Reducing Exercise-induced Bronchoconstriction in Children With Asthma and Obesity

Trial end date:
Target enrollment:
Participant gender:
Guidelines from the American Thoracic Society strongly recommend interval warm-up exercise before planned exercise to reduce exercise-induced bronchoconstriction severity. However, no empirical data on the effects of interval warm-up exercise on exercise-induced bronchoconstriction severity are available in obese asthmatic children, where excess fat exerts such an unfavorable burden on the respiratory system, particularly during exercise. The objective of this study is to investigate the effects of interval warm-up exercise on exercise-induced bronchoconstriction severity in obese and nonobese asthmatic children. Our approach will be to investigate exercise tolerance, respiratory function, and exercise-induced bronchoconstriction severity and the effects of (1) 8x30sec interval warm-up & (2) pretreatment with a bronchodilator compared with a no-treatment control on exercise-induced bronchoconstriction severity in 8-12 yr, prepubescent, obese and nonobese asthmatic children. [Aim]: To investigate the effects of interval warm-up exercise on exercise-induced bronchoconstriction severity. [Hypothesis]: Interval warm-up exercise will reduce exercise-induced bronchoconstriction severity after an exercise challenge test to a similar extent as bronchodilator and better than control.
Phase 4
Accepts Healthy Volunteers?
Accepts Healthy Volunteers
Lead Sponsor:
University of Nevada, Las Vegas
Inclusion Criteria:

- no history of smoking, no history or evidence of heart disease, no history of
uncontrolled hypertension, no documented and/or diagnosed sleep disorders, no
diagnosed diabetes, no metabolic disorders, no history of significant mental illness,
no dietary restrictions, no serious health conditions, or no musculoskeletal
abnormality that would preclude exercise.

- Normal weight children with a body mass index between the 16th and 84th percentile

- Obese children with a body mass index > 95th percentile but less than 170% above the
95th percentile and less than an absolute body mass index of 40 kg·m2

- Pulmonary function criteria 1) forced vital capacity ≥ 80% predicted, 2) forced
expiratory volume in the first second (FEV1) ≥ 75% predicted, and total lung capacity
≥ 80% predicted

Exclusion Criteria:

- Children with significant diseases other than obesity and mild asthma will be
excluded. A significant disease is defined as either a disease that in the opinion of
the PI or medical consultant Dr. Craig Nakamura may put the participant at risk
because of participation in the study or a disease that may influence the results of
the study or the patient's ability to participate in the study.

- Children who cannot follow directions (e.g., eating before testing), adequately
perform procedures (e.g., pulmonary function tests), or keep appointments (e.g., no
shows for testing), will be excluded from study participation.

- Because the risk of severe exercise induced bronchoconstriction increases in children
with moderate or severe obstructive airway disease, children with FEV1 < 75% predicted
will be excluded from the study. Diagnosis of asthma (i.e., airway responsiveness with
reversible obstruction) will be established by spirometry (i.e., improvement of FEV1
of ≥8% after administration of bronchodilator).

- Children without reversible airway obstruction will also be excluded from the study.

- Children who have been hospitalized for an asthma exacerbation or who have taken oral
glucocorticoids for asthma in the past year, and children who have been admitted to an
intensive care unit or been intubated because of their asthma in the past five years,
will be excluded to reduce the risk of exacerbation during the study.