Clinical Trial: Exercise Challenge in a Cold Chamber

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

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

Brief Summary: 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 Summary:

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.


Sponsor: Johann Wolfgang Goethe University Hospital

Current Primary Outcome: Agreement of metacholine challenge and the combined exercise/cold-air challenge [ Time Frame: 3 months ]

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.



Original Primary Outcome: Same as current

Current Secondary Outcome: Repeatability of the combined exercise/cold-air challenge [ Time Frame: 3 months ]

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.


Original Secondary Outcome: Same as current

Information By: Johann Wolfgang Goethe University Hospital

Dates:
Date Received: December 19, 2013
Date Started: June 2013
Date Completion:
Last Updated: March 16, 2015
Last Verified: March 2015