Insulin resistance as predictor of the angiographic severity and extent of coronary artery disease

Background. Insulin resistance (IR) is frequently observed in patients with coronary artery disease (CAD). Aim. To examine the association between IR and severity and extent of CAD. Methods. Quantitative coronary angiography (QCA) was used to assess coronary atherosclerosis in 107 patients with clinically suspected CAD. QCA-derived indexes reflecting CAD severity, extent, and overall atheroma burden were calculated for the entire coronary tree, and separately for different coronary segments. IR was quantified using the homeostasis model assessment insulin resistance index (HOMA IR). Nondiabetic subjects (n=83) were divided into group 1 (n=41) with HOMA IR < 1.8 (the median value), and group 2 (n=42) with HOMA IR >= 1.8. Group 3 comprised diabetic subjects (n=24). Results. Global age- and gender-adjusted indexes for severity (P=0.007), extent (P=0.038), and atheroma burden (P=0.035) of CAD were higher in group 2 than in group 1. Similarly, the global severity (P=0.027), extent (P=0.090), and global atheroma burden (P=0.024) indexes were higher in group 3 compared with group 1. IR was correlated with quantitative angiographic indexes for distal segments only, but not for proximal or mid segments of coronary vessels. Conclusions. Patients with more severe degree of IR have a more severe, extensive, and distal type of CAD than patients with lower degree of IR.