Correlation of serum testosterone with insulin resistance in elderly male type 2 diabetes mellitus patients with osteoporosis

AIMS/INTRODUCTION: The present study was designed to investigate the correlations between the serum testosterone level and insulin sensitivity in elderly male type 2 diabetes patients with osteoporosis. MATERIALS AND METHODS: A total of 35 elderly male patients with type 2 diabetes (type 2 diabetes group), 30 elderly male type 2 diabetes patients combined with osteoporosis (DO group) and 30 healthy elderly men (normal control group) participated in the present study. The fasting plasma glucose, fasting insulin, testosterone (T) and estradiol (E(2)) were measured. The insulin sensitivity index (ISI), homeostasis model assessment of insulin resistance (HOMA-IR) and E(2)/T were calculated. Then, the correlations of serum testosterone level with ISI and HOMA-IR were analyzed by statistical methods. RESULTS: The HOMA-IR, E(2) and E(2)/T of the type 2 diabetes group and DO group were significantly increased, whereas the bone mineral density, ISI, T and sex hormone binding globulin were decreased compared with those of the normal control group. Serum testosterone levels of the type 2 diabetes group and DO group were negatively correlated to the HOMA-IR (r = −0.496, −0.506; P < 0.05), whereas they were positively correlated to the fasting insulin (r = 0.281, 0.292; P < 0.05) and ISI (r = 0.364, 0.403; P < 0.05). CONCLUSIONS: The reduced level of serum testosterone in elderly male type 2 diabetes patients with osteoporosis might promote insulin resistance.