title: CPAP reduces hypercoagulability, as assessed by thromboelastography, in severe obstructive sleep apnoea.
abstract: Obstructive sleep apnoea (OSA) is associated with increased cardiovascular morbidity and mortality and hypercoagulability may be an underlying factor. We tested the hypotheses that patients with severe OSA are hypercoagulable and that two weeks of continuous positive airway pressure (CPAP) treatment reduces this hypercoagulability. In a prospective crossover study, twelve patients were randomized to either CPAP or no-CPAP for two weeks, a one week washout period, and then the other testing period for two weeks. Thromboelastography was used to assess coagulability at the start and end of each period and the apnoea-hypopnea indices (AHI) were measured at the end of each period. At baseline, ten patients had, compared to reference values, shorter clotting times, six increased rate of clot formation, twelve increased clot strength, and ten increased clotting indices. CPAP significantly reduced AHI (p=0.0003), clot strength (p=0.019) and clotting index (p=0.014). Hypercoagulability in patients with OSA can be detected by thromboelastography, and is reduced by CPAP.
authors: Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada.
authors: Mazen
authors: M
authors: Toukh
authors: Effie J
authors: EJ
authors: Pereira
authors: Bani J
authors: BJ
authors: Falcon
authors: Christina
authors: C
authors: Liak
authors: Marina
authors: M
authors: Lerner
authors: Wilma M
authors: WM
authors: Hopman
authors: Steve
authors: S
authors: Iscoe
authors: Michael F
authors: MF
authors: Fitzpatrick
authors: Maha
authors: M
authors: Othman
mesh_terms: D000328:Adult; D045422:Continuous Positive Airway Pressure / Q000379:methods*; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D013916:Thrombelastography / Q000379:methods*; D019851:Thrombophilia / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D016896:Treatment Outcome