Reactive hypoglycaemia following GLP-1 infusion in pancreas transplant recipients

The aim of the study was to determine whether reactive hypoglycaemia in pancreas transplant recipients that followed administration of glucagon-like peptide-1 (GLP-1) was associated with excessive insulin, insufficient glucagon, or both. Methodology involved six portally drained pancreas recipients who received GLP-1 (1.5 pmol/kg/min) or placebo infusion on randomized occasions during glucose-potentiated arginine testing. The second subject developed symptomatic hypoglycaemia [plasma glucose (PG) 42 mg/dl] 1 h after GLP-1 administration; subsequent subjects received intravenous glucose following GLP-1, but not placebo, infusion for PG levels < 65 mg/dl. Following GLP-1 vs. placebo infusion, PG was lower (58 +/- 4 vs. 76 +/- 5 mg/dl; p < 0.05) despite administration of intravenous glucose. During hypoglycaemia, insulin levels and the insulin-to-glucagon ratio were greater after GLP-1 vs. placebo infusion (p < 0.05), while glucagon did not vary. It can be concluded from the study that GLP-1 can induce reactive hypoglycaemia in pancreas transplant recipients through excessive insulin secretion associated with an increased insulin-to-glucagon ratio.