0143: Serum thiolactonase activity and paraoxonase gene polymorphism in coronary artery Tunisian patients with or without diabetes

Abstract

Serum homocysteine thiolactonase activity is closely related to homocysteine and ox-LDL levels in coronary artery disease patients. Homocysteine thiolactonase activities are the result of environmental factors and genetic polymorphisms of paroxosonase. The relevance of gene polymorphism in coronary patients with or without diabetes was investigated in a case-control study. The population included 140 control subjects, 47 coronary artery disease patient without diabetes and 44 patients with type 2 diabetes. Serum thiolactonase activity decreased significantly in coronary artery disease patients: 318.9±156 U/l those without diabetes and 388.8±180 in the diabetic ones compared with the controls: 568.8±250U/l (p<0.001). These activities were associated with increased plasma homocysteine and ox-LDL levels (p<0.001). The paroxonase allele frequency is significantly higher in controls than coronary artery patients (p<0.001). The frequency of R high activity allele was also higher in diabetic coronary patients (11.3%), than in those without diabetes (4.2%). No significant association was found between paroxonase LN gene polymorphisms and diabetes in coronary patients. The difference in allele frequency for the paroxonase R gene polymorphism may be the cause of the high thiolactonase activity observed in coronary patients with type 2 diabetes mellitus. Further studies are needed to be conducted to elucidate the role of the enzyme in the development of vascular complications in these patients.