title: The duodenal glucose load impacts the oral disposition index in healthy subjects.
abstract: OBJECTIVE
  In healthy subjects, the oral disposition index (ratio of insulin response to insulin sensitivity) is predictive of the development of Type 2 diabetes. Gastric emptying, which exhibits a substantial interindividual variation, is a major determinant of postprandial glycaemia in health and diabetes. We sought to determine whether the rate of intraduodenal glucose delivery affects the disposition index in people without diabetes.
  
  
  METHODS
  Nineteen Caucasian males received glucose infusions via an intraduodenal catheter at either 2 kcal/min (ID2) or 4 kcal/min (ID4) for 120 min, on two separate days with measurements of blood glucose (G) and plasma insulin (I) at frequent intervals. The insulin response was estimated by the ratio of the change in insulin to that of change in glucose at 30 min (∆I(0-30)/∆G(0-30)) and 60 min (∆I(0-60)/∆G(0-60)). Insulin sensitivity was estimated as 1/fasting insulin. The oral disposition index (DI) was calculated as ∆I(0-30)/∆G(0-30) × 1/fasting insulin and ∆I(0-60)/∆G(0-60) × 1/fasting insulin.
  
  
  RESULTS
  The overall glycaemic response was comparable on both days, but the insulin response was much greater at ID4 when calculated at either 30 or 60 min (P < 0.05). DI was also greater (P < 0.05) in response to ID4 than ID2.
  
  
  CONCLUSIONS
  The rate of duodenal glucose delivery has a major impact on insulin release and, thereby, DI. This suggests that the rate of gastric emptying, which determines duodenal glucose delivery, is a determinant of DI.
authors.affiliation: Discipline of Medicine, University of Adelaide, Royal Adelaide Hospital, Australia.|Centre of Research Excellence (CRE) in Translating Nutritional Science to Good Health, University of Adelaide, Australia.
authors.forename: C S
authors.initials: CS
authors.lastname: Marathe
authors.affiliation: Discipline of Medicine, University of Adelaide, Royal Adelaide Hospital, Australia.|Centre of Research Excellence (CRE) in Translating Nutritional Science to Good Health, University of Adelaide, Australia.
authors.forename: C
authors.initials: C
authors.lastname: Feinle-Bisset
authors.affiliation: Discipline of Medicine, University of Adelaide, Royal Adelaide Hospital, Australia.
authors.forename: A
authors.initials: A
authors.lastname: Pilichiewicz
authors.affiliation: Discipline of Medicine, University of Adelaide, Royal Adelaide Hospital, Australia.|Centre of Research Excellence (CRE) in Translating Nutritional Science to Good Health, University of Adelaide, Australia.
authors.forename: K
authors.initials: K
authors.lastname: Lange
authors.affiliation: Discipline of Medicine, University of Adelaide, Royal Adelaide Hospital, Australia.|Centre of Research Excellence (CRE) in Translating Nutritional Science to Good Health, University of Adelaide, Australia.
authors.forename: K L
authors.initials: KL
authors.lastname: Jones
authors.affiliation: Discipline of Medicine, University of Adelaide, Royal Adelaide Hospital, Australia.|Centre of Research Excellence (CRE) in Translating Nutritional Science to Good Health, University of Adelaide, Australia.
authors.forename: C K
authors.initials: CK
authors.lastname: Rayner
authors.affiliation: Division of Metabolism, Endocrinology and Nutrition, VA Puget Sound Health Care System and University of Washington, Seattle, USA.
authors.forename: S E
authors.initials: SE
authors.lastname: Kahn
authors.affiliation: Discipline of Medicine, University of Adelaide, Royal Adelaide Hospital, Australia.|Centre of Research Excellence (CRE) in Translating Nutritional Science to Good Health, University of Adelaide, Australia.
authors.forename: M
authors.initials: M
authors.lastname: Horowitz
mesh_terms: D000328:Adult; D000465:Algorithms; D001786:Blood Glucose / Q000032:analysis; D004040:Dietary Carbohydrates / Q000008:administration & dosage / Q000378:metabolism*; D004386:Duodenum / Q000378:metabolism*; D005746:Gastric Emptying; D005947:Glucose / Q000008:administration & dosage / Q000378:metabolism*; D000067940:Glycemic Load; D006801:Humans; D007328:Insulin / Q000097:blood / Q000378:metabolism*; D007333:Insulin Resistance; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000378:metabolism*; D007408:Intestinal Absorption; D007413:Intestinal Mucosa / Q000378:metabolism*; D007441:Intubation, Gastrointestinal; D007700:Kinetics; D008297:Male
chemical_list: D001786:Blood Glucose; D004040:Dietary Carbohydrates; D007328:Insulin; D005947:Glucose