Association between Dietary Inflammatory Index and Metabolic Syndrome in Iran

Introduction: We examined the relationship between the Dietary Inflammatory Index (DII) and metabolic syndrome (MetS) in a cross-sectional study in Iran.Materials & Methods: This was a cross-sectional survey of 949 randomly selected adults aged > 18 years. Dietary assessment was conducted by a validated food frequency questionnaire from which the DII was calculated. Fasting serum lipids, anthropometric indicators and blood pressure were measured by standard methods. Analyses were restricted to participants with data available on dietary intake, biochemical and anthropometric measurements. Analysis of covariance was used to compare metabolic syndrome components according to teriles of energy-adjusted DII. To expose the effect of potential confounders, hierarchical logistic regression models were utilised to determine adjusted odds ratios (OR) and 95% CI.Results: Participants in the most pro-inflammatory diet category (tertile 3) were more likely to be younger, have lower waist circumference, family income and education compared to subjects in tertile 1. After adjustment for age, gender, body mass index and energy intake, subjects in tertile 3 were found to be significantly associated with MetS [OR (95% CI)] [1.49 (1.05–2.08)]. This persisted and stronger after additionally adjusting for food groups like fruits, vegetables, fast food, sweet and soft drink [1.72 (1.18–2.50)]. Conclusion: This study provides further evidence of an association between increasing inflammatory potential of diet and MetS. These results reinforce the fact that diet plays an important role in the occurrence of MetS-associated chronic diseases.