CPAP Effect on Vascular Function in Obstructive Sleep Apnea
Condition: Obstructive Sleep Apnea
MeSH terms: Apnea; Sleep Apnea Syndromes; Sleep Apnea, Obstructive
Study type: Observational

Summary: 
      Obstructive sleep apnea syndrome is responsible of endothelial dysfunction, which is a
      independent cardio-vascular risk factor.

      Assessment of pulse wave velocity (PWV) and peripheral arterial tone (PAT) are study
      measurements of arterial stiffness, and are strong predictors of late cardiovascular events.

      This study will compare long term evolution in arterial stiffness (PWV) and endothelial
      dysfunction (PAT) for patients treated by Positive Airway Pressure Therapies.
    

Detailed description: 
      Obstructive sleep apnea (OSA) syndrome is responsible of vascular damage. Intermittent
      hypoxia causes oxidative stress and low-grade inflammation. By the way of increased
      sympathetic outflow, it's resulting endothelial dysfunction, atherosclerosis and an increase
      of arterial stiffness.

      Finally these mechanisms are responsible of cardiovascular comorbidities: hypertension,
      cardiac arrhythmias or Left ventricular dysfunction. This patients presented coronary
      diseases or Strokes.

      OSA characterized by intermittent hypoxia, is associated with atherosclerosis and vascular
      inflammation. Polymorphonuclear leukocytes (PMNs) are implicated in vascular inflammation by
      producing oxidizing radicals and proteolytic enzymes during PMN-endothelium interactions.

      Reactive oxygen species (ROS) production is increased in activated cells and after
      attachment, PMNs release additional ROS inducing endothelial cell injury.

      Continuous positive airway pressure (CPAP) is the current "gold standard" treatment for OSA,
      Use of CPAP restored the respiratory flow, prevents nocturnal respiratory events and daytime
      symptoms.

      Arterial stiffness and endothelial dysfunction are linked to obstructive sleep apnea severity
      with a dose-effect relationship. And meta-analyse showed significant improvements in all
      indices of arterial stiffness after CPAP treatment in patients with OSA.

      Assessment of pulse wave velocity and peripheral arterial tone are study measurements of
      arterial stiffness. And are strong predictors of late cardiovascular events

      The investigators will compare long term evolution in arterial stiffness (PWV) and
      endothelial dysfunction (Peripheral arterial tone) for patients with OSA treated by Positive
      Airway Pressure Therapies.
    

Intervention name(s): PAP Therapies (CPAP)
Intervention type(s): Other
Intervention description(s): Patients with sleep apnea syndrome treated by PAP Therapies (CPAP) after diagnosis and followed 5-7 years.
Other intervention name(s): CPAP
Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Patients with sleep apnea syndrome treated by CPAP after diagnosis and followed 5-7 years,
        as part of a clinical research.
      
Biospecimen description: 
      Serum Bank
    
Keywords: Obstructive Sleep Apnea; Endothelial dysfunction; Arterial stiffness; PAP therapies