The Association of Dietary Inflammatory Index with the Risk of Type 2 Diabetes: A Case-Control Study

Background: The prevalence rate of type 2 diabetes (T2DM) is increasing worldwide, and the role of diet in its etiology has been established. The Dietary inflammatory index (DII) has attracted significant attention in evaluating associations between diet and diseases due to the role of chronic inflammation as an underlying cause of numerous disease processes. Therefore, the relationship between DII score and the risk of T2DM is evaluated in the Iranian population for the first time. Methods: 113 newly diagnosed T2DM patients and 226 apparently disease-free control cases aged 23–59 participated in this case-control study. A valid semi-quantitative food frequency questionnaire was used to assess dietary intake. Then, energy-adjusted DII (E-DII) scores were computed and categorized into quartiles based on values in the population study. A logistic regression model was used to estimate the association between DII and the risk of T2DM after controlling for important potential confounders and effect modifiers. Results: A significant association was observed between E-DII score and T2DM in the crude model (P_-trend<0.001), model I (adjusted for physical activity, gender, education level, and family history of T2DM, P_-trend<0.001), model II (adjusted for model I + body mass index, P_-trend=0.005) (OR_quartile4vs1 =2.98 (95% CI: 1.18, 9.12; P= 0.005). Conclusions: A direct association was observed between DII score and the risk of T2D, implying that consuming a more anti-inflammatory diet would help to prevent T2DM. Future longitudinal studies should be conducted to further explore this association.