Familial resemblance for free androgens and androgen glucuronides in sedentary black and white individuals: the HERITAGE Family Study

Familial correlation analyses were used to evaluate the familial aggregatio n of plasma androgens and androgen glucuronides (testosterone (TESTO), dihy drotestosterone (DHT) androstane-3 alpha ,17 beta -diol glucuronide (3 alph a -DIOL-G), and androsterone glucuronide (ADT-G)) in 505 members of 99 whit e families and 296 members of Ill black families participating in the Healt h, Risk Factors, Exercise Training and Genetics (HERITAGE) Family Study. Ea ch of these tour measures was determined by RIA after separation of conjuga ted and unconjugated steroid using C18 Column chromatography. All participa nts were sedentary prior to being including in this study. Significant spou se correlations, as well as parent-offspring and sibling correlations, were found for TESTO, DHT, 3 alpha -DIOL-G, and ADT-G in the white sample, sugg esting that common familial environments and genes contribute to the famili al resemblance. In the black sample, significant sibling and parent-offspri ng correlations were found for all four phenotypes, while the spouse correl ation,vas marginally significant for 3 alpha -DIOL-G and not significant fo r TESTO, DHT, and ADT-G. The non-significance of spouse correlations in the black individuals may be due to the small number of spouse pairs. The maxi mal heritability estimates of TESTO, DHT, 3 alpha -DIOL-G. and ADT-G were 6 9%. 87%, 74%, and 56%, for white individuals and 70%, 73%, 62%, and 48% for black individuals respectively. Sex differences in heritability estimates were found in the white individuals, but they were less dramatic in the bla ck individuals. In conclusion. plasma levels of androgens and androgen gluc uronides are highly heritable in both white individuals and black individua ls. There are notable sex differences in the white individuals.