title: Biochemical oxidative stress-related markers in patients with obstructive sleep apnea.
abstract: BACKGROUND
  Obstructive sleep apnea (OSA) is a condition contributing to oxidative stress. The aim of this study was to ascertain if there is any connection between OSA and novel oxidative stress-related markers. Matrix metalloproteinases 2 and 9 (MMP-2, MMP-9), high sensitive C-reactive protein (hsCRP), pregnancy-associated plasma protein-A (PAPP-A), soluble receptors for advanced glycation end-products (sRAGE), zinc (Zn) and copper (Cu) were measured. Further biochemical markers were evaluated.
  
  
  METHODS
  Fifty-one men suspected for OSA indicated for night polygraphy were included. Apnea/hypopnea index (AHI), oxygen desaturation index (ODI), mean blood hemoglobin oxygen saturation (SpO2) and time of blood hemoglobin oxygen saturation below 90% (SpO2 <90%) were measured. Morning venous blood samples were taken.
  
  
  RESULTS
  For body mass index (BMI) we found strong positive correlation with levels of Cu, MMP-9, hsCRP and fibrinogen, and negative correlation with sRAGE. Concerning ventilation parameters, we found positive correlation of ODI and SpO2 <90% with markers MMP-9 and hsCRP. sRAGE level correlated with AHI and ODI negatively. SpO2 correlated negatively with Cu, MMP-9, hsCRP and fibrinogen. There was no correlation between ventilation parameters and markers MMP-2, PAPP-A and Zn. Compared to severity of OSA, there was significant difference in levels of hsCRP and Cu between patients with AHI ≤5 and AHI ≥30 independent of BMI.
  
  
  CONCLUSIONS
  MMP-9, hsCRP, sRAGE and Cu seem to be strong predictors of oxidative stress in OSA patients. The strong correlation between oxidative stress-related markers and OSA is elucidated by connection of these to BMI, which is probably a primary condition of oxidative stress, but OSA is an additive condition.
authors.affiliation: Department of Neurology, 1st Faculty of Medicine, Charles University and General Teaching Hospital, Prague. volja@seznam.cz
authors.forename: Jana
authors.initials: J
authors.lastname: Volná
authors.forename: David
authors.initials: D
authors.lastname: Kemlink
authors.forename: Marta
authors.initials: M
authors.lastname: Kalousová
authors.forename: Jana
authors.initials: J
authors.lastname: Vávrová
authors.forename: Veronika
authors.initials: V
authors.lastname: Majerová
authors.forename: Otto
authors.initials: O
authors.lastname: Mestek
authors.forename: Jana
authors.initials: J
authors.lastname: Svarcová
authors.forename: Karel
authors.initials: K
authors.lastname: Sonka
authors.forename: Tomás
authors.initials: T
authors.lastname: Zima
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000378:metabolism*; D002097:C-Reactive Protein / Q000378:metabolism; D003300:Copper / Q000378:metabolism; D006801:Humans; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D008875:Middle Aged; D018384:Oxidative Stress; D010100:Oxygen / Q000378:metabolism; D020181:Sleep Apnea, Obstructive / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology*
chemical_list: D015415:Biomarkers; D003300:Copper; D002097:C-Reactive Protein; D020780:Matrix Metalloproteinase 9; D010100:Oxygen