title: Increased circulating malondialdehyde-modified LDL levels in patients with coronary artery diseases and their association with peak sizes of LDL particles.
abstract: Recent establishment of a sensitive ELISA system using antibodies against malondialdehyde-modified low density lipoprotein (MDA-LDL) made it possible to determine the circulating oxidized lipoprotein levels. Here, we investigated the serum levels of MDA-LDL in 62 patients with coronary artery disease (CAD) compared with the levels in 42 patients without CAD [groups CAD(+) and CAD(-), respectively], which are adjusted for age, serum total cholesterol, LDL and high density lipoprotein cholesterol, and triglyceride levels. Serum MDA-LDL levels were 113.4+/-49.1 IU/L in CAD(+), which were significantly higher than the levels in CAD(-) (85.2+/-22.5 IU/L, P<0.0005). The ratio of MDA-LDL/LDL cholesterol was 0.95+/-0.32 in CAD(+), indicating a significant increase compared with the ratio in CAD(-) (0.68+/-0.19, P<0.0005). The positive correlation of MDA-LDL level and the ratio of MDA-LDL/LDL cholesterol with intima-media thickness in carotid arteries was observed. Age was not clearly associated with the MDA-LDL level (P=0.865). The serum MDA level was positively correlated with LDL cholesterol (P<0.0001) and with triglycerides (P<0.001) and negatively correlated with high density lipoprotein cholesterol (P<0.05). Furthermore, the MDA-LDL level was negatively correlated with the peak size of the LDL particle (P<0.01). The LDL subclasses that were identified by using the sera collected from the subjects by sequential ultracentrifugation showed that the ratios of MDA-LDL/apolipoprotein B in LDL3 and LDL4 were nearly 3-fold higher than those in LDL1 and LDL2 for CAD(+) and CAD(-). These results indicate that the circulating MDA-LDL level is increased in CAD(+), independent of the serum LDL cholesterol level but in association with the peak size of LDL particles. The measurement of serum MDA-LDL level may be useful for the identification of patients with advanced atherosclerosis.
authors.affiliation: Department of Clinical Cell Biology, M6, Chiba University Graduate School of Medicine, Chiba.
authors.forename: Kosei
authors.initials: K
authors.lastname: Tanaga
authors.forename: Hideaki
authors.initials: H
authors.lastname: Bujo
authors.forename: Masahiro
authors.initials: M
authors.lastname: Inoue
authors.forename: Keiji
authors.initials: K
authors.lastname: Mikami
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kotani
authors.forename: Kazuo
authors.initials: K
authors.lastname: Takahashi
authors.forename: Takashi
authors.initials: T
authors.lastname: Kanno
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Saito
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D002340:Carotid Artery Diseases / Q000097:blood / Q000473:pathology; D016022:Case-Control Studies; D002784:Cholesterol / Q000097:blood; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood*; D003327:Coronary Disease / Q000097:blood* / Q000473:pathology; D004730:Endothelium, Vascular / Q000473:pathology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D006801:Humans; D008077:Lipoproteins, LDL / Q000097:blood*; D008297:Male; D008315:Malondialdehyde / Q000097:blood*; D008875:Middle Aged; D010084:Oxidation-Reduction; D014280:Triglycerides / Q000097:blood
chemical_list: D015415:Biomarkers; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D008077:Lipoproteins, LDL; D014280:Triglycerides; D008315:Malondialdehyde; D002784:Cholesterol