Abstract
BACKGROUND: Emerging evidence suggests that insulin resistance (IR) may influence coronary artery disease (CAD) progression. However, the relationship between dietary insulinemic potential and IR surrogate markers and CAD severity remains unclear. METHODS: This cross-sectional study utilized data from the Nutrition Heshmat Registry (NUTHER) in Guilan, Iran, including 930 patients at risk for CAD. CAD severity was assessed using the Gensini score based on angiographic findings. Dietary intake was evaluated using a validated 168-item food frequency questionnaire (FFQ), with energy-adjusted dietary insulin load, and dietary insulin index calculated accordingly. The triglyceride-glucose (TyG)-BMI index was derived as a surrogate marker of insulin resistance. RESULTS: Of the 930 patients analyzed, 565 were categorized as having less severe CAD (Gensini score < 60) and 365 as severe CAD (Gensini score ≥ 60). Multiple regression models adjusted for various confounding factors showed that participants in the highest quartile of the TyG-BMI index had a 1.98-fold higher odds of severe CAD (OR (95%CI) = 1.98 (1.31-2.99); P-for-trend = 0.001), while those in the highest quartile of energy-adjusted dietary insulin load, and dietary insulin index had 2.41-fold and 2.22-fold increased odds of severe CAD, respectively (Q4 ORs (95%CIs) = 2.41 (1.41-4.12) for e.a.IL, and 2.22 (1.29-3.82) for e.a.II; P-for-trend < 0.001). CONCLUSION: Our significant findings suggest that higher TyG-BMI, dietary insulin load, and insulin index are likely associated with an increased odds of severe CAD. Monitoring and modifying dietary insulinemic potential and improving metabolic health may serve as practical strategies for reducing CAD severity in at-risk populations.