Effect of testosterone on insulin sensitivity, oxidative metabolism and body composition in aging men with type 2 diabetes on metformin monotherapy. Issue 10 (12th July 2016)

• Record Type: Journal Article
• Authors: Magnussen, Line V.; Glintborg, Dorte; Hermann, Pernille; Hougaard, David M.; Højlund, Kurt; Andersen, Marianne
• Is Part Of: Diabetes, obesity & metabolism. Volume 18:Issue 10(2016)
• Page Start: 980
• Page End: 989
• Publication Date: 2016-07-12
• Subjects: clinical trial -- insulin sensitivity -- male hypogonadism -- testosterone therapy -- type 2 diabetes mellitus; Diabetes -- Periodicals; Obesity -- Periodicals; Metabolism -- Disorders -- Periodicals; Clinical pharmacology -- Periodicals; 616.462
• DOI: 10.1111/dom.12701
• Languages: English
• ISSNs: 1462-8902

Abstract

Abstract : Aims: To evaluate the effect of testosterone replacement therapy (TRT) on body composition, insulin sensitivity, oxidative metabolism and glycaemic control in aging men with lowered bioavailable testosterone (BioT) levels and type 2 diabetes mellitus (T2D) controlled on metformin monotherapy. Materials and methods: We conducted a randomized, double‐blind, placebo‐controlled study in 39 men aged 50‐70 years with BioT levels <7.3 nmol/L and T2D treated with metformin monotherapy. Patients were randomized to testosterone gel (TRT, n = 20) or placebo (n = 19) for 24 weeks. Lean body mass (LBM), total and regional fat mass were measured using whole‐body dual‐energy X‐ray absorptiometry scans. Whole‐body peripheral insulin sensitivity, endogenous glucose production (EGP) and substrate oxidation were assessed by euglycaemic‐hyperinsulinaemic clamp with glucose tracer and combined with indirect calorimetry. Coefficients (β) represent the placebo‐controlled mean effect of intervention. Results: LBM (β = 1.9 kg, p = 0.001) increased after TRT, while total fat mass (β = −1.3 kg, p = 0.009), fat mass trunk (β = −0.7 kg, p = 0.043), fat mass legs (β = −0.7 kg, p = 0.025), fat mass arms (β = −0.3 kg, p = 0.001), and HDL cholesterol (β = −0.11 mmol/L, p = 0.009) decreased after TRT compared with placebo. Insulin‐stimulated glucose disposal rates did not change in response to TRT compared with placebo (p = 0.18). Moreover, glycated haemoglobin, and basal and insulin‐stimulated rates of EGP, lipid‐ and glucose‐oxidation were unaltered after TRT. Conclusion: TRT in aging men with lowered BioT levels and T2D controlled on metformin monotherapy improved body composition; however, glycaemic control, peripheral insulin sensitivity, EGP and substrate metabolism were unchanged.