Understanding airflow limitation in moderate to severe asthma

Evaluation of Mechanism(s)Limiting Expiratory Airflow in Chronic, Stable Asthmatics Who Are Non-smokers

Gelb, Arthur F., M.D. · NCT00576069

This study is trying to find out what causes breathing problems in people with moderate to severe asthma by looking at how their lungs work during stable times and flare-ups.

Quick facts

Study typeObservational
Enrollment60 (estimated)
Ages10 Years to 95 Years
SexAll
SponsorGelb, Arthur F., M.D. (indiv)
Locations1 site (Lakewood, California)
Trial IDNCT00576069 on ClinicalTrials.gov

What this trial studies

This observational study aims to evaluate the mechanisms responsible for expiratory airflow limitation in chronic, treated, non-smoking asthmatics with moderate to severe persistent airflow obstruction. It will investigate whether the large or small airways are primarily responsible for this limitation and assess the impact of lung elastic recoil and airway conductance. Participants will receive inhaled corticosteroids and long-acting bronchodilators, and their lung function will be monitored through spirometry and exhaled nitric oxide measurements. The study will compare results during stable periods and exacerbations to better understand the underlying mechanisms.

Who should consider this trial

Good fit: Ideal candidates are non-smoking individuals aged 12 to 95 with stable, treated asthma and specific lung function criteria.

Not a fit: Patients who are pregnant or have a significant smoking history may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to improved treatment strategies for patients with moderate to severe asthma.

How similar studies have performed: While there have been studies on asthma mechanisms, this specific approach to evaluating airflow limitation is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Current non-smoking (\<10 pack yr smoking history)
* Stable, treated asthmatics
* Age 12-95 yr
* post 180ug albuterol by MDI: FEV 1/FVC \< 70% and FEV 1 \<80% predicted

Exclusion Criteria:

* Pregnancy

Where this trial is running

Lakewood, California

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Asthma, asthma, lung function, inflammation

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.