Long-term treatment with testosterone undecanoate injections in men with hypogonadism alleviates erectile dysfunction and reduces risk of major adverse cardiovascular events, prostate cancer, and mortality.

The association between erectile dysfunction (ED), hypogonadism, cardiovascular disease, and type 2 diabetes is well documented, but long-term data are limited. The aim of this study is to investigate effects of long-term testosterone therapy (TTh) with testosterone undecanoate in men with hypogonadism and ED. Observational, prospective registry of 805 hypogonadal men with different degrees of ED, evaluated by the International Index of Erectile Function - Erectile Function Domain. Four hundred and twelve patients underwent TTh, 393 patients served as controls, with an observation period up to 12 years. TTh led to substantial and sustained reduction of ED; improvement in erectile function was significant for each successive year until year 9. This was accompanied by improvements in cardiometabolic risk factors and urinary function throughout the 12-year follow-up period. Benefits of TTh were stronger for patients with moderate/severe ED than for patients with no/minor ED. Incidence of prostate cancer, major adverse cardiovascular events, and mortality were significantly lower in men on TTh compared with untreated men. Long-term TTh for up to 12 years alleviates ED, improves cardiometabolic risk factors, and reduces prostate cancer. Patients must stay on TTh consistently for a long time to achieve maximum benefits of TTh.