Research Publications Archive - Foundation for Prader-Willi Research

Macronutrient regulation of Ghrelin and Peptide YY in Pediatric Obesity and Prader Willi Syndrome (PWS)

Written by jessicab | Aug 18, 2015 4:25:50 PM

Abstract

BACKGROUND:

The roles of macronutrients and GH in the regulation of food intake in pediatric obesity and PWS are poorly understood.

OBJECTIVE:

We compared effects of high carbohydrate (HC) and high fat (HF) meals and GH therapy on ghrelin, insulin, PYY, and insulin sensitivity in children with PWS and BMI-matched obese controls (OC).

METHODS:

In a randomized, cross-over study, 14 PWS (median 11.35 yr; BMI-z 2.15) and 14 OC (median 11.97 yr; BMI-z 2.35) received iso-caloric breakfast meals (HC or HF) on separate days. Blood samples were drawn at baseline and q30 min for 4 hr. Mixed linear models were adjusted for age, sex, and BMI-z.

RESULTS:

Relative to OC, PWS children had lower fasting insulin and higher fasting ghrelin and ghrelin/PYY. Ghrelin levels were higher in PWSacross all postprandial time points (p<0.0001). Carbohydrate was more potent than fat in suppressing ghrelin levels in PWS (p=0.028); HC and HF were equipotent in OC but less potent than in PWS (p=0.011). The rise in PYY following HF was attenuated in PWS (p=0.037); thus postprandialghrelin/PYY remained higher throughout. A lesser rise in insulin and lesser fall in ghrelin were observed in GH-treated PWS patients than in untreated patients; PYY responses were comparable.

CONCLUSION:

Children with PWS have fasting and postprandial hyperghrelinemia and an attenuated PYY response to fat, yielding a highghrelin/PYY ratio. GH therapy in PWS is associated with increased insulin sensitivity and lesser postprandial suppression of ghrelin. The ratioGhrelin/PYY may be a novel marker of orexigenic drive.

PMID: 26259133 [PubMed - as supplied by publisher]