Abstract
INTRODUCTION: This study aimed to examine the relationship between the C-reactive protein-albumin-lymphocyte (CALLY) index, a composite measure of inflammation, nutritional status, and immune function, and chronic kidney disease (CKD). METHODS: The study employed a population-based cohort retrospective analysis design, integrating the NHANES dataset (n = 24,538) and the clinical cohort of China (n = 7,102). The present study sought to assess the association and predictive efficacy of the CALLY index for CKD. To this end, multistage logistic regression modeling, receiver operating characteristic (ROC) analysis, and restricted cubic spline analysis were employed. The analysis controlled for demographic factors, lifestyle, and metabolic diseases. RESULTS: The study indicated a negative correlation between the CALLY index and CKD, with a 1% reduction (odds ratio [OR] = 0.99, 95% confidence interval [CI] = 0.99-0.99) and a 3% reduction (OR = 0.97, 95% CI = 0.96-0.98) in CKD risk for every 1-unit increase in the index, respectively, in the US and Chinese cohorts. The ROC analyses yielded a multifactorial-adjusted AUC for the US cohort of 0.803 (95% CI: 0.795-0.810), and the Chinese cohort was 0.676 (95% CI: 0.657-0.695). Threshold effect analyses demonstrated that the risk significantly reduced when CALLY<2.313 (OR = 0.77 for the US cohort and OR = 0.63 for the Chinese cohort), and the association disappeared above the threshold. Subgroup analyses indicated that hypertension and obesity status modified the predictive efficacy of the CALLY index. CONCLUSION: The CALLY index demonstrates a negative correlation with CKD. Its cross-cohort robustness and threshold effect provide a foundation for implementing early screening and stratified intervention strategies. However, the index's clinical translational value remains to be validated in future studies.