[Testosterone treatment of sarcopenia]

Testosterone increases muscle mass and decreases fat mass by mechanism including androgen receptors. Testosterone induces skeletal muscle fibre hypertrophy and increases the number of satellite cells. It also promotes the differentiation of mesenchymal multipotent cells into myogenic lineage and inhibits their differentiation into the adipogenic lineage. Meta-analyses of clinical trials provide evidence that testosterone treatment, depending on dose, increases the skeletal muscle mass and to some degree also muscle strength. The most frequent adverse effects of testosterone treatment in aging men are an increase of hematocrit and increased risk of prostate events.