How Long Does it Take to Achieve Maximal Improvements of Erectile Function in Men with Functional Hypogonadism Receiving Long-term Testosterone Therapy? Results from a Registry Study

Abstract

ABSTRACT Introduction While beneficial effects of testosterone therapy (TTh) on erectile function (EF) are well established, there is limited information about the duration of TTh required to achieve maximum effects. Hackett et al. demonstrated that EF kept improving for 3.8 years in men with hypogonadism and type 2 diabetes receiving continuous TTh (World J Men's Health 2020;38:68-77). Objective to investigate year-to-year changes in IIEF-EF in men receiving long-term TTh up to 11 years in comparison to an untreated control group. Methods In an ongoing registry study in men with hypogonadism (defined by total testosterone ≤350 ng/mL and at least a moderate symptom score on the Aging Males’ Symptoms scale) in a single urology office, men with primary hypogonadism (for instance, Klinefelter's syndrome) were excluded from the analysis. 779 men had functional hypogonadism. 386 men received testosterone undecanoate (TU) injections 1000 mg/12 weeks following an initial 6-week interval (T-group), 393 opted against TTh and served as controls (CTRL). IIEF-EF (5+1 questions, maximum score: 30) was assessed at each visit. Changes over time between groups were compared by a mixed effects model for repeated measures with a random effect for intercept and fixed effects for time, group and their interaction and adjusted for age, weight, waist circumference, blood pressure, fasting glucose, lipids and quality of life to account for baseline differences between groups. Results Mean (median) follow-up: T-group 8.9±2.6 (10), CTRL 9.6±2.3 (11) years, total observation time: T-group 3431, CTRL 3765 years. Baseline age was 58.4±6.4 (T-group) and 63.1±4.8 years (CTRL) (p<0.0001). At baseline, PDE5-Inhibitors were used by 25.9% (T-group) and 22.1% (CTRL) (p=0.2181). T-group: IIEF-EF increased by 9.8±0.2 (least squares means ± standard errors) in year 11, p<0.0001 vs. baseline. For the first 6 years, the change was always statistically significant vs. previous year with p<0.0001, from year 7 to 6 with p<0.005, from year 8 to 7 with p<0.0005, from year 9 to 8 with p<0.0001, from year 10 to 9 with p<0.05, and from year 11 to 10 with p<0.0001. CTRL: IIEF decreased by 12.7±0.2. Estimated adjusted difference between groups: 20.8. The year-to-year changes were statistically significant at a level of p<0.0001 throughout the observation time. The estimated adjusted difference between groups at 11 years was 22.5 (95% confidence interval: 21.9;23.2). Adherence to TTh was 100 per cent as all injections were administered in the office and documented. Conclusions Long-term testosterone therapy in men with functional hypogonadism improved erectile function continuously over the full observation time, despite advancing age. In the untreated control group, erectile function deteriorated progressively. Hypogonadism is a chronic disease which requires lifelong treatment to achieve maximum benefits. Disclosure Yes, this is sponsored by industry/sponsor: Bayer Clarification: Industry funding only - investigator initiated and executed study Any of the authors act as a consultant, employee or shareholder of an industry for: Bayer