title: Passive and active smoking and exhaled nitric oxide levels according to asthma and atopy in adults.
abstract: BACKGROUND
  No data are available regarding the utility of fractional exhaled nitric oxide (FeNO) level in guiding therapy in smoking asthmatic patients. Identification of the effect of smoking in a large sample is needed.
  
  
  OBJECTIVE
  To study the association between smoking and FeNO level according to current asthma and atopy status in adults from the French EGEA (Epidemiological study on the Genetics and Environment of Asthma, bronchial hyperresponsiveness and atopy).
  
  
  METHODS
  Levels of FeNO were measured at 50 mL/s in 654 adults (268 asthmatic participants). Active smoking and environmental tobacco smoke (ETS) exposure at home, at work, and during leisure activities were recorded. Participants were categorized as having no exposure to ETS, mild exposure (ETS <2 h/d), and noticeable exposure (ETS > or = 2 h/d). Multivariate analyses were performed, with adjustment for age, sex, height, and center.
  
  
  RESULTS
  Mean adjusted FeNO values increased with asthma (15.1 vs 19.5 ppb), atopy (14.2 vs 18.9 ppb), and eosinophilia (15.8 vs 24.8 ppb) (P < .001 for all). Mean FeNO levels decreased with smoking (18.4, 17.5, and 14.5 ppb in nonsmokers, ex-smokers, and current smokers, respectively; P for trend = .001). The association with smoking was observed in nonasthmatic and asthmatic participants, especially in atopic asthmatic participants. Multivariate analyses showed that ETS exposure of at least 2 h/d and active smoking were negatively and significantly associated with FeNO levels independent of age, sex, height, and center in nonasthmatic participants (mean [SE], -0.13 [0.06], P = .03 and -0.10 [0.03], P < .001) and in asthmatic participants (mean [SE], -0.18 [0.07], P = .01 and -0.14 [0.04], P = .02).
  
  
  CONCLUSIONS
  Active and passive smoking decreased FeNO levels in adults. Careful consideration of asthma, atopy, and active and passive smoking are needed to interpret FeNO values.
authors.affiliation: Inserm, CESP Centre for Research in Epidemiology and Population Health, Respiratory and Environmental Epidemiology Team U1018, Villejuif, France. rachel.nadif@inserm.fr
authors.forename: Rachel
authors.initials: R
authors.lastname: Nadif
authors.forename: Regis
authors.initials: R
authors.lastname: Matran
authors.forename: Jean
authors.initials: J
authors.lastname: Maccario
authors.forename: Magali
authors.initials: M
authors.lastname: Bechet
authors.forename: Nicole
authors.initials: N
authors.lastname: Le Moual
authors.forename: Pierre
authors.initials: P
authors.lastname: Scheinmann
authors.forename: Jean
authors.initials: J
authors.lastname: Bousquet
authors.forename: Francine
authors.initials: F
authors.lastname: Kauffmann
authors.forename: Isabelle
authors.initials: I
authors.lastname: Pin
mesh_terms: D000328:Adult; D001249:Asthma / Q000175:diagnosis / Q000453:epidemiology* / Q000378:metabolism; D001944:Breath Tests / Q000379:methods; D003876:Dermatitis, Atopic / Q000175:diagnosis / Q000453:epidemiology* / Q000378:metabolism; D004802:Eosinophilia / Q000453:epidemiology / Q000378:metabolism; D045853:Exhalation; D005260:Female; D005602:France / Q000453:epidemiology; D006801:Humans; D008297:Male; D009569:Nitric Oxide / Q000032:analysis / Q000378:metabolism*; D012680:Sensitivity and Specificity; D012907:Smoking / Q000378:metabolism*; D014028:Tobacco Smoke Pollution
chemical_list: D014028:Tobacco Smoke Pollution; D009569:Nitric Oxide