Disconnect between standardized field-based testing and mannitol challenge in Scottish elite swimmers

K. L. Clearie, P. A. Williamson, S. Vaidyanathan, P. Short, A. Goudie, P. Burns, Pippa Hopkinson, K. Meldrum, L. Howaniec, B. J. Lipworth

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    Abstract

    Background

    Elite swimmers have high rates of rhinoconjunctivitis and exercise-induced bronchoconstriction. Moreover, exposure to chlorine and chlorine metabolites is known to induce bronchial hyper-reactivity.

    Objective

    To assess the early and late effects of chlorine and exercise on the unified airway of elite swimmers, and to compare the response to mannitol and field-based exercise challenge.

    Methods

    The Scottish national squad underwent exhaled tidal (FENO) and nasal (N-NO) nitric oxide measurement, peak nasal inspiratory flow (PNIF), and forced expiratory volume in 1 s before, immediately after, and 4-6 h post-swimming. A sport-specific exercise test was carried out during an intensive lactate set (8 min at >= 80% maximum hear rate). All swimmers underwent mannitol challenge, and completed a health questionnaire.

    Results

    N=61 swimmers were assessed: 8/59 (14%) of swimmers had a positive mannitol challenge. Nine out of 57 (16%) of swimmers had a positive exercise test. Only one swimmer was positive to both. Swimmers with a positive mannitol had a significantly higher baseline FENO (37.3 vs. 18.0 p.p.b., P=0.03) than those with a positive exercise challenge. A significant decrease in FENO was observed pre vs. immediate and delayed post-chlorine exposure: mean (95% CI) 18.7 (15.9-22.0) p.p.b. vs. 15.9 (13.3-19.1) p.p.b. (P < 0.01), and 13.9 (11.5-16.7) p.p.b. (P < 0.01), respectively. There were no significant differences in N-NO. Mean PNIF increased from 142.4 L/min (5.8) at baseline to 162.6 L/min (6.3) immediately post-exposure (P < 0.01). Delayed post-exposure PNIF was not significantly different from pre-exposure.

    Conclusions

    No association was found between mannitol and standardized field-based testing in elite swimmers. Mannitol was associated with a high baseline FENO; however, exercise/chlorine challenge was not. Thus, mannitol may identify swimmers with a 'traditional' inflammatory asthmatic phenotype, while field-based exercise/chorine challenge may identify a swimmer-specific bronchoconstrictor response. A sustained fall in FENO following chlorine exposure suggests that a non-cellular, perhaps neurogenic, response may be involved in this group of athletes.

    Cite this as: K. L. Clearie, P. A. Williamson, S. Vaidyanathan, P. Short, A. Goudie, P. Burns, P. Hopkinson, K. Meldrum, L. Howaniec and B. J. Lipworth, Clinical & Experimental Allergy, 2010 (40) 731-737.

    Original languageEnglish
    Pages (from-to)731-737
    Number of pages7
    JournalClinical and Experimental Allergy
    Volume40
    Issue number5
    DOIs
    Publication statusPublished - May 2010

    Keywords

    • Bronchial challenge
    • Exercise-induced asthma
    • Mannitol
    • Nitric oxide
    • Airway hyperresponsiveness
    • Bronchial responsiveness
    • Induced bronchospasm
    • Methacholine
    • Hyperventilation
    • Reactivity
    • Responses
    • Severity
    • Symptoms

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