Abstract
Introduction: After 30 years of age, testosterone levels decline at a rate of 1-2% per year, which correlates with an increased incidence of late-onset hypogonadism diagnosed in middle-aged and elderly men. Testosterone replacement therapy (TRT) is emerging as a promising solution for aging-related problems. Objective: This study aimed to present the main clinical studies on the relationship between testosterone levels and aging in men, as well as an analysis of the reduction in physical and metabolic comorbidities. Methods: The systematic review rules of the PRISMA Platform were followed. The search was conducted from August to September 2024 in the Scopus, PubMed, Science Direct, Scielo, and Google Scholar databases. The quality of the studies was based on the GRADE instrument, and the risk of bias was analyzed according to the Cochrane instrument. Results and Conclusion: A total of 86 articles were found. A total of 23 articles were fully evaluated, and 11 were included and developed in the present systematic review study. Considering the Cochrane tool for risk of bias, the overall assessment resulted in 23 studies with a high risk of bias and 21 studies that did not meet GRADE and AMSTAR-2. Most studies showed homogeneity in their results, with X2=77.4%>50%. It was concluded that in the setting of aging in men, late-onset hypogonadism is the clinical entity characterized by low testosterone concentrations associated with clinical symptoms in the absence of organic disease in elderly men. It has been associated with metabolic syndrome, reduced bone mineral density, and increased risk of cardiovascular morbidity and mortality. Although testosterone replacement therapy reverses most of these conditions in young hypogonadal men, the risk/benefit ratio of testosterone replacement therapy in older men is debatable. In middle-aged and older men with hypogonadism and low libido, testosterone replacement therapy for 2 years improved sexual activity, hypogonadal symptoms, and sexual desire, but not erectile function. Furthermore, men with low testosterone, elevated luteinizing hormone, or deficient estradiol concentrations had increased all-cause mortality. Testosterone treatment aimed at achieving physiological concentrations in middle-aged and older men may improve lean body mass, while exercise training improves lean body mass, aerobic fitness, and strength.