Exercise-Induced Bronchoconstriction Diagnostics: Impact of a Repeated Exercise Challenge Test

Maj R Angell,Anne Frostad,Thor Arne Grønnerød,Liv Berit Augestad,Thorbjørn S Haugen,Trine Stensrud

doi:10.4236/ojrd.2014.42009

Abstract

Exercise-Induced bronchoconstriction (EIB) is related to increased ventilation (VE) during exercise and describes the transient airway narrowing following exercise. A reliable diagnosis is essential for optimal treatment. The impact of a repeated exercise challenge test (ECT) in a clinical setting is not well established and conducting a repeated ECT with the possibility to adjust the exercise intensity on an individual basis may give more information. The aim of the study was to evaluate the test-retest reliability of an ECT for EIB and its association with exercise intensity. Methods: After examination by a pulmonologist, 20 referred subjects with symptoms strong indications of Exercise-Induced bronchoconstriction performed two consecutive exercise challenge tests on a treadmill. The exercise intensity of the repeated test was adjusted. Forced expiratory volume in 1 second (FEV1) was measured before and 1, 3, 6, 10, and 15 minutes after exercise. EIB was defined as a reduction of ≥ 10% in FEV1. Ventilation and heart rate were measured during exercise. Results: Five subjects tested positive in both tests, and ten subjects tested negative in both tests. Three subjects tested positive in the first test only, while two subjects tested positive in the second test only. The exercise intensity was not significantly different between the two tests for any of the subjects. Conclusion: There were 25% divergences in the diagnostic results of two consecutive exercise challenge tests. The difference in the test results was not explained by a difference in the exercise intensity.

Highlights

Exercise-Induced bronchoconstriction (EIB) is related to increased ventilation (VE) during exercise and describes the transient airway narrowing following exercise [1]
ECG, static lung volumes, and diffusing capacities were normal for all subjects
There were no significant differences in the group with regard to lung function (FEV1 and forced vital capacity (FVC)) or fractional exhaled nitric oxide (FENO) between baseline and test day 1 or between baseline and test day 2

Summary

Introduction

Exercise-Induced bronchoconstriction (EIB) is related to increased ventilation (VE) during exercise and describes the transient airway narrowing following exercise [1]. The symptoms of EIB include coughing, wheezing, shortness of breath, premature fatigue, and chest tightness [1] [2]. As EIB may be the first sign of asthma [3], a reliable diagnosis is essential for optimal treatment. The prevalence of EIB in the general population worldwide is poorly defined [4], and the reported prevalence in the literature varies due to discrepancy in methods used for diagnosis, e.g. self-reported symptoms as opposed to objective lung-function measurements [5]. Rupp [4] reports a 12% - 15% prevalence of EIB in the general population. EIB is reported in most asthmatic patients and is more frequent in atopic individuals [4]

Objectives

Methods

Results

Conclusion