Assessment of Airway Responsiveness and Treatment Efficacy in Asthmatics

Study Overview
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Brief Summary
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Bronchial asthma is a common chronic respiratory disease. Patients usually manifest variable symptoms (such as short of breath, chest tightness, cough, etc.) and variable airflow limitation and often associated with airway hyper-responsiveness and airway inflammation. About 1-18% of the global population suffered from the disease, causing huge economic burden for patients and countries. Airway reactivity measurement is an important way of diagnosis of asthma. Methacholine (Mch) bronchial provocation test(BPT) is the gold standard for the determination of airway reactivity, and other measuring methods(like adenosine monophosphate(AMP)-BPT, leukotriene D4(LTD4)-BPT, Astograph-BPT, etc.) were also brought into hot research fields. The investigators' purposes were to compare different kinds of methodologies(Mch,AMP,LTD4-BPT, Astograph-BPT) assessing airway responsiveness and to investigate treatment efficacy of budesonide /formoterol in asthmatics.

Detailed Description
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This study composed of two parts, that were the diagnosing part and the treatment part.

Official Title
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Comparison of Different Methodologies Assessing Airway Responsiveness and Investigation of Treatment Efficacy of Budesonide /Formoterol in Asthmatics

Conditions
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Asthma

Intervention / Treatment
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* Drug: methacholine
* Drug: adenosine monophosphate
* Drug: leukotriene D4
* Device: Astograph Jupiter-21 airway reaction testing apparatus
* Drug: budesonide /formoterol


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Clinically diagnosed Asthmatic patients aged from14 to 65 years； Had a had a normal chest radiographic result； Had a baseline spirometry with the forced expiratory volume in one second (FEV1) of not less than 60% predicted； Without acute upper respiratory tract infection for the past 2 weeks Exclusion Criteria: Smokers； Had a poor cooperation to the test or limited understandings; Had a past confirmed history of respiratory disease other than bronchial asthma (COPD, bronchiectasis, pulmonary thromboembolism, etc.) or other severe systemic disease（myocardial infarction, malignant tumor, etc.）; Pregnancy or breast-feeding women; Taken related drugs before measurements（Leukotriene receptor antagonists (LTRA) for 5 days，oral glucocorticosteroid or anti-histamine for 3 days，oral xanthenes or long-acting bronchodilators for 2 days，inhaled corticosteroid or long-acting bronchodilator for a day , short-acting bronchodilator for 4 hours ）

Ages Eligible for Study
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Minimum Age: 14 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Methacholine diagnosing group<br>Methacholine bronchial provocation test was performed by using Jaeger spirometry with Aerosol Provocation System | Drug: methacholine<br>* Methacholine,inhaled cumulative dosage 2.5mg<br>|
| Experimental: Adenosine monophosphate diagnosing group<br>Adenosine monophosphate bronchial provocation test was performed by using Jaeger spirometry with Aerosol Provocation System | Drug: adenosine monophosphate<br>* Adenosine monophosphate ,inhaled cumulative dosage 40mg<br>|
| Experimental: Leukotriene D4 diagnosing group<br>Leukotriene D4 bronchial provocation test was performed by using Jaeger spirometry with Aerosol Provocation System | Drug: leukotriene D4<br>* Leukotriene D4,inhaled cumulative dosage 2.4 μg<br>|
| Experimental: Astograh diagnosing group<br>Methacholine bronchial provocation test was performed by using Astograph Jupiter-21 airway reaction testing apparatus | Device: Astograph Jupiter-21 airway reaction testing apparatus<br>* Methacholine bronchial provocation test was performed by using Astograph Jupiter-21 airway reaction testing apparatus<br>|
| Experimental: budesonide /formoterol treatment group<br>budesonide 160μg and formoterol 4.5ug,1 inhalation ,twice daily ,for three month | Drug: budesonide /formoterol<br>* budesonide 160μg and formoterol 4.5ug,1 inhalation ,twice daily ,for three months in all participants (80 Anticipated)<br>* Other names: Symbicort;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| positive rate of BPT in each group | comparing positive rates of BPT in experimental groups and control group | 3months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Forced expiratory volume at one second（FEV1） | change of FEV1 measured by pulmonary function test（PFT）at one month interval for 3 consecutive months | 3months | 
| Fractional exhaled nitric oxide(FeNO) | change of FeNO at one month interval for 3 consecutive months | 3months | 
| Provocative dosage causing a 20% fall in FEV1(PD20-FEV1) | change of PD20-FEV1 at one month interval for 3 consecutive months in each group | 3months |