Screening and diagnosis of sarcopenia in rheumatic and musculoskeletal diseases: findings from a cross-sectional study

Sarcopenia is characterized by loss of muscle mass and reduced muscle function, presenting various adverse events, especially when inflammation is present. The present study aimed to determine the prevalence of sarcopenia and sarcopenic obesity among patients with rheumatic and musculoskeletal diseases (RMDs) and identify the risk for sarcopenia using two screening tools the Strength, assistance with walking, rising from a chair, climbing stairs, and falls (SARC-F) and the Mini Sarcopenia Risk Assessment (MSRA). In this single-center cross-sectional study, 220 consecutive patients visiting the Department of Rheumatology and Clinical Immunology at the University General Hospital of Larissa were interviewed. The EWGSOP criteria were used for the diagnosis of sarcopenia, while sensitivity, specificity, positive predictive values, number needed to screen, and positive and negative likelihood ratios were used to validate the diagnostic validity of the SARC-F and the MSRA. Univariate and multivariate logistic regression analyses were also applied to model the relationship between sarcopenia and other variables. In the total sample, 15.9% of patients were diagnosed with sarcopenia and one patient with sarcopenic obesity. The SARC-F (sensitivity 22.2%, specificity 75.6%), the 5-item (sensitivity 88.9%, specificity 18.9%), and the 7-item MSRA (sensitivity 91.7%, specificity 9.2%) presented poor clinical performance when used for screening alone. Univariate logistic regression analyses showed that underweight status, systemic sclerosis and appetite loss are strong contributors to sarcopenia diagnosis. Sarcopenia is prevalent among RMDs, and screening is essential within RMD clinics. None of the screening tools (SARC-F and MSRA) can stand alone in assessing sarcopenia in patients with RMDs. More research is required to understand sarcopenia in RMDs and validate the wide-using screening tools.