Testosterone Raises Insulin Sensitivity

Giving testosterone to men with type 2 diabetes who are deficient in the hormone improved their insulin sensitivity, reports researchers from the University of Buffalo (New York, USA).  Paresh Dandona and colleagues conducted a randomized controlled trial of 81 men with type 2 diabetes.  Men were randomized to treatment with testosterone or placebo for 6 months. At baseline, those with hypogonadism had a higher body mass index (BMI) and a higher fat mass than those who didn't have low testosterone.  The team found that hypogonadal men with type 2 diabetes had significantly lower insulin sensitivity than those who did not have hypogonadism; further, that association remained even when controlling for weight and age (P=0.017). As well, free testosterone rose dramatically (4.1 nmol/L to 12.4 nmol/L), while placebo subjects had no significant changes in this parameter. Commenting that there was a "dramatic" 25% increase in insulin sensitivity … after these men took testosterone for 6 months,” the study authors note total lean body mass increased significantly for testosterone patients while fat mass significantly diminished in this group.