Short-term isocapnic hypoxia and coagulation activation in patients with sleep apnea

Clin Hemorheol Microcirc. 2005;33(4):369-77.


Hemostatic changes might contribute to the increased risk of cardiovascular and cerebrovascular events in patients with obstructive sleep apnea (OSA). We investigated the effect of a short-term isocapnic hypoxic challenge on coagulation activation markers thrombin/antithrombin III complexes (TAT) and D-dimer in OSA. Thirty-two OSA patients (mean age 48 +/- 11 years) inhaled a gas mixture containing 10% O(2) and 90% N(2) and further adjusted to yield pulse oximetry saturation of 80-85% for 5 minutes. Plasma levels of TAT and D-dimer were measured immediately before and immediately after the hypoxic challenge. The hypoxic challenge provoked a significant increase in TAT (p < 0.001) and in D-dimer (p = 0.037). Mean nocturnal oxygen saturation from the sleep recordings correlated with D-dimer increase (r = -0.37, p = 0.041). Also, OSA patients with a history of hypertensive parents had greater D-dimer increase in response to hypoxia than patients having normotensive parents (p = 0.035). Parental hypertension independently explained 15% of the variance in D-dimer increase after hypoxia (p = 0.035). Oxygen desaturation during sleep may predispose OSA patients, in particular those with a parental history of hypertension, to a hypercoagulable state providing one explanation for the increased risk of atherothrombotic events in this population.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Blood Coagulation Factors / analysis*
  • Cardiovascular Diseases / blood
  • Cardiovascular Diseases / etiology
  • Female
  • Humans
  • Hypertension / blood
  • Hypoxia / blood*
  • Hypoxia / complications
  • Male
  • Middle Aged
  • Risk Factors
  • Sleep Apnea, Obstructive / blood*
  • Sleep Apnea, Obstructive / complications
  • Stroke / blood
  • Stroke / etiology


  • Blood Coagulation Factors