The term exercise-induced bronchospasm (EIB) describes acute, transient airway narrowing
that occurs during, and most often after, exercise. Manifestations of EIB can range from
mild impairment of performance to severe bronchospasm and respiratory failure.
The pathogenesis of EIB remains controversial and the role of airway inflammation has not
yet been definitively characterized. We plan on comparing markers of inflammation in
asthmatic participants with and without EIB at baseline and after bronchoprovocation with
eucapnic voluntary hyperventilation testing (EVH). We also will collect demographic
information as well as information about asthma control and exercise habits.
At Visit 1, participants will complete questionnaires about demographics, asthma control (if
asthmatic) and exercise habits. The participants will have baseline spirometry performed,
and skin prick testing for allergies. Skin testing is important as it can influence the
level of exhaled nitric oxide and hence we would like to adjust our results for the presence
of allergies. Subsequently, volunteers will undergo sputum induction and then have
peripheral blood drawn for microRNA analysis. MicroRNA's are single-stranded RNA molecules
of about 21-23 nucleotides in length regulating gene expression. Patterns of MicroRNA
expression have been linked to heart disease and cancer. Similar patterns have not been
identified in exercise-induced asthma. In total, including time for questions and recovery,
the time for Visit 1 will be approximately 3 hours.
At Visit 2, which will occur 24 hours to 7 days after Visit 1 in order to minimize risk of
asthma exacerbation, the participants will again have baseline spirometry. Baseline
exhaled nitric oxide will be performed. Eucapnic Voluntary hyperventilation testing will
then be performed. They then will have a second exhaled nitric oxide quantification, will
undergo sputum induction and then have peripheral blood drawn for microRNA analysis, all
occurring after EVH testing. In total, including time for questions and recovery, the time
for Visit 2 will be approximately 2 hours.
1. Men and women
2. History of physician-diagnosed asthma
3. Age between 18 and 70 years old.
4. Females of childbearing age may participate only if they have a negative pregnancy
test, are non-lactating, and agree to practice an adequate birth control method
(abstinence, combination barrier and spermicide, or hormonal) for the duration of the
study. These requirements for contraception also apply to women who may have
irregular or absent menstrual periods.
5. Non-smoker for 6 months or longer
6. Less than 10 pack year (number of packs per day (x) years of smoking = pack years)
1. Objective evidence of severe lung impairment on pulmonary function testing performed
at the beginning of the study.
2. Participation in another interventional research trial
3. Unable to provide consent
5. Asthma exacerbation within the last 4 weeks.
6. History of severe reaction to allergy skin testing