WITHDRAWN: Focusing on the influence of testosterone on leptin and resistin in male hypogonads: missing link in insulin resistance?

Endocr J (2010) PMID 20877139

The mechanism of testosterone therapy on insulin sensitivity is unclear. The aim of the present study was to determine effects of androgen therapy on glucose metabolism, body composition, and adipocytokines in patients with idiopathic hypogonadotrophic hypogonadism (IHH). One hundred two male subjects with IHH were enrolled in the study. Body fat and fat-free mass were determined by bioelectrical impedance analysis (BIA), fasting plasma leptin, resistin levels were measured by using ELISA kits commercially available and antropometric measurements were obtained before and after six months of androgen replacement therapy. Insulin sensitivity was calculated by HOMA-IR and QUICKI formulas. Following six months of androgen replacement therapy, statistically significant reductions were seen in body fat mass (27.41 ± 6.32% vs. 12.23 ± 3.74%, p= 0.001), HOMA-IR (5.61 ± 1.98 vs. 2.13 ± 0.72, p= 0.001), plasma leptin (15.32 ± 4.21 vs. 5.63 ± 1.34 ng/mL, p= 0.001) and resistin (6.48 ± 1.52 vs. 2.91 ± 1.94 ng/mL, p= 0.001) levels. Plasma free testosterone levels (2.64 ± 1.32 vs. 22.74 ± 2.52 pg/mL, p= 0.001), body fat-free mass (72.92 ± 6.73 % vs. 89.64 ± 4.18 %, p= 0.001), body mass index (21.71 ± 2.2 vs. 22.41 ± 1.89 kg/m(2), p= 0.001) and QUICKI index (0.31 ± 0.02 vs. 0.35 ± 0.01, p= 0.001) significantly increased after androgen replacement therapy. It was demonstrated that testosterone therapy may not only treat hypogonadism, but also have ameliorating effects on insulin sensitivity. Reduction in leptin and resistin concentrations may contribute to this phenomenon.