Effects of Obstructive Sleep Apnea Treatment by Fixed CPAP and by Auto-CPAP (Somnosmart2)

Study Overview
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Brief Summary
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The main purpose of this study is to investigate if treatment of obstructive sleep apnea syndrome (OSAS) by continuous positive airway pressure (CPAP) given by a traditional CPAP device administering a fixed air pressure, or by one automatic CPAP device (Somnosmart2, Weinmann, Hamburg) administering variable pressures, have different effects on sympathetic nervous system tone (as reflected by urinary excretion of norepinephrine and its catabolite normetanephrine) and on blood pressure.

Detailed Description
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A nocturnal home cardiorespiratory recording will performed for diagnosis of OSA. During the same night, patients will be asked to collect their urines. Twentyfour-hour ambulatory BP monitoring (ABPM) will be performed starting from the next morning. After analysis of the polygraphic recording, subjects with AHI <15 will be excluded from the study, while CPAP will be proposed as a treatment to the other patients. Before starting treatment, a full night standard polysomnography will be performed: in subjects assigned to fixed CPAP for attended CPAP titration; in the other subjects during application of the Somnosmart2 device, to verify if obstructive events are adequately eliminated by it. After analysis of polysomnography, patients will be given a fixed CPAP or the auto-CPAP device for nocturnal home use. Two months later, compliance to treatment will be verified measured by the in-built time counter of the devices. Then, cardiorespiratory monitoring during application of the device used for treatment, nocturnal urine collection and 24-hour ABPM will be repeated.

Official Title
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Differential Effects of Chronic Treatment of OSAS by CPAP and SOMNOsmart2 on Norepinephrine and Blood Pressure

Conditions
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Obstructive Sleep Apnea Syndrome

Intervention / Treatment
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* Device: Automatic (variable, automatically controlled) pressure CPAP
* Device: fixed continuous positive airway pressure (CPAP)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Obstructive sleep apnea syndrome deserving CPAP treatment Exclusion Criteria: current pharmacological treatment

Ages Eligible for Study
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Minimum Age: 25 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: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: fixed CPAP<br> | Device: fixed continuous positive airway pressure (CPAP)<br>* CPAP at a constant level, whose efficacy on respiratory disorders has been determined by nocturnal titration. Home nocturnal usage. Two-month treatment.<br>* Other names: fixed CPAP, constant level CPAP;|
| Experimental: Auto-CPAP<br>Auto-CPAP Weinmann Somnosmart2 | Device: Automatic (variable, automatically controlled) pressure CPAP<br>* CPAP at a variable level according to instantaneous patients' needs for treatment of sleep respiratory disorders, as evaluated by machine's software. Home nocturnal usage. Two-month treatment.<br>* Other names: Automatic CPAP SOMNOsmart2, Weinmann, Hamburg Germany;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Blood pressure and urinary catecholamines after conventional or auto-CPAP |  | 2 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Relationship between catecholamines / blood pressure changes and compliance to treatment |  | 2 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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OSAS, blood pressure, sympathetic nervous system, treatment, CPAP