Submitted on March 5, 2008
Accepted on June 8, 2008
Effect of small intestinal glucose load on plasma ghrelin in healthy men
Kimberly Cukier1, Amelia N Pilichiewicz2, Reawika Chaikomin2, Ixchel M Brennan2, Judith M. Wishart3, Christopher K Rayner2, Karen L. Jones4, Michael Horowitz5, and Christine Feinle-Bisset6*
1 Endocrinology, Royal Adelaide Hospital, Adelaide, South Australia, Australia
2 Medicine, University of Adelaide, Royal Adelaide Hospital, Adelaide, South Australia, Australia
3 United States; Medicine, University of Adelaide, Royal Adelaide Hospital, Adelaide, South Australia, Australia
4 Department of Medicine, University of Adelaide, Adelaide, Australia
5 Department of Medicine, University of Adelaide, Adelaide, South Australia, Australia
6 Medicine, Royal Adelaide Hospital, Adelaide, South Australia, Australia
* To whom correspondence should be addressed. E-mail: christine.feinle{at}adelaide.edu.au.
Background: Postprandial ghrelin suppression arises from the interaction of meal contents with the small intestine and may relate to elevations in blood glucose and/or plasma insulin.
Objective: To determine whether the suppression of ghrelin by small intestinal glucose is dependent on the glucose load and can be accounted for by changes in blood glucose and/or plasma insulin.
Subjects and methods: Blood glucose, plasma insulin and plasma ghrelin levels were measured in ten healthy males (age: 32 ± 4 yr; body mass index: 25.1 ± 0.4 kg/m2) during intraduodenal glucose infusions at 1 kcal/min ("G1"), 2 kcal/min ("G2") and 4 kcal/min ("G4") and intraduodenal hypertonic saline ("control") for 120 min.
Results: There was a progressive decrease in ghrelin with all treatments, control at 45 min and between 90 - 120 min (P < 0.05) and G1 (P < 0.05), G2 (P < 0.0001) and G4 (P < 0.0001) between 30 - 120 min to reach a plateau at ~ 90 min. There was no difference in plasma ghrelin between G1, G2 or G4. Control suppressed ghrelin to a lesser extent than intraduodenal glucose (P < 0.05). The suppression of ghrelin was not related to rises in blood glucose or plasma insulin.
Conclusion: Suppression of ghrelin by intraduodenal glucose in healthy males is apparently independent of the glucose load and unrelated to blood glucose or insulin levels.
