title: Modulation of amino acid metabolic signatures by supplemented isoenergetic diets differing in protein and cereal fiber content.
abstract: BACKGROUND
  Amino-acid (AA) metabolic signatures differ in insulin-resistant (IR) obese vs normal-weight subjects, improve after weight loss, and seem to predict the risk of type 2 diabetes. It is unknown whether weight-maintaining dietary measures aimed at influencing IR alter AA signatures of high-risk subjects.
  
  
  METHODS
  In the randomized controlled Protein, Fiber and Metabolic Syndrome (ProFiMet) trial we investigated effects of four isoenergetic, moderately fat-reduced diets varying in protein and cereal-fiber contents on complete AA metabolic signatures in 76 group-matched overweight or obese high-risk subjects. We analyzed the relation of whole-body and hepatic IR with AA signatures, body fat composition and liver fat, after 0, 6, and 18 weeks of dietary intervention. Discrimination between diets was further enhanced by providing tailored dietary supplements for twice-daily consumption over 18 weeks in all groups.
  
  
  RESULTS
  Baseline AA, including branched-chain signatures significantly related to IR, liver fat, and visceral fat mass. Isoenergetic variation of protein and cereal-fiber dietary contents, but not fat restriction, significantly influenced IR, whereas the relation of AA with IR changed with all diets. The tryptophan ratio was significantly suppressed in obese vs overweight participants, but increased after 6 weeks of high cereal-fiber intake to a nonobese phenotype. Modeling analyses revealed diet-induced alterations of complex AA profiles to relate to 70% and 62% of changes in whole-body and hepatic IR.
  
  
  CONCLUSIONS
  We demonstrate that relatively short-term isoenergetic changes in the diet significantly alter the relation of AA signatures with IR, with possible implications on the determination and treatment of diabetes risk.
authors.affiliation: Warwickshire Institute for the Study of Diabetes (J.G.H., H.S.R. M.O.W.), Endocrinology and Metabolism, University Hospitals Coventry and Warwickshire NHS Trust, CV2 2DX Coventry, United Kingdom; and Division of Metabolic and Vascular Health, Warwick Medical School, University of Warwick, CV4 7AL Coventry, United Kingdom; Human Metabolic Research Unit (J.G.H.), University Hospitals Coventry and Warwickshire NHS Trust, CV2 2DX Coventry, United Kingdom; Department of Clinical Nutrition (A.F.H.P., D.H., N.N.R., M.O., Ö.G., S.H., M.M. A.M.A., M.O.W.), German Institute of Human Nutrition, D-14558 Potsdam-Rehbruecke, Germany; and Department of Endocrinology, Diabetes and Nutrition, Campus Benjamin Franklin, Charité-University-Medicine, D-12203 Berlin, Germany; Institute for Clinical Diabetology (M.R., P.N.), German Diabetes Center (Leibniz Center for Diabetes Research), Heinrich-Heine University Düsseldorf, D-40225 Düsseldorf, Germany; and Department of Endocrinology and Diabetology, University Clinics and Heinrich-Heine University Düsseldorf, D-40225 Düsseldorf, Germany; Stable Isotope Group (K.-J.P.), German Institute of Human Nutrition, D-14558 Potsdam-Rehbruecke, Germany; Nuffield Department of Obstetrics and Gynaecology (M.V.), University of Oxford, Level 3, Womens Centre Oxford, OX3 9DU Oxford, United Kingdom; Section on Experimental Radiology (J.M.), Department of Diagnostic and Interventional Radiology, Eberhard-Karls University Tübingen, D-72076 Tübingen, Germany; Diagnostic and Interventional Radiology (J.H.), Klinikum Ernst von Bergmann, Academic Teaching Hospital, Charité University Medicine, D-14467 Potsdam, Germany; andIntegrated Research and Treatment Center (C.v.L.), Center for Sepsis Control and Care (CSCC), Jena University Hospital and Department of Anesthesiology and Intensive Care, Friedrich Schiller University of Jena, D-07747 Jena, Germany.
authors.forename: John G
authors.initials: JG
authors.lastname: Hattersley
authors.forename: Andreas F H
authors.initials: AF
authors.lastname: Pfeiffer
authors.forename: Michael
authors.initials: M
authors.lastname: Roden
authors.forename: Klaus-Jürgen
authors.initials: KJ
authors.lastname: Petzke
authors.forename: Daniela
authors.initials: D
authors.lastname: Hoffmann
authors.forename: Natalia N
authors.initials: NN
authors.lastname: Rudovich
authors.forename: Harpal S
authors.initials: HS
authors.lastname: Randeva
authors.forename: Manu
authors.initials: M
authors.lastname: Vatish
authors.forename: Martin
authors.initials: M
authors.lastname: Osterhoff
authors.forename: Özlem
authors.initials: Ö
authors.lastname: Goegebakan
authors.forename: Silke
authors.initials: S
authors.lastname: Hornemann
authors.forename: Peter
authors.initials: P
authors.lastname: Nowotny
authors.forename: Jürgen
authors.initials: J
authors.lastname: Machann
authors.forename: Johannes
authors.initials: J
authors.lastname: Hierholzer
authors.forename: Christian
authors.initials: C
authors.lastname: von Loeffelholz
authors.forename: Matthias
authors.initials: M
authors.lastname: Möhlig
authors.forename: Ayman M
authors.initials: AM
authors.lastname: Arafat
authors.forename: Martin O
authors.initials: MO
authors.lastname: Weickert
mesh_terms: D000596:Amino Acids / Q000097:blood*; D001823:Body Composition / Q000187:drug effects; D004038:Diet, Reducing; D004043:Dietary Fiber / Q000494:pharmacology*; D004044:Dietary Proteins / Q000494:pharmacology*; D002523:Edible Grain / Q000737:chemistry*; D005223:Fats / Q000378:metabolism; D005260:Female; D006801:Humans; D007333:Insulin Resistance; D008099:Liver / Q000378:metabolism; D008297:Male; D024821:Metabolic Syndrome / Q000178:diet therapy* / Q000378:metabolism; D008875:Middle Aged; D009765:Obesity / Q000178:diet therapy / Q000378:metabolism; D050177:Overweight / Q000178:diet therapy / Q000378:metabolism
chemical_list: D000596:Amino Acids; D004043:Dietary Fiber; D004044:Dietary Proteins; D005223:Fats