Serum Uric Acid-to-creatinine Ratio and Sarcopenia Risk under AWGS 2025 Criteria: a Nationwide Study on the Interaction with Physical Activity

This study evaluated the independent relationship between the serum uric acid-to-creatinine ratio (UA/Cr) and sarcopenia phenotypes under the latest AWGS 2025 criteria, alongside the moderating role of physical activity (PA). Data were analyzed from 3,685 participants (aged ≥ 50 years) in the 2015 China Health and Retirement Longitudinal Study (CHARLS). Firth’s logistic regression and linear models assessed associations between UA/Cr and muscle phenotypes, while diagnostic performance was evaluated using receiver operating characteristic (ROC) analysis. In the fully adjusted model, UA/Cr was significantly associated with increased sarcopenia risk (OR = 1.122, 95