None listed
Conditions
Brief summary
Airway hyperresponsiveness (AHR) is an important feature of asthma, but its cause is unknown. Recently, we discovered that uneven distribution of air within the lungs is a strong predictor of AHR. We hypothesise that structural changes in the airways cause this uneven distribution and make the airways prone to AHR. Older people with asthma, particularly those with permanently narrowed airways, have more structural changes in their airways, whereas people with chronic obstructive pulmonary disease (COPD) have a different pattern of structural changes from that in asthma. Evidence that there is a consistent relationship between AHR and uneven ventilation in these populations would support our hypothesis
Interventions
Ventilation heterogeneity and airway hyperresponsiveness are both observed on the same day in the one study visit (duration 2 hours) in asthmatic and COPD patients.
Sponsors
Woolcock Institute of Medical Research
Eligibility
Sex/Gender
All
Age
50 Years to No maximum
Healthy volunteers
No
Inclusion criteria
For asthmatic subjects: Inclusion criteria are doctor diagnosis of asthma, and FEV1 ³ 50% predicted. For COPD subjects: Inclusion criteria are doctor diagnosis of COPD, 15 pack year smoking history, FEV1 ³ 50% predicted.
Exclusion criteria
Asthmatic exclusion criteria: are current smoking, or > 10 pack year history of smoking, respiratory infection or prednisone use in the last 4 weeks. COPD exclusion criteria are current smoking and respiratory infection in the last 4 weeks.
Outcome results
None listed