title: Effect of continuous positive airway pressure treatment on elderly Chinese patients with obstructive sleep apnea in the prethrombotic state.
abstract: OBJECTIVE
  To characterize the prethrombotic state (PTS) in elderly Chinese patients with obstructive sleep apnea hypopnea syndrome (OSAHS) and the effect of nasal continuous positive airway pressure (nCPAP) ventilation on their PTS.
  
  
  METHODS
  Forty-one elderly patients with moderate and severe OSAHS were enrolled into the OSAHS group and underwent nCPAP treatment. Their blood samples were drawn at 6:00 am and 4:00 pm before and during nCPAP treatment, respectively, to test hemocrit, platelet aggregation (PAG), whole blood viscosity (WBV), plasma fibrinogen (fng), prothrombin time (PT) and activated partial thromboplastin time (APTT). All blood factors were also tested in a control group consisting of 32 healthy elderly Chinese with neither OSAHS nor cerebrocardiac vascular disease.
  
  
  RESULTS
  In the OSAHS group there was a significantly higher hemocrit, WBV, fng, and a significantly shorter PT and APTT at 6:00 am compared to 4:00 pm before nCPAP treatment, while there was no significant difference among all blood test factors between 6:00 am and 4:00 pm on day 30 of the nCPAP treatment. In the OSAHS group, the hemocrit, WBV, PAG and plasma fng were significantly lower and the PT and APTT were significantly longer at 6:00 am on day 30 of the nCPAP treatment compared to 6:00 am before the nCPAP treatment. A significantly lower hemocrit, but a much longer PT and APTT were observed at 4:00 pm on day 30 of the treatment, compared with 4:00 pm before the treatment. No significant difference among the blood test factors was found between 6:00 am and 4:00 pm blood in the control group or between the control and OSAHS groups after 30 days of nCPAP treatment.
  
  
  CONCLUSIONS
  In elderly Chinese OSAHS patients, PTS could be effectively eliminated by nCPAP treatment.
authors.affiliation: Department of Respiratory Medicine, First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China. zhangxil@jlonline.com
authors.forename: Xilong
authors.initials: X
authors.lastname: Zhang
authors.forename: Kaisheng
authors.initials: K
authors.lastname: Yin
authors.forename: Hong
authors.initials: H
authors.lastname: Wang
authors.forename: Mei
authors.initials: M
authors.lastname: Su
authors.forename: Yu
authors.initials: Y
authors.lastname: Yang
mesh_terms: D000368:Aged; D002561:Cerebrovascular Disorders / Q000517:prevention & control; D002681:China; D045422:Continuous Positive Airway Pressure; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020181:Sleep Apnea, Obstructive / Q000097:blood* / Q000628:therapy*