Long-Term Outcomes of Testosterone Treatment in Men: A T4DM Post-Randomisation Observational Follow-Up Study.

Abstract

The T4DM study randomized 1007 men with impaired glucose tolerance or newly diagnosed diabetes to testosterone undecanoate (TU, 1000 mg) or matching placebo (P) injections every 12 weeks for 24 months with a lifestyle program with T treatment reducing diabetes diagnosis by 40%. A follow-up email survey after a median of 5.1 years since last injection obtained 599 (59%) completed surveys (316 T, 283 P) with participants in follow-up survey like non-participants in 23 anthropometric and demographic variables. Randomization to TU associated with stronger belief in study benefits during (64% vs 49%, p < 0.001) but no longer after the study (44% vs 40%, p = 0.07) and high interest in future studies. At T4DM entry, 25% had sleep apnea with new diagnosis more frequent on TU (3.0% vs 0.4%, p = 0.03) during, but not after, the study. Post-study resuming prescribed testosterone treatment was more frequent among TU treated men (6% vs 2.8%, p = 0.03). Five years after cessation of TU treatment there was no difference in self-reported rates of new diagnosis of diabetes, prostate or cardiovascular disease nor change in weight maintenance or weight loss behaviours. We conclude that randomized T treatment for 24 months in men with impaired glucose tolerance or new diabetes but without pathological hypogonadism was associated with higher levels of self-reported benefits and diagnosis of sleep apnea during, but not after, the study as well as more frequent prescribed post-study testosterone treatment consistent with androgen dependence in some men receiving prolonged injectable TU.