REDUCED TESTOSTERONE AND ADRENAL C-19 STEROID-LEVELS IN OBESE MEN

It has been reported that a high proportion of abdominal fat is associ ated with increased plasma androgen concentrations in women. Although less evidence is available, abdominal obesity appears to be associated with low plasma testosterone (T) levels in men. We have therefore exa mined in 80 men (aged 36.3 +/- 3.2 years, mean +/- SD) the correlation s between body fatness, adipose tissue (AT) distribution measured by c omputed tomography (CT). and circulating levels of the following stero ids measured by radioimmunoassay after extraction from serum and chrom atography: dehydroepiandrosterone (DHEA), androstenedione (Delta(4)-DI ONE), androst-5-ene-3 beta,17 beta-diol (Delta(5)-DIOL), T, estrone, a nd estradiol. Sex hormone-binding globulin (SHBG) levels were also det ermined. T, adrenal C-19 steroids, and SHBG levels were negatively cor related with total body fatness indices and abdominal fat deposition m easured by CT (-.23 less than or equal to r less than or equal to -.55 , .0001 less than or equal to P less than or equal to .05), whereas es t positive correlations with these body fatness and AT distribution in dices. Covariance analysis showed that after control for the concentra tion of the adrenal steroid precursor Delta(5)-DIOL, there was no resi dual association between T levels and adiposity variables. Furthermore , multivariate analyses showed that steroid and SHBG levels could expl ain from 20% (visceral AT area measured by CT) to 40% and 42% (body ma ss index [BMI], waist circumference, and waist to hip ratio [WHR]) of the variation in adiposity variables (.0001 less than or equal to P le ss than or equal to .05), with Delta(5) DIOL being the best single cor relate of body fatness and abdominal fat deposition in men. On the oth er hand, total body fat mass was the best and sole predictor of DHEA, Delta(5)-DIOL, estradiol, and SHBG levels, explaining up to 22% of the variance (Delta(5)-DIOL). These results suggest that reduced concentr ations of T and of adrenal C-19 steroid precursors are associated with increased body fatness rather than with excess visceral fat accumulat ion. Furthermore, they emphasize the importance of adrenal steroids as correlates of body composition in men. Copyright (C) 1995 by W.B. Sau nders Company