title: Macronutrient Regulation of Ghrelin and Peptide YY in Pediatric Obesity and Prader-Willi Syndrome.
abstract: BACKGROUND
  The roles of macronutrients and GH in the regulation of food intake in pediatric obesity and Prader-Willi Syndrome (PWS) are poorly understood.
  
  
  OBJECTIVE
  We compared effects of high-carbohydrate (HC) and high-fat (HF) meals and GH therapy on ghrelin, insulin, peptide YY (PYY), and insulin sensitivity in children with PWS and body mass index (BMI) -matched obese controls (OCs).
  
  
  METHODS
  In a randomized, crossover study, 14 PWS (median, 11.35 y; BMI z score [BMI-z], 2.15) and 14 OCs (median, 11.97 y; BMI-z, 2.35) received isocaloric breakfast meals (HC or HF) on separate days. Blood samples were drawn at baseline and every 30 minutes for 4 hours. Mixed linear models were adjusted for age, sex, and BMI-z.
  
  
  RESULTS
  Relative to OCs, children with PWS had lower fasting insulin and higher fasting ghrelin and ghrelin/PYY. Ghrelin levels were higher in PWS across all postprandial time points (P < .0001). Carbohydrate was more potent than fat in suppressing ghrelin levels in PWS (P = .028); HC and HF were equipotent in OCs but less potent than in PWS (P = .011). The increase in PYY following HF was attenuated in PWS (P = .037); thus, postprandial ghrelin/PYY remained higher throughout. A lesser increase in insulin and lesser decrease in ghrelin were observed in GH-treated PWS patients than in untreated patients; PYY responses were comparable.
  
  
  CONCLUSIONS
  Children with PWS have fasting and postprandial hyperghrelinemia and an attenuated PYY response to fat, yielding a high ghrelin/PYY ratio. GH therapy in PWS is associated with increased insulin sensitivity and lesser postprandial suppression of ghrelin. The ratio Ghrelin/PYY may be a novel marker of orexigenic drive.
authors.affiliation: Division of Pediatric Endocrinology and Diabetes (P.G.B., M.F.), Duke University Medical Center, Durham, North Carolina 27710; Advanced Analytics (M.B.), SAS Institute Inc., Cary, North Carolina 27513; Duke Molecular Physiology Institute (M.J.M., M.F.), Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, North Carolina 27710; Knight Cardiovascular Institute (J.Q.P.), Oregon Health & Science University, Portland, Oregon 97239; and Department of Medicine (D.B.) and Division of Pediatric Endocrinology and Diabetes (A.M.H.), University of Alberta, Edmonton, AB T6G 2R3 Canada.
authors.forename: Pinar
authors.initials: P
authors.lastname: Gumus Balikcioglu
authors.affiliation: Division of Pediatric Endocrinology and Diabetes (P.G.B., M.F.), Duke University Medical Center, Durham, North Carolina 27710; Advanced Analytics (M.B.), SAS Institute Inc., Cary, North Carolina 27513; Duke Molecular Physiology Institute (M.J.M., M.F.), Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, North Carolina 27710; Knight Cardiovascular Institute (J.Q.P.), Oregon Health & Science University, Portland, Oregon 97239; and Department of Medicine (D.B.) and Division of Pediatric Endocrinology and Diabetes (A.M.H.), University of Alberta, Edmonton, AB T6G 2R3 Canada.
authors.forename: Metin
authors.initials: M
authors.lastname: Balikcioglu
authors.affiliation: Division of Pediatric Endocrinology and Diabetes (P.G.B., M.F.), Duke University Medical Center, Durham, North Carolina 27710; Advanced Analytics (M.B.), SAS Institute Inc., Cary, North Carolina 27513; Duke Molecular Physiology Institute (M.J.M., M.F.), Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, North Carolina 27710; Knight Cardiovascular Institute (J.Q.P.), Oregon Health & Science University, Portland, Oregon 97239; and Department of Medicine (D.B.) and Division of Pediatric Endocrinology and Diabetes (A.M.H.), University of Alberta, Edmonton, AB T6G 2R3 Canada.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Muehlbauer
authors.affiliation: Division of Pediatric Endocrinology and Diabetes (P.G.B., M.F.), Duke University Medical Center, Durham, North Carolina 27710; Advanced Analytics (M.B.), SAS Institute Inc., Cary, North Carolina 27513; Duke Molecular Physiology Institute (M.J.M., M.F.), Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, North Carolina 27710; Knight Cardiovascular Institute (J.Q.P.), Oregon Health & Science University, Portland, Oregon 97239; and Department of Medicine (D.B.) and Division of Pediatric Endocrinology and Diabetes (A.M.H.), University of Alberta, Edmonton, AB T6G 2R3 Canada.
authors.forename: Jonathan Q
authors.initials: JQ
authors.lastname: Purnell
authors.affiliation: Division of Pediatric Endocrinology and Diabetes (P.G.B., M.F.), Duke University Medical Center, Durham, North Carolina 27710; Advanced Analytics (M.B.), SAS Institute Inc., Cary, North Carolina 27513; Duke Molecular Physiology Institute (M.J.M., M.F.), Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, North Carolina 27710; Knight Cardiovascular Institute (J.Q.P.), Oregon Health & Science University, Portland, Oregon 97239; and Department of Medicine (D.B.) and Division of Pediatric Endocrinology and Diabetes (A.M.H.), University of Alberta, Edmonton, AB T6G 2R3 Canada.
authors.forename: David
authors.initials: D
authors.lastname: Broadhurst
authors.affiliation: Division of Pediatric Endocrinology and Diabetes (P.G.B., M.F.), Duke University Medical Center, Durham, North Carolina 27710; Advanced Analytics (M.B.), SAS Institute Inc., Cary, North Carolina 27513; Duke Molecular Physiology Institute (M.J.M., M.F.), Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, North Carolina 27710; Knight Cardiovascular Institute (J.Q.P.), Oregon Health & Science University, Portland, Oregon 97239; and Department of Medicine (D.B.) and Division of Pediatric Endocrinology and Diabetes (A.M.H.), University of Alberta, Edmonton, AB T6G 2R3 Canada.
authors.forename: Michael
authors.initials: M
authors.lastname: Freemark
authors.affiliation: Division of Pediatric Endocrinology and Diabetes (P.G.B., M.F.), Duke University Medical Center, Durham, North Carolina 27710; Advanced Analytics (M.B.), SAS Institute Inc., Cary, North Carolina 27513; Duke Molecular Physiology Institute (M.J.M., M.F.), Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, North Carolina 27710; Knight Cardiovascular Institute (J.Q.P.), Oregon Health & Science University, Portland, Oregon 97239; and Department of Medicine (D.B.) and Division of Pediatric Endocrinology and Diabetes (A.M.H.), University of Alberta, Edmonton, AB T6G 2R3 Canada.
authors.forename: Andrea M
authors.initials: AM
authors.lastname: Haqq
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D018592:Cross-Over Studies; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D004041:Dietary Fats / Q000008:administration & dosage*; D005260:Female; D054439:Ghrelin / Q000097:blood*; D019382:Human Growth Hormone / Q000627:therapeutic use; D006801:Humans; D008297:Male; D063766:Pediatric Obesity / Q000097:blood*; D019894:Peptide YY / Q000097:blood*; D019518:Postprandial Period; D011218:Prader-Willi Syndrome / Q000097:blood* / Q000188:drug therapy
chemical_list: D004040:Dietary Carbohydrates; D004041:Dietary Fats; D054439:Ghrelin; D019894:Peptide YY; D019382:Human Growth Hormone