Role of β 2 -Glycoprotein I,LDL-,and Antioxidant Levels in Hypercholesterolemic Elderly Subjects

Abstract

The levels of electronegative low-density lipoprotein (LDL-), LDL cholesterol oxidability, and plasma levels of molecular antioxidants and of β ₂-glycoprotein I (β ₂ GPI) were studied in a group of 10 hypercholesterolemic (HC) and 10 normocholesterolemic (NC) elderly subjects. HC subjects showed significantly higher levels of cholesterol, LDL cholesterol, LDL-, andβ ₂GPI than NC, whereas high-density lipoprotein cholesterol and α-tocopherol levels were lower in HC as compared with NC subjects. Correlations among LDL- levels, LDL oxidation lag time, β ₂GPI, and antioxidant plasma levels were studied in 100 HC elderly subjects. Lag time for in vitro LDL oxidation positively correlated with ubiquinol-10 levels (p= 0.008), but not with other antioxidants studied or β ₂GPI. LDL- and α-tocopherol levels showed an inverse and significant correlation (p = 0.018). β ₂GPI and LDL cholesterol levels were correlated (p = 0.001), whereas no significance was found between LDL- and β ₂GPI levels (p = 0.057). The physiological significance ofα-tocopherol and ubiquinol-10 levels on LDL- levels, and the presence of high levels of β ₂-GPI, are discussed in terms of protective mechanisms operating during the overall atherosclerosis process.