#2332 Systemic immune-inflammation index is associated with chronic kidney disease: evidence from NHANES 2009-2018

Background and Aims The systemic immune-inflammation index (SII), a novel inflammation index, reflects systemic inflammatory and immunologic conditions throughout the human body. However, the relationship between SII and chronic kidney disease (CKD) remains unknown. The purpose of this study was to investigate the possible relationship between SII and CKD. Method The cross-sectional study included participants with complete information on SII (platelet × neutrophil/lymphocyte count), serum creatinine (Scr), or urinary albumin-to-creatinine ratio (UACR) from the 2009-2018 National Health and Nutrition Examination Survey (NHANES). CKD was defined as the presence of either low estimated glomerular filtration rate (eGFR) or albuminuria. Univariate and multivariate logistic regression and restricted cubic spline regression were used to assess the linear and nonlinear association between SII and renal function. Subgroup and interactive analyses were performed to explore potential interactive effects of covariates. Missing values were imputed using random forest. Results A total of 23 236 participants were enrolled in the study, of whom 4518 (17.9%) were diagnosed with CKD. After adjustment for covariates, the odds ratios (ORs) for prevalent CKD were 1.01 (95% CI = 0.91-1.11, p >0.05) for the Q2 group, 1.18 (95% CI = 1.08-1.30, p < 0. 001) for the Q3 group, and 1.64 (95% CI = 1.50-1.80, p < 0.001) for the Q4 group. In the association between SII and CKD, there was a significant interaction in age (p for interaction < 0.05). And non-linear association between SII levels and CKD in the whole population (p for non-linear = 0.001). All sensitivity analyses supported the positive association between SII and CKD. Conclusion SII was positively correlated with increased risk of CKD. The SII may serve as a practical and cost-effective tool for identifying and intervening the individuals at risk for CKD.