Epidemiology of sarcopenia and insight into possible therapeutic targets

Key Points Sarcopenia, the age-related loss of muscle mass and function, is associated with considerable morbidity and health care costs Approaches to defining sarcopenia remain controversial, although several groups have proposed ways of defining the condition Moderate-quality evidence suggests that exercise interventions improve muscle strength and physical performance in patients with sarcopenia, whereas the benefits of nutritional interventions are more equivocal Most pharmacological agents for sarcopenia investigated to date are hormonal (testosterone and selective androgen receptor modulators) although therapies targeting myostatin signalling are emerging as new developments With the ageing population, sarcopenia is becoming a public health concern. However, controversy remains over how it can best be defined. In this Review, the authors discuss the various approaches to defining sarcopenia, its prevalence and potential lifestyle modifications and potential therapeutic strategies. Musculoskeletal ageing is a major public health concern owing to demographic shifts in the population. Sarcopenia, generally defined as the age-related loss of muscle mass and function, is associated with considerable risk of falls, loss of independence in older adults and hospitalization with poorer health outcomes. This condition is therefore associated with increased morbidity and health care costs. As with bone mass, muscle mass and strength increase during late adolescence and early adulthood, but begin to decline substantially from ∼50 years of age. Sarcopenia is characterized by many features, which include loss of muscle mass, altered muscle composition, infiltration with fat and fibrous tissue and alterations in innervation. A better understanding of these factors might help us to develop strategies that target these effects. To date, however, methodological challenges and controversies regarding how best to define the condition, in addition to uncertainty about what outcome measures to consider, have delayed research into possible therapeutic options. Most pharmacological agents investigated to date are hormonal, although new developments have seen the emergence of agents that target myostatin signalling to increase muscle mass. In this review we consider the current approaching for defining sarcopenia and discuss its epidemiology, pathogenesis, and potential therapeutic opportunities.