Recruiting

Inspiratory Training

Sponsor:

Duke University

Code:

NCT05945355

Conditions

Asthma in Children

Obesity

Pediatric Obesity

Pediatric Asthma

Eligibility Criteria

Sex: All

Age: 6 - 17

Healthy Volunteers: Not accepted

Interventions

Pro2 - Low Dose - 40% of participant's MIP

Pro2 - High Dose - 75% of participant's MIP

Pro2 - SHAM - 15% of participant's MIP

Study Details

Brief summary:

This is single-center cross-sectional mechanistic study in lean and obese children with moderate-severe asthma, followed by a randomized, SHAM-controlled trial of Inspiratory Training (IT). The primary outcome is to describe the contributions of inspiratory muscle dysfunction (IMD) and Small Airway Dysfunction (SAD) to obesity-related versus non-obesity-related asthma. The study will involve training (IT) for 8 weeks at three intensity levels (SHAM, low and high). Target dose: 150 inspirations three times weekly. The population includes 6 to 17-year-old children with moderate to severe asthma and with a body mass index qualifying as normal habitus (BMI 5th to 84th CDC percentile) or obese habitus (≥95th percentile BMI and less than 170% of the 95th CDC percentile). Participants will be involved for 10 weeks. The investigators will use analysis of covariance (ANCOVA) to estimate and test the difference in mean values of baseline measures between obese and non-obese cohorts. Covariates will include age, sex (male/female), race/ethnicity, baseline asthma severity (NAEPP step 2 vs ≥3), and atopy status

Conditions

Asthma in Children

Obesity

Pediatric Obesity

Pediatric Asthma

Study ID

NCT05945355

Start date

Aug 1, 2024

Status verified date

Aug, 2026

Completion date

Oct 30, 2027

Anticipated

Primary completion date

Oct 30, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 6 - 17

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • 6-17 years of age
  • Documented clinician-diagnosed asthma
  • Currently requiring 2 or more controller prescriptions to treat disease (i.e. moderate to severe persistent disease)
  • Either obese (≥95th percentile BMI and less than 170% of the 95th CDC percentile) or have a normal BMI (BMI 5th to 84th CDC percentile)

Exclusion Criteria:

  • ACT (asthma control test) score <17
  • Ever intubated for asthma
  • FEV1 < 50% of predicted at enrollment
  • Currently pregnant
  • Legal guardian unable to consent in English or Spanish
  • Any major chronic illness that, in the opinion of the PI, would interfere with participation
  • Younger than 6 years of age

Study Design

Enrollment

76 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Active Low Dose inspiratory muscle rehabilitation (IMR) group

Each participant will be provided a PrO2™ device and trained on its use as well as its accompanying PrO2 Fit™ app. Participants will be instructed to inspire forcefully through PrO2™ until the device signals that the user has achieved the target resistance (via audible alarm and visible light signal). The research team will implement biofeedback signals at a specific inspiratory resistance to provide precise and individualized training target. Successful IMR repetitions will require that subjects achieve a pressure target that is 40% of their MIP (maximum inspiratory pressure).

experimental: Active High Dose inspiratory muscle rehabilitation (IMR) group

Each participant will be provided a PrO2™ device and trained on its use as well as its accompanying PrO2 Fit™ app. Participants will be instructed to inspire forcefully through PrO2™ until the device signals that the user has achieved the target resistance (via audible alarm and visible light signal). The research team will implement biofeedback signals at a specific inspiratory resistance to provide precise and individualized training target. Successful IMR repetitions will require that subjects achieve a pressure target that is 75% of their MIP (maximum inspiratory pressure).

active comparator: SHAM

Each participant will be provided a PrO2™ device and trained on its use as well as its accompanying PrO2 Fit™ app. Participants will be instructed to inspire forcefully through PrO2™ until the device signals that the user has achieved the target resistance (via audible alarm and visible light signal). The research team will implement biofeedback signals at a specific inspiratory resistance to provide precise and individualized training target. Successful IMR repetitions will require that subjects achieve a pressure target that is 15% of their MIP (maximum inspiratory pressure).

Interventions

Pro2 - Low Dose - 40% of participant's MIP

Each participant will be provided a PrO2™ device and trained on its use as well as its accompanying PrO2 Fit™ app. The PrO2™ is a flow-resistive device that provides inspiratory resistance via a fixed 2mm orifice and has Bluetooth connectivity to most IOS/Android devices or Mac/Windows computers. The PrO2™ device and app allows for both 100% adherence monitoring and immediate user biofeedback. Successful IMR repetitions will require that subjects achieve a pressure target that is 40% of their MIP (maximum inspiratory pressure).

Pro2 - High Dose - 75% of participant's MIP

Each participant will be provided a PrO2™ device and trained on its use as well as its accompanying PrO2 Fit™ app. The PrO2™ is a flow-resistive device that provides inspiratory resistance via a fixed 2mm orifice and has Bluetooth connectivity to most IOS/Android devices or Mac/Windows computers. The PrO2™ device and app allows for both 100% adherence monitoring and immediate user biofeedback. Successful IMR repetitions will require that subjects achieve a pressure target that is 75% of their MIP (maximum inspiratory pressure).

Pro2 - SHAM - 15% of participant's MIP

Each participant will be provided a PrO2™ device and trained on its use as well as its accompanying PrO2 Fit™ app. The PrO2™ is a flow-resistive device that provides inspiratory resistance via a fixed 2mm orifice and has Bluetooth connectivity to most IOS/Android devices or Mac/Windows computers. The PrO2™ device and app allows for both 100% adherence monitoring and immediate user biofeedback. Successful IMR repetitions will require that participants achieve a pressure target that is 15% of their MIP (maximum inspiratory pressure).

Primary outcome measure

  • Number of participants with inspiratory muscle dysfunction in obesity-related versus non-obesity-related asthma [ Time Frame: 10 weeks ]
  • Number of participants with small airway dysfunction in obesity-related versus non-obesity-related asthma [ Time Frame: 10 weeks ]

Central Contacts and Locations

Central contacts

Jason Lang, MD

9196843364jason.lang@duke.edu

Locations

Duke Health Center Creekstone

Recruiting

Durham, North Carolina, United States, 27703

Contacts

Jason Lang

919-684-3364jason.lang@duke.edu

Duke Healthy Lifestyles Clinic

Recruiting

Durham, North Carolina, United States, 27704

Contacts

Veronica Carrion, BS

919-704-1523vmp19@duke.edu

More Information

Sponsor

Duke University

Last update posted

Aug 5, 2026

Last verified

Aug, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by Duke University on 2026-08-05.