Diagnosis of sarcopenia in age-associated diseases using non-instrumental methods: analysis of literary sources

Sarcopenia is defined as a decrease in muscle mass, strength, and function. The primary population affected by sarcopenia consists of elderly and old-aged individuals, which is caused by an imbalance between anabolic and catabolic processes in the muscles, leading to a reduction in their volume and function. Loss of muscle mass during aging due to chronic diseases has serious negative effects: development of weakness, inability to perform self-care, worsening of existing somatic pathology, and an increased risk of mortality. As the global elderly population continues to grow, a sharp increase in sarcopenia cases is expected. Currently, the prevalence of sarcopenia worldwide ranges from 10 to 27% among people aged 60 and older. Sarcopenia is classified into primary sarcopenia, which is considered an independent disease, and secondary sarcopenia, which occurs against the background of existing chronic illnesses. The diagnosis of sarcopenia is confirmed based on measurements of muscle mass, strength, and physical performance. Assessment of muscle mass is performed using dual-energy X-ray absorptiometry (DXA) and bioimpedance analysis (BIA) — these are the most common methods. Muscle strength is evaluated with handgrip dynamometry, while physical performance (daily activity) is assessed using specific tests: the Short Physical Performance Battery (SPPB) and the “Get Up and Go” test (Timed Up and Go, TUG).Special questionnaires also play a significant role in confirming sarcopenia: the SARC-F questionnaire for rapid screening of sarcopenia (SARC-F-Sarcopenia Fast), the “Sarcopenia and Quality of Life” (SarQol) questionnaire, and the short form of the International Physical Activity Questionnaire (IPAQ-SF).The aim of this work was to analyze the prevalence and role of non-instrumental methods in diagnosing sarcopenia based on data from literary sources in foreign and domestic bibliographic and abstract databases (PubMed, Science Direct, Google Scholar, Elibrary) from 2014 to 2024.