Testosterone supplementation: why and for whom?

Androgen levels decline over a man's lifetime. In a proportion of men (increasing with age), levels fall below values that have been established by conventional laboratory criteria as indicative of hypogonadism. Testosterone has a wide range of non-reproductive actions: it preserves bone and muscle mass, it acts on non-sexual mental functioning and it stimulates red blood cell formation. Long-term androgen deficiency has a great impact on quality of life. The first intervention studies provide indications that androgen treatment of men with true androgen deficiency is helpful. Obviously, only men who are testosterone-deficient will benefit from androgen supplementation. The diagnosis of testosterone deficiency in old age is not unambiguous. Signs and symptoms of aging sometimes clinically overlap with those of testosterone deficiency. The groups that are at higher risk of testosterone deficiency are those men with disease (pulmonary disease, gastro-intestinal disease, rheumatoid disease, etc.). Usually, sex hormone binding globulin levels increase with aging, leading to lower levels of free, biologically available testosterone. For the time being, arbitrary criteria for testosterone deficiency in aging men have to be adopted. The best practical approach is to calculate the free testosterone level. The calculation can be found at www.issam.ch under 'Tools'.