Increased LDL susceptibility to oxidation accelerates future carotid artery atherosclerosis

We selected 394 individuals (169 males and 225 females) who underwent a second carotid artery ultrasonographic examination in 2001 - 2002 for the present study. The susceptibility of LDL to oxidation was determined as the photometric absorbance and electrophoretic mobility of samples that had been collected in 1996 - 1997. The measurements were compared with ultrasonographic findings obtained in 2001 - 2002.The multivariate-adjusted model showed that age (odds ratio (OR), 1.034; 95% confidence interval (95%CI), 1.010 - 1.059), HbA1c (OR, 1.477; 95%CI, 0.980 - 2.225), and photometric O/N (OR, 2.012; 95%CI, 1.000 - 4.051) were significant variables that could independently predict the risk of new carotid artery atherosclerosis.The susceptibility of LDL to oxidation was a significant parameter that could predict new carotid artery atherosclerosis over a 5-year period, and higher susceptibility was associated with a higher incidence of new carotid artery atherosclerosis.The oxidation of low-density lipoprotein (LDL) is widely believed to be an important event in the pathogenesis of atherosclerosis. Macrophages endocytose oxidized LDL in an uncontrolled manner, which results in the generation of cholesterol-laden foam cells that characterize atherosclerotic lesions [1,2]. The oxidation of LDL in vitro can be mediated by cells or mimicked in a cell free system using transition metal ions such as copper or iron as prooxidants [3,4]. Metal ions are usually prerequisite for LDL oxidation, at least in vitro. Catalytically active copper and iron are also present in human atherosclerotic lesions [5].The initial step of LDL oxidation is the peroxidation of polyunsaturated fatty acids among LDL lipids. Fragments of modified fatty acids covalently attach to apolipoprotein B-100 (apoB-100) and neutralize its positively charged epsilon-amino acid group [2,6]. Another possible mechanism of the oxidation is that copper directly binds to apoB-100 at sites that are located at least on r