Pulmonary Disorders During Exercise in Patients With Obstructive Sleep Apnea

Study Overview
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Brief Summary
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Purposes: To investigate whether patients with severe obstructive sleep apnea syndrome (OSAS) are at higher risk for exercised-induced bronchoconstriction (EIB) due to baseline airway inflammation compared with age, gender, and body mass index (BMI)-matched controls. To investigate the effect of 3-month continuous positive airway pressure (CPAP) therapy on EIB for patients with severe OSAS.

Detailed Description
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Obstructive sleep apnea syndrome (OSAS) is characterized by repeated episodes of upper airway obstruction during sleep. Recent studies have found evidence of airway inflammation in patients with OSAS. Individuals with chronic airway inflammation are at higher risk for exercise-induced bronchoconstriction (EIB). We hypothesized patients with OSAS are at higher risk for EIB due to baseline airway inflammation. Continuous positive airway pressure (CPAP) is a known standard treatment for OSAS, thus the second aim of the study will be investigating the effect of 3-month CPAP therapy on EIB for patients with OSAS. Twenty severe OSAS patients and 20 control individuals matched for age, gender, and body mass index (BMI) will be recruited. All participants will come to the laboratory on 2 separate days (5 14 days interval). On the 1st visit, baseline pulmonary function test (PFT) and airway inflammation assess by induced sputum will be performed. On the 2nd visit, an exercise challenge test will be performed using standard testing protocol and post-exercise forced expiratory volume in one second (FEV1) will be measured at 2.5, 5, 10, 15,20, and 30 minutes. For patients with severe OSAS, all measurements will be repeated after 3-month CPAP therapy.

Official Title
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Exercised-Induced Bronchoconstriction in Patients With Severe Obstructive Sleep Apnea

Conditions
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Sleep Apnea, Obstructive, Asthma, Exercise-Induced

Intervention / Treatment
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* Device: continuous positive airway pressure (CPAP)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age ranged 18-65 y/o Severe OSA (AHI≧30/hr) BMI<35 kg/m2 Exclusion Criteria: Clinical asthma Chronic lung disease (FEV1<70% predicted or FEV1/FVC<70%) Exercise contraindication: Stroke or heart attack in last 3 months Major cardiovascular disease Unstable angina Unable to perform cycle ergometry due to musculoskeletal problems Respiratory tract infection in the past 2 weeks Inability to perform acceptable-quality spirometry Refuse to participate

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Intervention/Treatment |
| --- |
|Device: continuous positive airway pressure (CPAP)|CPAP of optimal pressure used during sleep for 3 months|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of changed forced expiratory volume in 1 second. (to determine if an exercise-induced bronchoconstriction attacked) |  | 3 month | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of different inflammatory cells in induced sputum. (to determine to severity of baseline airway inflammation) |  | 3 month | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Obstructive sleep apnea, Airway inflammation, Exercise-induced bronchoconstriction, Continuous positive airway pressure