Pharmacological therapy of sarcopenia: Past, present and future

Sarcopenia, defined as the loss of muscle mass and function, has important consequences in terms of increasing frailty, disability, and social and healthcare costs. The diagnosis of sarcopenia should be considered in all patients presenting a decline in physical function, muscle strength and general health conditions. Given that the progressive reduction of muscle mass and strength occurs also in aging, the switch towards a pathological condition has been established by combining diagnostic cut-offs and risk factors for reduced mobility, poor quality of life, and increased morbidity and mortality. On the other hand, the introduction of different criteria for the diagnosis of sarcopenia has hindered the development of guidelines for the management of this disorder. The objective of the treatment of muscle wasting is to maintain or improve muscle mass, and both mechanical and metabolic muscle functions. The management of sarcopenia should be multifactorial and interdisciplinary, including exercise, particularly muscle strengthening training, intake of proteins and Vitamin D, and treatment of diseases causing muscle loss. To date there are no drugs that have been specifically approved for the treatment of sarcopenia (or other conditions causing reduced muscle function) although many substances are commonly used for this purpose. Several drugs have been studied to improve muscle mass and function, such as testosterone, estrogens, selective modulators of the androgen receptor (SARMs), ghrelin, anti-cytokines (IL-1, IL-6,TNF-α), and myostatin inhibitors. Identification of novel molecules targeting specific biological pathways whose stimulation or inhibition produces net anabolic effects on skeletal muscle might be a significant step forward for the treatment of muscle disorders.