Dietary Inflammatory Index and Coronary Artery Disease Risk and Mortality: A Nonlinear Dose-Response Systematic Review and Meta-Analysis.

BACKGROUND: This systematic review and meta-analysis study aims to investigate the association between dietary inflammatory index (DII) and coronary artery disease (CAD) risk and mortality. METHODS: A comprehensive search in PubMed, Web of Science, Embase, and Scopus was implemented for relevant observational studies investigating the relation between DII and risk of CAD and CAD mortality published up to May 2024. Articles that reported the relative risk, odd ratio (OR), or hazard ratio for the highest score of DII versus the lowest score of DII were retrieved. For quantitative analyses, categorical analysis, linear and nonlinear analyses, and subgroup analysis are performed. RESULTS: Finally, 18 studies [CAD (n = 13) and CAD mortality (n = 5)] were included. Individuals with the highest score of DII versus the lowest ones have 38% (1.38; 95% CI: 1.22 to 1.56) and 40% (1.40; 95% CI: 1.13 to 1.75) more risk to CAD and CAD mortality, respectively. The linear analysis declared that the summary OR for CAD is 1.16 (95% CI: 1.08 to 1.24) and for CAD mortality 1.09 (95% CI: 1.03 to 1.14) per each 1-point increase in DII. There was also evidence of nonlinear relationship between the DII and CAD as the relation became even more significant when the DII were more than 2 points (P < 0.001). A positive association was revealed in the DII score (proinflammatory diet) and risk of CAD and CAD mortality. CONCLUSIONS: However, due to the large heterogeneity and some aforementioned limitations, more high-quality prospective studies can validate our results.