Inhibitory effect of alcohol on ghrelin secretion in normal man

Background: Human appetite is stimulated by alcohol but the underlying mechanism is unknown. It is possible that hunger-stimulating hormones are mediators of this effect of alcohol. Ghrelin stimulates hunger, but how alcohol affects human ghrelin secretion has never been studied before. Objective: To investigate whether alcohol ingestion exerts an acute influence on serum ghrelin concentrations in healthy subjects. Subjects and design: Eight healthy non-obese subjects participated in the study. All were investigated on two occasions (experiments A and 13). Alcohol (0.55 g ethanol/kg body weight) was ingested in experiment A, and drinking-water in experiment B. Venous blood was collected before, and 30 and 60 min after consumption of the drinks. Serum concentrations of ghrelin, cortisol and ethanol were determined and neuropeptide Y (NPY) concentrations were determined in plasma. Results: Alcohol lowered the ghrelin level by 13.9 +/- 5.0% at 30 min and by 17.5 +/- 2.6% at 60 min, in contrast to drinking-water which was without significant effect. Serum levels of cortisol and insulin were similar after alcohol and water as was plasma NPY. Conclusion: Alcohol has an acute inhibitory influence on human ghrelin secretion but no measurable effect on the secretion of NPY and cortisol. Hence, none of these hormones mediate the orexigenic effect of the drug.