冠動脈疾患でのインスリン抵抗性の役割 : グルコースクランプ法を用いた検討

Abstract

Although diabetes mellitus is one of the established risk factors for coronary artery disease (CAD), the role of insulin resistance in the development of CAD has not been studied adequately. The purpose of this study was to evaluate the relationship between insulin resistance and the individual types of CAD. One hundred and twenty-seven patients with chest pain and 10 control patients without evidence of CAD were enrolled in this study. All patients with chest pain received cardiac catheterization, and were diagnosed as having cardiological syndrome X (n=17), vasospas- tic angina pectoris (n=37), or CAD with coronary artery stenosis (n=73). The insulin sensitivity was assessed by the euglycemic hyperinsulinemic clamp (EHC) method, as well as oral glucose tolerance test (OGTT). M-value, the mean glucose infusion rate during EHC study, was used as an index of insulin resistance. M-values of patients with either vasospastic angina pectoris or CAD with coronary artery stenosis were significantly lower than those of control patients, while no difference was noted between patients with car- diological syndrome X and control patients. Insulin areas of OGTT of CAD patients with coronary artery stenosis were significantly higher than those of control patients and patients with vasospastic angina. The ratio of insulin area to glucose area in CAD patients with coronary artery stenosis was significantly lower than in control patients and patients with vasospastic angina, while no difference was noted between patients with cardiological syndrome X and control patients. These findings suggest that insulin resistance plays an important role in the development of both coronary arteriosclerosis and coronary vasospasm, but not of cardiological syn- drome X.