Associations of dietary inflammatory index with metabolic syndrome and its components: A systematic review and meta-analysis

Abstract

Objective: Inflammation has been suggested to play an important role in the development and progression of metabolic syndrome (MetS). Dietary inflammatory index (DII), a measurement of inflammatory potential in diets, was suggested to be associated with MetS. The aim of this systematic review and meta-analysis was to establish the associations of DII with MetS and its components based on available observational studies. Design: Systematic review and meta-analysis. Setting: A comprehensive literature search of studies that assessed the associations between DII and MetS was conducted in PubMed, Medline and Embase, using a combination of search terms relating to DII and MetS. Participants: Eighteen articles were eligible, of which fourteen were cross-sectional, and four were cohort in design. Results: Results from the random-effects meta-analysis showed significantly positive associations of higher DII (top vs. bottom quartiles) with MetS (OR:1.23 [95% CI: 1.10-1.37]), abdominal obesity (OR: 1.15 [95% CI: 1.02-1.29]), high blood pressure (BP) (OR: 1.17 [95% CI: 1.07-1.29]), hyperglycaemia (OR: 1.18 [95% CI: 1.05-1.33]), and hypertriacylglycerolaemia (OR: 1.17 [95% CI: 1.07-1.28]). The effects of summary OR became stronger when analyses were restricted to cohorts, studies that adjudged for covariates (including body mass index [BMI], physical activity and total energy intake). Conclusions: Higher DII, representing pro-inflammatory diet, is associated with higher odds of MetS and its components, except for low high-density lipoprotein cholesterol (HDL-C). The findings prompt dietary interventions for preventing MetS from the aspect of inflammation.