Effect of positive airway pressure therapy of obstructive sleep apnea on circulating Angiopoietin-2

Sleep Med. 2022 Aug:96:119-121. doi: 10.1016/j.sleep.2022.05.007. Epub 2022 May 16.


Background: Obstructive sleep apnea (OSA) has been identified as a possible contributor to interstitial lung disease. While positive airway pressure (PAP) is effective therapy for OSA, it causes large increases in lung volumes during the night that are potentially deleterious, analogous to ventilator-induced lung injury, although this has not been previously studied. The goal of this study was to assess the impact of PAP therapy on four biomarkers of alveolar epithelial and endothelial injury and extracellular matrix remodeling in patients with OSA.

Methods: In 82 patients with moderate to severe OSA who were adherent to PAP therapy, surfactant protein D, osteopontin, angiopoietin-2, and matrix metalloprotease-7 were measured by ELISA in serum samples collected before and 3- to 6-months after initiation of PAP therapy.

Results: An increase in angiopoietin-2 level of 0.28 ng/mL following PAP therapy was observed (p = 0.007). This finding was replicated in an independent sample of OSA patients. No significant change was detected in surfactant protein D, osteopontin, or matrix metalloprotease-7.

Conclusions: This finding raises concern for a possible adverse impact of PAP therapy on vascular endothelium.

Keywords: Angiopoietin-2; Lung injury; Obstructive sleep apnea; Positive airway pressure.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angiopoietin-2* / administration & dosage
  • Continuous Positive Airway Pressure*
  • Humans
  • Metalloproteases / blood
  • Osteopontin / blood
  • Pulmonary Surfactant-Associated Protein D / blood
  • Sleep Apnea, Obstructive* / blood
  • Sleep Apnea, Obstructive* / therapy


  • Angiopoietin-2
  • Pulmonary Surfactant-Associated Protein D
  • Osteopontin
  • Metalloproteases