Plasma levels of platelet-derived microparticles in patients with obstructive sleep apnea syndrome

Aim: 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. result: 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,plt;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.