Potentiation of the Plasma Insulin Response to Glucose by Prior Administration of Alcohol: An Apparent Islet-Priming Effect

Abstract

Ethyl alcohol which has been reported to be without effect on insulin secretion apparently modifies beta-cell function nevertheless, as indicated by the plasma insulin responses to glucose loading after prior administration of alcohol. Glucose was injected intravenously in nine young adults on three separate occasions at intervals of at least two weeks. During the twelve hours preceding each test the subjects received ethanol either by mouth or by vein or, as a control, no ethanol. Plasma insulin and glucose concentrations were not noticeably affected by the ethanol alone but alcohol pretreatment was followed in all instances by heightened plasma insulin responses to the glycemic pulse stimulus and by accelerated rates of plasma glucose disappearance. The mean plasma insulin response was increased 50 per cent by the alcohol, irrespective of the route of administration. Unlike recognized insulin secretogogues, therefore, ethanol appears to augment insulin secretion only on demand. The route of administration appeared not to be a factor in determining the magnitude of the alcohol effect. Other alcohol effects included blunting of the plasma pyruvate and exaggeration of the plasma lactate elevations after glucose.