Importance: Obese men with modest reductions in circulating testosterone commonly report non-specific symptoms consistent with androgen-deficiency. Whether testosterone treatment leads to improvements in androgen deficiency-like symptoms over and above the effects of dieting is unknown.
Objective: To determine whether testosterone treatment improves androgen deficiency-like symptoms among dieting men.
Design: Secondary analysis of a randomised double-blind, placebo-controlled trial.
Participants: Obese men with a total testosterone level <12nmol/L.
Intervention: 100participants receiving 10 weeks of a very low energy diet (VLED) followed by weight maintenance were randomisedat baseline to 56 weeks of intramuscular testosterone undecanoate (n=49, cases) or placebo (n=51, controls).
Main Outcomes: The pre-specified outcomes were the between-group differences in Aging male symptoms score (AMS) and international index of erectile function (IIEF).
Results: Cases and controls lost the same weight after VLED (testosterone -12.0kg; placebo -13.5kg, p=0.40) and maintained this at study end (testosterone -11.4kg; placebo -10.9kg, p=0.80). There was no difference in AMS between groups after VLED (mean adjusted difference (MAD) -0.44, 95% CI -4.6; 3.8, p = 0.84) or at study end (MAD -1.7, 95% CI -6.2; 2.7, p = 0.44). Both cases and controls had improvements in AMS by approximately 20% after VLED (cases from 35.6 to 27.3 and controls from 34.6 to 27.9, both p < 0.05) which was maintained in cases (improved by 4.6 points, p = 0.006 relative to baseline) but not controls (improved by 2.3 points, p = 0.131) compared to baseline. Men had mild erectile dysfunction at baseline (IIEF cases 20.0, controls 19.3), with no between or within group differences during the study.
Conclusions: In relatively healthy obese men, androgen deficiency-like symptoms are primarily a consequence of excess weight rather than due to their reduced testosterone levels. For symptomatic benefit, weight loss rather than testosterone treatment should be the first line approach.