Reducing Exercise-induced Bronchoconstriction in Children With Asthma and Obesity
|The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details.|
|ClinicalTrials.gov Identifier: NCT03586544|
Recruitment Status : Recruiting
First Posted : July 13, 2018
Last Update Posted : October 11, 2018
In obese children, excess fat exerts an increased mechanical burden on the respiratory system, particularly during exercise. It is unclear whether this burden reduces respiratory function and exercise tolerance and increases severity of exercise-induced bronchoconstriction in obese asthmatic children. The investigators propose that most of the respiratory effects in obese asthmatic children are the result of low lung volume breathing (i.e., reduced functional residual capacity). The first objective of this study is to investigate respiratory function, exercise tolerance, and exercise-induced bronchoconstriction in obese vs. nonobese asthmatic children. 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. Thus, the second 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 1]: To investigate respiratory function and exercise tolerance [Hypothesis]: Obesity in children with asthma will reduce respiratory function and exercise tolerance [Aim 2]: To investigate exercise-induced bronchoconstriction. [Hypothesis]: Obesity in children with asthma will increase exercise-induced bronchoconstriction severity as evidenced by a greater maximum % fall in forced expiratory volume in the first second after an exercise challenge test.
[Aim 3]: 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, although to a greater extent in nonobese asthmatic children.
|Condition or disease||Intervention/treatment||Phase|
|Asthma in Children Obesity, Childhood Exercise Induced Bronchospasm||Behavioral: Interval Warm-up exercise Drug: Albuterol Other: Control||Phase 4|
The investigators will enroll prepubescent, 8 - 12 yr old, obese (body mass index > 95th percentile; N=25) and nonobese (body mass between 16th and 84th percentile; N=25) children with mild asthma. The investigators will investigate the severity of exercise-induced bronchoconstriction during planned exercise performed 15 minutes after the following three conditions performed on separate days in a random order: (1) 8x30sec interval warm-up, (2) short-acting beta agonist or albuterol, & (3) control, in prepubescent, 8 - 12 yr old, obese and nonobese children with mild asthma. The investigators will also investigate differences in pulmonary function, exercise tolerance, and severity of exercise-induced bronchoconstriction between obese and nonobese children.
The investigators will measure the following in all participants:
- Pulmonary function: spirometry, lung volumes, diffusing capacity of lung for carbon monoxide, maximum voluntary ventilation, maximal inspiratory and expiratory pressures, airway resistance, and expired nitric oxide
- Exercise tolerance during graded cycle ergometry: Gas exchange, ventilation, heart rate, blood pressure, pulse oximetry, electrocardiogram
- Ratings of perceived breathlessness and exercise induced bronchoconstriction in response to a 6 minute high-intensity exercise challenge after three conditions performed on three separate days:
Three conditions that will precede the exercise challenge include:
- 8x30sec of interval warm-up 15min prior to exercise challenge: This includes eight 30sec bouts of high-intensity interval exercise at 85-95% of HRmax, with 45sec of recovery between.
- Two puffs of albuterol 15 min prior to exercise challenge
- Control: seated rest for 15min prior to exercise challenge
|Study Type :||Interventional (Clinical Trial)|
|Estimated Enrollment :||50 participants|
|Intervention Model:||Single Group Assignment|
|Intervention Model Description:||2x3 mixed ANOVA. 2 between groups: children with and without obesity. 3 within groups: control, interval warm-up, pretreatment with bronchodilator|
|Masking:||None (Open Label)|
|Official Title:||Asthma and Childhood Obesity: Understanding Potential Mechanisms and Identifying Strategies to Improve Respiratory Symptoms|
|Actual Study Start Date :||September 18, 2018|
|Estimated Primary Completion Date :||December 30, 2020|
|Estimated Study Completion Date :||May 30, 2021|
Children will complete an exercise induced bronchoconstriction test preceded by: 1) pretreatment with 'Albuterol' 2) interval warm-up exercise and 3) Control
Behavioral: Interval Warm-up exercise
Participants will undergo eight 30 sec bouts of high intensity exercise with 45 second recovery between bouts. After 15 minutes, participants will undergo an exercise induced bronchoconstriction test
Other Name: High intensity interval training
Participants will inhale 2 puffs of albuterol (90mcg per actuation). After 15 minutes, participants will undergo an exercise induced bronchoconstriction test
Other Name: Ventolin
This is the control arm. After 15 minutes of seated rest, participants will undergo an exercise induced bronchoconstriction test
- Maximum % fall in forced expiratory volume in the first second (FEV1) [ Time Frame: The fall in FEV1 will be assessed for up to 30 minutes after completing the exercise induced bronchoconstriction test ]The change in FEV1 from before to after the exercise induced bronchoconstriction test
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03586544
|Contact: Dharini M Bhammar, Ph.D.||email@example.com|
|United States, Nevada|
|Childrens Lung Specialists||Recruiting|
|Las Vegas, Nevada, United States, 89109|
|Contact: Manager, Office of Research Compliance 702-784-7840 Janet.Gallegos@hcahealthcare.com|
|Principal Investigator: Dharini M Bhammar, Ph.D.|
|Sub-Investigator: Craig Nakamura, M.D.|
|Principal Investigator:||Dharini M Bhammar, Ph.D.||University of Nevada, Las Vegas|