Ab0895 Unmasking Sarcopenia in Axial Spondyloarthritis: A Comparative Analysis of Screening Tools

Background: Sarcopenia, characterized by a reduction in muscle strength, mass, and physical performance, is often aggravated by chronic inflammation in axial spondyloarthritis (axSpA), leading to the deleterious condition of muscle wasting and poor function. Objectives: This research aims to compare the accuracy of SARC-F, SARC-CalF, SARC-F+EBM, handgrip strength, chair stand time, gait speed, and time and go test as screening tools for sarcopenia in patients with ax-SpA. Methods: A cross-sectional study involving 104 ax-SpA patients was conducted at Phramongkutklao Hospital between January 2020 and February 2021. Sarcopenia-related factors and disease characteristics were recorded. Sarcopenia was diagnosed according to the Asian Working Group for Sarcopenia (AWGS) 2019 criteria. Appendicular skeletal muscle mass was measured using dual-energy X-ray absorptiometry. The SARC-F, SARC-CalF, and SARC-F+EBM were evaluated. Muscle strength was measured using hand grip strength and chair stand time. Physical performance was assessed through the 6-meter walk and time up and go tests. The screening tests were evaluated using receiver operating characteristic (ROC) curves. The optimal cut-offs were identified by Youden index. Results: Most patients were male (74%), with a mean age (standard deviation: SD) of 42.6 (12.2) years and a mean disease duration of 8.3 (8.5) years. The mean BMI (SD) was 23.8 (4.4). The prevalence of sarcopenia, as determined by AWGS 2019 criteria, was 22.1%. The area under the ROC curve for SARC-F, SARC-CalF, SARC-F+EBM, handgrip strength, chair stand time, gait speed, and time and go test for sarcopenia screening were 0.509, 0.782, 0.856, 0.710, 0.640, 0.689, and 0.711, respectively, with 95% confidence intervals of 0.373-0.645, 0.670-0.894, 0.758-0.954, 0.594-0.825, 0.508-0.772, 0.539-0.839, and 0.576-0.846. The optimal cut-off for SARC-F, SARC-CalF, and SARC-F+EBM were 1, 10, and 10, with a sensitivity and specificity of 81.0% and 29.7%, 90.5% and 68.9%, and 77.3% and 87.2%, respectively. Conclusion: Despite the relatively young age of axSpA patients, sarcopenia emerges as a prevalent concern. Notably, calf circumference, SARC-CalF, and SARC-F+EBM exhibited superior screening efficacy compared to SARC-F alone, underscoring their potential as adept tools for sarcopenia identification within the ax-SpA population. This study advocates for heightened awareness and proactive management of sarcopenia in patients with axSpA. REFERENCES: 1 Kanjanavaikoon N, et al. Clin Rheumatol 2023. Dec;42(12):3257-3265 Acknowledgements: The authors would like to express our deepest appreciation to Phramongkutklao Hospital for funding and supporting this study. We also thank Ms. Wajee Matkummee, who works at the Division of Nuclear Medicine, Department of Radiology, Phramongkutklao Hospital, for performing skeletal muscle mass measurement and Ms. Sujittra Suriwong, Institute of HIV Research and Innovation, Bangkok, Thailand, for performing statistical analyses. Disclosure of Interests: Sumapa Chaiamnuay Pfizer, ZP therapeutics, GSK, Amgen, Alvogen, Natnicha Kanjanavaikoon: None declared, PANNARAT SAISIRIVECHAKUN: None declared.