Paraoxonase 1 polymorphisms as the risk factor of coronary heart disease in a Thai population

Objective - Two common polymorphisms of the paraoxonase (PON1) gene, L55M and Q192R, were proven to mitigate atherosclerosis pathogenesis by protecting lipoproteins against peroxidation. This study was to evaluate the associations between both PON1 gene polymorphisms in Thai hyper-lipidaemia with and without coronary heart disease (CHD). Methods - Both PON1 genotypes were determined using PCR-RFLP in 103 healthy control subjects, 103 primary hyperlipidaemia without history of such diseases and 106 angiographically documented CHD patients. Results - The frequencies of PON1 192R allele and 192RR genotype were significantly higher in CHD patients than in normal control subjects (P = 0.009 and 0.037, respectively). The significantly higher frequencies of 55M allele and 55LM genotype were also observed in CHD patients (P = 0.037 and P = 0.034, respectively). The frequencies of both PON1 polymorphisms were not different in primary hyperlipidaemia as compared to the normal control subjects. The odds ratio (OR) of 192RR genotype and 192R allele for CHD were 2.84 (1.17-6.99, P = 0.011) and 1.70 (1.11-2.61, P = 0.009), respectively. The age-adjusted OR for CHD was 2.72 (1.25-5.94, P = 0.012). These frequencies of both PON1 alleles were similar to those seen in other Asian populations. Conclusions - The association between PON1 polymorphisms and CHD risk was demonstrated in a Thai population.These new data underscore the essence of ethnic variations in the interpretation of CHD associated with PON1 polymorphism.