Interrelation between angiographic severity of coronary artery lesions and insulin sensitivity in patients with coronary heart disease

Objective To study the interrelation between the severity of coronary artery lesions and insulin-sensitivity in patients with coronary heart disease (CHD). Methods The study included 20 healthy control subjects and 50 CHD patients. Oral glucose tolerance test was conducted in all subjects. Venous blood samples were taken during fasting and at 30, 60, 120 and 180 minutes after the glucose loading (100 g). Samples were analyzed for glucose, immunoreactive insulin and C-peptides. Selective coronary arteriography was performed in all patients. Coronary arteriograms were analyzed, and the severity of coronary lesions was quantified, respectively, by three score systems (coronary lesion score, diseased vessel score and diseased vessel number). Correlation between the severity scores for coronary lesions and 9 insulin-sensitivity parameters was respectively obtained using linear regression analysis, and the stepwise regression analysis was used to assess independence of associations. Results Insulin-sensitivity in CHD group was significantly lower than those in control group. Insulin-sensitivity index (ISI, eg. the natural logarithmic value of the reverse of fasting serum glucose and insulin product) in CHD group was correlated with coronary lesion score or diseased vessel score ( r = -0 41, P 0 01; r = -0 37, P 0 05). After excluding the effects of hypertension, the correlation was still significant. Diseased vessel number was not correlated with any independent variables. Stepwise regression analysis showed that only ISI was independently correlated with the severity of coronary lesions. Conclusions The severity of coronary lesions significantly correlates with insulin resistance. ISI is the only independently correlated variable. There might be certain inner associations between insulin resistance and the pathophysiology of CHD.