title: Secondhand smoke exposure induces acutely airway acidification and oxidative stress.
abstract: Previous studies have shown that secondhand smoke induces lung function impairment and increases proinflammatory cytokines. The aim of the present study was to evaluate the acute effects of secondhand smoke on airway acidification and airway oxidative stress in never-smokers. In a randomized controlled cross-over trial, 18 young healthy never-smokers were assessed at baseline and 0, 30, 60, 120, 180 and 240 min after one-hour secondhand smoke exposure at bar/restaurant levels. Exhaled NO and CO measurements, exhaled breath condensate collection (for pH, H(2)O(2) and NO(2)(-)/NO(3)(-) measurements) and spirometry were performed at all time-points. Secondhand smoke exposure induced increases in serum cotinine and exhaled CO that persisted until 240 min. Exhaled breath condensate pH decreased immediately after exposure (p < 0.001) and returned to baseline by 180 min, whereas H(2)O(2) increased at 120 min and remained increased at 240 min (p = 0.001). No changes in exhaled NO and NO(2)/NO(3) were observed, while decreases in FEV(1) (p < 0.001) and FEV(1)/FVC (p < 0.001) were observed after exposure and returned to baseline by 180 min. A 1-h exposure to secondhand smoke induced airway acidification and increased airway oxidative stress, accompanied by significant impairment of lung function. Despite the reversal in EBC pH and lung function, airway oxidative stress remained increased 4 h after the exposure. Clinical trial registration number (EudraCT): 2009-013545-28.
authors.affiliation: Respiratory Medicine Department, University of Thessaly Medical School, Larissa, Greece. ktk@otenet.gr
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Kostikas
authors.forename: Markos
authors.initials: M
authors.lastname: Minas
authors.forename: Eftychia
authors.initials: E
authors.lastname: Nikolaou
authors.forename: Andriana I
authors.initials: AI
authors.lastname: Papaioannou
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Liakos
authors.forename: Sofia
authors.initials: S
authors.lastname: Gougoura
authors.forename: Konstantinos I
authors.initials: KI
authors.lastname: Gourgoulianis
authors.forename: Petros C
authors.initials: PC
authors.lastname: Dinas
authors.forename: Giorgos S
authors.initials: GS
authors.lastname: Metsios
authors.forename: Athanasios Z
authors.initials: AZ
authors.lastname: Jamurtas
authors.forename: Andreas D
authors.initials: AD
authors.lastname: Flouris
authors.forename: Yiannis
authors.initials: Y
authors.lastname: Koutedakis
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D001944:Breath Tests / Q000379:methods; D003367:Cotinine / Q000097:blood; D018592:Cross-Over Studies; D045853:Exhalation / Q000502:physiology; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism; D018384:Oxidative Stress / Q000502:physiology*; D012137:Respiratory System / Q000378:metabolism*; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*; D014797:Vital Capacity / Q000502:physiology; D055815:Young Adult
chemical_list: D015415:Biomarkers; D014028:Tobacco Smoke Pollution; D009569:Nitric Oxide; D006861:Hydrogen Peroxide; D003367:Cotinine