Impact of testosterone therapy on bone turnover markers in obese males with type 2 diabetes and functional hypogonadism

Abstract

Methods: Fifty-five obese males with type 2 diabetes mellitus and functional hypogonadism participated in a 2-year, double-blind, placebo-controlled study of testosterone undecanoate (TU). Bone turnover markers C-telopeptide of type I collagen (CTX) and procollagen I N-terminal propeptide (PINP) were assessed at baseline, 12 and 24 months. Bone mineral density (BMD) changes were evaluated after 24 months using dual-energy X-ray absorptiometry. Group T (n = 28) received TU both years. Group P (n = 27) received placebo first year and TU second year. Results: CTX decreased in group P from 1055 (676–1344) to 453 (365–665) pmol/L (p < 0.001) and from 897 (679–1506) to 523 (364–835) pmol/L (p < 0.001) in T. PINP decreased by 4.30 ± 8.05 μg/L in group P (p = 0.030) and 4.64 ± 8.86 μg/L in T (p < 0.023) after first year of therapy. No femoral neck BMD changes were observed in 32 patients from both groups (n = 16 per group). Lumbar spine BMD increased (by 0.075 ± 0.114 g/cm2; p = 0.019) in group T following two years of treatment. Conclusions: We observed decreased CTX, decreased PINP and increased lumbar spine BMD after two years of testosterone treatment. Clinical trials: NCT03792321; retrospectively registered trial on 4 January 2019.