Airway responses to eucapnic hyperpnea, exercise, and methacholine in elite swimmers.
OBJECTIVE
The International Olympic Committee Medical Commission (IOC-MC) requires athletes to provide the result of an objective test to support a diagnosis of asthma or exercise-induced bronchoconstriction (EIB) if they want to inhale a beta-2-agonist. The purpose of the study was to evaluate the airway response to a methacholine challenge and to hyperpnea induced by exercise in the field and in the laboratory or that induced voluntarily by eucapnic hyperpnea in a group of female elite swimmers.


METHODS
Sixteen female nonasthmatic elite swimmers performed a eucapnic voluntary hyperpnea (EVH) test, a field-based exercise test (FBT), a laboratory-based exercise test (LBT), and a methacholine challenge. The criteria suggested by the IOC-MC were used to define a positive response to the challenges (EVH, field test, and laboratory test: minimum 10% decrease in FEV1; methacholine: PD20 < or = 2 micromol).


RESULTS
Eight swimmers (50%) had at least one positive test to hyperpnea. Five were identified with the EVH test, four with FBT, and four with LBT. None were identified using methacholine. Three swimmers with airway hyperresponsiveness to exercise would have been identified using a higher cutoff for methacholine (PD20 < or = 8 micromol).


CONCLUSIONS
The EVH test is the test that diagnoses most swimmers with an abnormal response to hyperpnea, but not all cases of EIB are identified with the EVH test. Performing a methacholine test using IOC-MC's cutoff value does not improve the chances of diagnosing EIB. We recommend performing the EVH test when diagnosing and evaluating EIB in elite swimmers and if EVH test negative then proceeding to a strenuous LBT.
Pedersen
Lars
L
Respiratory and Allergy Research Unit, Department of Respiratory Medicine L, Bispebjerg Hospital, Copenhagen University Hospital, Copenhagen, Denmark. lars.pedersen@dadlnet.dk
Winther
Simon
S
Backer
Vibeke
V
Anderson
Sandra D
SD
Larsen
Klaus R
KR
D000293:Adolescent; D000403:Airway Resistance / Q000187:drug effects*; D001249:Asthma / Q000175:diagnosis; D001980:Bronchi / Q000503:physiopathology; D016085:Bronchoconstrictor Agents / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D015444:Exercise; D005260:Female; D006801:Humans; D006985:Hyperventilation / Q000503:physiopathology; D016210:Methacholine Chloride / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D013550:Swimming; D055815:Young Adult
D016085:Bronchoconstrictor Agents; D016210:Methacholine Chloride