Bronchial hyperresponsiveness, airway inflammation, and airflow limitation in endurance athletes.
BACKGROUND
Whereas a high prevalence of bronchial abnormalities has been reported in endurance athletes, its underlying mechanisms and consequences during exercise are still unclear.


OBJECTIVE
The purpose of this study was to assess the following: (1) bronchial responsiveness to methacholine and to exercise; (2) airway inflammation; and (3) airflow limitation during intense exercise in endurance athletes with respiratory symptoms.


METHODS
Cross-sectional observational study.


METHODS
Lung function and exercise laboratory at a university hospital.


METHODS
Thirty-nine endurance athletes and 13 sedentary control subjects were explored for the following: (1) self-reported respiratory symptoms; (2) bronchial hyperresponsiveness (BHR) to methacholine and exercise; (3) airflow limitation during intense exercise; and (4) bronchial inflammation using induced sputum and nitric oxide (NO) exhalation.


RESULTS
Fifteen athletes (38%) showed BHR to methacholine and/or exercise in association with bronchial eosinophilia (mean [+/- SD] eosinophil count, 4.1 +/- 8.5% vs 0.3 +/- 0.9% vs 0%, respectively), higher NO concentrations (19 +/- 10 vs 14 +/- 4 vs 13 +/- 4 parts per billion, respectively), a higher prevalence of atopy, and more exercise-induced symptoms compared with non-hyperresponsive athletes and control subjects (p < 0.05). Furthermore, airflow limitation during intense exercise was observed in eight athletes, among whom five had BHR. Athletes with airflow limitation reported more symptoms and had FEV1, FEV1/FVC ratio, and forced expiratory flow at midexpiratory phase values of 14%, 9%, and 29%, respectively, lower compared with those of nonlimited athletes (p < 0.05).


CONCLUSIONS
BHR in endurance athletes was associated with the criteria of eosinophilic airway inflammation and atopy, whereas airflow limitation during exercise was primarily a consequence of decreased resting spirometric values. Both BHR and bronchial obstruction at rest with subsequent expiratory flow limitation during exercise may promote respiratory symptoms during exercise in athletes.
Vergès
Samuel
S
HP2 Laboratory, Department of Medicine, CHU Grenoble, Joseph Fourier University, France.
Devouassoux
Gilles
G
Flore
Patrice
P
Rossini
Eliane
E
Fior-Gozlan
Michèle
M
Levy
Patrick
P
Wuyam
Bernard
B
D000328:Adult; D000402:Airway Obstruction / Q000175:diagnosis* / Q000453:epidemiology; D016535:Bronchial Hyperreactivity / Q000175:diagnosis* / Q000453:epidemiology; D001985:Bronchial Provocation Tests; D001991:Bronchitis / Q000175:diagnosis* / Q000453:epidemiology; D016084:Bronchoconstriction / Q000502:physiology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D016210:Methacholine Chloride; D010807:Physical Endurance; D011336:Probability; D012016:Reference Values; D012129:Respiratory Function Tests; D018570:Risk Assessment; D013147:Spirometry; D013177:Sports / Q000502:physiology*; D018709:Statistics, Nonparametric
D016210:Methacholine Chloride