Obstructive sleep apnoea syndrome, endothelial function and markers of endothelialization. Changes after CPAP

PLoS One. 2015 Mar 27;10(3):e0122091. doi: 10.1371/journal.pone.0122091. eCollection 2015.


Study objectives: This study tries to assess the endothelial function in vivo using flow-mediated dilatation (FMD) and several biomarkers of endothelium formation/restoration and damage in patients with obstructive sleep apnoea (OSA) syndrome at baseline and after three months with CPAP therapy.

Design: Observational study, before and after CPAP therapy.

Setting and patients: We studied 30 patients with apnoea/hypopnoea index (AHI) >15/h that were compared with themselves after three months of CPAP therapy. FMD was assessed non-invasively in vivo using the Laser-Doppler flowmetry. Circulating cell-free DNA (cf-DNA) and microparticles (MPs) were measured as markers of endothelial damage and the vascular endothelial growth factor (VEGF) was determined as a marker of endothelial restoration process.

Measurements and results: After three month with CPAP, FMD significantly increased (1072.26 ± 483.21 vs. 1604.38 ± 915.69 PU, p< 0.005) cf-DNA and MPs significantly decreased (187.93 ± 115.81 vs. 121.28 ± 78.98 pg/ml, p<0.01, and 69.60 ± 62.60 vs. 39.82 ± 22.14 U/μL, p<0.05, respectively) and VEGF levels increased (585.02 ± 246.06 vs. 641.11 ± 212.69 pg/ml, p<0.05). These changes were higher in patients with more severe disease. There was a relationship between markers of damage (r = -0.53, p<0.005) but not between markers of damage and restoration, thus suggesting that both types of markers should be measured together.

Conclusions: CPAP therapy improves FMD. This improvement may be related to an increase of endothelial restoration process and a decrease of endothelial damage.

Publication types

  • Observational Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Biomarkers / blood
  • Cell-Derived Microparticles / pathology
  • Continuous Positive Airway Pressure*
  • DNA / blood
  • Endothelium, Vascular / pathology*
  • Endothelium, Vascular / physiopathology
  • Female
  • Humans
  • Male
  • Middle Aged
  • Sleep Apnea, Obstructive / diagnosis
  • Sleep Apnea, Obstructive / therapy*
  • Vascular Endothelial Growth Factor A / blood


  • Biomarkers
  • Vascular Endothelial Growth Factor A
  • DNA

Grant support

This work was supported by two grants: 1) Instituto de Salud Carlos III, PI/0044/07, to Dr. P. Stiefel. 2) Consejeria de Salud, Junta de Andalucía, P09-CTS-4971, to Dra. M.A Sánchez-Armengol. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.