Young infants with recurrent wheezing and positive asthma predictive index have higher levels of exhaled nitric oxide

J Asthma. 2013 Mar;50(2):162-5. doi: 10.3109/02770903.2012.754030. Epub 2013 Jan 3.

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).

Conclusion: 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.

MeSH terms

  • Asthma / diagnosis
  • Asthma / metabolism*
  • Breath Tests
  • Cross-Sectional Studies
  • Female
  • Humans
  • Infant
  • Logistic Models
  • Male
  • Nitric Oxide / analysis
  • Nitric Oxide / metabolism*
  • Respiratory Sounds / diagnosis
  • Respiratory Sounds / etiology*
  • Retrospective Studies

Substances

  • Nitric Oxide