ÎÎExercise itself is not necessary to cause airways to narrow; voluntary
hyperpnea of dry air may induce bronchoconstriction similar to exercise.
Eucapnic voluntary hyperpnea (EVH) is used as a surrogate for exercise in
the diagnosis of EIB, particularly in athletes. (B)
ÎÎPeople who have EIB without asthma associated with airway inflammation
and the presence of eosinophils are likely to be responsive to
corticosteroids. (B)
ÎÎExercise-induced bronchoconstriction is accompanied by release of
mediators such as prostaglandins, leukotrienes and histamine. (B)
ÎÎIn approximately half of patients who have EIB, there is an interval of
refractoriness lasting approximately 2 to 3 hours immediately after an
episode of EIB during which additional exercise produces little or no
bronchoconstriction. (B)
Genetics and Environment
ÎÎGene expression and environmental interaction may be relevant to the EIB
phenotype. (D)
ÎÎOxidative stress caused by environmental pollutants that are inhaled
during exercise may play an important role in the development and
exaggeration of EIB. (B)
ÎÎThe pathogenesis of EIB in elite athletes may relate to effects on the
airways arising from humidifying large volumes of dry air over months of
training with or without exposure to environmental irritants, allergens, and
viral agents. (D)
Diagnosis and Assessment
ÎÎSelf-reported symptoms alone are not reliable for diagnosis of EIB. (B)
ÎÎOptimal EIB management may require confirmation of the diagnosis using
objective methods. (A)
ÎÎSelf-reported symptom-based diagnosis of EIB in the elite athlete lacks
sensitivity and specificity and establishes the necessity for standardized,
objective challenges using spirometry. (B)
ÎÎThe indirect challenge (eg, exercise or surrogate such as EVH) is preferred
over a direct challenge (eg, methacholine) for assessing EIB in the elite
athlete. (D)
ÎÎEVH is the preferred surrogate challenge for the elite athlete participating
in competitive sports. (D)
