The Relationship Study Between Insulin Resistance And The Severity Of Coronary Artery Lesions As Well As The Clinic Characteristics

Objective: The purpose of this study was to investigate the mechanism of insulin resistance (IR) with coronary heart disease (CHD) by the relationship study between insulin resistance and clinic characteristics as well as the severity of coronary artery lesion of patients with coronary heart disease who received coronary angiography (CAG), left ventriculo-graphy (LVG), ^99mTc-methodxy isobutyl isomitrile (^99mTc-MIBI) myocardial perfusion image (MPI), eqeilibrium radionuclide angiography (ERNA), oral glucose tolerance test (OGTT), and the homeostasis model assessment(HOMA) evaluating the IR index, so that we can assess the risk of patients with coronary heart disease, find those who should be strengthened therapy, and draft effective treatment. Methods: 157 patients (135 male and 22 female) who were admitted in our department with coronary heart disease or suspicious coronary heart disease, received coronary angiography and left ventriculography. All patients had at least one vessel ≥50% stenosis, and excluding patients who suffer from hepatic, renal, pancreatic diseases, thyroid disorders, diabetes mellitus (DM) with insulin or treatment of improving insulin sensitivity, severe valve cardiac disease, dilated or hypertrophic cardiomyopathy. Patients were divided into control group (group A) in which the coronary artery was normal, and CHD group (group B) by the results of coronary angiography .Group B were divided into group B1,B2 and B3 according to the insulin resistance index (HOMA index). After empty stomach 12 hours, fasting blood glucose, fasting insulin, blood lipid and high sensitive C reactive protein (hs-CRP) were performed in all patients. Detailed medical history were asked, clinic data were collected after admittance. We used quantitative coronary analysis (QCA) to analysis the severe of coronary lesion, patients whose lesion ≥70% stenosis received percutaneous coronary intervention(PCI) treatment. The number of coronary lesion was main vessel of epicardium including left anterior descend (LAD), left circumflex artery (LCX) and right coronary artery (RCA). The score of coronary lesion used Gensini method. All patients received ERNA and MIBI MPI to evaluate the heart function and myocardial infarction area. Then compared the insulin resistance between group A, B, the severity, type of the coronary artery lesion among group B₁, B₂, B₃, the condition of collateral circulation and ventricular aneurysm. We evaluated the ratio of main adverse cardiac events(MACE) and complication, and compared the clinic characteristics and the results of every clinic examination among group B1, B2, B3 with the severity of insulin resistance. We used SAS 6.12 statistics software to analysis all of the data. Differences among groupmeans were assessed with the analysis of variance. The χ² analysis or the fisher exact test was used to test differences of proportions. The correlation between two parameters was analyzed by Spearman correlation analysis. Statistical significance was indicated by P value<0.05. Results: There were no significant differences about age, sex, history of smoking between group A and B. The HOMA index and level of TG, LDL, FIS and Hs-CRP were significantly elevated in patients with obstructive coronary artery disease compare with control subjects. The results of CAG and LVG showed that the rate of single-vessel lesion in the group B₁ was higher than that in the group B₂ and B₃ (79.42% vs 46.21% vs 22.94%) P<0.01, on the other hand, the rate of multi-vessel lesion in the group B₃ was higher than that in the group B₂ and B₁(77.06% vs 53.79% vs 20.58%) P<0.01.There were no significant differences about the location of coronary artery lesion among group B₁, B₂ and B₃. The rate of coronary lesion type A in the group B1 was higher than that in group B₂, B₃(77.50 % vs 38.10% vs 10.53%) P<0.01,the rate of coronary lesion type C in the group B3 was higher than that in group B₁, B₂ (71.05% vs 12.50% vs 52.38%)P<0.01。The mean coronary lesion score of group B₃ was higher than that of group B₁ and B₂(9.54±2.53 vs 4.02±2.78 vs 7.57±2.58) P<0.05. There were no significant differences about the incidence of collateral circulation, ventricular aneurysm and the grade of thrombolusis in myocardial infarction (TIMI) blood flow. There wasincreased trend of left ventricular end diastolic pressure(LVEDP) (9.32±1.48 vs 12.64±1.38 vs 16.32±1.56),P<0.05. In the group B₃ , the clinic characteristics and results of every examination indicated that the rate of hypertension, diabetes mellitus was higher than that of group (84.21% vs 47.50% vs 64.29%,52.63% vs 15.00% vs 30.95%, respectively) P<0.01. With the HOMA index increasing, the trend of FBG, FIS, HbA₁C, TG, LDL and hs-CRP among group B₁, B₂, B₃ elevated, furthermore, which had statistical significance. By analyzing the incidence of MACE, complication and the clinic characteristics, it showed that the incidence of MACE and complication in the group B₃ was higher than that in group B₁,B₂, and the heart function of group B₁ was better than that of group B₂, B₃ on the whole. The HOMA index was significantly correlated with coronary lesion score, FBG, FIS, TG and hs-CRP, the coefficients of correlation were (0.5493 vs 0.4263 vs 0.90403 vs 0.28987 vs 0.32272, respectively), which all had statistical significance. Conclusions: We can conclude that the patients of coronary heart disease exist insulin resistance of different extent, meanwhile the level of insulin resistance is related with the severity of coronary artery lesions, the rate of metabolism syndrome (hypertension, diabetes mellitus, hyprercholesterolea-mia and obesity), the incidence of MACE and complication, the systolic or diastolic heart function. We can say that IR may play important roles as risk factor for CHD. It may indirectly indicate...