Sex-Specific Dietary Inflammation and Metabolic Syndrome: A Cross-Cultural Population-Attributable Gradient Across Three Nations

Abstract Objective To test whether higher dietary inflammatory potential (Dietary Inflammatory Index, DII) is associated with metabolic syndrome (MetS) in a sex-specific manner across three nations. Methods We harmonised individual-participant data from 56,475 adults (US NHANES 2017-2018; Korean KNHANES 2015-2021; Mexican ENSANUT 2018-2019). Sex-stratified logistic regression estimated DII-MetS associations. Two-sample Mendelian randomization (MR) used CRP genetic instruments. Population-attributable fractions (PAFs) quantified cross-country consistency. Results A female-specific DII-MetS association was observed (pooled OR=1.15 per DII unit, 95% CI 1.04-1.27; Q5-vs-Q1 OR=1.56; sex interaction FDR q