title: Young infants with recurrent wheezing and positive asthma predictive index have higher levels of exhaled nitric oxide.
abstract: OBJECTIVE
  The aim of this post hoc analysis was to establish the relationship between FE(NO) levels and the asthma predictive index (API) among infants with recurrent wheezing.
  
  
  METHODS
  Infants with recurrent wheezing (three or more episodes) were recruited consecutively and online FE(NO) tests at tidal breathing with multiple breaths were performed.
  
  
  RESULTS
  Twenty-seven (84%) out of 32 infants (median age of 12 months) who met the inclusion criteria for this post hoc analysis, successfully performed the FE(NO) determinations. Eighteen (66%) infants were classified with positive stringent API. FE(NO) levels were significantly higher among patients with positive API than those with negative (median [IQR] of 12.3 [14.8] ppb vs. 4.1 [7.9] ppb, respectively, p = .016). Furthermore, FE(NO) and positive API had a significant correlation (Spearman's rho, ρ = 0.4741, p = .0125). After logistic regression analysis including FE(NO) levels, gender, age, and use of controller therapy, FE(NO) was the only variable that was marginally related to API (OR = 1.12, 95% CI: 0.99-1.27, p = .07).
  
  
  CONCLUSIONS
  Infants with recurrent wheezing who had a positive stringent API already had higher FE(NO) levels than those with a negative API. This finding needs to be corroborated in a larger prospective study.
authors.affiliation: Division of Respiratory Medicine, Department of Pediatrics, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile. jacastro17@hotmail.com
authors.forename: Jose A
authors.initials: JA
authors.lastname: Castro-Rodriguez
authors.forename: Olaia
authors.initials: O
authors.lastname: Sardón
authors.forename: Eduardo G
authors.initials: EG
authors.lastname: Pérez-Yarza
authors.forename: Javier
authors.initials: J
authors.lastname: Korta
authors.forename: Ane
authors.initials: A
authors.lastname: Aldasoro
authors.forename: Paula
authors.initials: P
authors.lastname: Corcuera
authors.forename: Javier
authors.initials: J
authors.lastname: Mintegui
mesh_terms: D001249:Asthma / Q000175:diagnosis / Q000378:metabolism*; D001944:Breath Tests; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007223:Infant; D016015:Logistic Models; D008297:Male; D009569:Nitric Oxide / Q000032:analysis / Q000378:metabolism*; D012135:Respiratory Sounds / Q000175:diagnosis / Q000209:etiology*; D012189:Retrospective Studies
chemical_list: D009569:Nitric Oxide