The treatment of late-onset hypogonadism.

Late-onset hypogonadism (LOH) in aging men is a clinical and biochemical syndrome caused by an age-related decline in testosterone. Despite published in guidelines and recommendations, uncertainty surrounds the profile of clinical symptoms as well as the biochemical threshold of diagnosis. The only evidence-based treatment of late-onset hypogonadism is testosterone replacement therapy. The actual available evidence of the long-term risks and outcomes of testosterone-replacement therapy remains very limited, and carefully designed placebo-controlled trials of testosterone administration to assess the risks and benefits of such a therapy are required. Until such evidence is available, testosterone treatment should be restricted to elderly men with very low testosterone levels in the presence of clinical symptoms, and the advantages and disadvantages need to be accurately assessed. Careful monitoring of potential side effects is necessary. The purpose of this review is to discuss what is known and what remains unclear with respect to the benefits and risks of testosterone replacement treatment.