title: 8-isoprostanes and resistin as markers of vascular damage in non-hypersomnolent obstructive sleep apnoea patients.
abstract: BACKGROUND
  Oxidative stress and inflammation are assumed as the main pathological triggers for vascular damage in hypersomnolent obstructive sleep apnoea (OSA) patients, whereas their exact role in less symptomatic population is currently unknown.
  
  
  OBJECTIVE
  To determine whether oxidative stress (urinary 8-isoprostane concentration) and inflammation (plasma resistin levels) are associated with vascular damage in non-hypersomnolent (Epworth Sleep Score <11) OSA patients.
  
  
  METHODS
  A total of 325 consecutive patients have undergone standard polysomnography, and 256 of them were diagnosed with OSA. Excessive daytime sleepiness was assessed by the Epworth Sleepiness Scale (ESS). Only 86 patients with ESS <11 participated in the study. The control group was presented by 45 subjects without OSA. Endothelial function was assessed by ultrasonographic measurement of flow-mediated dilatation (FMD). Intima-media thickness (IMT) and ankle-brachial index (ABI) were determined by ultrasonography. Urinary 8-isoprostanes (Cayman Chemical, USA) were measured, applying mass spectrometry. Resistin (RayBio_ Human ResistinCat#:ELH-Resistin-001) plasma levels were detected by ELISA.
  
  
  RESULTS
  In patients with OSA, flow-mediated dilatation was significantly lower than in control subjects (4·62% ±1·9) and (7·1% ±2·8), respectively (P: 0·013). The prevalence of plaques in a.carotis communis was higher in OSA (16% versus 4%). The same is observed regarding a.tibialis posterior (81% vs. 29%). The average IMT and ABI in OSA and in the control group were, respectively, (IMT - 800 µm versus. 666 µm); (ABI -1·06 versus 1·20). Urinary isoprostanes were higher in OSA patients (0·091 versus 0·078) and correlated negatively to FMD (r: -0·825, P: 0·00), IMT (r: -0·324, P: 0·003) and ABI (r: -0·226, P: 0·043). No association between resistin and the degree of vascular injury was found.
  
  
  CONCLUSIONS
  In comparison with the control group, increased prevalence of endothelial dysfunction and vascular damage was established in OSA patients without excessive daytime sleepiness. Urinary 8-isoprostanes (oxidative stress markers) are closely associated with FMD (endothelial dysfunction), IMT and ABI (vascular damage). Resistin plasma levels correlated neither to FMD, nor to IMT or ABI.
authors.affiliation: Department of Internal Medicine, Division of Pulmonary Medicine, Medical University Sofia, Georgi Sofiiski 1str, Sofia, Bulgaria.
authors.forename: Radostina Vlaeva
authors.initials: RV
authors.lastname: Cherneva
authors.affiliation: Department of Cardiology, Medical University Sofia, Georgi Sofiiski 1str, Sofia, Bulgaria.
authors.forename: Zheina Vlaeva
authors.initials: ZV
authors.lastname: Cherneva
authors.affiliation: Department of Internal Medicine, Division of Pulmonary Medicine, Medical University Sofia, Georgi Sofiiski 1str, Sofia, Bulgaria.
authors.forename: Ognian Borisov
authors.initials: OB
authors.lastname: Georgiev
authors.affiliation: Department of Internal Medicine, Division of Pulmonary Medicine, Medical University Sofia, Georgi Sofiiski 1str, Sofia, Bulgaria.
authors.forename: Daniela Stoichkova
authors.initials: DS
authors.lastname: Petrova
authors.affiliation: Department of Neurology, Medical University, Sofia; Georgi Sofiiski 1 str, Sofia, Bulgaria.
authors.forename: Julia Ivanova
authors.initials: JI
authors.lastname: Petrova
mesh_terms: D000328:Adult; D000368:Aged; D055109:Ankle Brachial Index; D015415:Biomarkers / Q000097:blood / Q000652:urine; D002031:Bulgaria / Q000453:epidemiology; D059168:Carotid Intima-Media Thickness; D015237:Dinoprost / Q000031:analogs & derivatives* / Q000652:urine; D004730:Endothelium, Vascular / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D006801:Humans; D018836:Inflammation Mediators / Q000097:blood*; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress; D015995:Prevalence; D052243:Resistin / Q000097:blood*; D012307:Risk Factors; D012890:Sleep; D020181:Sleep Apnea, Obstructive / Q000097:blood / Q000453:epidemiology / Q000503:physiopathology / Q000652:urine; D014652:Vascular Diseases / Q000097:blood / Q000453:epidemiology / Q000503:physiopathology; D014664:Vasodilation
chemical_list: D015415:Biomarkers; D018836:Inflammation Mediators; C499624:RETN protein, human; D052243:Resistin; C075750:8-epi-prostaglandin F2alpha; D015237:Dinoprost
keywords: isoprostanes; non-hypersomnolent; resistin; vascular damageOSA