An observational study in Asthma, sponsored by University of California, San Francisco. Active, not recruiting at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-07-14.
Sponsored by University of California, San Francisco · Observational
This is a single-center study of 80 subjects with asthma including those with obesity and metabolic dysfunction (MD), those with obesity and without metabolic dysfunction, those with severe asthma and mucus plugging and those with severe asthma and without mucus plugging. Screening data will be reviewed to determine participant eligibility. Participants who meet all inclusion criteria will participate in a cardiopulmonary exercise testing (CPET) visit to compare lung function markers and change in oxygen saturation between obese patients with and without MD and severe asthma patients with and without mucus plugging.
The mechanism of poor exercise tolerance in patients with severe asthma is poorly understood. In preliminary data, the investigators have identified increases in air trapping in patients with obese asthma and metabolic dysfunction and patients with asthma and mucus plugs. The investigators have also found air trapping on CT (Computerized Tomography) scans of severe asthma patients with mucus plugs. Therefore, the investigators hypothesize that obese patients with metabolic dysfunction (MD) and severe asthma patients with mucus plugs develop changes in lung function during exercise.
To test this hypothesis, this protocol will plan for cardiopulmonary exercise testing in patients with obesity or severe asthma. The analyses will compare dynamic hyperinflation, expiratory flow limitation, and the RV/TLC ratio (ratio of residual volume to total lung capacity) before and after exercise between obese patients with and without MD and severe asthma patients with and without mucus plugs.
3,921 studies on the registry are indexed under Asthma; 506 are open to participants now.
This study's planned enrollment of 80 is below the median of 150 across 970 observational studies indexed under Asthma.
Browse Asthma studies →University of California, San Francisco is the lead sponsor of 2,132 studies on the registry; 375 are open to participants now.
Of its 262 completed or terminated interventional studies of FDA-regulated products, 196 (75%) have results posted.
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The study will recruit up to 80 asthma participants, at least 20 with obesity and MD, 20 with obesity and no MD, 20 with severe asthma and mucus plugs and 20 with severe asthma and no mucus plugs.
1. IL-6 high: Plasma IL-6 > 3.0 pg/mL 2. Insulin resistance: HOMA-IR > 3 mass units b. Severe asthma: Requires treatment with high dose inhaled corticosteroids plus a second controller, systemic corticosteroid, or biologic therapy.
i. Mucus Plugging is defined as mucus plug score ≥ 4
Exclusion Criteria:
History of smoking
Otherwise healthy asthmatic subjects with: 1. Body Mass Index (BMI) ≥ 30; and 2. Metabolic dysfunction evidenced by at least one of the following: * high plasma IL-6 (\> 3.0 pg/mL) * insulin resistance (HOMA-IR \> 3 mass units)
Otherwise healthy asthmatic subjects with: 1. Body Mass Index (BMI) ≥ 30; and 2. No evidence of metabolic dysfunction
Otherwise healthy asthmatic subjects: 1. Requiring treatment with high dose inhaled corticosteroids plus a second controller, systemic corticosteroid, or biologic therapy; and 2. Evidence of mucus plugs as defined by a mucus plug score ≥ 4
Otherwise healthy asthmatic subjects: 1. Requiring treatment with high dose inhaled corticosteroids plus a second controller, systemic corticosteroid, or biologic therapy; and 2. No evidence of mucus plugs as defined by a mucus plug score \< 4
Change in EELV (End Expiratory Lung Volume)
We will compare change in EELV during the CPET (Cardiopulmonary Exercise Test) between the obese asthma patients with MD or without MD and between the patients with severe asthma with mucus plugs or without mucus plugs.
Time frame: At CPET visit.
Change in RV (Residual Volume) and TLC (Total Lung Capacity)
We will compare change in RV and TLC during the CPET between the obese asthma patients with MD or without MD and between the patients with severe asthma with mucus plugs or without mucus plugs.
Time frame: At CPET Visit
Change in oxygen saturation during exercise
Change in oxygen saturation during the CPET will be assessed and compared between the obese asthma patients with MD or without MD and between the patients with severe asthma with mucus plugs or without mucus plugs.
Time frame: At CPET Visit
Plan to share: No
No publications or documents are linked to this record.
This study is active, not recruiting, as verified in Jul 2026. You cannot join it, but the record below documents what was studied.
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University of California, San Francisco