title: On the role of glucose-dependent insulintropic polypeptide in postprandial metabolism in humans.
abstract: We investigated the role of glucose-dependent insulintropic polypeptide (GIP) in the regulation of gastric emptying (GE), appetite, energy intake (EI), energy expenditure (EE), plasma levels of triglycerides (TAG), and free fatty acids (FFA) in humans. First, 20 healthy males received intravenous infusion of GIP (0.8 pmol.kg(-1).min(-1)) or saline for 300 min during and after a fixed meal (protocol 1). GE was measured using paracetamol, appetite sensations using visual analog scales, EE using indirect calorimetry, and EI during a subsequent ad libitum meal (at 300 min). Next, 10 healthy males received intravenous infusions of Intralipid, glucose, or Intralipid plus glucose, with and without GIP (1.5 pmol.kg(-1).min(-1)) for 300 min (protocol 2). In protocol 1, GIP did not have any effect on GE, EI, EE, removal of TAG, or FFA and did not influence the subjective feeling of hunger, satiety, fullness or prospective food consumption compared with saline. In protocol 2, no difference was seen in the plasma TAG on Intralipid + GIP/saline and Intralipid + glucose + GIP/saline days. FFA concentrations were lower on Intralipid + glucose + GIP/saline days (P < 0.05) compared with Intralipid + GIP/saline days and on Intralipid + GIP day (P < 0.004) compared with Intralipid + saline day. Insulin increased on all GIP days compared with saline days (P < 0.05). In conclusion, while confirming its insulinotropic effects, these data suggest that GIP does not affect GE, appetite, energy intake, EE, or the clearance rate of the applied TAG formulation in humans. However, both insulin and GIP lower post-Intralipid FFA concentration, GIP probably via stimulation of insulin secretion, increasing FFA reesterification.
authors.affiliation: Department of Endocrinology, Hvidovre Hospital, Denmark.
authors.forename: Meena
authors.initials: M
authors.lastname: Asmar
authors.forename: Winnie
authors.initials: W
authors.lastname: Tangaa
authors.forename: Sten
authors.initials: S
authors.lastname: Madsbad
authors.forename: Kristine
authors.initials: K
authors.lastname: Hare
authors.forename: Arne
authors.initials: A
authors.lastname: Astrup
authors.forename: Anne
authors.initials: A
authors.lastname: Flint
authors.forename: Jens
authors.initials: J
authors.lastname: Bülow
authors.forename: Jens Juul
authors.initials: JJ
authors.lastname: Holst
mesh_terms: D000328:Adult; D001066:Appetite / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D004734:Energy Metabolism / Q000502:physiology; D005746:Gastric Emptying / Q000502:physiology; D005749:Gastric Inhibitory Polypeptide / Q000008:administration & dosage* / Q000378:metabolism* / Q000493:pharmacokinetics; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D008297:Male; D019518:Postprandial Period / Q000187:drug effects / Q000502:physiology*
chemical_list: D007328:Insulin; D005749:Gastric Inhibitory Polypeptide; D005947:Glucose