Epidemiology of sarcopenia: A narrative review

Sarcopenia is a progressive loss of skeletal muscle mass and strength that contributes to adverse outcomes such as falls, fractures, and mortality in aging populations. Its prevalence varies widely across studies, influenced by intrinsic factors (eg, age, comorbidities, lifestyle), environmental conditions (eg, urban-rural differences, institutionalization), and the diagnostic criteria applied. This review synthesizes evidence mainly from systematic reviews and meta-analyses to examine how these factors shape the epidemiology of sarcopenia. The use of different definitions, such as EWGSOP 1/2, AWGS 2014/2019, IWGS, and FNIH, leads to large variations in prevalence estimates. This limits regional comparisons and hampers surveillance. The review also highlights key risk factors such as physical inactivity, malnutrition, smoking, irregular sleep, and cognitive impairment, although the overall certainty of evidence remains low to moderate. These findings emphasize the need for harmonized diagnostic standards and greater methodological consistency in future studies. Clinically, integrating sarcopenia screening into routine care and implementing targeted lifestyle interventions may help reduce disease burden. Future longitudinal and interventional research is essential to clarify causal pathways and guide effective public health strategies for sarcopenia prevention and management.