Risk factors for Complex and Severe Coronary Artery Disease in Type 2 Diabetes Mellitus

Abstract

Background: Type 2 diabetes mellitus is often associated with severe Coronary artery disease (CAD). Since patients with higher risk of severe disease are likely to get better benefit from aggressive management, it is essential to identify factors which are associated with severe macrovascular disease. We looked at the possibility of hyperinsulinemia being a marker for severe and complex coronary artery disease in type 2 diabetes mellitus, to select patients who would benefit from aggressive treatment. Methods: A cross sectional study of 290 type 2 diabetic patients, who underwent coronary angiogram for the evaluation of clinically suspected CAD at a tertiary care hospital were recruited. Biochemical and anthropometric parameters were analysed. Insulin resistance was measured by homeostasis model assessment method. Angiographically measured syntax score of more than 22 is considered to be severe and complex CAD. Receiver operating curve characteristic was performed to find out the optimal cut-off value for insulin resistance and fasting insulin. Predictors of syntax score greater than 22 were identified by multiple logistic regression analysis. Results: An insulin level > 20 μIU/ml (OR: 6.86, 95% CI: 2.25-20.88) emerged as an independent predictor of severe and complex CAD. The optimal cut-off of insulin for predicting severe CAD was 20 with sensitivity and specificity of 80% (95% CI: 0.68 - 0.88) and 79% (95% CI: 0.73 - 0.83) respectively. Conclusion: Hyperinsulinemia could serve as a marker to identify severe and complex CAD in type 2 diabetes at an earlier stage of diabetes. Key words: Coronary Artery Disease, Hyperinsulinemia, Insulin resistance, Syntax score, Type 2 diabetes mellitus.