): 1.09, 1.87) and 1.52 (95% CI: 1.15, 2.02), respectively, for follow-up between baseline and year 9; they were 0.94 (95% CI: 0.51, 1.72) and 0.98 (95% CI: 0.56, 1.72), respectively, for follow-up between year 9 and year 18. Men with low free and bioavailable testosterone levels may have a higher risk of mortality within 9 years of hormone measurement. Future studies should be conducted to fully characterize the association of low free and bioavailable testosterone concentrations and mortality in men and to describe the mechanism underlying the association.

Objective Obesity is associated with a variety of chronic diseases, including cancer, which may partly be explained by its influence on sex steroid hormone concentrations. Whether different measures of obesity, i.e., body mass index (BMI), waist circumference, and percent body fat were differentially associated with circulating levels of sex steroid hormones was examined in 1,265 men, aged 20 to 90+ years, attending the morning examination session of the Third National Health and Nutrition Examination Survey (NHANES III). Methods and Methods Serum hormones were measured by immunoassay. Weight, height, and waist circumference were measured by trained staff. Percent body fat was estimated from bioelectrical impedance. Multivariate linear regression was used to estimate associations between body fatness measures and hormone levels. Results Total and free testosterone and sex hormone binding globulin concentrations decreased, whereas total and free estradiol increased with increasing BMI, waist circumference, and percent body fat (all P-trend <0.05). The magnitude of change in these hormones was similar for a one quartile increase in each body fatness measure. Conclusion Measured BMI, waist circumference, and percent body fat led to similar inferences about their association with hormone levels in men.