RESUMO
BACKGROUND: Paraoxonase1 (PON1), an enzyme connected to high density lipoproteins (HDL) particles, plays an important role in protecting arteries against atherosclerosis. The serum activity and concentration of PON1 depends on several genetic polymorphisms as well as environmental factors. MATERIALS AND METHODS: Investigated population consisted of 71 patients aged 43â»76 years with confirmed coronary heart disease (CHD). Established risk factors of CHD such as hypertension, elevated total cholesterol and LDL cholesterol (LDL-C), low HDL cholesterol (HDL-C), diabetes mellitus, obesity, smoking and premature CHD in family history were assessed. PON1 genotype for â»108C/T promotor region was determined by polymerase chain reaction-restriction fragments length polymorphism (PCRâ»RFLP) method. Paraoxonase activity towards paraoxon and arylesterase activity towards phenyl acetate were measured spectrophotometrically. RESULTS: Significant correlations between diabetes mellitus and paraoxonase activity (R = â»0.264, p = 0.026) and between the premature coronary heart disease in family history and PON1 activity (R = â»0.293, p = 0.013) were found. In multivariate analysis, PON1 paraoxonase activity was independently of confounding factors associated with diabetes (OR = 0.985; p = 0.024) and premature CHD in family history (OR = 0.983; p = 0.027). PON1 activity towards aryl acetate positively correlated with HDL-C level (R = 0.255, p = 0.032). In patients treated with statins, PON1 paraoxonase activity was significantly (p = 0.033) higher than in patients without treatment. CONCLUSIONS: In diabetic patients with CHD, paraoxonase activity is lower than in normoglycemic patients despite similar lipid profiles. Diabetes and positive family history in patients with overt CHD are associated with the serum PON1 activity, which might be an additional factor helpful in evaluating cardiovascular risk in this group of patients.