Evaluating airflow limitation in COPD, emphysema, and asthma overlap

Site and Mechanism(s) of Expiratory Airflow Limitation in COPD, Emphysema and Asthma-COPD Overlap

Gelb, Arthur F., M.D. · NCT03263130

This study is trying to see how airflow problems in chronic smokers with COPD, emphysema, and asthma overlap are caused by different parts of the lungs and how they relate to lung health.

Quick facts

Study typeObservational
Enrollment60 (estimated)
Ages30 Years and up
SexAll
SponsorGelb, Arthur F., M.D. (indiv)
Locations2 sites (Lakewood, California and 1 other locations)
Trial IDNCT03263130 on ClinicalTrials.gov

What this trial studies

This observational study aims to assess the site and mechanisms of expiratory airflow limitation in chronic smokers with COPD, emphysema, and asthma-COPD overlap. It involves detailed lung function testing, including spirometry and high-resolution CT scans, to identify whether airflow limitation is due to large central airways or small peripheral airways. The study also examines the relationship between airflow limitation and lung elastic recoil, as well as the extent of emphysema. Blood tests will be conducted to gather additional health information relevant to the conditions being studied.

Who should consider this trial

Good fit: Ideal candidates include current or former smokers with a history of COPD, emphysema, or asthma-COPD overlap and mild to severe expiratory airflow limitation.

Not a fit: Patients with other pulmonary diagnoses or non-smokers are unlikely to benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to improved understanding and management of airflow limitation in patients with COPD and related conditions.

How similar studies have performed: While similar studies have explored airflow limitation, this study's specific focus on the mechanisms in a defined patient population may provide novel insights.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* asthma- copd overlap
* emphysema in smokers with smoking history \> 15 pack years
* COPD/ bronchitis and bronchiectasis in smokers with smoking history
* \>15 pack years

Exclusion Criteria:other pulmonary or systemic diagnosis

* non smokers
* any other pulmonary diagnosis
* pulmonary fibrosis

Where this trial is running

Lakewood, California and 1 other locations

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: COPD, Emphysema, Asthma COPD Overlap, Emphysema

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.