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

TY - JOUR

T1 - Disconnect between standardized field-based testing and mannitol challenge in Scottish elite swimmers

AU - Clearie, K. L.

AU - Williamson, P. A.

AU - Vaidyanathan, S.

AU - Short, P.

AU - Goudie, A.

AU - Burns, P.

AU - Hopkinson, Pippa

AU - Meldrum, K.

AU - Howaniec, L.

AU - Lipworth, B. J.

PY - 2010/5

Y1 - 2010/5

N2 - 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.

AB - 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.

KW - Bronchial challenge

KW - Exercise-induced asthma

KW - Mannitol

KW - Nitric oxide

KW - Airway hyperresponsiveness

KW - Bronchial responsiveness

KW - Induced bronchospasm

KW - Methacholine

KW - Hyperventilation

KW - Reactivity

KW - Responses

KW - Severity

KW - Symptoms

U2 - 10.1111/j.1365-2222.2010.03461.x

DO - 10.1111/j.1365-2222.2010.03461.x

M3 - Article

C2 - 20214665

SN - 0954-7894

VL - 40

SP - 731

EP - 737

JO - Clinical and Experimental Allergy

JF - Clinical and Experimental Allergy

IS - 5

ER -