Yonsei Med J.  2011 Mar;52(2):257-262. 10.3349/ymj.2011.52.2.257.

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

• Lee HJ
• Choe YH
• Lee JH
• Sohn YB
• Kim SJ
• Park SW
• Son JS
• Kim SW
• Jin DK

• KMID: 1779660
• DOI: http://doi.org/10.3349/ymj.2011.52.2.257

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.

Keyword

Prader-Willi syndrome; amylin; child; oral glucose challenge

MeSH Terms

Adolescent
Blood Glucose/analysis
Child
Female
Glucagon/blood
Glucose/*pharmacology
Glucose Tolerance Test
Humans
Insulin/blood
Islet Amyloid Polypeptide/*blood/physiology
Male
Obesity/blood/physiopathology
Prader-Willi Syndrome/blood/*physiopathology

Figure

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  Fig. 1 Changes in plasma insulin, amylin, glucose, and glucagon levels after the glucose challenge. Repeated-measures ANOVA showed a significant amylin × time interaction, indicating that changes in amylin over time were significantly different between the two study groups (*p = 0.0154). Amylin levels between 0 and 60 min after glucose loading were statistically different between the two groups (†p = 0.0076). PWS, Prader-Willi syndrome; ANOVA, anlysis of variance.

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  Fig. 2 No significant differences in the amylin/insulin molar ratio were observed between the study groups.

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  Fig. 3 Relationships between glucagon and amylin levels. Amylin levels at 60 min after glucose loading were found to be correlated with glucagon levels at 60 min in the children with Prader-Willi syndrome (r=0.6667, p = 0.0150).

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  Fig. 4 HOMA-IR had a positive correlation with fasting amylin levels in both study groups (PWS: r = 0.6966, p = 0.0065; control r = 0.7885, p = 0.0005). HOMA-IR, homeostasis model assessment for insulin resistance; PWS, Prader-Willi syndrome.

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