Conditions: Congenital Hyperinsulinism
Keywords: hyperinsulinism hypoglycemia KATP channel Kir6.2
Allocation: RANDOMIZED | Intervention model: CROSSOVER
Enrollment: 9
Healthy volunteers: no

Brief summary:
The purpose of this study is to determine if Exendin-(9-39), an antagonist of the glucagon-like peptide-1 (GLP-1) receptor with effects on the pancreatic beta cell, increases fasting blood glucose levels in subjects with congenital hyperinsulinism.

Detailed description:
This is an open-label, pilot study , to determine if Exendin-(9-39), an antagonist of the glucagon-like peptide-1 (GLP-1) receptor with effects on the pancreatic beta cells, increases fasting blood glucose levels in subjects with congenital hyperinsulinism. Our overall hypothesis is that abnormal GLP-1 secretion resulting from dysfunctional nutrient sensing in intestinal L-cells plays a role in the dysregulated insulin secretion characteristic of this disorder, and that antagonism of the GLP-1 receptor will increase fasting blood glucose levels.

Aim 1. To evaluate the dose of exendin-(9-39) required to elevate fasting blood glucose levels in subjects with congenital hyperinsulinism due to KATP channel mutations.

Aim 2. To determine therapeutic plasma levels, plasma half-life and pharmacokinetics of exendin-(9-39) during an intravenous short-term infusion in subjects with congenital hyperinsulinism due to Adenosine triphosphate (ATP)-sensitive potassium channel (KATP) mutations.

Arms:
arm 1: Exendin-(9-39) will be administered intravenously (IV) after an overnight fast. Exendin-(9-39) will be infused over 6 hours with the dose slowly escalating from 100pmol/kg/min for 2 hours, then 300pmol/kg/min for another 2 hours followed by 500pmol/kg/min for the last 2 hours of the infusion. The following day, after another overnight fast, normal saline (control) vehicle infusion will be administered intravenously (IV) over 6 hours. During both infusions, blood glucose levels will be measured every 20 minutes. arm 2: Normal saline vehicle infusion will be administered intravenously (IV) after an overnight fast. The infusion will be given over 6 hours. The following day, after another overnight fast, Exendin-(9-39) will be infused over 6 hours with the dose slowly escalating from 100pmol/kg/min for 2 hours, then 300pmol/kg/min for another 2 hours followed by 500pmol/kg/min for the last 2 hours of the infusion. During both infusions, blood glucose levels will be measured every 20 minutes.

Interventions: intervention 1: Exendin-(9-39) intervention 2: Vehicle
Intervention descriptions: intervention 1: A short term intravenous infusion of the study drug, exendin-(9-39), will be given over 6 hours. intervention 2: A short term intravenous infusion of normal saline, or the vehicle, will be given over 6 hours.

Protocol document: