title: LDL from obese patients with the metabolic syndrome show increased lipid peroxidation and activate platelets.
abstract: OBJECTIVE
  This study assessed oxidative stress in LDL from obese patients with the metabolic syndrome and compared it with that in LDL from type 2 diabetic patients or control volunteers. It also determined the effect on platelets of LDL from the three groups.
  
  
  METHODS
  The profiles of lipids, fatty acids and fatty acid oxidation products were determined in LDL isolated from plasma of patients with the metabolic syndrome, patients with type 2 diabetes and volunteers (n = 10 per group). The effects of LDL from the participant groups on the platelet arachidonic acid signalling cascade and aggregation were investigated.
  
  
  RESULTS
  Compared with LDL from control volunteers, LDL from obese metabolic syndrome and type 2 diabetic patients had lower cholesteryl ester, higher triacylglycerol and lower ethanolamine plasmalogen levels. Proportions of linoleic acid were decreased in phosphatidylcholine and cholesteryl esters in LDL from both patient groups. Among the markers of lipid peroxidation, oxidation products of linoleic acid (hydroxy-octadecadienoic acids) and malondialdehyde were increased by 59% and twofold, respectively in LDL from metabolic syndrome and type 2 diabetic patients. LDL from metabolic syndrome and type 2 diabetic patients were equally potent in activating the platelet arachidonic acid signalling cascade through increased phosphorylation of p38 mitogen-activated protein kinase and cytosolic phospholipase A(2), and through increased thromboxane B(2) formation. LDL from patients with the metabolic syndrome and type 2 diabetes potentiated platelet aggregation by threefold and 3.5-fold respectively, whereas control LDL had no activating effects on platelets.
  
  
  CONCLUSIONS
  The metabolic syndrome in obese patients, without or with diabetes, is associated with increased oxidative stress in LDL, which triggers platelet activation.
authors.affiliation: UMR INSERM 1060/Université de Lyon, Cardiovasculaire, Métabolisme, Diabétologie, et Nutrition (CarMeN), INSA-Lyon, IMBL, Bât. Louis Pasteur, 20 av. Albert Einstein, 69621 Villeurbanne, France.
authors.forename: R
authors.initials: R
authors.lastname: Colas
authors.forename: A
authors.initials: A
authors.lastname: Sassolas
authors.forename: M
authors.initials: M
authors.lastname: Guichardant
authors.forename: C
authors.initials: C
authors.lastname: Cugnet-Anceau
authors.forename: M
authors.initials: M
authors.lastname: Moret
authors.forename: P
authors.initials: P
authors.lastname: Moulin
authors.forename: M
authors.initials: M
authors.lastname: Lagarde
authors.forename: C
authors.initials: C
authors.lastname: Calzada
mesh_terms: D000328:Adult; D000368:Aged; D016718:Arachidonic Acid / Q000378:metabolism; D015415:Biomarkers / Q000097:blood; D001792:Blood Platelets / Q000201:enzymology / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000150:complications / Q000378:metabolism; D006801:Humans; D015227:Lipid Peroxidation; D008055:Lipids / Q000097:blood; D008077:Lipoproteins, LDL / Q000097:blood* / Q000737:chemistry / Q000378:metabolism; D008297:Male; D024821:Metabolic Syndrome / Q000150:complications*; D008875:Middle Aged; D009765:Obesity / Q000097:blood* / Q000150:complications* / Q000378:metabolism; D018384:Oxidative Stress; D054497:Phospholipases A2, Secretory / Q000097:blood / Q000378:metabolism; D015539:Platelet Activation; D015398:Signal Transduction
chemical_list: D015415:Biomarkers; D008055:Lipids; D008077:Lipoproteins, LDL; C099252:oxidized low density lipoprotein; D016718:Arachidonic Acid; D054497:Phospholipases A2, Secretory