Abstract
The systemic immune-inflammation index (SII) is a newly developed biomarker to assess inflammation, which plays a crucial role in chronic kidney disease (CKD). The objective of the investigation was to examine the connection between SII and early CKD. Retrospective clinical data from patients admitted to the Zhejiang Provincial People’s Hospital between 1996 and 2022 were analyzed. SII was calculated as platelet count × neutrophil count/lymphocyte count and estimated glomerular filtration rate (eGFR) slope as the difference between the first and last observed eGFR divided by the year interval. The independent connection between Sll and eGFR slope was explored employing the curves of Kaplan–Meier survival, Multivariable regression analysis, and subgroup analysis. This study included 3,419 patients who were separated into four groups depending on SII quartiles, with early decreased kidney function defined as eGFR slope ≥ 1. After adjustment for covariates, the adjusted HR (95%CIs) for the second, third, fourth quartiles were 1.36(1.18,1.56), 1.28(1.11,1.47) and 1.30(1.13,1.51), respectively. Subgroup analyses showed elevated SII levels were related to early CKD in patients aged ≤ 65, male, with no history of diabetes mellitus, and with or without hypertension. Kaplan–Meier survival curves showed that with increasing SII levels, the cumulative renal survival rate (eGFR slope < 1) significantly decreased. Our findings suggest that SII may act as a valuable novel marker for anticipating prognosis in individuals with early-stage CKD.