It has been proposed that the rapid gastric emptying of carbohydrate containing fluids into the intestine causes hyperglycemia followed by reactive hypoglycemia. The investigators have shown that glucagon-like peptide-1 (GLP-1) secretion in response to a glucose load is increased in children with Post-prandial hypoglycemia (PPH). This is a proof of concept study to investigate the causative role of GLP-1 in the pathophysiology of PPH after fundoplication by evaluating the effects of GLP-1 receptor antagonism on metabolic variables after a mixed meal. Hypothesis: In children with post-prandial hypoglycemia after fundoplication, antagonism of the GLP-1 receptor by exendin-(9-39) will elevate nadir blood glucose levels after a meal challenge and prevent post-prandial hypoglycemia.
PPH is a frequent complication of fundoplication in children. The mechanism responsible for the PPH is poorly understood, but involves an exaggerated insulin response to a meal and subsequent hypoglycemia. We have shown that children with PPH after Nissen fundoplication have abnormally exaggerated secretion of GLP-1, an incretin hormone with multiple glucose lowering effects including stimulation of insulin secretion and suppression of glucagon secretion. In this study we seek to examine the causal role of endogenous GLP-1 in PPH after fundoplication by evaluating the effects of antagonizing the GLP-1 receptor with exendin-(9-39) on key metabolic features of PPH.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
OTHER
Masking
NONE
Enrollment
7
IV infusion of exendin-(9-39) for 5 hours
Normal saline (vehicle) infusion for 5 hours at 0.06 mL/kg/hr
The Children's Hospital of Philadelphia
Philadelphia, Pennsylvania, United States
Mean Plasma Glucose Area Under the Curve (AUC 0-3h)
To examine the effect of Exendin-(9-39) on plasma glucose levels samples were collected at various time points before and during the infusion \[Exendin-(9-39) or vehicle\] including: 60 minutes before the start of the infusion, again at the start of the infusion (time 0), and then every 30 minutes until 3 hours after the start of the meal. Using this information, the mean plasma glucose area under the curve (AUC) from the start of the infusion to the end of the infusion (3 hours) was calculated for both doses of Exendin-(9-39) \[300pmol/kg/min \& 500pmol/kg/min\] and compared with the vehicle.
Time frame: 3 hours
Mean Plasma Insulin Area Under the Curve (AUC 0-3h)
To examine the effect of Exendin-(9-39) on plasma insulin levels, samples were collected at various time points before and during the infusion \[Exendin-(9-39) or vehicle\] including: 60 minutes before the start of the infusion, again at the start of the infusion (time 0), and then every 30 minutes until 3 hours after the start of the meal. Using this information, the mean plasma insulin area under the curve (AUC) from the start of the infusion to the end of the infusion (3 hours) was calculated for both doses of Exendin-(9-39) \[300pmol/kg/min \& 500pmol/kg/min\] and compared with the vehicle.
Time frame: 3 hours
Mean Acetaminophen Plasma Concentration Area Under the Curve (AUC 0-3h)
The effect of gastric emptying was examined using the acetaminophen method whereby acetaminophen (30mg/kg or maximum of 1500mg) was mixed into the Pediasure/formula during the meal tolerance testing. Blood samples were collected every 30 minutes and the absorption of acetaminophen was determined by the gastric emptying rate, as the serum concentrations correlate with gastric emptying of liquids. Mean acetaminophen levels for each group at each time point were used to calculate the Area Under the Concentration versus Time Curve (AUC expressed in μg\*min/l) after the consumption of formula for each of the two Exendin-(9-39) dose levels and normal saline vehicle.
Time frame: 3 hours
Peak Plasma Glucagon-like Peptide-1 (GLP-1) Concentration During Infusion
To examine the effect of Exendin-(9-39) on plasma glucagon-like peptide-1 levels, samples were collected at various time points before and during the infusion \[Exendin-(9-39) or vehicle\] including: 60 minutes before the start of the infusion, again at the start of the infusion (time 0), and then every 30 minutes until 3 hours after the start of the infusion. The mean peak glucagon-like peptide-1 concentration for both Exendin-(9-39) doses were compared with the peak glucagon-like peptide-1 during vehicle infusion.
Time frame: 60 minutes before the start of the infusion, again at the start of the infusion (time 0), and then every 30 minutes until 3 hours after the start of the infusion
Peak Glucagon Concentration During Infusion
To examine the effect of Exendin-(9-39) on plasma glucagon levels, samples were collected at various 3 hours after the start of the infusion. The mean peak glucagon concentration for both Exendin-(9-39) doses were compared with the peak glucagon during vehicle infusion.
Time frame: 60 minutes before the start of the infusion, again at the start of the infusion (time 0), and then every 30 minutes until 3 hours after the start of the infusion
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.