Airway response to exercise measured by area under the expiratory flow-volume curve in children with asthma

Paweł Majak; Lukasz Cichalewski; Agata Ożarek-Hanc; Włodzimierz Stelmach; Joanna Jerzyńska; Iwona Stelmach

doi:10.1016/j.anai.2013.08.026

Airway response to exercise measured by area under the expiratory flow-volume curve in children with asthma

Ann Allergy Asthma Immunol. 2013 Dec;111(6):512-5. doi: 10.1016/j.anai.2013.08.026. Epub 2013 Sep 25.

Authors

Paweł Majak¹, Lukasz Cichalewski, Agata Ożarek-Hanc, Włodzimierz Stelmach, Joanna Jerzyńska, Iwona Stelmach

Affiliation

¹ Department of Pediatrics and Allergy, Medical University of Lodz, N Copernicus Hospital, Lodz, Poland.

PMID: 24267361
DOI: 10.1016/j.anai.2013.08.026

Abstract

Background: The exercise challenge test is the gold standard for diagnosing exercise-induced bronchoconstriction; however, it produces negative results in many children with postexercise symptoms.

Objective: To assess the utility of the area under the expiratory flow-volume curve (Aex) to identify exercise-induced bronchoconstriction in children with asthma.

Methods: Data from the medical records of 221 children with asthma who underwent an exercise treadmill challenge (ETC) were analyzed. The relation between exercise-induced respiratory symptoms and results of the ETC were assessed, specifically, the maximal decrease in forced expiration in 1 second (FEV1) and the maximal decrease in the Aex.

Results: The receiver operating characteristic curve showed that a decrease greater than 6% in the Aex was an optimal cutoff point to produce the fewest misclassified ETC results based on a greater than 10% decrease in FEV1. The results of multivariable logistic regression showed that a decrease greater than 6% in the Aex was comparable to a decrease greater than 10% in FEV1 during an ETC and was more closely related to the presence of exercise-induced respiratory symptoms. Measuring the Aex during a routine ETC allowed a confirmation of bronchoconstriction in an additional 49 children (44%) with asthma and exercise-induced respiratory symptoms. The Aex measurement increased the sensitivity and negative predictive value of ETC without a significant effect on ETC specificity.

Conclusion: Measuring the Aex increases the sensitivity and negative predictive value of ETC without producing a significant change in ETC specificity. Applying a 6% decrease in the Aex as a cutoff point for a positive exercise challenge test result may prevent the underdiagnosis of exercise-induced bronchoconstriction in children with asthma and postexercise symptoms.

Trial registration: This study was registered at www.clinicaltrials.gov (NCT01798823).

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adolescent
Asthma, Exercise-Induced / diagnosis*
Asthma, Exercise-Induced / physiopathology*
Bronchoconstriction
Child
Exercise Test
Female
Forced Expiratory Volume
Humans
Male

Associated data

ClinicalTrials.gov/NCT01798823