CPAP in SAHS Patients With Hypertension

Study Overview
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Brief Summary
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Study objective: To assess the nocturnal changes in mechanosensitivity and chemosensitivity in hypertensive sleep apnea-hypopnea syndrome (SAHS) patients and in SAHS patients with isolated nocturnal hypertension. To value the continuous positive airway pressure (CPAP) effect on these parameters. Design: Controlled cross-over longitudinal study. Settings: Madrid metropolitan area. Patients: Day-night sustained hypertensive and isolated nocturnal hypertensive patients with SAHS without previous treatment. At least 30 patients are needed. Interventions: Patients will allocate in each treatment arm (CPAP vs. sham CPAP) during three months. Explorations will perform before and immediately after sleep at 0-, 3-, and 6-months of trial. Measurements: 24-h urinary catecholamine, local vascular factors, angiotensin and aldosterone levels. Diaphragmatic tension-time index, metabolic rate, hypoxic withdrawal test, and ventilatory and inspiratory neural drive responses to progressive isocapnic hypoxia.

Official Title
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CPAP Effect on Nocturnal Evolution of Chemosensitivity Determinants in Sleep Apnea-hypopnea Patients With Isolated Nocturnal Hypertension or Day-nigh Sustained Hypertension

Conditions
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Sleep Apnea Syndromes, Hypertension

Intervention / Treatment
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* Device: CPAP nasal
* Device: sham CPAP nasal


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Recent diagnosis of sleep apnea-hypopnea syndrome with an apnea-hypopnea index (AHI) > 10 h-1 No previous treatment for SAHS or hypertension Diagnosis by 24-h ambulatory monitoring of blood pressure (AMBP) of isolated nocturnal hypertension (nighttime blood pressure of ≥120 mm Hg systolic or 70 mm Hg diastolic and a daytime blood pressure <135/85 mm Hg) or day-night sustained hypertension (nighttime blood pressure of ≥120 mm Hg or 70 mm Hg diastolic and a daytime blood pressure of ≥135 mm Hg systolic). Exclusion Criteria: Severe hypertension (> 180/120 mmHg). Previous diagnosis of secondary hypertension. Myocardial infarction or stroke in the last three months. Severe diurnal sleepiness (Epworth score > 15) Previous diagnosis of chronic obstructive pulmonary disease, asthma, bronchiectasis, lung cancer, restrictive lung disease, chest wall disease or thoracic surgery. Previous diagnosis or clinical evidence of heart disease, neuromuscular disease or thyroid dysfunction. Morbid obesity (BMI > 40 Kg/m2) Respiratory infection in the last two months. Treatment with theophylline or systemic corticosteroids in the last two years. Excessive alcohol intake (>40 g/day) Absence of social or familiar support.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 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: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: CPAP nasal<br>Nasal continuous positive airway pressure, during the night | Device: CPAP nasal<br>* During the night<br>* Other names: Nocturnal support with continuous positive airway pressure;|
| Sham Comparator: sham CPAP nasal<br>Nasal sham continuous positive airway pressure, during the night | Device: sham CPAP nasal<br>* During the night<br>* Other names: sham CPAP;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Effect of CPAP on the night-morning change in the withdrawal response and in the ventilatory and central drive responses to progressive isocapnic hypoxia. | To compare the effect of three months of CPAP therapy versus sham CPAP on the night-morning (pre- vs. post-sleep) change in the withdrawal response (decrease in ventilation caused by two breaths of 100% oxygen, %ΔV'I) and in the ventilatory and inspiratory neural drive responses to progressive isocapnic hypoxia (ΔV'I/arterial oxygen saturation (SaO2)/body surface area (BSA)] and Δ occlusion pressure at 0.1 s (P0.1)/arterial oxygen saturation (SaO2), respectively). | 3 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| CPAP effect on the night-morning change in the sniff diaphragmatic tension-time index | To compare the effect of three months of CPAP therapy versus sham CPAP on the night-morning (pre- vs. post-sleep) change in the sniff diaphragmatic tension-time index (TTdi) | 3 months | 
| CPAP effect on blood pressure | To compare the effect of three months of CPAP therapy on the blood pressure in SAHS patients with isolated nocturnal hypertension and SAHS patients with day-nigh sustained hypertension | 3 months | 
| CPAP effect on the serum levels of endothelin-1 and vascular endothelial cell adhesion molecule (VCAM)-1 | To compare the effect of three months of CPAP therapy versus sham CPAP on the serum levels of endothelin-1 and VCAM-1 in SAHS patients with isolated nocturnal hypertension and SAHS patients with day-nigh sustained hypertension | 3 months | 
| CPAP effect on the night-morning change in the rest metabolic rate | To compare the effect of three months of CPAP therapy versus sham CPAP on the night-morning (pre- vs. post-sleep) change in the rest metabolic rate (carbon dioxide production/oxygen uptake ratio, RER) | 3 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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sleep apnea, hypertension, mechanosensitivity, chemosensitivity, adhesion factors