Aim: To explore the metabolic phenotype of Male Obesity-associated Secondary Hypogonadism (MOSH) and following treatment with long-acting intramuscular (IM) testosterone undecanoate.
Methods: A prospective observational pilot study on metabolic effects of IM testosterone undecanoate in MOSH (Hypogonadal [HG] group, n=13), including baseline comparisons with controls (Eugonadal [EG] group, n=15). Half the subjects (n=7 in each group) had Type 2 Diabetes Mellitus (T2D). Baseline metabolic assessment on Human Metabolism Research Unit (HMRU): fasting blood samples; BodPod (body composition), and; whole-body indirect calorimetry. The HG group was treated with testosterone undecanoate IM therapy for 6-29 months (mean 14.8-months [SD 8.7]), and HMRU assessment repeated. T-test comparisons were performed between baseline and follow-up data (HG group), and between baseline data (HG and EG groups). Data reported as mean (SD).
Results: Mean duration of Testosteorone IM therapy was 14.8 months (SD 8.7). Following Testosterone replacement IM therapy, there was a statistically significant reduction in fat mass (3.5Kg, P=0.03) and increase in lean body mass (2.9Kg, P=0.03). Overall, Testosteorone IM therapy resulted in a statistically significant improvement in HbA1C (9 mmol/mol, P=0.03), with 52% improvement in HOMA%B. Improvement in glycaemic control was driven by the HG subgroup with T2D, with 18 mmol/mol [P=0.02] improvement in HbA1C. Lipid profiles and energy expenditure were unchanged following Testosterone IM therapy. Comparisons between baseline data for HG and EG groups were equivalent apart from differences in testosterone, SHBG, BMR and vitamin D.
Conclusion: In patients with MOSH and T2D, Testosterone IM therapy improves body composition, beta cell function and glycaemic control.