Nazli Namazi - Diabetes Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
Bagher Larijani - Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
Leila Azadbakht - Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran

Background and Aim: We aimed to summarize studies on the association of the Dietary Inflammatory Index (DII) and the risk for cardiovascular disease (CVD), metabolic syndrome (MetS) and mortality in a systematic review and meta-analysis.Methods: We performed a systematic search in PubMed/Medline, Web of Knowledge, and Scopus databases for relevant studies written in English and published until 31 December 2017. Studies that reported the relative risk (RR), odd ratio (OR) or hazard ratio (HR) for the most pro-inflammatory vs. the most anti-inflammatory diets were included.Results: Finally, 17 studies (CVD (n=6), MetS (n=5), mortality (n=6)) were included. Findings indicated a trend toward a positive relationship between the DII and the risk for CVD (RR: 1.35; 95% CI: 1.13, 1.60; I2: 28.6%, p=0.21), all-cause mortality (RR: 1.21; 95% CI: 1.09, 1.35; I2: 72.6%, p= 0.003), CVD mortality (RR: 1.30, 95% CI: 1.07, 1.57; I2: 74.0 %, p=0.009) and cancer mortality (RR: 1.28; 95% CI: 1.07, 1.53; I2: 62.5 %, p= 0.03). However, no significant association was found between the DII and the risk for MetS (RR: 1.01; 95% CI: 0.82, 1.24; I2: 32.6%, p=0.20). Conclusion: Although in the current meta-analysis, the most pro-inflammatory diet vs. the most anti-inflammatory diet was not associated with the risk of MetS, we observed a substantial association between the DII and the risk for CVD and all types of mortality. However, further cohort studies in different populations are needed.

Inflammation; Cardiovascular disease; Metabolic syndrome; Death