Nandrolone, a 19-nortestosterone, enhances insulin-independent glucose uptake in normal men.

Abstract

The effect of exogenous androgens on glucose metabolism is controversial. This study was designed to clarify the impact of testosterone enanthate (TE), an aromatizable androgen, and nandrolone decanoate (ND), a nonaromatizable androgen, on glucose disposal. Eleven healthy men were enrolled in a randomized, double-blind cross-over study. All subjects completed two treatment cycles consisting of two weekly injections of placebo followed by six weekly injections of either TE (300 mg/week) or ND (300 mg/week). Treatment periods were separated by a 4-week washout. A tolbutamide-modified, frequently sampled, iv glucose tolerance test was used to assess insulin-dependent and insulin-independent glucose disposal. Data were analyzed using Bergman's minimal model. Parameters examined included acute insulin response to glucose, fasting insulin level, glucose disappearance constant, insulin sensitivity index, glucose effectiveness at basal insulin (SG), and glucose effectiveness at zero insulin (GEZI). Neither androgen adversely affected glucose disposal. To the contrary, treatment with ND actually improved noninsulin-mediated glucose disposal as expressed by SG and GEZI. In ND-treated men, SG (x 10(-2) min(-1)) rose from 2.4 +/- 0.2 at the end of the placebo period to 3.7 +/- 0.6 after treatment (P < 0.05), whereas GEZI (x 10(-2) min(-1)) increased from 1.8 +/- 0.2 to 3.1 +/- 0.6 (P < 0.01). We conclude that the treatment of normal men with supraphysiological doses of either TE or ND does not adversely affect glucose metabolism. Treatment with a nonaromatizable androgen, such as ND, actually improves glucose metabolism by enhancing noninsulin-mediated glucose disposal.