Ethanol ingestion inhibits human whole blood platelet impedance aggregation

The authors investigated the effect of ethanol on platelet impedance aggregation in whole blood (WB-PIA). Healthy moderate drinkers were given ethanol, 1 mL/kg body weight, to drink. Thirty minutes after ingestion of ethanol, WB-PIA was significantly inhibited when compared with baseline values. There was no significant inhibition when the same volunteers ingested water instead of ethanol. These observations suggest that WB-PIA is a sensitive technic for the detection of the effect of ethanol on platelets. These findings also support the view that blood ethanol levels achievable during social drinking impair platelet function, thus possibly accounting, at least in part, for the reported "protection" from ischemic heart disease in moderate drinkers. The sensitivity of human platelets to the inhibitory effect of ethanol suggests that continued drinking will adversely influence the incidence of initial bleeds and of rebleeding in gastrointestinal hemorrhage associated with alcoholism.