Oxidative Stress and Endothelial Dysfunction in Obstructive Sleep Apnea

Study Overview
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Brief Summary
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Patients with sleep apnea syndrome have repeated apneic events that induce periodic hypoxia-reoxygenation, drawing away an overproduction of oxidants. This exaggerated generation of oxidants is associated with a dysfunction of the vascular endothelium that evolves, in its turn, towards cardiovascular diseases such as systemic hypertension, stroke, and myocardial infarction. The major aim of our study is to examine the effect of CPAP treatment on biochemical (markers of oxidative stress) and functional (endothelium-dependent vascular relaxation reactivity) abnormalities at 1 and 4 weeks of treatment.

Detailed Description
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Subjects will undergo overnight polysomnography in the sleep laboratory (PSG1, D0), which will be immediately preceded and followed by measurements of oxidative stress in exhaled gas and vascular relaxation. Patients included in the OSAS group will be randomly assigned to treatment by either CPAP or Placebo (sham CPAP) for 4 weeks. Measurements of oxidative stress in exhaled gas and vascular reactivity will be repeated immediately before and after PSG2 and PSG3 at D7 and D30, respectively.

Official Title
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Exhaled Markers of Oxidative Stress and Endothelium-dependent Vascular Relaxation in Obstructive Sleep Apnea. Effect of Continuous Positive Airway Pressure Therapy.

Conditions
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Obstructive Sleep Apnea Syndrome, Endothelial Dysfunction, Oxidative Stress, Intermittent Hypoxia, Cardiovascular Risk

Intervention / Treatment
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* Device: CPAP device
* Device: Placebo device


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: No smoking 30-70 years old subjects being referred for daytime hyper- somnolence and snoring apnea hypopnea index >=30/hour and desaturation index>=30/hour Exclusion Criteria: Chronic lung diseases. Exposure to occupational contaminants. Active smoking within last 2 years. Alcoholism. Chronic systemic disease other than OSAS. Treatment with vasoactive drugs or antioxidants Respiratory infection or vaccination during the 6 weeks preceding the PSG1.

Ages Eligible for Study
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Minimum Age: 30 Years
Maximum Age: 70 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: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 1<br>CPAP | Device: CPAP device<br>* for 4 weeks<br>* Other names: CPAP;|
| Sham Comparator: 2<br>sham CPAP | Device: Placebo device<br>* for 4 weeks<br>* Other names: Placebo;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To examine the effect of CPAP treatment on biochemical (markers of oxidative stress) abnormalities |  | 1 and 4 weeks of treatment | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To compare between patients with severe OSAS and controls, the degree of the production of markers of oxidative stress non-invasively measured in both the exhaled gas and urine samples |  | before and after a nocturnal polysomnography | 
| To compare between patients and controls, the endothelium-dependent vascular relaxation |  | before and after nocturnal polysomnography | 
| To analyze the relationship between these biochemical and functional abnormalities and the standard criteria of severity of OSAS. |  | before and after nocturnal polysomnography | 
| To examine the effect of CPAP treatment on functional (endothelium-dependent vascular relaxation reactivity) abnormalities |  | 1 and 4 weeks of treatment | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Isoprostane, Alkane, Exhaled condensate, Peripheral arterial tonometry, Polysomnography, Obstructive Sleep Apnea, Hypoxia