Recruiting

Mechanistic Study of Inspiratory Training in Childhood Asthma (MICA)

ClinicalTrials.gov IDNCT05945355

PhaseNA

Enrollment76

SponsorDuke University

Age6 Years

SexALL

I'm interested View official listing

Conditions studied

Asthma in Children, Obesity, Pediatric Obesity, Pediatric Asthma

About this study

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

Interventions

Device: 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).
Device: 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).
Device: 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 outcomes

Number of participants with inspiratory muscle dysfunction in obesity-related versus non-obesity-related asthma (10 weeks)
Number of participants with small airway dysfunction in obesity-related versus non-obesity-related asthma (10 weeks)

Eligibility information

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 locations

Duke Health Center Creekstone, Durham, North Carolina 27703 United States
Duke Healthy Lifestyles Clinic, Durham, North Carolina 27704 United States

Before you participate: Varda Clinical is an independent discovery tool, not the study sponsor or a medical provider. Eligibility can only be determined by the official study team. Discuss potential risks and benefits with a qualified healthcare professional.

Source: ClinicalTrials.gov. Record last refreshed by Varda Clinical: 2026-09-27.