title: Postprandial metabolism in adults with Prader-Willi syndrome.
abstract: Individuals with Prader-Willi syndrome (PWS) are commonly restricted to 60-75% of height-appropriate calorie intake because they rapidly become obese on a normal diet. This study measured changes in energy expenditure, glucose and lipid homeostasis, and metabolic flexibility in response to a meal in PWS adults.
  
  
  
  11 adults with PWS were compared with 12 adiposity-matched and 10 lean subjects. Indirect calorimetry was conducted at baseline and 210 min after a standardized 600 kCal breakfast to assess energy expenditure and substrate utilization. Circulating glucose, insulin, C-peptide, glucagon, nonesterified fatty acids, and triglycerides were measured up to 240 min. Insulin sensitivity and insulin secretion rate were assessed by HOMA-IR and C-peptide deconvolution, respectively. Body composition was determined by dual-energy X-ray absorptiometry.
  
  
  
  The PWS group had lower lean mass than the obesity control group. Corrected for lean mass, there were no differences between the PWS and obesity groups in resting metabolic rate or metabolic flexibility. Total and abdominal fat mass, insulin sensitivity, and insulin secretion rate were also similar between these groups.
  
  
  
  This study did not detect an intrinsic metabolic defect in individuals with PWS. Rather, lower lean mass, combined with lower physical activity, may contribute to weight gain on an apparent weight-maintenance diet.
authors.affiliation: Diabetes and Metabolism Division, Garvan Institute of Medical Research, Sydney, New South Wales, Australia. Correspondence: Louise Purtell (l.purtell@garvan.org.au)
authors.forename: Louise
authors.initials: L
authors.lastname: Purtell
authors.affiliation: Diabetes and Metabolism Division, Garvan Institute of Medical Research, Sydney, New South Wales, Australia. Correspondence: Louise Purtell (l.purtell@garvan.org.au)|Department of Endocrinology, St Vincent's Hospital Sydney, Sydney, New South Wales, Australia
authors.forename: Alexander
authors.initials: A
authors.lastname: Viardot
authors.affiliation: Division of Endocrinology and Diabetes, Kantonsspital St. Gallen, St. Gallen, Switzerland
authors.forename: Lisa
authors.initials: L
authors.lastname: Sze
authors.affiliation: Prader‐Willi Syndrome Clinic, Department for Metabolism and Obesity, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia
authors.forename: Georgina
authors.initials: G
authors.lastname: Loughnan
authors.affiliation: Prader‐Willi Syndrome Clinic, Department for Metabolism and Obesity, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia|Academic Department of Adolescent Medicine, University of Sydney, Sydney, New South Wales, Australia
authors.forename: Katharine
authors.initials: K
authors.lastname: Steinbeck
authors.affiliation: The Boden Institute of Obesity, Nutrition, Exercise and Eating Disorders, Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia
authors.forename: Amanda
authors.initials: A
authors.lastname: Sainsbury
authors.affiliation: Neuroscience Research Program, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
authors.forename: Herbert
authors.initials: H
authors.lastname: Herzog
authors.affiliation: Department of Cytogenetics, The Children's Hospital, Westmead Clinical School, Sydney, New South Wales, Australia
authors.forename: Arabella
authors.initials: A
authors.lastname: Smith
authors.affiliation: Diabetes and Metabolism Division, Garvan Institute of Medical Research, Sydney, New South Wales, Australia. Correspondence: Louise Purtell (l.purtell@garvan.org.au)|Department of Endocrinology, St Vincent's Hospital Sydney, Sydney, New South Wales, Australia
authors.forename: Lesley V
authors.initials: LV
authors.lastname: Campbell
mesh_terms: D015502:Absorptiometry, Photon; D050154:Adiposity; D000328:Adult; D001481:Basal Metabolism; D001823:Body Composition; D002096:C-Peptide / Q000378:metabolism; D004734:Energy Metabolism; D005260:Female; D005947:Glucose; D006801:Humans; D007328:Insulin / Q000378:metabolism; D007333:Insulin Resistance; D008297:Male; D009765:Obesity / Q000378:metabolism; D019518:Postprandial Period / Q000502:physiology*; D011218:Prader-Willi Syndrome / Q000378:metabolism*; D014280:Triglycerides
chemical_list: D002096:C-Peptide; D007328:Insulin; D014280:Triglycerides; D005947:Glucose