Genetic predisposition, lifestyle inflammation score, food-based dietary inflammatory index, and the risk for incident diabetes: Findings from the KoGES data

Background and aims: We investigated whether genetic predisposition, the Lifestyle Inflammation Score (LIS), or the Food-based Dietary Inflammatory Index (FDII) were associated with diabetes incidence and whether these factors interact. Methods and results: The study was conducted using population-based cohort data derived from the Korean Genome and Epidemiology Study, which included 6568 people aged 40–69 years. Based on 25 genetic variants related to diabetes, genetic risk scores (GRSs) were determined and LISs and FDIIs were calculated and stratified into quartiles. We investigated the effects of gene–lifestyle interactions on the incident diabetes. The multivariate Cox proportional hazard model was used to generate hazard ratios with 95 % CIs. During the 16-year follow-up period, diabetes incidence was 13.6 per 1000 person-years. A dose–response association with diabetes was observed for both GRS and LIS quartiles but not for FDII quartiles. The GRS and LIS were also independently associated with diabetes incidence in a multivariate model. Compared to the bottom quartile, the top LIS quartile and the top GRS quartile had a 2.4-fold (95 % CI, 2.0–2.8) and a 1.4-fold (95 % CI, 1.2–1.7) higher diabetes risk, respectively. However, the FDII exhibited null association. When each genetic variant was evaluated, the top versus bottom LIS quartiles exhibited heterogeneous diabetes risks for rs560887 within G6PC2, rs7072268 within HK1, and rs837763 within CDT1; however, these differences were not statistically significant in multiple comparison. Conclusion: Both GRS and LIS factors independently affect the incident diabetes, but their interaction effect showed insignificant association. Therefore, regardless of genetic susceptibility, more effort is needed to lower the risk for diabetes by improving lifestyle behaviors.