The Association Between Dietary Inflammatory Index and Risk of Chronic Kidney Disease: An Updated Systematic Review and Dose-Response Meta-Analysis of Observational Studies

Abstract

Objective: We aimed to conduct a systematic review and meta-analysis to evaluate the association between the Dietary Inflammatory Index (DII) and its energy-adjusted version (E-DII) and chronic kidney disease (CKD). Methods: We conducted an updated systematic review and meta-analysis of observational studies, searching PubMed/MEDLINE, Scopus, and Web of Science until December 2024, using pertinent keywords. Included studies reported effect estimates (odds ratio or hazard ratio) for DII/E-DII and CKD associations. These estimates were pooled using random effects models, whereas dose-response analyses assessed both linear and nonlinear trends. Results: Our systematic review and meta-analysis incorporated data from 246,449 participants (34,199 cases with CKD) across 12 eligible studies. Comparing the highest versus the lowest DII categories revealed a summary relative risk of 1.35 (95 confidence interval: 1.24-1.48), with even stronger effects observed for the energy-adjusted version (E-DII; relative risk = 1.66; 95 confidence interval: 1.39-1.98), indicating significant positive associations between proinflammatory diets and CKD prevalence. Dose-response analyses demonstrated that each 1-unit increase in E-DII and DII corresponded to 28 and 5 higher likelihood of CKD, respectively, with distinct nonlinear patterns: a progressive increase in CKD prevalence across the full DII spectrum (P for nonlinearity <.001), contrasted with a threshold effect for E-DII where the association plateaued beyond a score of 2 (P for nonlinearity = .0048). Conclusions: Proinflammatory diets are significantly associated with a higher prevalence of CKD, with E-DII showing stronger associations than absolute DII. These findings support dietary interventions targeting inflammatory pathways for CKD prevention. Future research should prioritize longitudinal designs to establish temporality and evaluate anti-inflammatory dietary interventions in high-risk populations.