Abstract
PURPOSE: The prevalence of chronic kidney disease (CKD) in ethnic minority areas of southern China is outdated. The association between fat-to-muscle ratio (FMR) and CKD in these populations remains unclear. This study aims to investigate the prevalence of CKD and the relationship between FMR and CKD and to evaluate the potential utility of FMR in CKD risk assessment. PATIENTS AND METHODS: A cross-sectional study was conducted using data from the 2020-2021 China Cardiovascular Disease and Risk Factors Surveillance in Guangxi. CKD is defined as estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m² or urine albumin-to-creatinine ratio (UACR) ≥30 mg/g. Data from questionnaires, physical exams, and laboratory tests were used to estimate CKD prevalence. Fat and muscle mass were assessed via bioelectrical impedance analysis. The association between FMR and CKD was examined using multivariable logistic regression. RESULTS: Among 8940 participants (median age 50; 41.9% male, 42.0% Zhuang), crude CKD prevalence was 13.8% (awareness: 1.4%), with ethnic disparity (Zhuang: 12.9% vs non-Zhuang: 14.5%, P=0.025). The overall age- and sex-adjusted CKD prevalence was 10.9%; corresponding figures were 9.6% for Zhuang and 17.1% for non-Zhuang participants after further adjustment for ethnicity. FMR was independently associated with CKD (OR=1.03 per 0.1-unit, P<0.05), even after adjusting for demographic, lifestyle, and comorbidities. Interactions were observed between FMR and ethnicity, hypertension, and diabetes (P-interaction<0.05). FMR increased progressively with CKD stage and albuminuria grade (P<0.001 for trend). A threshold effect was observed at FMR >0.84, with a higher prevalence of CKD (16.7% vs 11.1%), albuminuria (12.5% vs 7.9%), and impaired kidney function (6.0% vs 4.4%) (all P<0.001). CONCLUSION: The relatively high prevalence but extremely low awareness of CKD in Guangxi highlights a critical detection and prevention gap. Incorporating FMR measurement into population-based screening may help identify individuals at high risk of CKD and guide targeted integrated prevention strategies.