Exercise test using dry air in random adolescents: Temporal profile and predictors of bronchoconstriction.
2016 (English)In: Respirology (Carlton South. Print), ISSN 1323-7799, E-ISSN 1440-1843, Vol. 21, no 2, 289-296 p.Article in journal (Refereed) Published
BACKGROUND AND OBJECTIVE: Guidelines recommend exercise tests using dry air to diagnose exercise-induced bronchoconstriction (EIB). Lung function changes subsequent to these tests have not been investigated in a general adolescent population, and it remains unknown whether signs of airway inflammation, measured using exhaled nitric oxide (FeNO), can predict a positive response. The aim of this study was to investigate the temporal aspect of decline in forced expiratory volume in 1 s (FEV1 ) after an exercise test using dry air, and to investigate predictors of EIB.
METHODS: From a cross-sectional study on adolescents aged 13-15 years (n = 3838), a random subsample of 146 adolescents (99 with and 47 without self-reported exercise-induced dyspnoea) underwent standardized treadmill exercise tests for EIB while breathing dry air.
RESULTS: Of the adolescents, 34% had a positive EIB test (decline of ≥10% in FEV1 from baseline) within 30 min. Of the subjects with EIB, 53% showed the greatest decline in FEV1 at 5 to 10 min (mean decline 18.5%), and the remaining 47% of the subjects showed the greatest decline at 15 to 30 min (mean decline 18.9%) after exercise. Increased FeNO (>20 ppb), female gender and self-reported exercise-induced dyspnoea were independently associated with a positive EIB test.
CONCLUSION: When assessing general adolescents for EIB with exercise test using dry air, there is a temporal variation in the greatest FEV1 decline after exercise. Therefore, lung function should be measured for at least 30 min after the exercise. Increased FeNO, female gender and self-reported exercise-induced dyspnoea can be predictors of a positive EIB test.
Place, publisher, year, edition, pages
2016. Vol. 21, no 2, 289-296 p.
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:uu:diva-270372DOI: 10.1111/resp.12682ISI: 000373127300011PubMedID: 26588807OAI: oai:DiVA.org:uu-270372DiVA: diva2:889631
FunderSwedish Heart Lung Foundation