[Involvement of glucose metabolism abnormalities and insulin resistance in atherosclerotic coronary artery disease: semiquantitative coronary angiography study].

Insulin resistance is known to be important in the aggravation of established coronary risk factors, but it is unclear whether insulin resistance might cause coronary artery disease as diabetes mellitus. To evaluate the relationship between insulin resistance and coronary atherosclerosis, the angiographic semiquantitative score of coronary atherosclerosis was investigated in 216 patients (175 males, 41 females) with coronary artery disease and the varying degrees of glucose metabolism including insulin resistance. Insulin resistance was estimated by plasma insulin level at 120 min after the 75g oral glucose tolerance test. Patients were divided into 3 groups according to the levels of glucose metabolism: 37 patients with treated diabetes mellitus, 48 with glucose intolerance and non-treated diabetes, and 131 with normal glucose tolerance. Multivessel disease was more frequently seen in the treated diabetes group (67.6%) than in the glucose intolerance and non-treated diabetes groups (43.8%) and in the normal glucose tolerance group (40.5%). The severity of coronary artery stenosis (8.5 +/- 3.9 vs 7.6 +/- 3.7 vs 6.6 +/- 3.7) and calcification (6.5 +/- 6.3 vs 3.3 +/- 3.3 vs 4.0 +/- 4.8) were significantly higher in the treated diabetes group than in other groups. Distal coronary lesions were significantly more frequent in the treated diabetes group (61.1% vs 17.6% vs 27.4%) than in other groups. Half of the patients in the normal glucose tolerance group had hyperinsulinemia. Multivessel disease was significantly more frequent in the insulin resistant subgroup than in the insulin non-resistant subgroup (59.4% vs 25.0%, p = 0.011). The severity of coronary artery stenosis was significantly higher in the insulin resistant subgroup than in the insulin non-resistant subgroup (8.6 +/- 3.9 vs 5.6 +/- 3.0, p < 0.001), but the severity of coronary artery calcification was not significant. Distal coronary lesions showed a tendency to increase in the insulin resistant subgroup (37.5% vs 12.0%, p = 0.081). These results suggest that insulin resistance is an important risk factor for coronary artery disease in patients with normal glucose tolerance, and is related to the severity and multiplicity of coronary atherosclerosis as in patients with diabetes.