Ghrelin is gastric peptide with appetite stimulating and growth hormone (GH) releasing properties. Circulating ghrelin levels decrease after nutrient ingestion, oral and iv glucose challenge. It has been hypothesized that vagal system may have a major role in initiating this decrease.
The aim of this study was to investigate circulating ghrelin levels during oral glucose challenge in gastrectomized (GASTRX)- vagotomized patients. The study was approved by the local ethics committee.
In six GASTRX- vagotomized patients and eleven healthy age and sex matched subjects standard (75 g) oral glucose tolerance test (OGTT) was performed. Glycemia, insulin, GH and ghrelin levels were determined at baseline and every 30 min for two hours.
Serum ghrelin levels at baseline were reduced by 55% in GASTRX-vagotomized patients compared to the control group, P<0.01. OGTT induced significant reduction in serum ghrelin levels in healthy but not in GASTRX-vagotomized subjects (Δghrelin 214.2±44.0 vs 19.5±11.8 pg/ml). Significantly higher increase in blood glucose (Δglycemia 9.2±1.3 mmol/l vs 2.8±0.8 mmol/l, P<0.01) and serum insulin levels (Δinsulin 75.0±15.6 mU/l vs 30.6±5.7 mU/l, P<0.01) were observed in GASTRX-vagotomized patients compared to healthy controls during OGTT. GH response to OGTT in GASTRX-vagotomized patients was not different from the control group.
In conclusion, circulating ghrelin levels in GASTRX-vagotomized patients do not decline after oral glucose administration supporting the hypothesis that in human subjects post glucose fall in ghrelin levels may be vagally mediated.
01 - 05 Apr 2006
European Society of Endocrinology