Testosterone replacement therapy for late-onset hypogonadism.

Cross-sectional and longitudinal studies have shown that testosterone levels fall with increasing age. Low testosterone levels are reported in 20% of men aged 60-69 years, and 30% of men in this age-group are thought to have low free testosterone levels. The prevalence of low testosterone levels increases in older men and, therefore, as the average age of men in developed countries is increasing, there will be even more hypogonadal men in the future. Many of the symptoms and signs associated with testosterone deficiency in younger men are present in aging men. Several small studies suggest that testosterone replacement therapy (TRT) can be beneficial for some aging men, but men in these studies have not been uniformly testosterone-deficient, and responses have been inconsistent. TRT might be more beneficial and safer in men aged below 65 years than in men aged 65 years or older. There is a need for large clinical trials in both age-groups to provide more definitive information for patients and clinicians as to the safety and efficacy of TRT. Before such data are available, clinicians must be cautious in offering these treatments to aging men. Close monitoring of patients undergoing testosterone supplementation is essential.