Intensity, Specificity and Reversibility of Inspiratory Muscle Training in Asthmatics

Study Overview
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Brief Summary
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Inspiratory muscle training (IMT) can reverse or delay the complications from the deterioration of inspiratory muscle function in asthma. Thus, the IMT has been considered a treatment option for people with asthma. The aim of this study is to investigate the training principles of intensity, specificity and reversibility of IMT in asthmatics.

Official Title
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Intensity, Specificity and Reversibility of Inspiratory Muscle Training in Asthmatics: a Randomized Clinical Trial

Conditions
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Asthma

Intervention / Treatment
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* Device: High-intensity IMT
* Device: Low-intensity IMT


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Diagnosis of asthma Adults (18 - 60 years) Exclusion Criteria: Inability to perform the protocol established by the study Others respiratory diseases Request for study withdrawal

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 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

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: High-intensity IMT<br>Participants enrolled in this arm received high-intensity IMT | Device: High-intensity IMT<br>* 30 breaths at 50% of the maximal inspiratory pressure, twice daily for 6 weeks<br>|
| Active Comparator: Low-intensity IMT<br>Participants enrolled in this arm received low-intensity IMT | Device: Low-intensity IMT<br>* 30 breaths at 15% of the maximal inspiratory pressure, twice daily for 6 weeks<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in inspiratory muscle strength | Maximal inspiratory pressure | Baseline, 6 weeks later and 6 weeks after training | 
| Change in expiratory muscle strength | Maximal expiratory pressure | Baseline, 6 weeks later and 6 weeks after training | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in asthma control | Asthma Control Questionnaire measures the adequacy of asthma control and change in asthma control which occurs either spontaneously or as a result of treatment. Scores range between 0 (totally controlled) and 6 (severely uncontrolled) | Baseline, 6 weeks later and 6 weeks after training | 
| Change in quality of life | Asthma Quality of Life Questionnaire is a disease-specific health-related quality of life instrument that taps both physical and emotional impact of disease. Scores range 1-7, with higher scores indicating better quality of life. | Baseline, 6 weeks later and 6 weeks after training | 
| Change in six minute walk test distance | Six-minute walk test (6MWT) | Baseline, 6 weeks later and 6 weeks after training | 
| Change in forced vital capacity | Forced vital capacity in litres and % of predicted | Baseline, 6 weeks later and 6 weeks after training | 
| Change in forced expiratory volume | Forced expiratory volume in litres and % of predicted | Baseline, 6 weeks later and 6 weeks after training | 
| Change in forced expiratory volume/forced vital capacity | Forced expiratory volume/forced vital capacity | Baseline, 6 weeks later and 6 weeks after training | 
| Change in inspiratory muscle activity | Surface electromyography of inspiratory muscles | Baseline, 6 weeks later and 6 weeks after training |