Novel Approaches to the Diagnosis of Sarcopenia.

Sarcopenia is common in older people and is associated with disability, reduced mobility, hospitalization, and various comorbidities. Although it has been recognized for over a quarter of a century, we do not currently have a universally adopted definition. This limits our ability to compare results from different studies and impedes the development of novel therapies. Although sarcopenia was initially defined purely based on low muscle mass, the importance of measures of muscle function has been realized and these have been included in recent operational definitions. These continue to evolve with some including an assessment of adiposity and others adding further components of musculoskeletal health in a score-based approach. This review describes the importance of reaching a widely accepted method to define sarcopenia in both research and clinical practice. It details the ways in which the definition has changed since its initial inception and explores how it may continue to evolve in the future. The different methods by which components of sarcopenia can be measured are described, and the various advantages and disadvantages of these techniques are evaluated. Clearly, there are several other similar syndromes in older people, such as frailty and cachexia; their relationships and overlap with sarcopenia are also explored.