ABSTRACT
OBJECTIVES: Paraoxonase is a high-density-lipoprotein- associated enzyme capable of hydrolysing lipid peroxides. Thus it might protect lipoproteins from oxidation. It has two isoforms, which arise from a glutamine (A isoform) to arginine (B isoform) interchange at position 192. More recently, Ruiz et al. investigated the relationship between the paraoxonase genetic polymorphism and coronary heart disease in a case-control study of NIDDM in France. We investigated the correlation between the polymorphism of paraoxonase gene and cardiovascular disease in Korean diabetic patients. METHODS: Of 106 patients with NIDDM, 50 had confirmed cardiovascular disease (coronary heart disease or ischemic stroke). The other 56 patients had no history of such disease and ECG abnormality. An additional control group of non-diabetic, healthy subjects (N=55) was selected. The polymorphism of paraoxonase gene was assessed by PCR-RFLP in their blood leukocytes DNA. RESULTS: The healthy control revealed paraoxonase genotype frequencies of 18.1% AA, 36.4% AB and 45.5% BB. The NIDDM group revealed paraoxonase genotype frequencies of 11.3% AA, 39.6% AB, 49.1% BB. The genotype frequencies did not differ between healthy control with diabetic group. The genotype frequencies did not differ between diabetic group with coronary heart disease and diabetic control group (AA ; 8.4% vs 12.5%, AB ; 45.8% vs 37.5%, BB ; 45.8% vs 50.0%). There was also no difference in genotype frequencies between diabetic group with ischemic stroke and diabetic control (AA ; 11.5% vs 12.5%, AB ; 38.5% vs 37.5%, BB ; 50.0% vs 50.0%). In multiple logistic regression analysis with other risk factors, hypertension emerged as the most related factors for cardiovascular disease, but paraoxonase genotype was not associated with the presence of cardiovascular disease. CONCLUSION: In Korean diabetic patients, the polymorphism of paraoxonase gene might not be associated with the presence of coronary heart disease or ischemic stroke.