title: Oxidative stress levels in exhaled breath condensate associated with COPD and smoking.
abstract: BACKGROUND
  COPD is characterized by chronic air-flow limitation. Smoking is the most important factor in the pathogenesis of COPD. Smoking is associated with increased oxidative stress in the lungs. In this study our aim was to evaluate the differences in the burden of oxidative stress  in patients with COPD, smokers, and non-smokers by measuring hydrogen peroxide (H(2)O(2)), malondialdehyde (MDA), and 8-isoprostane levels in the exhaled breath condensate (EBC) samples.
  
  
  METHODS
  Eighty subjects were included in the study. Group I (no. = 25) had COPD, Group  II (no. = 26) was smokers, and Group III (no. = 29) was nonsmokers. The severity of the COPD and dyspnea was assessed according to the results of pulmonary function tests (PFTs) and Medical Research Council (MRC) scale.
  
  
  RESULTS
  The mean age of the subjects was 58 ± 8.9 years. While  8-isoprostane and H(2)O(2) levels were significantly higher in subjects with COPD (44.8 ± 40.2 pg/mL and 1.9 ± 0.8 μmol/L) and smokers (41.3 ± 26 pg/mL and 1.7 ± 0.7 μmol/L) than non-smokers (15.8 ± 6.9 pg/mL and 0.8 ± 0.4 μmol/L),  levels were similar between smokers and COPD subjects. MDA levels were similar between the 3 groups (P = .31). There was no correlation between 8-isoprostane and H(2)O(2) levels and PFT parameters. There was a significant positive correlation between dyspnea grade  on the MRC scale and 8-isoprostane levels (r = 0.805, P < .001).
  
  
  CONCLUSIONS
  Even if respiratory function tests are within normal limits, oxidant burden in lungs of smokers is equivalent to that in COPD patients. 8-isoprostane could be useful in assessing symptom severity and health  status of COPD patients.
authors.affiliation: Department of Pulmonary Diseases, Gaziosmanpasa University, Faculty of Medicine, Tokat, Turkey. handaninonu@gmail.com
authors.forename: Handan
authors.initials: H
authors.lastname: Inonu
authors.forename: Sibel
authors.initials: S
authors.lastname: Doruk
authors.forename: Semsettin
authors.initials: S
authors.lastname: Sahin
authors.forename: Unal
authors.initials: U
authors.lastname: Erkorkmaz
authors.forename: Deniz
authors.initials: D
authors.lastname: Celik
authors.forename: Serhat
authors.initials: S
authors.lastname: Celikel
authors.forename: Zehra
authors.initials: Z
authors.lastname: Seyfikli
mesh_terms: D000368:Aged; D001944:Breath Tests; D015237:Dinoprost / Q000031:analogs & derivatives / Q000378:metabolism; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D008875:Middle Aged; D018384:Oxidative Stress; D029424:Pulmonary Disease, Chronic Obstructive / Q000378:metabolism*; D012129:Respiratory Function Tests; D012907:Smoking / Q000378:metabolism*
chemical_list: C075750:8-epi-prostaglandin F2alpha; D008315:Malondialdehyde; D015237:Dinoprost; D006861:Hydrogen Peroxide