Long-term Outcomes of Testosterone Treatment in Men: A T4DM Postrandomization Observational Follow-up Study

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 testosterone (T) treatment reducing diabetes diagnosis by 40%.

The long-term effects on new diagnosis of diabetes, cardiovascular and prostate disease, sleep apnea, weight maintenance trajectory and androgen dependence were not yet described.

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 the follow-up survey compared with nonparticipants in 23 anthropometric and demographic variables.

Randomization to was TU associated with stronger belief in study benefits during (64% vs 49%, P < .001) but not after the study (44% vs 40%, P = .07); there is high interest in future studies. At T4DM entry, 25% had sleep apnea with a new diagnosis more frequent on TU (3.0% vs 0.4%, P = .03) during, but not after, the study. Poststudy, resuming prescribed T treatment was more frequent among TU-treated men (6% vs 2.8%, P = .03). Five years after cessation of TU treatment there was no difference in self-reported rates of new diagnosis of diabetes, and prostate or cardiovascular disease, nor change in weight maintenance or weight loss behaviors.

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 poststudy T treatment consistent with androgen dependence in some men receiving prolonged injectable TU.