Significant relationship between platelet activation and apnea-hypopnea index in patients with obstructive sleep apnea syndrome.

Obstructive sleep apnea syndrome (OSAS) is an independent risk factor for arterial thrombosis, which is associated with high cardiovascular morbidity and mortality. To investigate the possible involvement of activated platelets, we evaluated the relationship between severity of OSAS and appearance of platelet aggregates (a marker of activated platelets) in 35 OSAS patients. Platelet aggregates were quantitatively determined by means of flow cytometry. There was a significant correlation between platelet aggregates and apnea-hypopnea index in the severe (AHI≥30 events/hour) group (r=0.756, p<0.001), but not in the mild-moderate (5≤AHI<30 events/hour) group (r=-0.032, p=0.905). The results indicate that the appearance of platelet aggregates increases with an increase in the severity of OSAS.