Association Between Paraoxonase-1 Activity and the Extent of Coronary Stenosis

Paraoxonase (PON1) can prevent oxidized low-den sity lipoprotein formation and development of atherosclerotic lesions. However, studies on the association between PON1 activity and the extent of coronary stenosis and underlying mechanism(s) are limited. In this study, the relationship between paraoxonase and arylesterase activities of PON1 with extent of coronary stenosis together with determination of PON1 phenotypes in the studied patients have been investigated. Paraoxonase and arylesterase activities were measured in 61 patients with coronary stenosis of <50% and 63 patients with coronary stenosis of >70%. Individual human serum phenotyping for the PON1 Q192R polymorphism was achieved through dividing the paraoxonase activity in the presence of 1M NaCl by arylesterase activity. Patients with stenosis of <50% had significantly higher PON1 activity (p<0.05) and HDL-Cholesterol (p<0.03) compared to those with stenosis of >70%. No significant difference (p>0.05) was observed in the phenotype distribution of males and females. According to the current study, there are significant differences in paraoxonase and arylesterase activities and also HDL-C levels between patients with coronary stenosis of <50% and those with coronary stenosis of >70%. Therefore, this study provides further support for the important role of paraoxonase activity in coronary atherosclerosis.