title: Circulating oxidized LDL: determinants and association with brachial flow-mediated dilation.
abstract: Circulating oxidized LDL (oxLDL) levels are strongly correlated to LDL-cholesterol (LDL-c) and apolipoprotein-B100 (apoB100), making it difficult to disentangle their independent contributions to cardiovascular risk. We explored the determinants of oxLDL and the relation between oxLDL and flow-mediated dilation (FMD) of the brachial artery to investigate whether the oxLDL/LDL-c and oxLDL/apoB100 ratios are more informative than the separate variables. FMD of the brachial artery and plasma concentrations of oxLDL, LDL-cholesterol, and apoB100 were measured in 624 men and women (age range 50 to 87 years), participating in a population-based cohort study. OxLDL was strongly correlated with apoB100 (r = 0.82, P < 0.001) and LDL-c (r = 0.67, P < 0.001). Other major independent determinants of oxLDL were sex, HDL-cholesterol, and LDL particle size. LDL-c and apoB100 concentrations were not significantly associated with FMD. After adjustment for age, sex, glucose tolerance status, and Framingham risk score, the oxLDL/apoB100 ratio was negatively related to FMD (P = 0.017). This association was weaker for the oxLDL/ LDL-c ratio (P = 0.062) and absent for oxLDL level (P = 0.27). In contrast to oxLDL, the oxLDL/apoB100 ratio, and to a lesser extent the oxLDL/LDL-c ratio, are related to a functional measure of atherosclerosis. Therefore correction of oxLDL for LDL particle number may improve the clinical usefulness of oxLDL measurement.
authors.affiliation: Metabolic Laboratory, Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Leonard P
authors.initials: LP
authors.lastname: van der Zwan
authors.forename: Tom
authors.initials: T
authors.lastname: Teerlink
authors.forename: Jacqueline M
authors.initials: JM
authors.lastname: Dekker
authors.forename: Ronald M A
authors.initials: RM
authors.lastname: Henry
authors.forename: Coen D A
authors.initials: CD
authors.lastname: Stehouwer
authors.forename: Cornelis
authors.initials: C
authors.lastname: Jakobs
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Heine
authors.forename: Peter G
authors.initials: PG
authors.lastname: Scheffer
mesh_terms: D000368:Aged; D053299:Apolipoprotein B-100 / Q000097:blood; D001783:Blood Flow Velocity; D001916:Brachial Artery / Q000502:physiology*; D008078:Cholesterol, LDL / Q000097:blood; D005260:Female; D006801:Humans; D008077:Lipoproteins, LDL / Q000097:blood* / Q000378:metabolism; D008297:Male; D010316:Particle Size; D014664:Vasodilation
chemical_list: D053299:Apolipoprotein B-100; D008078:Cholesterol, LDL; D008077:Lipoproteins, LDL; C099252:oxidized low density lipoprotein