DIAGNOSTIC CRITERIA OF SARCOPENIA: A NARRATIVE REVIEW FROM CLINICAL, BIOCHEMICAL, LABORATORY, AND EPIGENETIC PERSPECTIVES

Abstract

Sarcopenia is a progressive, generalized skeletal muscle disorder characterized by accelerated loss of muscle mass, strength, and physical function. This narrative review comprehensively evaluates the diagnostic criteria for sarcopenia across clinical, biochemical, laboratory, and epigenetic domains. Clinically, diagnosis hinges on structured assessments such as grip strength protocols, physical performance batteries, and validated imaging techniques such as muscle ultrasound. Biochemically, chronic systemic inflammation—potentiated by cytokines and the NLRP-3 inflammasome—is identified as a critical pathophysiological driver of muscle catabolism. Laboratory advancements emphasize the utility of circulating metabolomic signatures in detecting early metabolic dysregulation, while epigenetic studies elucidate how cellular senescence and microRNA alterations drastically accelerate muscle aging, particularly in oncological and post-menopausal contexts. By systematically synthesizing evidence from exactly 15 selected high-quality peer-reviewed articles, this review identifies the current unmet need for a globally standardized diagnostic consensus. Bridging this gap requires the integration of multi-domain parameters to optimize early risk stratification and tailor therapeutic interventions.