title: Oxidative and carbonyl stress in patients with obstructive sleep apnea treated with continuous positive airway pressure.
abstract: OBJECTIVE
  The pathogenesis of cardiovascular complications of obstructive sleep apnea syndrome (OSAS) can be explained by oxidative and carbonyl stress due to oxygenation and reoxygenation injury during sleep. This hypothesis has yet to be proved experimentally, although several clinical observations have found increased oxidative damage in plasma. Continuous positive airway pressure (CPAP) improves symptoms and prognosis of patients with OSAS.
  
  
  METHODS
  Patients with confirmed SAS (n = 89) underwent polysomnography and received CPAP treatment. Plasma and saliva samples were taken before CPAP therapy as well as after 1 and 6 months of CPAP treatment. Selected markers of oxidative and carbonyl stress were measured in plasma and saliva, and their dynamics was statistically analyzed.
  
  
  RESULTS
  Plasma levels of thiobarbituric acid reacting substances-a marker of lipoperoxidation-and advanced glycation end products (AGEs)-a marker of carbonyl stress-were decreased by the CPAP therapy. The decrease of AGEs and fructosamine was also found in saliva. Interestingly, no gender differences and no changes of antioxidant status measured as total antioxidant capacity and ferrous reducing ability were found in either of the samples.
  
  
  CONCLUSIONS
  Previous findings of lowered plasma markers of oxidative stress were confirmed. Plasma AGEs were lowered by CPAP therapy. This is the first study analyzing markers of oxidative and carbonyl stress in saliva. Non-invasive sampling of saliva makes it a very interesting source of information for repeated monitoring of therapy success. Salivary AGEs and fructosamine as markers of carbonyl stress were decreased by the CPAP therapy and might therefore have potential informative value for clinical observations, as well as for the understanding of the pathogenesis of OSAS complications.
authors: Institute of Molecular Biomedicine, Comenius University, Sasinkova 4, 811 08, Bratislava, Slovakia. petercelec@gmail.com
authors: Peter
authors: P
authors: Celec
authors: Július
authors: J
authors: Hodosy
authors: Michal
authors: M
authors: Behuliak
authors: Roland
authors: R
authors: Pálffy
authors: Roman
authors: R
authors: Gardlík
authors: Lukáč
authors: L
authors: Halčák
authors: Imrich
authors: I
authors: Mucska
mesh_terms: D000328:Adult; D000368:Aged; D000975:Antioxidants / Q000378:metabolism*; D015415:Biomarkers / Q000097:blood*; D045422:Continuous Positive Airway Pressure; D005260:Female; D005500:Follow-Up Studies; D019270:Fructosamine / Q000097:blood*; D017127:Glycation End Products, Advanced / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000502:physiology*; D017286:Polysomnography; D012016:Reference Values; D012463:Saliva / Q000737:chemistry; D020181:Sleep Apnea, Obstructive / Q000097:blood* / Q000175:diagnosis / Q000628:therapy*; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism*; D016896:Treatment Outcome
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D017127:Glycation End Products, Advanced; D017392:Thiobarbituric Acid Reactive Substances; D019270:Fructosamine