Systematic Analysis of Risk Factors for Coronary Heart Disease in Japanese Patients with Type 2 Diabetes: A Matched Case-Control Study

Aim: To identify predictors of coronary heart disease (CHD) in Japanese patients with type 2 diabetes (T2DM). Methods: A matched case-control study was performed using 800 patients with T2DM admitted for treatment of hyperglycemia from January 2002 to June 2010. Cases comprised 16 patients who had developed acute myocardial infarction and/or received a coronary artery bypass by June 2010, and controls comprised 48 age- and sex-matched patients without CHD events. The mean age, glycated hemoglobin (HbA1c), and body mass index (BMI) were 61.5 yrs, 9.7% and 24.4 kg/m2, respectively. The relationship of baseline variables, including lipid values, HbA1c, BMI, blood pressure, fasting blood sugar, 2h-post-breakfast blood sugar, delta blood sugar0-2h, urinary albumin excretion, estimated glomerular filtration rate and treatment modalities (insulin/sulfonylurea/biguanide), to CHD development was analyzed by conditional logistic regression analysis. Results: Total cholesterol (TC) (OR 2.35, 95%CI 1.11-4.98, p=0.03), non-HDL-cholesterol (OR 3.07, 95%CI 1.33-7.10, p=0.009), LDL-cholesterol (OR 2.84, 95%CI 1.24-6.51, p=0.01), non-HDL-cholesterol/HDL-cholesterol (OR 2.07, 95%CI 1.10-3.90, p=0.02) and LDL-cholesterol/ HDL-cholesterol (OR 2.74, 95%CI 1.22-6.15, p=0.01) were significantly related to CHD. Fold risk increment per 1-SD increase in basal TC, non-HDL-cholesterol, LDL-cholesterol, non-HDL-cholesterol/HDL-cholesterol and LDL-cholesterol/HDL-cholesterol was 2.33, 2.89, 2.52, 2.37 and 2.60, respectively. Only non-HDL-cholesterol was an independent risk factor. From the receiver operating characteristic curve, 3.89 mmol/L non-HDL-C was the best cutoff value. None of the non-lipid variables were significantly related to CHD. Conclusion: Non-HDL-cholesterol was the most dominant predictor of the development of CHD in Japanese patients with T2DM.