Reducing Exercise-induced Bronchoconstriction in Children With Asthma and Obesity

Asthma in Children Clinical Trial

Official title: Asthma and Childhood Obesity: Understanding Potential Mechanisms and Identifying Strategies to Improve Respiratory Symptoms

Status Terminated

Clinical Trial Summary

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.

Clinical Trial Description

Note related to early termination: Although the intent of the study was to compare obese and nonobese children, early termination precluded us from completing this analysis and thus the pooled results are included in the results. The brief summary has been updated to reflect the presented results.

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 measure the following in all participants:

1. 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

2. Exercise tolerance during graded cycle ergometry: Gas exchange, ventilation, heart rate, blood pressure, pulse oximetry, electrocardiogram

3. 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:

1. 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.

2. Two puffs of albuterol 15 min prior to exercise challenge

3. Control: seated rest for 15min prior to exercise challenge

Control visit was always completed first. The order of the albuterol and interval warm-up exercise visits was randomized. ;

Related Conditions & MeSH terms

• Asthma
• Asthma in Children
• Asthma, Exercise-Induced
• Bronchial Spasm
• Exercise Induced Bronchospasm
• Obesity
• Obesity, Childhood
• Pediatric Obesity

• NCT number: NCT03586544
• Study type: Interventional
• Source: University of Nevada, Las Vegas
• Status: Terminated
• Phase: Phase 4
• Start date: September 18, 2018
• Completion date: March 30, 2021