The present study aims to compare muscle sympathetic neural activity by microneurography after one month treatment of fixed versus auto-adjusting CPAP treatment and its impact on arterial blood pressure
Background: Sleep apnea syndrome (SAS) currently affects 10% of general population. It is characterized by the occurrence during the sleep of the upper airways closure which cause repeated asphyxia. It is a public health problem due to its cardiometabolic complications. Indeed, the absence of SAS treatment increases cardiovascular mortality by 12% at 10 years. The main physiopathological mechanism is the activation of cardiovascular sympathetic control (the short-term regulation of blood pressure which bring in the sympathetic nervous system) An exposure to intermittent chronic hypoxia (caused by SAS) bring an increased of muscle sympathetic nerve activity (MSNA) contributing to elevated blood pressure Continuous Positive Airway Pressure (CPAP) can partly reduce this risk by decreasing elevation of blood pressure caused by the SAS. It has recently been demonstrated that all CPAP devices are not equivalent. Indeed, the auto-adjusted CPAP treatment induces a reduction in blood pressure lower than the reference treatment fixed CPAP. To this extent it is interesting to conduct a new randomized trial comparing these two treatments with vascular sympathetic tone. This will be assessed by peroneal microneurography recording. Objective: Compare Muscle Sympathetic Neural Activity (MSNA) by microneurography after one month of fixed versus auto-adjusted CPAP treatment in OSA patients naive from pressure therapy Methods: Prospective study, single-site, randomized, double-blind, parallel, one month controlled trial. After the diagnosis of sleep apnea, patients will be randomized for one month treatment with fixed ou auto-adjusting CPAP. Measurements of MSNA, heart rate variability and catecholamines will be held before and after treatment. An interim analysis will be performed after the inclusion of 24 patients based on group sequential design. Assuming an α error of 5%, a statistical power of 80%, and a unilateral situation : 34 patients per arm will be needed to be enrolled in the study. The enrollment target for the study will be reviewed and may be refined following the study interim analysis and taking account 20% of study drop-out.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
OTHER
Masking
DOUBLE
Enrollment
57
CPAP is a device that applies continous fixed positive pressure to the airways in order to keep them opened during sleep
Auto-adjusting CPAP is a device that applies auto-adjusting continous positive pressure to the airways in order to keep them opened during sleep
CHU Grenoble Alpes
Grenoble, France
Sympathetic tone (MSNA)
Change from Baseline Sympathetic tone at 1 months
Time frame: Change from baseline after one month of intervention
24 hours Systolic Blood pressure (AMBP)
Change from Baseline in 24 hours ambulatory systolic blood pressure
Time frame: Change from baseline after one month of intervention
Systolic Blood pressure (office)
Clinical BP on 3 occasions, SBP and BP will be assessed. Mean BP calculated as DBP+1/3(SBP-DBP)
Time frame: Change from baseline after one month of intervention
Diastolic Blood pressure (office) change after 1 month
Clinical BP on 3 occasions, SBP and BP will be assessed. Mean BP calculated as DBP+1/3(SBP-DBP)
Time frame: Change from baseline after one month of intervention
Mean Blood pressure (office)
Clinical BP on 3 occasions, SBP and BP will be assessed. Mean BP calculated as DBP+1/3(SBP-DBP)
Time frame: Change from baseline after one month of intervention
Catecholamines (epinephrine)
24h urine samples will be collected and acidified with acetic acid, stored at -20°C until analysis. Catecholamines (epinephrine, norepinephrine, and dopamine) will be measured in one milliliter of urine by high-performance liquid chromatography with electrochemical detection (CoulArray® Detector from ESA- Dionex, Chelmsford, USA).
Time frame: Change from baseline after one month of intervention
Norepinephrine)
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24h urine samples will be collected and acidified with acetic acid, stored at -20°C until analysis. Catecholamines (epinephrine, norepinephrine, and dopamine) will be measured in one milliliter of urine by high-performance liquid chromatography with electrochemical detection (CoulArray® Detector from ESA- Dionex, Chelmsford, USA).
Time frame: Change from baseline after one month of intervention
Dopamine (Catecholamine)
24h urine samples will be collected and acidified with acetic acid, stored at -20°C until analysis. Catecholamines (epinephrine, norepinephrine, and dopamine) will be measured in one milliliter of urine by high-performance liquid chromatography with electrochemical detection (CoulArray® Detector from ESA- Dionex, Chelmsford, USA).
Time frame: Change from baseline after one month of intervention
High-frequency component of Heart rate variability
We will use these mathematical methods to analyze a signal over time: temporal analysis, Fourier transformation and wavelet transformation. High-frequency (HF) translates fluctuations in parasympathetic activity to cardiac destination, modulated by ventilatory characteristics (frequency, courant volume).
Time frame: Change from baseline after one month of intervention
Low frequency component of Heart rate variability
We will use these mathematical methods to analyze a signal over time: temporal analysis, Fourier transformation and wavelet transformation. Low frequency (LF) is classically considered to reflect the activity of the sympathetic system rather than the parasympathetic system.
Time frame: Change from baseline after one month of intervention
24 hours Diastolic blood pressure change (AMBP)
ambulatory measurements over 24h
Time frame: Change from baseline after one month of intervention
24 hours Mean Blood pressure (AMBP)
ambulatory measurements over 24h
Time frame: Change from baseline after one month of intervention