ABSTRACT

The aim of this study was to investigate the possible relationship between serum oxidized low-density lipoprotein (Ox-LDL) concentration, recently shown to be a cardiovascular risk factor, paraoxonase 1 (PON1) activity and Thiobarbituric Acid Reactive Substance (TBARS) levels, and the severity of Coronary Artery Disease (CAD) as determined by the obstructive vessel number inpatients.

We determined plasma PON1 activity, serum Ox-LDL concentration, Apolipoprotein A1 (ApoA1) levels, TBARS levels and lipid profiles, including total cholesterol (TC), triglycerides (TG), Low-Density Lipoprotein cholesterol (LDL-C), High-Density Lipoprotein cholesterol (HDL-C), and Very Low-Density Lipoprotein cholesterol (VLDL-C), in patients with CAD (n=42) and in a healthy control group (n=17). The CAD group was divided into three subgroups with single- (n=13), double- (n=15) and triple-vessel (n=14) disease according to their angiography results. PON1 activity and TBARS levels were measured spectrophotometrically; Ox-LDL levels were determined by ELISA; ApoA1levels were determined immunoturbidometrically; and TC, TG, and HDL-C levels were determined enzymatically.

In the study we observed that PON1 activity decreases when the number of affected vessels increases (r=-0,537, p<0.01). Ox-LDL levels in single-, double- and triple-vessel disease groups and in the total CAD group were significantly higher than in the healthy control group (p <0.01). TBARS levels in single-, double- and triple-vessel disease groups were significantly higher than the healthy control group (p<0.01). Moreover, ApoA1 levels in the single-, double- and triple-vessel disease groups were significantly lower than in the healthy control group (p<0.01).

Our results show that low PON1 activity, high Ox-LDL levels, high TBARS levels and low ApoA1 levels may play an important role in the pathogenesis of CAD.

Keywords: PON1, protein, human, oxidized low-density lipoprotein, Thiobarbituric Acid Reactive Substances