Effect of continuous positive airway pressure therapy on sexual function and serum testosterone in males with type 2 diabetes and obstructive sleep apnoea

Summary Objective There have been no studies of the effect of continuous positive airway pressure ( CPAP ) therapy on erectile dysfunction ( ED ) and serum testosterone in men with type 2 diabetes and obstructive sleep apnoea ( OSA ), a patient group at increased risk of ED and hypogonadism. The aim of this study was to determine whether CPAP improves sexual and gonadal function in males with type 2 diabetes and a pre‐ CPAP apnoea–hypopnoea index >15/h. Design Substudy of a trial assessing the effect of 3 months of CPAP on cardiovascular risk in type 2 diabetes. Patients Of 35 males starting CPAP , 27 (mean ±  SD age 65·4 ± 9·6 years, median [interquartile range] diabetes duration 12·1 [5·2–15·3] years) completed the trial. Measurements Serum total and free testosterone, responses to the A ndrogen D eficiency in the A ging A ale ( ADAM ) and S exual H ealth I nventory for M en ( SHIM ) questionnaires. Results There were no significant changes in mean total or free testosterone (baseline concentrations 12·7 ± 4·5 n m and 0·26 ± 0·07 p m , respectively), or SHIM score (baseline 13 [5–17]), after 3 months of CPAP ( P  >   0·20). The ADAM score (baseline 6·2 ± 2·1) fell after 1 month (to 5·0 ± 2·6) and was maintained at this level at 3 months ( P  =   0·015). The Epworth Sleepiness Scale score decreased and self‐reported physical activity increased over 3 months ( P  ≤   0·017) without a change in body mass index ( P  =   1·00). Conclusions These findings imply that CPAP therapy improves somnolence and promotes exercise in men with type 2 diabetes, but that there is no direct benefit for gonadal or sexual function.