Effect of Continuous Positive Airway Pressure (CPAP) Versus Auto-titrating Continuous Positive Airway Pressure (APAP) on Resistant Hypertension (HTN) and Arterial Stiffness

Study Overview
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Brief Summary
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The primary objective is to evaluate the relative effectiveness of fixed CPAP in comparison to APAP in reducing arterial blood pressure in patients with resistant hypertension and obstructive sleep apnea (OSA). The secondary objectives are: a) to evaluate the relative effectiveness of fixed CPAP versus APAP in improving arterial stiffness, sleep-disordered breathing, sleep quality, inflammatory markers and glucose regulation; b) to identify specific characteristic of persons who respond to the two CPAP modalities in order to identify which device is better for each subject.

Detailed Description
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The confirmatory hypothesis is that subjects with resistant hypertension and OSA will show a greater degree of blood pressure reduction after 6 weeks of treatment with fixed CPAP in comparison to those treated with APAP. Explanatory and exploratory hypotheses are that a greater reduction in arterial stiffness will be noted when compared with the benefit in blood pressure, that reductions in arterial stiffness will be associated with benefits to serum measurements of inflammatory markers and glucose regulation, and that control of sleep apnea and the attendant improvement in sleep quality will be better with fixed CPAP than APAP.

Official Title
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Effect of Fixed Versus Auto-titrating Continuous Positive Airway Pressure on Blood Pressure and Arterial Stiffness in Patients With Resistant Hypertension and Obstructive Sleep Apnea

Conditions
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Resistant Hypertension, Obstructive Sleep Apnea

Intervention / Treatment
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* Device: CPAP
* Device: APAP


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Resistant Hypertension Moderate Obstructive Sleep Apnea Exclusion Criteria: Creatinine >150 μmol/l Systolic blood pressure > 170 mmHg Diastolic blood pressure > 105 mmHg Secondary cause of hypertension other than OSA Treatment within the last 3 months or current treatment for sleep-disordered breathing or some other sleep disorder Current treatment or recent treatment within the last 3 months for any other medical condition which has resulted or would be expected to result in a change in blood pressure medications

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 100 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: Crossover Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: auto-titrating<br>Patients being treated for 6 weeks with auto-titrating continuous airway pressure. | Device: APAP<br>* 6 weeks of treatment with auto-titrating positive airway pressure<br>* Other names: auto-titrating airway pressure;|
| Active Comparator: Fixed<br>Patients receiving 6 weeks of treatment with fixed continuous positive airway pressure. | Device: CPAP<br>* 6 weeks treatment with fixed CPAP<br>* Other names: Continuous Positive Airway Pressure;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 24 hour blood pressure. |  | 6 weeks and 12 weeks after initial intervention | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Non-invasive measures of arterial stiffness using applanation tonometry. |  | 6 weeks and 12 weeks after initial intervention | 
| Standard measures of OSA severity, including AHI and measures of nocturnal oxygenation and sleep quality using polysomnography. |  | 6 weeks and 12 weeks after initial intervention | 
| Blood tests to assess levels of aldosterone, hsCRP, fasting glucose, HbA1c, and plasma insulin. |  | 6 weeks and 12 weeks after initial intervention | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Resistant Hypertension, Obstructive Sleep Apnea, 24 Hour Blood Pressure, Arterial Stiffness, Insulin Resistance, CPAP, APAP