Aims: To evaluate the association of plasma proinsulin and insulin resistance (IR) with coronary artery disease (CAD) in non-diabetic subjects.
Methods: In this case control study, 41 normoglycaemic men with angiographic evidence of CAD were compared with 41 control men matched for age and glycaemia and with no history or evidence of cardiac diseases. Estimations of plasma glucose, lipids, fasting plasma specific insulin (SI) and proinsulin (PI) were performed. IR was calculated by the homeostasis model assessment (HOMA) method. Multiple logistic regression analysis was performed to test the association of the variables with the prevalence of CAD.
Results: Subjects with CAD had a higher body mass index (BMI) (25.4 +/- 4.3 vs. 22.9 +/- 3.2 kg/m2, P = 0.003) and waist to hip ratio (WHR) (0.95 +/- 0.05 vs. 0.89 +/- 0.09, P = 0.001) and a lower high-density lipoprotein (HDL) cholesterol level (0.97 +/- 0.2 vs. 1.1 +/- 0.2 mmol/l, P = 0.002). They also had higher mean SI values (107.5 vs. 62.3 pmol/l, P = 0.002), PI values (19.3 vs. 5.7 pmol/l, P < 0.0001), PI/SI ratios (21.4 vs. 10.3, P < 0.0001) and HOMA IR (4.2 vs. 2.4, P = 0.004) compared with non-CAD subjects. These variables were associated with CAD in the unadjusted multiple regression analysis. In the multiple regression with the forward entry of the variables, WHR and PI only showed independent association with CAD.
Conclusions: Subjects with CAD had higher levels of obesity and WHR. CAD showed an association with low HDL cholesterol, circulating PI, PI/SI ratios and IR.