Platelet function in patients with obstructive sleep apnoea syndrome

Patients with obstructive sleep apnoea syndrome (OSAS) are subject to an increased cardiovascular morbidity including myocardial infarction and stroke. Platelets play an important role in the pathogenesis and triggering of acute cardiovascular syndromes. So far, the influence of OSAS on platelet function is not fully understood. Platelet aggregability to epinephrine, collagen, arachidonic acid, and adenosine diphosphate in vitro was measured in 17 consecutive male patients (53.0±2.1 yrs) with polysomnographically verified OSAS and compared with that of 15 male controls (50.1±3.6 yrs) at 20:00 h, 24:00 h, and 06:00 h. In addition, the long‐term effects of continuous positive airway pressure (CPAP) therapy on platelet aggregability was assessed after 6 months. Platelet aggregation in vitro induced by epinephrine showed a slight increase overnight in the untreated OSAS patients ( ns) whereas it decreased slightly ( ns) in the controls and in the treated OSAS patients. Pretherapeutic platelet aggregability was significantly lowered by CPAP therapy both at 24:00 h (64.0±6.5 versus 55.3±6.7%, p