The Relationship Between Plasma Insulin Levels and Angiographical Severity of Coronary Artery Disease

The aim of this study was to investigate the relationship between plasma insulin levels and the angiographical severity of coronary artery disease in male patients with normal glucose tolerance and unstable angina. Two days before coronary angiography, a standard OGTT was performed on 126 patients with normal fasting blood glucose levels. Twenty-four patients were excluded because of impaired glucose tolerance. One-hundred-two patients with normal glucose tolerance underwent coronary angiography. To exclude possible confounding effects, angiographically normal two patients were excluded and the remaining 100 patients were included in the study. Significant coronary artery disease was determined in 68 patients (Group I). Angiographical results demonstrated that 32 patients had no significant coronary artery disease (Group II). The presence of significant coronary artery disease and total atherosclerosis score were used to determine the severity of coronary artery disease. While significant coronary artery disease was correlated with age, Lp(a), fasting plasma insulin level and tobacco consumption (r=0.34, r=0.30, r=0.28, r=0.21, respectively), total atherosclerosis score was correlated with fasting plasma insulin level, Lp(a), age and glucose level in the first hour (r=0.26, r=0.36, r=0.90, r=0.26 respectively). In multivariate analysis, log fasting plasma insulin levels proved to be a significant independent determinant both of significant coronary artery disease and of total coronary atherosclerosis score in patients with normal glucose tolerance and unstable angina.