Plasma Oxidized Low-Density Lipoprotein Is an Independent Risk Factor in Young Patients with Coronary Artery Disease

OBJECTIVES Oxidized low-density lipoprotein (ox-LDL) is considered to be a key factor of initiating and accelerating atherosclerosis. The objective of this study was to investigate the role of ox-LDL in young patients with coronary artery disease (CAD). METHODS 128 consecutive angiographically proven young CAD patients (aged ⩽ 55 years) were enrolled, and 132 age-matched non-CAD individuals (coronary angiography normal or negative finding by coronary ultrafast CT) were set as control group. Conventional risk factors (hypertension, dyslipidemia, diabetes mellitus, obesity, smoking) were evaluated in the two groups. Ox-LDL was measured by competitive ELISA. Framingham risk score (FRS) and absolute 10-year CAD events risk were calculated for each individual. RESULTS Male sex was more prevalent in group CAD than in control (87.5% vs. 62.1%; P< 0.01). There were significant differences in smoking history (P< 0.01) and triglyeride (TG) and ratio of apolipoprotein B/apolipoprotein A1 (ApoB/ApoA1) (both P< 0.05) but no remarkable difference in other conventional risk factors (all P> 0.05) between group CAD and control. Level of ox-LDL was significantly higher in group CAD than in control (P< 0.01). Multivariate logistic regression showed that male sex (OR, 4.54; 95%CI, 1.76-9.77), smoking quantity (OR, 2.78; 95%CI, 1.34-4.25), TG (OR, 1.42; 95%CI, 1.18-2.83), ApoB/ApoA1 (OR, 1.73; 95%CI, 1.32-4.23), and ox-LDL (OR, 2.15; 95%CI, 1.37-6.95) were independently correlated with CAD in young patients. Area under the curve (AUC) of receiver operating characteristic (ROC) curve of TG, ApoB/ApoA1, and ox-LDL was 0.831, 0.866, and 0.935, respectively (P< 0.001). CONCLUSIONS Ox-LDL is an important independent risk factor for CAD in young patients after adjusting other risk factors such as smoking, TG, and ApoB/ApoA1.