Efficacy of CPAP Treatment on Blood Pressure of Resistant Hypertension Patients With Obstructive Sleep Apnea Syndrome

Study Overview
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Brief Summary
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The aim is to evaluate the effect of treatment with Continuous Positive Airway Pressure (CPAP) device on clinic and ambulatory blood pressures (BP) of 200 resistant hypertensive patients with moderate-severe obstructive sleep apnea syndrome (OSAS).

Detailed Description
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Obstructive sleep apnea syndromes (OSAS) have been demonstrated to be highly prevalent in patients with resistant hypertension (defined as uncontrolled clinic BP despite being on anti-hypertensive treatment with at least 3 drugs in optimal doses and including a diuretic). Nevertheless, the effect of treating OSAS with Continuous Positive Airway Pressure (CPAP) device on clinic and ambulatory BPs in patients with resistant hypertension is largely unknown. Hence, the primary aim of this randomized clinical trial is to evaluate the effect of CPAP on BP levels in resistant hypertensive patients with moderate-severe OSAS (defined as an apnea-hypopnea index [AHI] greater than 15 on a full polysomnographic examination). Two-hundred patients will be randomly allocated either to treatment with CPAP device plus their usual anti-hypertensive treatment or to continue their usual treatment alone for 6 months. Clinic and 24-hour ambulatory BP monitoring, laboratory evaluation (including microalbuminuria and aldosterone-to-renin ratio), 24-hour Holter monitoring, ergospirometric treadmill test, and carotid-femoral pulse wave velocity measurement will be performed before and after the 6-month treatment, with the observers blinded to the allocation group.

Official Title
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Efficacy of Continuous Positive Airway Pressure (CPAP) on Blood Pressure Control of Resistant Hypertension Patients With Obstructive Sleep Apnea Syndrome (OSAS).

Conditions
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Obstructive Sleep Apnea Syndrome, Resistant Hypertension

Intervention / Treatment
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* Procedure: Continuous positive airway pressure treatment


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with resistant hypertension and moderate-severe obstructive sleep apnea syndrome Exclusion Criteria: Older than 80 years Pregnant women Non-adherent to anti-hypertensive treatment Severe cognitive deficits

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 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: CPAP<br>Treatment with Continuous Positive Airway Pressure | Procedure: Continuous positive airway pressure treatment<br>* Treatment with CPAP for 6 months, pressure will be titrated during a second polysomnography.<br>|
| No Intervention: Control<br>Usual anti-hypertensive treatment without CPAP treatment | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| clinic and ambulatory blood pressures | Clinic and ambulatory blood pressures (during 24-hour ambulatory blood pressure monitoring, which included both daytime and nighttime blood pressures, as well as the nocturnal dipping pattern). | 6 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Microalbuminuria | Urinary albumin excretion rate on 24-hour urine collection | 6 months | 
| Aldosterone excess measurements | Serum aldosterone concentration, plasma renin activity, aldosterone-to-renin ratio and 24-hour urinary aldosterone excretion. | 6 months | 
| Arterial stiffness | Carotid-femoral pulse wave velocity and aortic pulse wave contour analysis (which include aortic systolic and pulse pressure and augmentation index) | 6 months | 
| Autonomic system measurements | Measures of autonomic system balance derived from 24-hour Holter monitoring, which includes heart rate variability on time and frequency domains. | 6 months | 
| Cardiorespiratory fitness | Cardiorespiratory fitness by 6 min walking test with maximum oxigen consumption measurement and by complete ergospirometric treadmill test. | 6 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Continuous positive airway pressure, Ambulatory blood pressures