Delayed Response of Amylin Levels after an Oral Glucose Challenge in Children with Prader-Willi Syndrome

ABSTRACT

PURPOSE: Amylin secretion is increased parallel to insulin in obese subjects. Despite their marked obesity, a state of relative hypoinsulinemia occurs in children with Prader-Willi syndrome (PWS). Based on the hypothesis that amylin levels may be relatively low in PWS children, contributing to their excessive appetite, we studied amylin levels after oral glucose loading in children with PWS and overweight controls. MATERIALS AND METHODS: Plasma levels of amylin, glucagon, insulin, and glucose were measured at 0, 30, 60, 90, and 120 min after a glucose challenge in children with PWS (n = 18) and overweight controls (n = 25); the relationships among the variables were investigated in these two groups. RESULTS: Amylin levels were significantly correlated with insulin during fasting and during the oral glucose tolerance test in both groups. Amylin levels between 0 and 60 min after glucose loading were statistically different between the two groups. They were lower in children with PWS than in the controls between 0 and 30 min after glucose loading. CONCLUSION: The relatively low levels of amylin, compared to those in overweight controls, during the early phase of glucose loading in patients with PWS, may contribute, in part, to the excessive appetite of PWS patients as compared to the overweight controls.