Endothelial repair capacity and apoptosis are inversely related in obstructive sleep apnea

Vasc Health Risk Manag. 2009;5:909-20. doi: 10.2147/vhrm.s8123. Epub 2009 Nov 16.

Abstract

Purpose: To investigate the impact of obstructive sleep apnea (OSA) on endothelial repair capacity and apoptosis in the absence of potentially confounding factors including obesity.

Patients and methods: Sixteen patients with a body mass index <30 and newly diagnosed OSA and 16 controls were studied. Circulating levels of endothelial progenitor cells, a marker of endothelial repair capacity, and endothelial microparticles, a marker of endothelial apoptosis, were quantified before and after four-week therapy with continuous positive airway pressure (CPAP). Endothelial cell apoptotic rate was also quantified in freshly harvested venous endothelial cells. Vascular reactivity was measured by flow-mediated dilation.

Results: Before treatment, endothelial microparticle levels were greater and endothelial progenitor cell levels were lower in patients with OSA than in controls (P < 0.001 for both). Levels of endothelial microparticles and progenitors cells were inversely related (r = -0.67, P < 0.001). Endothelial progenitor cell levels increased after effective treatment (P = 0.036).

Conclusions: In the absence of any co-morbid conditions including obesity, OSA alone impairs endothelial repair capacity and promotes endothelial apoptosis. These early endothelial alterations may underlie accelerated atherosclerosis and increased cardiovascular risk in OSA.

Keywords: apoptosis; endothelial repair capacity; endothelium; sleep apnea.

Publication types

  • Controlled Clinical Trial

MeSH terms

  • Adult
  • Apoptosis*
  • Body Mass Index
  • Brachial Artery / physiopathology
  • Cardiovascular Diseases / etiology
  • Cardiovascular Diseases / pathology
  • Cell Proliferation*
  • Cell-Derived Microparticles / pathology*
  • Continuous Positive Airway Pressure*
  • Endothelial Cells / pathology*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Obesity / complications*
  • Obesity / pathology
  • Obesity / physiopathology
  • Sleep Apnea, Obstructive / etiology
  • Sleep Apnea, Obstructive / pathology
  • Sleep Apnea, Obstructive / physiopathology
  • Sleep Apnea, Obstructive / therapy*
  • Stem Cells / pathology*
  • Time Factors
  • Treatment Outcome
  • Vasodilation