An Empirical Dietary Inflammatory Pattern Score Is Associated with Circulating Inflammatory Biomarkers in a Multi-Ethnic Population of Postmenopausal Women in the United States

Abstract

The empirical dietary inflammatory pattern (EDIP) score has been associated with concentrations of circulating inflammatory biomarkers in European Americans. We used the EDIP score, a weighted sum of 18 food groups that characterizes dietary inflammatory potential based on circulating concentrations of inflammatory biomarkers, to test the hypothesis that a pro-inflammatory dietary pattern is associated with inflammatory biomarker concentrations in a US multi-ethnic population. In this cross-sectional study, we calculated EDIP scores using baseline food frequency questionnaire data from 31,472 women, aged 50-79 y, in the Women's Health Initiative observational study and clinical trials. Circulating biomarkers outcomes at baseline were: C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor (TNF)-α, TNF receptor (TNFR) 1 and 2, and adiponectin. We used multivariable-adjusted linear regression analyses to estimate absolute concentrations and relative differences in biomarker concentrations, overall and in subgroups of race/ethnicity and BMI (body mass index) categories. Independent of energy intake, BMI, physical activity, and other potential confounding variables, higher EDIP scores were significantly associated with higher (lower for adiponectin) absolute concentrations of all 6 biomarkers. On the relative scale, the percentage of difference in the concentration of biomarkers, among women in the highest compared to the lowest EDIP quintile, was: CRP, +13% (P-trend<0.0001); IL-6, +15% (P-trend<0.0001); TNF-α, +7% (P-trend=0.0007); TNFR1, +4% (P-trend=0.0009); TNFR2, +5% (P-trend<0.0001); and adiponectin, -13% (P-trend <0.0001). These associations differed by racial/ethnic groups and by BMI categories. Whereas the absolute biomarker concentrations were lower among European-American women and among normal-weight women, the associations with diet were stronger than among women of African-American or Hispanic/Latino origin and among overweight and obese women. Findings demonstrate the successful replication of an empirical hypothesis-oriented a posteriori dietary pattern score in a multi-ethnic population of postmenopausal women, with subgroup differences by race/ethnicity and body weight. Future research needs to apply the score in non-US populations.