Endocrine Abstracts

Sex hormones are important determinant of body composition. The significant negative correlation between testosterone and obesity, positive correlation between testosterone and muscle mass and that testosterone therapy increases muscle mass in hypogonadal men is well-known.

Objectives: To assess the impact of total testosterone (TT) level on body composition in men with T2D.

Methods: A cross-sectional study involving men with T2D (N=200) assessing the impact of TT level on fat mass % (FM) and fat-free mass % (FFM). Men were divided into 2 groups according to their TT level: group 1 - untreated (TT<12 nmol/l), and sub-optimally treated hypogonadal men (TT<12 nmol/l 2–4 h after the testosterone gel application or trough testosterone level <12 nmol/l if on the testosterone injections) (N=102) and group 2 - eugonadal and optimally treated hypogonadal men (TT≥12 nmol/l) (N=98). Also, we assessed the significance between body composition and the quartiles of SHBG, HbA1c, ALT and AST/ALT ratios.

Results: Mean age 63.9±8.7 years (range 41–83). Mean TT level for group 1 8.1±2.6 nmol/l (range 0.4–11.8); for group 2 18.3±6.2 nmol/l (range 12.0–52.1). Comparing FM and FFM between the groups, we found significant difference in FM (P=0.021) and FFM (P=0.021) between the groups. Taking into account that FM+FFM=100%, the difference for FM and FFM is the same. In regard to FM and FFM, there was significant difference between the SHBG quartiles 1&4 (P=0.003), the HbA1c quartiles 2&4 (P=0.035), the AST/ALT ratio quartiles 1&4 (P=0.004) and 2&4 (P=0.048). The difference between the ALT quartiles 1&4 was trending towards statistical significance (P=0.108).

Conclusion: i) TT, SHBG and AST/ALT ratio are positively correlated to FFM and inversely correlated to FM. ii). HbA1c and ALT are inversely correlated to FFM and positively correlated to FM. iii). Testosterone should be replaced to the mid-normal range as per guidelines.