PON1 activities and oxidative markers of LDL in patients with angiographically proven coronary artery disease

Background: There is growing evidence that ox-LDL plays an important role during the atherosclerosis process and PON1 can significantly inhibit generation of lipid peroxidation during LDL oxidation and thus play a role in the in vivo protection by HDL against atherosclerosis. Methods: Twenty-four healthy volunteers and one-hundred and one patients were taken into study, sixty-eight patients had coronary artery disease which was confirmed by coronary angiography. Serum PON1, erythrocyte superoxide dismutase and catalase activities, oxidative markers of LDL were determined along with the routine biochemical parameters in all groups. Results: The indicators of oxidative stress were higher in the patients compared with the controls. No statistically significant difference in any of parameters were observed between the patients who had obstruction with different degrees except for erythrocyte TBARS [24.5 nmol/g Hb in patients with one vessel disease (VD) (n=22), 29.6 nmol/g Hb in patients with two VD (n=26) and 33.5 nmol/g Hb in patients with three VD (n=20)]. Basal and stimulated diene levels were higher in patients who had more diseased vessels than those who had less. Conclusion: The increase in erythrocyte TBARS and CRP levels with the severity of disease supports the reports that showed the inflammatory and oxidative nature of atherosclerosis. In the light of the fact that the well-known classical risk factors for atherosclerosis are closely associated with increased oxidative stress, we propose that the elevation in TBARS levels might be a more marked indicator for the degree of atherosclerosis than the insufficiency in antioxidant enzymes such as SOD and PON1.