Exercise Capacity and Daily Physical Activity in Obese Subjects With Treated Obstructive Sleep Apnea

Study Overview
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Brief Summary
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Obesity is very common worldwide and breathing problems at night (obstructive sleep apnea, OSA) are common in obesity. Despite the best treatment, obesity and OSA are linked to early death from heart problems. They are also associated with lower levels of physical activity. Exercise strategies for weight loss, increasing physical activity and improving fitness are needed for obesity. In Obese individuals with OSA The investigators will compare corridor walking tests compared to laboratory exercise tests. The null hypothesis is that the peak oxygen uptake achieved and the cardiopulmonary response during both the six-minute walk test and Incremental Shuttle Walk Test would not be different from that observed during an Incremental Treadmill Test. The investigators will investigate whether cycling or walking uses more calories for the same intensity. We hypothesise that cycling (weight supported) will be endured for long. The investigators will compare commonly used exercise tests with levels of daily physical activity. The information from these three projects will help us set up the optimal exercise program for obese individuals.

Official Title
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Exercise Capacity and Daily Physical Activity in Obese Subjects With Treated Obstructive Sleep Apnea

Conditions
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Obstructive Sleep Apnea, Obesity

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Obstructive Sleep Apnea Obesity BMI>30 Controlled on Continuous Positive Airway Pressure for three months Exclusion Criteria: cardiac co-morbidity e.g ischaemic heart disease, chronic heart failure, valvular heart disease pulmonary co-morbidity neurological condition limiting the ability to perform walking or cycling orthopaedic condition limiting the ability to perform walking or cycling

Ages Eligible for Study
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Minimum Age: 18 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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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Peak oxygen uptake (Peak VO2) measured at the end of the Incremental Shuttle Walk Test (ISWT) | Two Incremental Shuttle Walk tests will be performed within two hours on the same day with expired gas analysis measured by a portable gas analyser. An ISWT is conducted over a 10m course and the speed is externally paced and increases each minute. The participant is asked to continue until they are either too breathless or too tired to continue. | All outcome measures will be performed within four weeks of each other | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Six minute walk test (6MWT) | The 6MWT will be performed over a 30 m level, straight course within an enclosed corridor. The test protocol described by the American Thoracic Society will be modified to include standardized encouragement every 15 seconds to recommence walking if the participant chooses to rest during the test. Participants will be familiarized with the test prior to participating in the study and, therefore, only one test will be performed. | Four weeks | 
| Incremental Treadmill Test (ITM) | A maximal treadmill test will be performed once with expired gas analysis. | Four weeks | 
| Incremental cycle test (ICE) | A maximal symptom limited cardio-pulmonary exercise test on a cycle ergometer. | Four weeks | 
| Endurance cycle ergometer | Two endurance cycle tests will performed at 60% and 80% of the maximal peak oxygen obtained on either the ICE or ITM | Four weeks | 
| Endurance treadmill test | Constant speed endurance treadmill test will be performed at 60% and 80% of the peak oxygen uptake achieved on either the ITM or ICE to symptom limitation | Four weeks | 
| Daily physical activity | A sensewear armband will be worn for 7 days and only taken off for showering/bathing. | Four weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Obesity, Obstructive Sleep Apnea, Exercise, Walking tests, Cardiopulmonary exercise tests, Physical activity