Association between the dietary inflammatory index, waist-to-hip ratio and metabolic syndrome

Abstract

Inflammation due to poor diet may contribute to the development of metabolic syndrome (MetSyn). The Dietary Inflammatory Index (DII) was created to characterize diet on a scale from anti- to pro-inflammatory. Our hypothesis was that higher (i.e., more pro-inflammatory) DII scores are associated with an increased prevalence of MetSyn compared to those with lower (i.e., more anti-inflammatory) DII scores. Data from the Polish-Norwegian (PONS) Study were analyzed using logistic and linear regression procedures in SAS (version 9.4). Comparisons of interest were between the first and fourth DII quartiles; analyses were stratified by sex. Mean waist-to-hip ratio (WHR) and diastolic blood pressure were greater among those in DII quartile 4 compared to 1. No statistically significantly increased MetSyn risks were observed for DII quartile 4 among men or women. Men in DII quartile 4 had elevated odds of fulfilling the waist component of MetSyn (odds ratio=1.65, 95% confidence interval=1.01-2.69). Although this study benefited from the DII and large sample sizes for both men and women, its cross-sectional nature and use of self-reported data may limit interpretation of results. Further work must be done in longitudinal studies to understand whether pro-inflammatory diets are associated with an increased risk of MetSyn, its components or other metabolic-related conditions. Additionally, further examination of the DII in relation to body habitus will be needed to understand the role of pro-inflammatory diets on anthropometrics, as observed in this study.