The Role of Insulin Resistance in Korean Patients With Coronary Atherosclerosis

To determine whether dietary modification improves insulin resistance and coronary atherosclerosis, we randomly assigned 14 Korean patients to an experimental group (low-fat, low-cholesterol diet, high polyunsaturated/saturated fatty acid ratio, and calorie restriction) or to a control group (no dietary change). Coronary artery lesions were analyzed by quantitative coronary angiography, and postglucose insulin responses were measured. At baseline, there were no significant differences in body weight, BMI, waist-to-hip ratio (WHR), and plasma lipid and insulin levels between the two groups. After completion of the 1-year diet program, the experimental group showed significant reductions in body weight (66.0 ± 3.2 to 61.6 ± 3.8 kg [means ± SE], <0.01) and WHR (0.96 ± 0.01 to 0.93 ± 0.01, P < 0.05). Total cholesterol (5.45 ± 0.45 to 4.50 ± 0.44 mmol/l, P < 0.05), LDL cholesterol (3.71 ± 0.36 to 2.98 ± 0.37 mmol/l, P < 0.05), and triglyceride (1.91 ± 0.28 to 1.29±0.17 mmol/l, P < 0.05) were also significantly reduced in the experimental group. The mean insulin response during an oral glucose tolerance test was also significantly decreased (258.6 ± 26.4 to 181.8 ± 6.6 mmol/1, P < 0.05). In contrast, there were no significant changes in these parameters in the control group. When only coronary artery lesions >50% stenosed were analyzed, the average percentage diameter stenosis regressed from 63.2 to 56.8% in the experimental group. However, there were no significant changes in the control group. Our trial suggests that decreases in body weight and WHR and an improvement in insulin resistance with a low-fat, low-cholesterol diet and caloric restriction may reduce risk factors and reverse coronary atherosclerotic lesions in 1 year.