The impact of testosterone replacement therapy on glycemic control, vascular function, and components of the metabolic syndrome in obese hypogonadal men with type 2 diabetes

Abstract

Objective: This study set out to assess effects of testosterone replacement therapy (TRT) on parameters of metabolic syndrome and vascular function in obese hypogonadal males with type 2 diabetes mellitus (DM2).

Study design: Fifty-five obese hypogonadal diabetic males on oral hypoglycemic treatment were enrolled into this one-year, double-blind, randomized, placebo-controlled clinical study. Group T (n = 28) was treated with testosterone undecanoate (1000 mg i.m. every 10 weeks) while group P (n = 27) received placebo.

Methods: Anthropometrical and vascular measurements - flow-mediated dilatation (FMD) and intima media thickness (IMT) - biochemical and hormonal blood sample analyses were performed at the start of the study and after one year. Derived parameters (BMI, HOMA-IR, calculated free testosterone (cFT) and bioavailable testosterone (BT)) were calculated.

Results: TRT resulted in reduction of HOMA-IR by 4.64 ± 4.25 (p < .001), HbA1c by 0.94 ± 0.88% points (p < .001), and an increase in FMD by 2.40 ± 4.16% points (p = .005).

Conclusion: TRT normalized serum testosterone levels, improved glycemic control and endothelial function while exerting no ill effects on the study population.

Keywords: Diabetes; endothelial function; hypogonadism; insulin resistance; intima media thickness; metabolic syndrome; replacement therapy; testosterone.