Endothelial function in obstructive sleep apnea and response to treatment

Am J Respir Crit Care Med. 2004 Feb 1;169(3):348-53. doi: 10.1164/rccm.200306-767OC. Epub 2003 Oct 9.


Impaired endothelium-dependent vascular relaxation is a prognostic marker of atherosclerosis and cardiovascular disease. We evaluated endothelium-dependent flow-mediated dilation (FMD) and endothelium-independent nitroglycerin (NTG)-induced dilation of the brachial artery with Doppler ultrasound in 28 men with obstructive sleep apnea (OSA) and 12 men without OSA. Subjects with OSA (apnea-hypopnea index; mean +/- SD, 46.0 +/- 14.5) had lower FMD compared with subjects without OSA (5.3 +/- 1.7% vs. 8.3 +/- 1.0%, p < 0.001), and major determinants of FMD were the apnea-hypopnea index and age. There was no significant difference in NTG-induced dilation. Subjects with OSA were randomized to nasal continuous positive airway pressure (nCPAP) or observation for 4 weeks. Subjects on nCPAP had significant increase in FMD, whereas those on observation had no change (4.4% vs. -0.8%, difference of 5.2%, p < 0.001). Neither group showed significant change in NTG-induced vasodilation. Eight subjects who used nCPAP for over 3 months were reassessed on withdrawing treatment for 1 week. On nCPAP withdrawal, FMD became lower than during treatment (p = 0.02) and were similar to baseline values. Our findings demonstrated that men with moderate/severe OSA have endothelial dysfunction and treatment with nCPAP could reverse the dysfunction; the effect, however, was dependent on ongoing use.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Blood Pressure Determination
  • Echocardiography, Doppler
  • Endothelium, Vascular / physiopathology*
  • Humans
  • Laryngeal Masks
  • Linear Models
  • Male
  • Middle Aged
  • Multivariate Analysis
  • Polysomnography
  • Positive-Pressure Respiration*
  • Probability
  • Reference Values
  • Sensitivity and Specificity
  • Severity of Illness Index
  • Sleep Apnea, Obstructive / diagnosis*
  • Sleep Apnea, Obstructive / therapy*
  • Treatment Outcome
  • Vascular Resistance / physiology*
  • Vasoconstriction / physiology
  • Vasodilation / physiology