title: Oxidized-LDL and paraoxonase-1 as biomarkers of coronary artery disease in patients with sleep-disordered breathing.
abstract: Coronary Artery Disease (CAD) and
  
  
  OBJECTIVE
  Sleep Disordered Breathing (SDB) are both oxidative stress disorders. SDB intermittent hypoxia induces oxidative stress, and reduces NO(·) availability, causing endothelial dysfunction. Low-density lipoprotein (LDL) peroxidation is involved in atherosclerosis, and is reported in SDB. Oxidized LDL (ox-LDL) and malondialdehyde (MDA) are lipid peroxidation markers. High-density lipoprotein (HDL) presents antiatherosclerotic properties related to paraxonase-1 (PON-1) activity. PON-1 hydrolyseyses lipid peroxides as ox-LDL. This study compares the relationship of HDL and PON-1, the lipid peroxidation markers ox-LDL and MDA, and 8-OHdG DNA damage marker in the association of SDB and CAD.
  
  
  METHODS
  29 controls and 27 cases with CAD (defined as > 30% coronary narrowing) patients were included. The apnea-hypopnea index (AHI), and several lipid and oxidative stress parameters were measured in these patients.
  
  
  RESULTS
  AHI is increased in CAD patients, and PON-1 activity and HDL levels are decreased. Regression analyseyses showed that lower PON-1 activity and higher ox-LDL levels are important CAD predictors, compared to HDL or MDA levels and present an age-dependent increase. Nitrites and nitrates, indirect NO(·) markers, are positive vs correlated with PON-1 and are negatively correlated to ox-LDL. SDB is not correlated to PON-1 activity decrease or ox-LDL increase. AHI is inversely correlated to HDL levels.
  
  
  CONCLUSIONS
  These results indicate that PON-1 and ox-LDL are important predictors of CAD, however they may not be directly related to SDB.
authors.affiliation: Departamento de Biofísica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: F S
authors.initials: FS
authors.lastname: Hackenhaar
authors.forename: D
authors.initials: D
authors.lastname: Martinez
authors.forename: T M
authors.initials: TM
authors.lastname: Medeiros
authors.forename: C
authors.initials: C
authors.lastname: Klein
authors.forename: P V G
authors.initials: PV
authors.lastname: Alabarse
authors.forename: M V
authors.initials: MV
authors.lastname: Wainstein
authors.forename: S C
authors.initials: SC
authors.lastname: Gonçalves
authors.forename: M S
authors.initials: MS
authors.lastname: Benfato
mesh_terms: D043303:Aryldialkylphosphatase / Q000097:blood; D015415:Biomarkers / Q000032:analysis / Q000097:blood; D003324:Coronary Artery Disease / Q000097:blood / Q000150:complications* / Q000175:diagnosis*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008077:Lipoproteins, LDL / Q000097:blood; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D008875:Middle Aged; D009566:Nitrates / Q000097:blood; D009573:Nitrites / Q000097:blood; D012891:Sleep Apnea Syndromes / Q000097:blood / Q000150:complications*
chemical_list: D015415:Biomarkers; D008077:Lipoproteins, LDL; D009566:Nitrates; D009573:Nitrites; C099252:oxidized low density lipoprotein; D008315:Malondialdehyde; D043303:Aryldialkylphosphatase