Testosterone undecanoate improves sexual function in men with type 2 diabetes and severe hypogonadism: results from a 30-week randomized placebo-controlled study

Objective To evaluate the sexual function response to 30 weeks' treatment with long-acting testosterone undecanoate (TU) or placebo in 199 men with type 2 diabetes and either severe or mild hypogonadism (HG). Patients and Methods Men with HG were identified from seven primary care type 2 diabetes registers. A 30-week randomized placebo-controlled study of TU was carried out in 199 of these men (placebo, n = 107, TU, n = 92). The patient-reported outcome measure was the 15-item International Index of Erectile Function score. Men completing the study (n=189) were stratified, firstly, by baseline total testosterone (TT) or free testosterone (FT) into mild HG (TT 8.1-12 nmol/L or FT 0.18-0.25 nmol/L) and severe HG groups (TT <= 8 nmol/L and FT <= 0.18 nmol/L), and secondly, by intervention (placebo or TU), thereby creating four groups: mild HG/placebo; mild HG/TU; severe HG/placebo and severe HG/TU. Statistical Analysis Changes in sexual function score (a secondary outcome of the study) at each visit within group (from baseline) and between groups (TU vs placebo) at each assessment (6, 18 and 30 weeks) were compared using a Wilcoxon signed-rank and Wilcoxon rank-sum test, respectively. Results Significant improvement in erectile function was evident only in the severe HG group after 30 weeks of TU treatment; this finding persisted when TU was compared with placebo. Intercourse satisfaction and sexual desire scores were also improved at 6, 18 and 30 weeks in the severe HG group after TU treatment; this increase in scores was also evident when compared with placebo. TU did not appear to alter orgasmic function significantly in any of the patient groups. Conclusions The present study suggests that benefit in sexual symptoms after TU treatment is evident principally in patients with HG with TT levels <= 8 nmol/L and FT levels <= 0.18 nmol/L. We also suggest that 30 weeks of treatment is necessary before evaluating improvement in erectile function.