Contemporary sarcopenia diagnosis: evolving definitions, screening, and instrumental assessment – a narrative review

Abstract

Sarcopenia currently affects 10–27% of people worldwide and 30–37% in the Russian Federation. Its social burden is considerable: the condition is associated with fractures, disability, and increased mortality. Sarcopenia nonetheless remains underdiagnosed. Diagnosis is hindered by the absence of universal criteria, standardized cutoff values, and widely available screening tools, while applying non-adapted foreign reference values to the Russian population may cause both under- and overdiagnosis. Aim. To analyze the evolution of international and Russian approaches to sarcopenia diagnosis, assess the diagnostic value and limitations of available screening and instrumental methods, and formulate proposals for optimizing diagnostic strategies in clinical practice in the Russian Federation. Materials and methods. A literature review on sarcopenia diagnosis was conducted using PubMed/MEDLINE, Scopus, Google Scholar, and eLibrary.ru for 2006–2026. Systematic reviews, meta-analyses, randomized controlled trials and cohort studies, consensus documents, and clinical guidelines were included. Results. A shift was observed from the isolated assessment of muscle mass toward diagnostic models in which muscle strength serves as the primary criterion and physical performance as an indicator of disease severity. Handgrip dynamometry cutoff values varied across populations. In particular, muscle strength in Russians older than 65 years was at the lower limit of European reference values. No screening instrument demonstrated both high sensitivity and high specificity. The most balanced instrument, SARC-CalF, has not been validated in the Russian population. Instrumental methods are highly accurate; however, their use is limited by high cost, limited availability, dependence on hydration status, and the lack of standardized protocols. Conclusion. To improve the effectiveness of sarcopenia diagnosis in Russia, national reference values should be developed, diagnostic protocols standardized, and screening instruments validated.