Testosterone replacement therapy: improved sexual desire and erectile function in men with type 2 diabetes following a 30-week randomized placebo-controlled study

Although testosterone replacement treatment (TRT) can improve sexual function in many hypogonadal (HG) men with type 2 diabetes (T2DM), some show either no improvement or only in a limited number of domains. Indeed, it is often difficult for the clinician to offer an indication of the likely efficacy of TRT as little data exist on the proportion of TRT-treated men who will demonstrate improvement in domains such as sexual desire (SxD) and erectile function (EF). We describe in men with T2DM: firstly, the likelihood of improved sexual desire (SxD) and erectile function (EF) following TRT at various time points, and secondly, if probability of SxD change predicted likelihood of subsequent EF change. During a 30-week randomized controlled study of testosterone undecanoate (TU), 199 T2DM men with HG (189 men completing) identified from primary care registers (placebo (P): 107, TU: 92) were stratified using baseline total testosterone (TT)/free testosterone (FT) into Mild (TT 8.1-12nmol/L or FT 0.18-0.25nmol/L) and Severe HG groups (TT 8 nmol/L and FT 0.18 nmol/L) and placebo (P)- and TU-treated groups. Associations between TU, SxD and EF were investigated using chi-square and logistic regression analysis. The proportion of men with improved SxD after 6 weeks and EF improvement after 30 weeks was significantly higher following TU treatment compared to P, this particularly evident in Severe HG men. Changes in SxD and EF were significantly associated in all groups. Logistic regression showed that SxD change at 6 weeks predicted of EF change after 30 weeks. Our study confirms TRT leads to changes in SxD and EF at different time points and suggests SxD and EF changes are related. SxD change after 6 weeks predicting EF change at 30 weeks is possibly a useful clinical finding.