We aimed to investigate associations of the dietary inflammatory index (DII) with glucose-insulin homeostasis markers, and the risk of glucose intolerance. This cross-sectional study included 2975 adults from the Tehran Lipid and Glucose Study. Fasting plasma glucose (FPG), 2-h post-load glucose (2h-PG), and fasting serum insulin were measured. Homeostatic model assessment of insulin resistance index (HOMA-IR) and β-cell function (HOMA-B), and the quantitative insulin sensitivity check index (QUICKI) were calculated. Glucose tolerance abnormalities included impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and type 2 diabetes (T2DM). DII scores were positively associated with 2h-PG (β = 0.04; p = 0.05). There was no significant linear trend across quartiles of DII for adjusted means of glucose-insulin homeostasis markers. Participants in the highest quartile of DII score tended to have higher FPG compared to those in the second quartile of DII score (5.46 vs. 5.38 mmol/L, p = 0.07) and higher fasting insulin and HOMA-IR compared to those in the lowest quartile (8.52 vs. 8.12 µU/mL for fasting insulin, p = 0.07; 2.06 vs. 1.96 for HOMA-IR, p = 0.08). No significant associations were observed between DII and risk of IFG, IGT, T2DM, and insulin resistance. Among glucose-insulin homeostasis markers, DII had a positive weak association only with 2h-PG.
Keywords: dietary inflammatory index; glucose metabolism; glucose tolerance abnormality; insulin sensitivity.