Endothelial Dysfunction, Monocyte Activation, and Vasculopathy in Patients With Obstructive Sleep Apnea (OSA) and Effect of 6-month CPAP Treatment

Study Overview
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Brief Summary
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This purpose of this study is to Determine the change in endothelial dependent vascular reactivity and vascular properties Determine the changes in monocytes activation Determine the change in pro-inflammatory status Investigate the effect of six-month CPAP therapy on the above changes in patients with OSA

Detailed Description
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Obstructive sleep apnea (OSA), characterized with chronic intermittent hypoxia (CIH) and sleep fragmentation, is associated with three-fold higher risk of cardiovascular events. CIH could promote production of ROS which induced the adhesion of circulating monocytes, endothelium injury, and production of pro-inflammatory mediators and adhesion molecules and lead to formation of atherosclerotic plaque. Recent studies showed vascular endothelium function could be noninvasively assessed with Flow-mediated dilation (FMD) in brachial artery, whereas OSA patients have lower FMD compared to control subjects. However, the CPAP effects on vascular function have conflicting results. Conflicts usually involve the small sample size, lack of appropriate control, and inadequate control of confounding factors, like physical activity, and duration of CPAP treatment. Also, CPAP effect on other monocytes activation and inflammatory mediators are clear as well. Our previous studies showed 12-week CPAP treatment could not modify the levels of TNF-α and hsCRP. However, the 12-week treatment may be not long enough to draw the conclusions for benefit from long-term CPAP therapy. Therefore, we plan to conduct a cross-sectional followed by a double blind, randomized, placebo-control, parallel-group interventional study to prove our hypothesis that OSA can lead to endothelial dysfunction, monocytes activation, and pro-inflammatory state which leads to and vasculopathy and those changes can be reverted by CPAP.

Official Title
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Endothelial Dysfunction, Monocyte Activation, and Vasculopathy in Patients With Obstructive Sleep Apnea and Effect of Six-month CPAP Treatment: A Large-scale, Double-blind, Randomized, Placebo-controlled Trial

Conditions
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Sleep Apnea, Obstructive, Continuous Positive Airway Pressure, Endothelium, Inflammation, Vascular Function

Intervention / Treatment
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* Device: Therapeutic CPAP
* Device: Subtherapeutic CPAP


Participation Criteria
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Eligibility Criteria
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OSA patients Inclusion Criteria: male patients aged 30 to 65 year who have daytime sleepiness (ESS>=10) newly diagnosed OSA (AHI>30/hr) by overnight PSG but never been treated Exclusion Criteria: unwilling or unable to perform testing procedure past or current smoking history medical condition (including cardiovascular disease, chronic pulmonary disease, diabetes, endocrinologic disease, chronic renal failure, and psychiatric disease) systemic inflammatory conditions (system lupus erythematosus, rheumatoid arthritis, sarcoidosis, Crohn's disease, and ulcerative colitis) active neurologic event active infection two weeks prior to screening enrolled in other trials in the study period other sleep disorders sleepy driver using maintenance medications Control subjects Inclusion Criteria: Age-, sex-, body weight-, height-matched subjects with enrolled OSA patients non-sleepy no OSA confirmed by home sleep study (AHI<5/hr) Exclusion Criteria: unwilling or unable to perform testing procedure past or current smoking history medical condition (including cardiovascular disease, chronic pulmonary disease, diabetes, endocrinologic disease, chronic renal failure, and psychiatric disease) systemic inflammatory conditions (system lupus erythematosus, rheumatoid arthritis, sarcoidosis, Crohn's disease, and ulcerative colitis) active neurologic event active infection two weeks prior to screening enrolled in other trials in the study period other sleep disorders using maintenance medications

Ages Eligible for Study
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Minimum Age: 30 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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Male

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
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Healthy non-OSA control<br> | |
| Experimental: OSA receiving therapeutic CPAP<br> | Device: Therapeutic CPAP<br>* CPAP ventilator, optimal pressure decided by CPAP manual titration, daily use at sleep, six months<br>|
| Sham Comparator: OSA receiving subtherapeutic CPAP<br> | Device: Subtherapeutic CPAP<br>* Subtherapeutic CPAP ventilator, pressure <3 cmH2O, daily use at sleep, six months<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| vascular reactivity of brachial artery and pulse wave velocity |  | six months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| percentage of adhesion molecule expression on monocytes |  | six months | 
| levels of extra and intracellular cytokine |  | six months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Cardiovascular disease, Continuous positive airway pressure, Endothelium, Vascular function, Inflammation, Sleep Apnea, Obstructive