title: Exhaled nitric oxide indicates poorly athlete's asthma.
abstract: BACKGROUND
  In athletes, exercise-induced respiratory symptoms are common and their assessment is time and resource consuming.
  
  
  OBJECTIVE
  The objective was to evaluate fractional concentration of exhaled nitric oxide (FENO) as a predictor of bronchial hyperresponsiveness (BHR) and of asthma.
  
  
  METHODS
  Eighty-seven elite athletes and a control group of 87 sedentary patients with symptoms suggesting asthma underwent measurements of FENO and of BHR by using methacholine provocation test (MCH) and eucapnic voluntary hyperpnoea (EVH) (athletes) or histamine provocation test (HIST) (controls).
  
  
  RESULTS
  In athletes, elevated FENO (>30 ppb) was not associated with lung function-confirmed asthma or with MCH positivity, but receiver operating characteristics (ROC) analysis showed some predictive value for EVH positivity [Area Under Curve (AUC) 0.652, 95% confidence interval (CI): 0.53 to 0.78, P = 0.020]. However, the sensitivity (55%) and the specificity (71%) were poor. In sedentary patients, FENO was significantly associated with both confirmed asthma and HIST positivity, ROC analysis showing FENO to be significantly predictive for HIST positivity (AUC 0.83, 95% CI: 0.70 to 0.96, P = 0.001) and for asthma (AUC 0.74, 95% CI: 0.63 to 0.85, P < 0.001).
  
  
  CONCLUSIONS
  The results suggest that in contrast to sedentary patients, FENO seems to be a poor predictor of BHR and of clinical asthma in elite athletes. We find it unlikely that FENO could be a useful screening tool in athletes with exercise-induced respiratory symptoms.
authors.affiliation: Department of Allergy, Skin and Allergy Hospital, Helsinki University Hospital, Helsinki, Finland.
authors.forename: Mikko
authors.initials: M
authors.lastname: Voutilainen
authors.forename: Leo Pekka
authors.initials: LP
authors.lastname: Malmberg
authors.forename: Tommi
authors.initials: T
authors.lastname: Vasankari
authors.forename: Tari
authors.initials: T
authors.lastname: Haahtela
mesh_terms: D000293:Adolescent; D000328:Adult; D006631:Amine Oxidase (Copper-Containing); D001250:Asthma, Exercise-Induced / Q000175:diagnosis* / Q000378:metabolism; D056352:Athletes; D001944:Breath Tests / Q000379:methods*; D016535:Bronchial Hyperreactivity / Q000175:diagnosis / Q000378:metabolism; D016085:Bronchoconstrictor Agents; D005260:Female; D006801:Humans; D008297:Male; D016210:Methacholine Chloride; D009569:Nitric Oxide / Q000378:metabolism*; D011237:Predictive Value of Tests; D012372:ROC Curve; D012129:Respiratory Function Tests / Q000379:methods* / Q000592:standards*; D055815:Young Adult
chemical_list: D016085:Bronchoconstrictor Agents; D016210:Methacholine Chloride; D009569:Nitric Oxide; D006631:Amine Oxidase (Copper-Containing)
keywords: airway inflammation; exercise-induced asthma; respiratory function tests; sports