Clinical, laboratory and instrumental aspects of sarcopenia diagnostics

Sarcopenia is an age-associated progressive loss of muscle mass and strength that leads to decreased functional activity, increased risk of falls, fractures, hospitalizations, and significantly contributes to disability and mortality in the elderly. There is no universal explanation for the development of sarcopenia. The mechanisms of muscle mass reduction include the influence of external (chronic diseases, physical inactivity, intake of certain medications, insufficient protein intake with food) and internal factors (age-related neuromuscular degeneration, changes in the level of anabolic hormones, chronic inflammation, and oxidative stress). The multifactorial pathogenesis of sarcopenia explains the lack of generally accepted diagnostic tools for this condition. The purpose of this review is to summarize current information on algorithms for assessing muscle strength, muscle mass, physical performance, and diagnostic criteria for sarcopenia by various research groups. The review describes options for laboratory markers that are promising and of interest in relation to diagnostics and determining the effectiveness of therapeutic and preventive interventions.