title: Glycemic increase induced by intravenous glucose infusion fails to affect hunger, appetite, or satiety following breakfast in healthy men.
abstract: Meal-dependent fluctuations of blood glucose and corresponding endocrine signals such as insulin are thought to provide important regulatory input for central nervous processing of hunger and satiety. Since food intake also triggers the release of numerous gastrointestinal signals, the specific contribution of changes in blood glucose to appetite regulation in humans has remained unclear. Here we tested the hypothesis that inducing glycemic fluctuations by intravenous glucose infusion is associated with concurrent changes in hunger, appetite, and satiety. In a single blind, counter-balanced crossover study 15 healthy young men participated in two experimental conditions on two separate days. 500 ml of a solution containing 50 g glucose or 0.9% saline, respectively, was intravenously infused over a 1-h period followed by a 1-h observation period. One hour before start of the respective infusion subjects had a light breakfast (284 kcal). Blood glucose and serum insulin concentrations as well as self-rated feelings of hunger, appetite, satiety, and fullness were assessed during the entire experiment. Glucose as compared to saline infusion markedly increased glucose and insulin concentrations (peak glucose level: 9.7 ± 0.8 vs. 5.3 ± 0.3 mmol/l; t(14) = -5.159, p < 0.001; peak insulin level: 370.4 ± 66.5 vs. 109.6 ± 21.5 pmol/l; t(14) = 4.563, p < 0.001) followed by a sharp decline in glycaemia to a nadir of 3.0 ± 0.2 mmol/l (vs. 3.9 ± 0.1 mmol/l at the corresponding time in the control condition; t(14) = -3.972, p = 0.001) after stopping the infusion. Despite this wide glycemic fluctuation in the glucose infusion condition subjective feelings of hunger, appetite satiety, and fullness did not differ from the control condition throughout the experiment. These findings clearly speak against the notion that fluctuations in glycemia and also insulinemia represent major signals in the short-term regulation of hunger and satiety.
authors.affiliation: eSwiss Medical & Surgical Center, Brauerstrasse 97, CH-9016, St. Gallen, Switzerland.
authors.forename: Bernd
authors.initials: B
authors.lastname: Schultes
authors.affiliation: Department of Internal Medicine I, University Hospital Lübeck, Ratzeburger Allee 160, 23538, Lübeck, Germany.
authors.forename: Ann-Kristin
authors.initials: AK
authors.lastname: Panknin
authors.affiliation: Department of Medical Psychology and Behavioral Neurobiology, University of Tübingen, Otfried-Müller-Str. 25, 72076, Tübingen, Germany; German Center for Diabetes Research (DZD), Tübingen, Germany; Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the University of Tübingen (IDM), Tübingen, Germany.
authors.forename: Manfred
authors.initials: M
authors.lastname: Hallschmid
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Lübeck, Ratzeburger Allee 160, 23538, Lübeck, Germany.
authors.forename: Kamila
authors.initials: K
authors.lastname: Jauch-Chara
authors.affiliation: Department of Internal Medicine I, University Hospital Lübeck, Ratzeburger Allee 160, 23538, Lübeck, Germany.
authors.forename: Britta
authors.initials: B
authors.lastname: Wilms
authors.affiliation: Department of Internal Medicine I, University Hospital Lübeck, Ratzeburger Allee 160, 23538, Lübeck, Germany.
authors.forename: Felix
authors.initials: F
authors.lastname: de Courbière
authors.affiliation: Department of Internal Medicine I, University Hospital Lübeck, Ratzeburger Allee 160, 23538, Lübeck, Germany; German Center for Diabetes Research (DZD), Lübeck, Germany.
authors.forename: Hendrik
authors.initials: H
authors.lastname: Lehnert
authors.affiliation: Department of Internal Medicine I, University Hospital Lübeck, Ratzeburger Allee 160, 23538, Lübeck, Germany; German Center for Diabetes Research (DZD), Lübeck, Germany. Electronic address: Sebastian.Schmid@uksh.de.
authors.forename: Sebastian M
authors.initials: SM
authors.lastname: Schmid
mesh_terms: D000328:Adult; D001066:Appetite; D001069:Appetite Regulation; D001786:Blood Glucose / Q000378:metabolism*; D015992:Body Mass Index; D062408:Breakfast; D018592:Cross-Over Studies; D004032:Diet; D005947:Glucose / Q000008:administration & dosage*; D006801:Humans; D006815:Hunger; D007262:Infusions, Intravenous; D007328:Insulin / Q000097:blood; D008297:Male; D019518:Postprandial Period; D012527:Satiation; D016037:Single-Blind Method; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D007328:Insulin; D005947:Glucose
keywords: Appetite; Blood glucose; Hunger; Insulin; Nutritional sensing; Satiety