OBJECTIVETo investigate the relationship between paraoxonase (PON) polymorphisms and serum homocysteine thiolactone (HTL) and coronary heart diseases.

METHODIn this prospective study, serum complex of HTL levels using ELISA, and the lever of serum Hcy using high pressure liquid chromatography (HPLC), determined the PON1/T(-107)C and PON2/C311S genotypes using PCR-restriction fragment length polymorphisms 203 were measured in patients with angiographic documented coronary heart disease (CAD) and 117 controls.

RESULTSSerum levels of Hcy and the complex of HTL in CAD patients were significantly higher than that in controls (P < 0.05). No significant difference was found in frequencies of PON1/T(-107)C genotypes and alleles (P > 0.05) between CAD patient and controls. The PON2/C311S (SS) genotype was lower in CAD patients than that in controls (P < 0.05), while the frequency of allele was similar between the two groups (P > 0.05). The T allele of PON1/T(-107)C and S alleles of PON2/C311S polymorphism were associated with lower plasma Hcy and HTL complex [Hcy (11.83 +/- 4.76) micromol/L vs (15.32 +/- 10.32) micromol/L, P < 0.05; HTL complex (24.36 +/- 9.30) U/ml vs (32.05 +/- 10.44) U/ml, P < 0.05]. The genetype PON2 and allele C were higher in CAD patients with type 2 diabetes than that in CAD patients without type 2 diabetes and controls (P < 0.005).

CONCLUSIONSThe elevation of serum Hcy and the complex of HTL were associated with increased risk of coronary heart disease. The allele PON1/(-107)T and PON2/311S might be protective for the development of atherosclerosis.