title: Short-term isocapnic hypoxia and coagulation activation in patients with sleep apnea.
abstract: 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.
authors.affiliation: Department of General Internal Medicine, University Hospital Berne, Switzerland.
authors.forename: Roland
authors.initials: R
authors.lastname: von Känel
authors.forename: José S
authors.initials: JS
authors.lastname: Loredo
authors.forename: Frank L
authors.initials: FL
authors.lastname: Powell
authors.forename: Karen A
authors.initials: KA
authors.lastname: Adler
authors.forename: Joel E
authors.initials: JE
authors.lastname: Dimsdale
mesh_terms: D000328:Adult; D001779:Blood Coagulation Factors / Q000032:analysis*; D002318:Cardiovascular Diseases / Q000097:blood / Q000209:etiology; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood; D000860:Hypoxia / Q000097:blood* / Q000150:complications; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D020181:Sleep Apnea, Obstructive / Q000097:blood* / Q000150:complications; D020521:Stroke / Q000097:blood / Q000209:etiology
chemical_list: D001779:Blood Coagulation Factors