The effects of glucose-dependent insulinotropic polypeptide on net splanchnic blood flow in lean humans

Abstract Objective The aim of this study was to examine the effects of glucose-dependent insulinotropic polypeptide (GIP) on splanchnic blood flow, both independently and in combination with hyperglycemia and hyperinsulinemia. Design and Methods In a randomized, placebo-controlled, crossover trial, eight healthy, lean male participants underwent four separate experimental conditions. Splanchnic blood flow was measured by Fick’s Principle after catheterization of a hepatic vein, using indocyanine green as indicator. The interventions included intravenous infusions of either GIP at a rate of 1.5 pmol/kg/min or saline, administered alone or in combination with a hyperglycemia and hyperinsulinemia clamp, respectively. Results Splanchnic blood flow remained comparable across all experimental conditions, including GIP and saline infusions, both with and without the hyperglycemic and hyperinsulinemic clamp (P=0.42). Conclusion Under the applied conditions, GIP does not appear to play a substantial role in the acute regulation of net splanchnic blood flow, either alone or in combination with induced hyperglycemia and hyperinsulinemia.