The relationship of metabolic score for insulin resistance with risk and severity of premature coronary artery disease: Insights from Iran Premature Coronary Artery Disease (IPAD) study

Background This study aimed to investigate the association of the metabolic score for insulin resistance (METS-IR) with the presence and severity of premature coronary artery disease (PCAD) in a diverse Iranian population. Methods Using data from the Iran Premature Coronary Artery Disease (IPAD) study, a cross-sectional design was implemented involving 2,736 participants, including 1,708 individuals with PCAD and 1,028 controls. METS-IR was calculated using the following formula: ln [(2 × fasting blood glucose (mg/dL)) + fasting triglyceride (mg/dL)] × body-mass index (kg/m2) ÷ Ln [high-density lipoprotein cholesterol (mg/dL)]. Logistic regression analyses were conducted to evaluate the relationship between METS-IR quartiles and PCAD. Results Participants in quartile 4 of METS-IR showed a significant increased risk of having PCAD (OR: 3.15; 95% CI: 2.03–4.89; P for trend < 0.001) and severe PCAD (OR: 2.25; 95% CI: 1.37–3.68; P for trend < 0.001) compared to those in quartile 1. Ethnic subgroup analyses revealed significant associations in Fars, Gilak, and Kurd populations, indicating variability in the impact of insulin resistance across ethnic backgrounds. Conclusions This study found the potential of METS-IR as a non-invasive tool for assessing PCAD risk and severity, highlighting significant ethnic variations. Future studies should explore the underlying mechanisms and confirm these associations in longitudinal studies.