Atherosclerosis 141 (1998) 259 – 264 The Gln–Arg 191 polymorphism of the human paraoxonase gene is not associated with the risk of coronary artery disease among Chinese in Taiwan Yu-Lin Ko *, Yu-Shien Ko, Shu-Mei Wang, Lung-An Hsu, Chi-Jen Chang, Po-Hsien Chu, Nye-Jan Cheng, Wei-Jan Chen, Chen-Wen Chiang, Ying-Shiung Lee The First Cardioascular Diision, Chang -Gung Memorial Hospital, 199 Tung Hwa Road, Taipei, Taiwan, ROC Received 28 January 1997; received in revised form 27 May 1998; accepted 18 June 1998 Abstract Paraoxonase (PON1) is a high density lipoprotein-associated enzyme capable of hydrolyzing lipid peroxides, and thus, might protect lipoproteins from oxidation. A common polymorphism due to an amino acid substitution (Gln – Arg) at codon 191 is considered to be a major determinant of variation in serum PON1 activity. Recent studies have suggested that the PON1-191 polymorphism is an independent risk factor for coronary atherosclerosis in patients with or without diabetes mellitus. The association of PON1-191 polymorphism genotypes and coronary artery disease (CAD) among Chinese subjects in Taiwan was examined. The genotype of 218 angiographically documented CAD patients and the same number of age- and sex-matched control subjects was determined. Genotypes AA, AB and BB were present in 25 (11%), 102 (47%) and 91 (42%) of control subjects, respectively, and in 30 (14%), 96 (44%) and 92 (42%) of CAD patients, respectively ( 2 =0.57, P =0.75 between groups). The frequency of the A allele was 0.36 for the control group and 0.35 for CAD patients (P =0.94). No significant differences in the PON1-191 genotype frequencies could be found between groups when multivariate logistic regression analysis was performed, or different subgroups of age, sex or risk factors were analyzed. Among control subjects, there was also no significant difference between genotypes of the PON1-191 polymorphism and various clinical and lipid variables. In conclusion, our data suggest that there is no association between the Gln–Arg 191 polymorphism of the human PON1 gene and CAD among Chinese subjects in Taiwan. © 1998 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Coronary disease; Paraoxonase; Polymorphism 1. Introduction Atherosclerotic coronary artery disease (CAD) is now a major health problem in many industrialized countries, including Taiwan, and contributes signifi- cantly to morbidity and mortality. Numerous epidemio- logical studies have revealed that hypercholesterolemia, hypertension and smoking are major risk factors for CAD. There is also increasing evidence that genetic factors may play an important and independent role in predisposition to CAD and its thrombotic complication [1,2]. Recent reports of molecular genetic analyses using allelic association studies have suggested that genetic polymorphisms of the genes involved in lipid metabolism, coagulative and fibrinolytic pathways, and the renin – angiotensin system may be associated with coronary atherosclerosis or myocardial infarction (MI) [3 – 12]. These findings are, however, still controversial. Paraoxonase (PON1) has been implicated in the pathogenesis of atherosclerosis. PON1 is an aryldi- alkylphosphatase that hydrolyzes paraoxon, an active toxic metabolite of parathion, thus providing protec- tion against organophosphate poisoning. Its physiologi- * Corresponding author. Tel.: +1886-3-328-1200, Ext. 8171; fax: +1886-3-397-3459. 0021-9150/98/$ - see front matter © 1998 Elsevier Science Ireland Ltd. All rights reserved. PII:S0021-9150(98)00179-8