Serum paraoxonase activity and phenotype distribution in Turkish subjects with coronary heart disease and its relationship to serum lipids and lipoproteins

Recently, biochemical studies of paraoxonase in the serum of humans have sh own that much of this enzymes' activity is associated with high-density lip oprotein (HDL) and paraoxonase may play a role in lipid metabolism preventi ng the accumulation of the lipoperoxides. In this study, a possible relatio nship between coronary heart disease (CHD) and paraoxonase activity were in vestigated. Serum triglycerides, total cholesterol, HDL-cholesterol and par aoxonase activity were measured in unrelated healthy donors and CHD patient s. It was found that paraoxonase activity was trimodally distributed in bot h groups but no statistically significant difference was found between phen otype distributions of controls and CHD patients (gene frequencies; 0.632 a nd 0.382 of controls, 0.702 and 0.298 of patients for the A and B alleles, respectively). However, in CHD group, a high possibility was found to be ph enotype A compared with the control group. A relative risk of 1.48 (95% con fidence intervals (CI)? 0.986-2.227) was found for the relation between CHD and the paraoxonase activity. Patients' HDL-cholesterol values were lower and triglycerides were higher than controls (P < 0.001). It may be conclude d from the present study that although no statistically significant differe nce was found between paraoxonase phenotype distributions of controls and C HD patients, a decrease in paraoxonase activity could become a risk factor for this disease. (C) 1999 Elsevier Science Ireland Ltd. All rights reserve d.