Exercise Challenge in a Cold Chamber

Study Overview
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Brief Summary
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The purpose of this study is to compare the exercise-challenge in a cold chamber at 2-4°C to the gold standard the metacholine challenge in subjects showing symptoms of exercise-induced bronchoconstriction. The sensitivity and repeatability of the exercise test will be measured.

Detailed Description
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Subjects suffering form exercise-induced bronchoconstriction (EIB) usually have a normal lung function testing at rest. To provoke asthma symptoms a provocation test is necessary, e.g., by bronchial methacholine testing or by a standardised exercise test on a treadmill. The correlation between methacholine and exercise test is fair, possibly because both methods measure different kinds of bronchial hyperresponsiveness. Moreover, the sensitivity and the repeatability of the exercise test is fair. The value of the methacholine test to predict a positive exercise test will be measured. We hypothesize that the exercise test in a cold chamber, a combination of two provocation methods cold air and exercise, is more sensitive to detect EIB and that the test has a better repeatability.

Official Title
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Exercise-induced Bronchoconstriction in a Cold Chamber Compared to Methacholine Challenge

Conditions
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Exercise-induced Asthma

Intervention / Treatment
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* Other: Exercise challenge in a cold chamber
* Other: Methacholine challenge
* Other: Exercise challenge in room temperature


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Informed consent Patients: Age >6 and <18 years Subjects: Age >/=18 and <45 years sportive, 1-2x exercise per week bronchial hyperresponsiveness in the medical history Exclusion Criteria: lung function Forced vital capacity (FVC) <80% and Forced expiratory volume in 1 second (FEV1) <75% chronic diseases or infections (e.g. HIV, Tbc) pregnancy systemic corticosteroid-treatment inhalative corticosteroid therapy or leukotriene antagonists <14d alcohol, substance or drug abuse smokers inability to capture extend and consequences of the study

Ages Eligible for Study
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Minimum Age: 6 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Non-Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: 40 patients aged 6-18 years<br>All 40 patients with a diagnosis of asthma are recruited from the outpatients clinic of the department of Pediatric Pneumology and Allergology of the University Hospital Frankfurt. Patients undergo a methacholine challenge and two exercise challenges in a cold chamber and one exercise challenge in room temperature. | Other: Exercise challenge in a cold chamber<br>* Exercise challenge is defined as running on a treadmill for 6-8 minutes on submaximal work load in a cold chamber.<br>Other: Methacholine challenge<br>* nebulized metacholine administered at following doses: 0,01mg, 0,1mg, 0,4mg, 0,8mg und 1,6mg<br>Other: Exercise challenge in room temperature<br>* Exercise challenge is defined as running on a treadmill for 6-8 minutes on submaximal work load in room temperature.<br>|
| Other: 40 subjects aged 18-45 years<br>All subjects show bronchial hyperresponsiveness e.g. dyspnea when exercising in cold environment, in their medical history. Subjects undergo a methacholine challenge and exercise challenge in a cold chamber and one exercise challenge in room temperature. | Other: Exercise challenge in a cold chamber<br>* Exercise challenge is defined as running on a treadmill for 6-8 minutes on submaximal work load in a cold chamber.<br>Other: Methacholine challenge<br>* nebulized metacholine administered at following doses: 0,01mg, 0,1mg, 0,4mg, 0,8mg und 1,6mg<br>Other: Exercise challenge in room temperature<br>* Exercise challenge is defined as running on a treadmill for 6-8 minutes on submaximal work load in room temperature.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Agreement of metacholine challenge and the combined exercise/cold-air challenge | Lung function will be measured prior and after methacholine- and exercise/cold-air challenges. The maximal fall in forced expiratory volume in one second (FEV1, percent predicted) after methacholine and cold air challenge will be compared by statistical correlation. For both methods the sensitivity and the specificity to predict an exercise induced asthma will be calculated by a receiver operating characteristic (ROC analysis). All subjects receive Salbutamol to relief them from bronchial constriction at the end of the test. | 3 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Repeatability of the combined exercise/cold-air challenge | The combined exercise/cold-air challenge will be performed twice within one week. Post challenge the FEV1 will be measured after 5, 10, 20, and 30 minutes. The maximal fall in FEV1 (percent predicted) and the area under the curve (AUC) will be compared. The agreement and the repeatability of the maximal fall in FEV1 and of the AUC will be measured by correlation and by the method of Bland and Altman. | 3 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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exercise-induced bronchoconstriction, exercise-induced asthma, cold chamber, exercise challenge, cold air challenge, combined exercise- and cold-air challenge, methacholine challenge