Ghrelin is a novel gastric hormone that serves as a hunger signal and a putative growth hormone (GH) secretagogue in humans. In normal humans, ghrelin concentrations are inhibited by food intake, but the effect of specific nutrients on ghrelin dynamics has not been well studied. Conversely, ethanol has been reported to inhibit GH secretion through unknown mechanisms. We hypothesized that GH suppression by ethanol would be correlated to ghrelin suppression in both nondiabetic and T2DM subjects. Six subjects with T2DM (age = 56 ± 4 y, duration = 12 ± 7 y, HbA1C = 7.8 ± 1.7%, BMI = 28.1 ± 5.4 kg/m2) and nine nondiabetic subjects (age = 63 ± 6 y, HbA1C = 5.0 ± 0.2%, BMI = 26.5 ± 4.2 kg/m2) were admitted to the GCRC for two separate 24-hour studies. Glycemia was stabilized with a continuous infusion of IV insulin prior to study. At 2200, subjects ingested doses of either 95% ethanol in sugar-free punch or sugar-free punch alone (placebo) to achieve blood alcohol concentrations of 0.10% (mild intoxication) by midnight during the ethanol arm of the study. During sleep, glucose, insulin, and hormone concentrations were obtained at baseline and every 30 to 60 minutes between midnight and 0800. Results are shown below.
These data demonstrate that low-dose oral ethanol prior to sleep suppresses endogenous ghrelin in both nondiabetic and insulin-requiring T2DM subjects. Moreover, the doses of oral ethanol used in this study did not affect overnight GH concentrations. Ghrelin is unlikely to mediate the suppressive effect of ethanol on GH.