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Effect of age on relationship between exhaled nitric oxide and airway hyperresponsiveness in asthmatic children

Chikako Motomura1, Hiroshi Odajima1, Junichiro Tezuka1

  • 1Department of Pediatrics, Fukuoka National Hospital, Minami-ku, Fukuoka, Japan.

Chest
|April 28, 2009
PubMed

Insights

In children with asthma, airway hyperresponsiveness (AHR) correlates with airway inflammation, indicated by fractional exhaled nitric oxide (Feno). In adolescents, AHR is linked to structural changes, with a weaker association with inflammation.

Area of Science:

  • Pediatric Pulmonology
  • Respiratory Medicine
  • Allergy and Immunology

Background:

  • Fractional exhaled nitric oxide (Feno) and airway hyperresponsiveness (AHR) are key asthma indicators.
  • Age-related differences in the Feno-AHR relationship in pediatric asthma are not fully understood.

Purpose of the Study:

  • To investigate how age influences the association between Feno and AHR in children with asthma.
  • To differentiate the underlying mechanisms of AHR in younger children versus adolescents with asthma.

Main Methods:

  • Studied 267 asthmatic patients aged 5-20 years.
  • Assessed AHR using acetylcholine challenge tests to determine provocative concentration (PC(20)).
  • Measured Feno using the online method prior to the challenge test.

Main Results:

  • In children under 12, lower PC(20) (indicating AHR) strongly correlated with higher Feno levels.
  • In adolescents (12-20 years), lower PC(20) was associated with peripheral airway obstruction, with a weak correlation to Feno.
  • AHR in adolescents showed associations with FEV(1) and FVC parameters, suggesting structural changes.

Conclusions:

  • In pediatric asthma, AHR is primarily linked to airway inflammation, reflected by Feno.
  • In adolescent asthma, AHR appears to involve airway remodeling and structural changes, with inflammation playing a lesser role.
  • Age is a critical factor in understanding the pathophysiology of AHR in asthma.
Abstract

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