Racial/ethnic differences in androg

Racial/ethnic differences in androgen levels could account for differences in prostate cancer risk, body composition, and bone loss. The objective of the study was to investigate racial/ethnic variations in testosterone, bioavailable testosterone, dihydrotestosterone (DHT), SHBG, and dehydroepiandrosterone sulfate (DHEAS) levels. The Boston Area Community Health (BACH) Survey was a multistage stratified cluster random sample, recruiting from 2002 to 2005. The study was a community-based sample of Boston. Participants included black, Hispanic, or white individuals, aged 30-79 yr, competent to sign informed consent and literate in English/Spanish. Of 2301 men recruited, 1899 provided blood samples (538 black, 651 Hispanic, 710 white). Intervention consisted of data obtained during in-person at-home interview, conducted by a bilingual phlebotomist/interviewer. Testosterone, bioavailable testosterone, DHT, DHT to testosterone ratio, SHBG, and DHEAS were measured. With or without adjustment for covariates, there were no significant differences in testosterone, bioavailable testosterone, or SHBG levels by race/ethnicity. DHEAS levels differed by race/ethnicity before covariate adjustment; after adjustment this difference was attenuated. Before adjustment, DHT and DHT to testosterone ratios did not significantly differ by racial/ethnic group. After adjustment, there was evidence of racial/ethnic differences in DHT (P = 0.047) and DHT to testosterone (P = 0.038) levels. Black men had higher DHT levels and DHT to testosterone ratios than white and Hispanic men. Because there are no racial/ethnic differences in testosterone levels, normative ranges need not be adjusted by race/ethnicity for androgen deficiency diagnosis for men aged 30-79 yr. Further investigation is needed to determine whether differences in DHT levels and DHT to testosterone ratio can help explain racial/ethnic variations in prostate cancer incidence, body composition, and bone mass.