To investigate the presence and extent of small airways disease in subjects with asymptomatic AHR, patients with asthma and non-AHR controls. Specific research questions:1) Do subjects with asymptomatic AHR have less small airways disease than…
ID
Source
Brief title
Condition
- Bronchial disorders (excl neoplasms)
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
peripheral airway resistance, measured with IOS
Secondary outcome
Peripheral airway resistance measured with IOS during provocationtest
Other small airways parameters:
- FEF25-75
- alveolar NO
- RV, RV/TLC
mRNA expression in nasal epithelium.
Background summary
Bronchial hyperresponsiveness (BHR) is a feature of asthma. There are also
persons with asymptomatic BHR. These people do not experience symptoms, however
earlier research indicates that these subjects have increased inflammation and
remodelling of the airways. Furhtermore, asymptomatic BHR appears to be a risk
factor for asthma development. Recently, there has been increasing evidence
that dysfunction of the small airways (defined as airways with an internal
diameter >2 mm) contributes importantly to airflow obstruction and symptoms in
patients with asthma. We hypothesize that asymptomatic subjects with BHR do not
experience respiratory symptoms because they have less small airways disease
compared to symptomatic subjects.
Study objective
To investigate the presence and extent of small airways disease in subjects
with asymptomatic AHR, patients with asthma and non-AHR controls.
Specific research questions:
1) Do subjects with asymptomatic AHR have less small airways disease than
patients with asthma?
2) Do subjects with asymptomatic AHR have more small airways disease than
healthy non-AHR controls?
Study design
An observational study, comparing 3 groups:
- Asthmatics
- Subjects with asymptomatic AHR
- Healthy controls without AHR
Pulmonary function will be measured, as well as a provocation test with
methacholine during which dyspnea and IOS will be measuren
Study burden and risks
The burden shall be very limited for the patients. The study will take about 4
hours, divided over 2 visits. The risks are also limited. During the
provocation test, the subject may experience some dyspnea. The nasal brush may
cause a nosebleed.
This study may give insight into the origin of symptoms in ashtma en the
association between these symptoms and small airways disease. This knowledge
can be used to better treat asthma patients, e.g. with medication designed to
target the small airways.
Postbus 30.001
9700 RB Groningen
NL
Postbus 30.001
9700 RB Groningen
NL
Listed location countries
Age
Inclusion criteria
Inclusion criteria for asymptomatic subjects without AHR :
• Age between 18 and 65 years.
• FEV1 > 80% predicted post bronchodilator.
• PC20 methacholine <= 8 mg/ml.
• No history of asthma or previous use of asthma medication.;Inclusion criteria for asymptomatic subjects without AHR :
• Age between 18 and 65 years.
• FEV1 > 80% predicted post bronchodilator.
• PC20 methacholine >8 mg/ml.
• No history of asthma or previous use of asthma medication.;Inclusion criteria for patients with asthma:
• Age between 18 and 65 years.
• FEV1 > 80% predicted.
• PC20 methacholine <=8 mg/ml.
• Doctor's diagnosis of asthma
• No history of COPD
Exclusion criteria
• Use of inhaled or oral steroids, antihistamines, nedocromil, theophylline, leukotrien antagonists or long-acting beta-agonists for at least three weeks before the start of the study.
• Any disease that may affect the outcome of the study as judged by the Investigator.
• FEV1 <1.2 liter.
• A respiratory tract infection within 4 weeks prior to the start of the study.
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL40013.042.12 |
| Other | volgt |