The effect of acute ingestion of a large dose of alcohol on the hemostaticsystem and its circadian variation

Background and Purpose-Heavy binge drinking may trigger the onset of emboli c stroke and acute myocardial infarction, but the underlying mechanisms are unclear. The effects of binge drinking on the hemostatic system and its ci rcadian variation have not been investigated. We investigated the effects o f an acute intake of a large dose of alcohol (1.5 g/kg), Methods-Twelve healthy, nonsmoking men participated in sessions where they were served ethanol in fruit juice or served fruit juice alone and, lying i n a supine position, were followed up for 12 to 24 hours. The treatments we re randomized and separated from each other by a 1-week washout period. Blo od and urine were collected for hemostatic measurements. Results-The urinary excretion of the platelet thromboxane A, metabolite 2,3 -dinor-thromboxane B-2 was significantly (P<0.05) greater during the night after an evening intake of alcohol than during the control night. A smaller increase was observed during the daytime after an intake of alcohol in the morning. The effects on the endothelial prostacyclin metabolite 2,3-dinor- 6-ketoprostaglandin F-1 alpha excretion were negligible. A 7-fold increase in plasminogen activator inhibitor 1 activity was observed after both morni ng (P<0.05) and evening (P<0.01) intakes of alcohol. Conclusions-This is the first study to suggest that acute ingestion of a re latively large but tolerable dose of alcohol transiently enhances thromboxa ne-mediated platelet activation. The observations also demonstrate alcohol- induced changes in the normal circadian periodicity of the hemostatic syste m in subjects not accustomed to consumption of alcohol.