Association of pan-immune inflammation values with chronic kidney disease: Evidence from NHANES 1999–2018

The pan-immune-inflammation value (PIV) is a bioindicator that provides a broader evaluation of systemic immune and inflammatory responses. However, limited research exists regarding its ability to predict chronic kidney disease (CKD) and all-cause mortality, which this study intends to investigate. This analysis drew on data from 1999 to 2018 National Health and Nutrition Examination Survey. Logistic regression analyzed the association of PIV with CKD prevalence, while Cox proportional hazards regression and Kaplan-Meier curves assessed its link to all-cause mortality in CKD patients. To explore nonlinear relationships, we applied restrictive cubic splines (RCS) and two-piece regression models. Subgroup and interaction analyses assessed how covariates influence these associations. This study included 40,735 participants, all aged 20 or above (mean age 49.73 years, with 49% male). Among 6988 CKD patients, 2560 (36.6%) experienced all-cause mortality. Increased PIV levels showed a strong independent association with higher CKD prevalence (odds ratio = 1.69, 95% CI: 1.46-1.95) and all-cause mortality (hazard ratio = 1.47, 95% CI: 1.20-1.81). RCS analysis confirmed a nonlinear, progressively stronger association between PIV and CKD prevalence. A U-shaped link was found between PIV and all-cause mortality in CKD patients, with the inflection point at Log10-PIV 2.317. Mortality decreased before the inflection point and increased thereafter. Subgroup and interaction analyses showed their association was unaffected by covariates (all <i>p</i> > 0.05). Elevated PIV levels are linked to a higher incidence of CKD, while elevated or depressed PIV values are each linked to increased all-cause mortality risk among CKD patients.