Both authors contributed equally.
Heritability of blood concentrations of sex-steroids in relation to body composition in young adult male siblings
Article first published online: 28 JUN 2008
© 2008 The Authors. Journal compilation © 2008 Blackwell Publishing Ltd
Volume 69, Issue 1, pages 129–135, July 2008
How to Cite
Bogaert, V., Taes, Y., Konings, P., Van Steen, K., De Bacquer, D., Goemaere, S., Zmierczak, H., Crabbe, P. and Kaufman, J.-M. (2008), Heritability of blood concentrations of sex-steroids in relation to body composition in young adult male siblings. Clinical Endocrinology, 69: 129–135. doi: 10.1111/j.1365-2265.2008.03173.x
- Issue published online: 28 JUN 2008
- Article first published online: 28 JUN 2008
- (Received 3 September 2007; returned for revision 9 October 2007; finally revised 29 October 2007; accepted 28 December 2007)
Objective Sex steroid concentrations in men are related to body composition and both are determined by genetic and environmental factors. This study investigates heritability estimates of sex steroid serum concentrations and body composition as well as the genetic and environmental components of their interrelation.
Patients Six hundred and seventy-four men (25–45 years) were included in this study with 274 independent pairs of brothers.
Measurements Body composition and regional fat mass estimates were determined using dual-energy X-ray absorptiometry. Serum testosterone (T), SHBG, oestradiol (E2) and LH levels were determined by immunoassay; free T and E2 levels were calculated.
Results Both sex steroid hormone concentrations and indices of body composition exhibited significant heritability estimates. Among sex steroid hormones, T had the highest heritability (h2 = 0·65), followed by free T (h2 = 0·54). A heritability of 0·73 was observed for SHBG; a heritability estimate of 0·83 was obtained for body weight. Significant genetic correlations were found between whole body fat mass and serum T (ρG = –0·46), free T (ρG = –0·27) and SHBG (ρG = –0·48) concentrations. No genetic relationship was observed between total (F) E2 or LH concentrations, respectively, and body composition.
Conclusion Both sex steroid serum levels and body composition are under strong genetic control. Their interrelation is in part underlied by a genetic correlation, indicative of the action of shared genes.