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Published on: January 28, 2020
Disconnect between standardized field-based testing and mannitol challenge in Scottish elite swimmers.
K L Clearie1, P A Williamson, S Vaidyanathan
1Asthma & Allergy Research Group, Department of Medicine and Therapeutics, Ninewells Hospital & Medical School, University of Dundee, Dundee, Scotland, UK.
Summary
Elite swimmers experience airway issues due to chlorine exposure. Mannitol challenge may identify asthmatic phenotypes, while exercise tests reveal swimmer-specific responses to chlorine and exercise.
Area of Science:
- Sports Medicine
- Pulmonary Medicine
- Environmental Health
Background:
- Elite swimmers frequently report rhinoconjunctivitis and exercise-induced bronchoconstriction.
- Chlorine and its byproducts in swimming pools are known to induce bronchial hyper-reactivity in athletes.
Purpose of the Study:
- To evaluate the immediate and delayed effects of chlorine and exercise on the airways of elite swimmers.
- To compare the airway responses elicited by mannitol challenge versus a standardized field-based exercise test.
Main Methods:
- Sixty-one elite swimmers underwent measurements of exhaled nitric oxide (FE(NO)), nasal nitric oxide (N(NO)), peak nasal inspiratory flow (PNIF), and forced expiratory volume in 1 s.
- Participants completed a sport-specific exercise test and a mannitol challenge, along with a health questionnaire.
Main Results:
- A significant decrease in FE(NO) was observed post-chlorine exposure, suggesting a non-cellular or neurogenic response.
- Mannitol challenge identified swimmers with higher baseline FE(NO), potentially indicating an asthmatic phenotype.
- Peak nasal inspiratory flow increased immediately post-exercise, but this effect was not sustained.
Conclusions:
- Mannitol challenge and exercise/chlorine challenge may identify different airway responses in elite swimmers.
- Mannitol may be useful for identifying swimmers with a traditional asthmatic profile.
- The sustained fall in FE(NO) after chlorine exposure suggests a potential neurogenic mechanism in swimmers.
