Late-onset hypogonadism (LOH) is a syndromic condition that has a well-recognized association with sexual and reproductive failure. LOH is frequently associated with chronic conditions including cardiovascular diseases (CVD), obesity, osteoporosis, HIV infection, renal failure, and obstructive pulmonary diseases. Despite this evidence, in patients with these conditions, LOH is still only rarely investigated and testosterone replacement therapy (TRT) rarely considered. In this paper, we critically reviewed the available evidence on LOH treatment focusing on possible risks and benefits. Medical therapy of LOH should be individualized depending on the etiology of the disease and the patient's expectations. The fear of prostate cancer and the risk of erythrocytosis probably represent the main limitations of TRT in aging men. However, TRT in healthy older men in near physiological doses does not appear to incur serious adverse events, although regular monitoring of prostate-specific antigen and hematocrit levels is required. Available evidence also suggests that TRT might ameliorate central obesity and glycometabolic control in patients with metabolic syndrome and type 2 diabetes. In addition, TRT has been associated with an increase in bone mineral density in men with osteoporosis, with an improvement in lean body mass in subjects with human immunodeficiency virus infection or chronic obstructive pulmonary disease, as well as with peripheral oxygenation in patients with chronic kidney diseases. Despite this evidence, however, it should be recognized that the results of these trials were heterogeneous and limited by small sample sizes. Hence, further research is required regarding the long-term benefits and adverse effects of TRT in LOH.
Keywords: Diabetes mellitus; Erectile dysfunction; Hypogonadism; Prostate; Testosterone.