title: Plasma levels of platelet-derived microparticles in patients with obstructive sleep apnea syndrome.
abstract: OBJECTIVE
  Obstructive sleep apnea syndrome (OSAS) has been associated with high cardiovascular morbidity and mortality, and patients suffer from repeated episodes of hypoxia. Platelet-derived microparticles (PDMPs) are released via platelet activation by various agonists, including inflammatory cytokines or high shear stress. Plasminogen activator inhibitor -1 (PAI-1) is a fibrinolytic marker and soluble fibrin (SF) is a coagulation activation marker. We examined plasma levels of PDMPs, PAI-1 and SF in patients with OSAS. We also examined the effects of continuous positive airway pressure (CPAP) on plasma levels of PDMPs.
  
  
  METHODS
  Full polysomnography (PSG) monitoring was performed on 27 patients. The apneahypopnea index (AHI) of 5 events/h or less than 30 events/h indicated mild to moderate OSAS, and an AHI of 30 events/h or more indicated severe OSAS. Plasma levels of PDMPs were measured using an ELISA kit, and PAI and SF were determined by a latex immunoassay. In addition, the effects of CPAP treatment were studied in 7 patients.
  
  
  RESULTS
  The plasma level of PDMPs was significantly higher in patients with severe OSAS (15.8±10.4 U/mL) than normal controls (10.8±7.1 U/mL, p < 0.05) and patients with mild to moderate OSAS (9.2±3.5 U/mL, p < 0.05). The plasma levels of PDMPs correlated with the AHI (r = 0.39, p < 0.05). In addition, CPAP treatment decreased the plasma level of PDMPs (11.9±5.6 U/mL to 6.7±3.2 U/mL, p < 0.05).
  
  
  CONCLUSIONS
  Patients with OSAS might be at increased cardiovascular risk due to elevated PDMPs. Moreover a decrease in the plasma level of PDMPs by treatment with CPAP might reduce cardiovascular risk.
authors: Department of Clinical Laboratory Science, Kanazawa University Graduate School of Medical Science, Kanazawa, Ishikawa, Japan.
authors: Keiko
authors: K
authors: Maruyama
authors: Eriko
authors: E
authors: Morishita
authors: Akiko
authors: A
authors: Sekiya
authors: Mika
authors: M
authors: Omote
authors: Tadaaki
authors: T
authors: Kadono
authors: Hidesaku
authors: H
authors: Asakura
authors: Masami
authors: M
authors: Hashimoto
authors: Masako
authors: M
authors: Kobayashi
authors: Yasuto
authors: Y
authors: Nakatsumi
authors: Shigeo
authors: S
authors: Takada
authors: Shigeki
authors: S
authors: Ohtake
mesh_terms: D001792:Blood Platelets / Q000378:metabolism / Q000473:pathology*; D016022:Case-Control Studies; D055252:Cell-Derived Microparticles / Q000378:metabolism / Q000473:pathology*; D005260:Female; D005337:Fibrin / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D017395:Plasminogen Activator Inhibitor 1 / Q000097:blood; D015539:Platelet Activation; D017286:Polysomnography; D011379:Prognosis; D020181:Sleep Apnea, Obstructive / Q000097:blood / Q000175:diagnosis*
chemical_list: D017395:Plasminogen Activator Inhibitor 1; D005337:Fibrin