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Aims/hypothesis Metabolic effects of intermittent unhealthy lifestyle in young adults are poorly studied. We investigated the gluco-metabolic and hepatic effects of participation in Roskilde Festival (1 week of binge drinking and junk food consumption) in young, healthy males. Methods Fourteen festival participants (FP) were studied before, during and after 1 week’s participation in Roskilde Festival. Fourteen matched controls (CTRL) who did not participate in Roskilde Festival or change their lifestyle in other ways were investigated along a similar timeline. Results The FP group consumed more alcohol compared to their standard living conditions (2.0 ± 3.9 vs 16.3 ± 8.3 units/day, P < 0.001). CTRLs did not change their alcohol consumption. AUC for glucose during OGTT did not change in either group. C-peptide responses increased in the FP group (206 ± 24 vs 236 ± 17 min × nmol/L, P = 0.052) and the Matsuda index of insulin sensitivity decreased (6.2 ± 2.4 vs 4.7 ± 1.4, P = 0.054). AUC for glucagon during oral glucose tolerance test (OGTT) increased in the FP group (1037 ± 90 vs 1562 ± 195 min × pmol/L, P = 0.003) together with fasting fibroblast growth factor 21 (FGF21) (62 ± 30 vs 132 ± 72 pmol/L, P < 0.001), growth differentiation factor 15 (GDF5) (276 ± 78 vs 330 ± 83 pg/mL, P = 0.009) and aspartate aminotransferase (AST) levels (37.6 ± 6.8 vs 42.4 ± 11 U/L, P = 0.043). Four participants (29%) developed ultrasound-detectable steatosis and a mean strain elastography-assessed liver stiffness increased (P = 0.026) in the FP group. Conclusions/Interpretation Participation in Roskilde Festival did not affect oral glucose tolerance but was associated with a reduction in insulin sensitivity, increases in glucagon, FGF21, GDF15 and AST and lead to increased liver stiffness and, in 29% of the participants, ultrasound-detectable hepatic steatosis.

The glucose-dependent insulinotropic polypeptide (GIP) fragment GIP(3-30)NH2 is a selective, competitive GIP receptor antagonist, and doses of 800 to 1200 pmol/kg/min inhibit GIP-induced potentiation of glucose-stimulated insulin secretion by >80% in humans. We evaluated the effects of GIP(3-30)NH2 across a wider dose range in eight healthy men undergoing six separate and randomized 10-mmol/L hyperglycaemic clamps (A-F) with concomitant intravenous infusion of GIP (1.5 pmol/kg/min; A-E) or saline (F). Clamps A to E involved double-blinded, infusions of saline (A) and GIP(3-30)NH2 at four rates: 2 (B), 20 (C), 200 (D) and 2000 pmol/kg/min (E), respectively. Mean plasma concentrations of glucose (A-F) and GIP (A-E) were similar. GIP-induced potentiation of glucose-stimulated insulin secretion was reduced by 44 ± 10% and 84 ± 10% during clamps D and E, respectively. Correspondingly, the amounts of glucose required to maintain the clamp during D and E were not different from F. GIP-induced suppression of bone resorption and increase in heart rate were lowered by clamps D and E. In conclusion, GIP(3-30)NH2 provides extensive, dose-dependent inhibition of the GIP receptor in humans, with most pronounced effects of the doses 200 to 2000 pmol/kg/min within the tested range.

Background Ingestion of the calorically dense compound alcohol may cause metabolic disturbances including hypoglycaemia, hepatic steatosis and insulin resistance, but the underlying mechanisms are uncertain. The gastrointestinal tract is well recognised as a major influencer on glucose, protein and lipid metabolism, but its role in alcohol metabolism remains unclear. Objective To examine the effects of oral and intravenous alcohol, respectively, on plasma concentrations of several gluco-regulatory hormones including serum/plasma insulin, C-peptide, glucagon, glucose-dependent insulinotropic polypeptide (GIP), glucagon-like peptide 1 (GLP-1) and fibroblast growth factor 21 (FGF21). Design and methods In a double-blinded, randomised, crossover design, we subjected 12 healthy men to intragastric ethanol infusion (IGEI) and an isoethanolaemic intravenous ethanol infusion (IVEI) (0.7 g alcohol per kg body weight), respectively, on two separate experimental days. Results Isoethanolaemia during the two alcohol administration forms was obtained (P = 0.38). During both interventions, plasma glucose peaked after ~30 min and thereafter fell below baseline concentrations. GIP and GLP-1 concentrations were unaffected by the two interventions. Insulin concentrations were unaffected by IGEI but decreased during IVEI. C-peptide, insulin secretion rate and glucagon concentrations were lowered similarly during IGEI and IVEI. FGF21 concentrations increased dramatically (nine-fold) and similarly during IGEI and IVEI. Conclusions Alcohol does not seem to affect the secretion of incretin hormones but decreased insulin and glucagon secretion independently of gut-derived factors. IGEI as well as IVEI potently stimulate FGF21 secretion indicating a gut-independent effect of alcohol on FGF21 secretion in humans.

Ethanol intake increases plasma concentrations of triglycerides and chronic ethanol use impairs lipid metabolism and causes chronic inflammation. The gut plays an important role in metabolic handling of nutrients, including lipids, and a leaky gut associated with alcohol intake, allowing inflammatory signals to the portal vein, has been proposed to constitute a mechanism by which ethanol induces hepatic inflammation. We compared the effects of enteral and parenteral administration of ethanol on a range of circulating inflammation markers (including soluble CD163, a marker of liver macrophage activation), lipids, cholecystokinin (CCK) and fibroblast growth factor 19 (FGF19) as well as gallbladder volume. On two separate and randomized study days, we subjected healthy men (n = 12) to double-blinded intragastric ethanol infusion (IGEI) and isoethanolemic intravenous ethanol infusion (IVEI). Blood was sampled and ultrasonographic evaluation of gallbladder volume was performed at frequent intervals for 4 h after initiation of ethanol administration on both days. Little or no effects were observed on plasma levels of inflammation markers during IGEI and IVEI, respectively. Circulating levels of total, low-density lipoprotein and high-density lipoprotein cholesterol decreased after ethanol administration independently of the administration form. Triglyceride and very low-density lipoprotein (VLDL) cholesterol concentrations increased more after IGEI compared to IVEI. IVEI had no effect on plasma CCK and caused an increased gallbladder volume whereas IGEI elicited a CCK response (P < 0.0001) without affecting gallbladder volume. Circulating FGF19 concentrations decreased equally in response to both ethanol administration forms. In conclusion, by evaluating a range of circulating inflammation markers during IGEI and IVEI we were not able to detect signs of systemic low-grade inflammation originating from the presence of ethanol in the gut. IVEI increased gallbladder volume whereas IGEI increased plasma CCK (with neutral effect on gallbladder volume), increased plasma VLDL cholesterol and triglyceride concentrations; indicating that the enteral route of administration may influence ethanol's effects on lipid metabolism.

The glucose-dependent insulinotropic polypeptide (GIP) fragment GIP(3-30)NH

The incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1) are secreted postprandially and contribute importantly to postprandial glucose tolerance. In this study, we assessed the individual and combined contributions of endogenous GIP and GLP-1 to the postprandial changes in glucose and glucoregulatory hormones using the novel GIP receptor antagonist GIP(3-30)NH2 and the well-established GLP-1 receptor antagonist exendin(9-39)NH2. During 4-h oral glucose tolerance tests (75 g) combined with an ad libitum meal test, 18 healthy men received on four separate days in randomized, double-blinded order intravenous infusions of A) GIP(3-30)NH2 (800 pmol/kg/min) plus exendin(9-39)NH2 (0–20 min: 1,000 pmol/kg/min; 20–240 min: 450 pmol/kg/min), B) GIP(3-30)NH2, C) exendin(9-39)NH2, and D) saline, respectively. Glucose excursions were significantly higher during A than during B, C, and D, while glucose excursions during B were higher than during C and D. Insulin secretion (assessed by C-peptide/glucose ratio) was reduced by 37 ± 16% (A), 30 ± 17% (B), and 8.6 ± 16% (C) compared with D (mean ± SD). A and C resulted in higher glucagon levels and faster gastric emptying. In conclusion, endogenous GIP affects postprandial plasma glucose excursions and insulin secretion more than endogenous GLP-1, but the hormones contribute additively to postprandial glucose regulation in healthy individuals.

The incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1) are well known for their insulinotropic effects and they are thought to affect bone homeostasis as mediators in the so-called entero-osseous axis. We examined the contributions of endogenous GIP and GLP-1, respectively, to postprandial bone homeostasis, in healthy subjects in two randomized and double-blind crossover studies. We included healthy men who received either four oral glucose tolerance tests (OGTTs) (n = 18, median age 27 (range 20–70), BMI 27.2 (22.4–37.0) kg/m2) or liquid mixed meal tests (MMTs) (n = 12, age 23 (19–65), BMI 23.7 (20.3–25.5) kg/m2) with infusions of 1) the GIP receptor antagonist GIP(3-30)NH2, 2) the GLP-1 receptor antagonist exendin(9–39)NH2, 3) both GIP(3–30)NH2 and exendin(9–39)NH2, or 4) placebo infusions (saline) on four separate visits. Bone resorption was evaluated from levels of circulating carboxy-terminal collagen crosslinks (CTX) and bone formation from levels of procollagen type 1 amino-terminal propeptide (P1NP). During placebo infusions, baseline-subtracted area under the curve values for CTX were −39 ± 5.0 (OGTT) and −57 ± 4.3 ng/ml × min (MMT). When GIP(3–30)NH2 was administered, CTX suppression was significantly diminished compared to placebo (−30 ± 4.8 (OGTT) and −45 ± 4.6 ng/ml × min (MMT), P = 0.0104 and P = 0.0288, respectively, compared to placebo. During exendin(9–39)NH2 infusion, CTX suppression after OGTT/MMT was similar to placebo (P = 0.28 (OGTT) and P = 0.93 (MMT)). The relative contribution of endogenous GIP to postprandial suppression of bone resorption during both OGTT and MMT was similar and reached 22–25%. There were no differences in P1NP concentrations between interventions. In conclusion, endogenous GIP contributes by up to 25% to postprandial suppression of bone resorption in humans whereas an effect of endogenous GLP-1 could not be demonstrated.

Glucose-dependent insulinotropic polypeptide (GIP) is an incretin hormone secreted postprandially from enteroendocrine K cells, but despite therapeutically interesting effects, GIP physiology in humans remains incompletely understood. Progress in this field could be facilitated by a suitable GIP receptor antagonist. For the first time in humans, we investigated the antagonistic properties of the naturally occurring GIP(3-30)NH2 in in vivo and in in vitro receptor studies. In transiently transfected COS-7 cells, GIP(3-30)NH2 was evaluated with homologous receptor binding and receptor activation (cAMP accumulation) studies at the glucagon-like peptide 1 (GLP-1), glucagon-like peptide-2 (GLP-2), glucagon, secretin and growth hormone-releasing hormone (GHRH) receptors. Ten healthy men (eligibility criteria: age 20–30 years, HbA1c less than 6.5% [48 mmol/mol] and fasting plasma glucose [FPG] less than 7 mmol/l) were included in the clinical study. Data were collected as plasma and serum samples from a cubital vein cannula. As primary outcome, insulin secretion and glucose requirements were evaluated together with in a randomised, four-period, crossover design by infusing GIP(3-30)NH2 (800 pmol kg−1 min−1), GIP (1.5 pmol kg−1 min−1), a combination of these or placebo during hyperglycaemic clamp experiments. The content of the infusions were blinded to the study participants and experimental personnel. No study participants dropped out. GIP(3-30)NH2 neither bound, stimulated nor antagonised a series of related receptors in vitro. The elimination plasma half-life of GIP(3-30)NH2 in humans was 7.6 ± 1.4 min. Markedly larger amounts of glucose were required to maintain the clamp during GIP infusion compared with the other days. GIP-induced insulin secretion was reduced by 82% (p

Infusion of the incretin hormone glucose-dependent insulinotropic polypeptide (GIP) suppresses the bone resorption marker carboxy-terminal type 1 collagen crosslinks (CTX). Using separate and combined infusions of the selective GIP receptor (GIPR) antagonist, GIP(3-30)NH2, and GIP, we investigated how GIPR inhibition affects bone turnover markers. Ten healthy men (median age 22.5 years (range 21-25), BMI 21.3kg/m2 (19.9-24.7)) participated in a randomized, doubled blinded, placebo-controlled, crossover study with four 1h 12mmol/l-hyperglycemic clamps on four separate study days with concomitant infusions of GIP, GIP+GIP(3-30)NH2, GIP(3-30)NH2, and placebo, respectively, separated by a period of at least one week. GIP was infused at 1.5pmol/kg/min and GIP(3-30)NH2 at 800pmol/kg/min. Plasma glucose was clamped at 12.0±1.2mmol/l and plasma levels of GIP and GIP(3-30)NH2 amounted to ∼80pmol/l and ∼50nmol/l, respectively. GIP suppressed CTX more than placebo (baseline-subtracted AUC -6,811±1,260 vs. -3,012±3,018ng/l×min, P= 0.002) and resulted in CTX values of 53 ± 6.9% (GIP) versus 81 ± 10% of baseline (placebo), respectively (P = 0.0006), at the end of the hyperglycemic clamp. Co-infusion of GIP and GIP(3-30)NH2 attenuated the GIP-induced CTX suppression by 51±33% (P = 0.01). The peak value of the bone formation marker N-terminal propeptide of type 1 procollagen (P1NP) peaked at higher levels during GIP (109±6.7% of baseline) than during GIP(3-30)NH2 infusion (101±8.9%) (P = 0.049) and GIP suppressed PTH levels compared to GIP(3-30)NH2 alone (P = 0.0158). In conclusion, blockade of the GIPR with GIP(3-30)NH2 diminished GIP-induced CTX and P1NP responses, showing that these effects are GIPR-mediated and that GIPR antagonism might interfere with bone resorption.

Infusion of the incretin hormone glucose-dependent insulinotropic polypeptide (GIP) suppresses the bone resorption marker carboxy-terminal type 1 collagen crosslinks (CTX). Using separate and combined infusions of the selective GIP receptor (GIPR) antagonist, GIP(3-30)NH

Introduction: The mechanisms behind the detrimental effects of ethanol on the liver remain uncertain. It has been suggested that the presence of ethanol in the gut lumen promotes a ’leaky gut’ allowing bacterial products to translocate to the bloodstream causing an inflammatory response. Furthermore, the ethanol-induced hormone fibroblast growth factor 21 (FGF-21) has emerged as a potential safeguard from ethanol-induced liver injury. Here, we aimed to investigate how ethanol administered intragastrically and intravenously, respectively, influences circulating markers of inflammation and FGF-21. Materials and Method: In a double-blinded, randomized cross-over design, we subjected 12 fasted healthy men (age 25.3±3.9 years; body mass index (BMI) 22.6±2.6 kg/m2 (mean±SD)) to intragastrically instilled ethanol (0.70 g ethanol per kg body weight in a 20% (v/w) solution infused over 5 minutes) and isoethanolaemic iv ethanol infusion, respectively, on two separate experimental days, and evaluated a range of circulating markers of inflammation and liver function as well as FGF-21. Results: No increment in plasma sCD163, or any other inflammation markers (lipopolysaccharide binding protein, tumor necrosis factor-α, interferon-γ, interleukin-10 (IL), IL-12p70, IL-13, IL-1β, IL-2, IL-4, IL-6, and IL-8), was observed. Plasma FGF-21 levels increased significantly (nine times baseline level), similarly and throughout both experimental days. Conclusion: Neither ’oral’ nor iv ethanol elicited significant changes in circulating markers of macrophage activation or inflammation, but increased plasma FGF-21 significantly regardless of the administration form suggesting a direct ethanol effect on FGF-21 secretion. Disclosure A.R. Lanng: None. L.S. Gasbjerg: Stock/Shareholder; Self; Antag Therapeutics. N.C. Bergmann: Employee; Self; Zealand Pharma A/S. H. Møller: Other Relationship; Self; IQ-products. M. Gillum: None. H. Gronbaek: Board Member; Self; Ipsen Biopharmaceuticals, Inc., Novartis AG. Research Support; Self; Intercept Pharmaceuticals, Inc., AbbVie Inc., Novo Nordisk A/S. T. Vilsbøll: Advisory Panel; Self; Amgen Inc., Boehringer Ingelheim GmbH, Eli Lilly and Company, AstraZeneca, MSD K.K., Sanofi, Novo Nordisk A/S. Consultant; Self; Amgen Inc., Boehringer Ingelheim GmbH, Eli Lilly and Company, AstraZeneca, MSD K.K., Sanofi, Novo Nordisk A/S. Speaker's Bureau; Self; Amgen Inc., Boehringer Ingelheim GmbH, Eli Lilly and Company, AstraZeneca, MSD K.K., Sanofi, Novo Nordisk A/S. Research Support; Self; Eli Lilly and Company, Novo Nordisk A/S. F.K. Knop: Advisory Panel; Self; AstraZeneca. Consultant; Self; AstraZeneca. Research Support; Self; AstraZeneca. Speaker's Bureau; Self; AstraZeneca. Advisory Panel; Self; Eli Lilly and Company. Speaker's Bureau; Self; Eli Lilly and Company. Advisory Panel; Self; Amgen Inc.. Speaker's Bureau; Self; Merck Sharp & Dohme Corp.. Advisory Panel; Self; Novo Nordisk A/S. Consultant; Self; Novo Nordisk A/S. Speaker's Bureau; Self; Novo Nordisk A/S. Consultant; Self; Amgen Inc.. Advisory Panel; Self; MedImmune, Sanofi. Consultant; Self; Sanofi. Research Support; Self; Sanofi. Speaker's Bureau; Self; Sanofi.

The gut-derived incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1) are known for insulinotropic and glucose-lowering effects. However, their individual roles in postprandial glucose homeostasis are unknown. We infused the GIP receptor antagonist GIP(3-30)NH2 and the GLP-1 receptor antagonist exendin(9-39) during a meal to determine the roles of endogenous GIP and GLP-1 on postprandial glucose metabolism. On four separate days, 12 healthy men (age 19-65 years, BMI 20-25 kg/m2) received a liquid mixed meal test with randomized and double-blinded infusions of GIP(3-30)NH2 (800 pmol/kg/min) + Ex(9-39) (450 pmol/kg/min) (A), GIP(3-30)NH2 (B), Ex(9-39) (C), and saline (D). On Day A, B and C, glucose excursions were significantly increased by 85%, 55% and 15%, respectively, compared to D. Day A and B excursions were significantly higher than C (Figure). Glucagon levels at 60 min differed between Day A and B (11.5±1.2 vs. 7.5±0.6 pmol/l, P=0.01), and Day B and C (11.5±1.2 vs. 12.9±1.5 pmol/l, P=0.008). GLP-1 was higher on Day A (P=0.01) and C (P=0.02) than D. No significant effects on insulin, C-peptide, gastric emptying, or GIP were observed. We conclude that endogenous GIP affects postprandial plasma glucose excursions more pronouncedly than GLP-1, and that both hormones additively contribute to control postprandial glycemia in healthy subjects. Disclosure L.S. Gasbjerg: Stock/Shareholder; Self; Antag Therapeutics. M.M. Helsted: None. A.H. Sparre-Ulrich: Employee; Self; Antag Therapeutics ApS. A.R. Lanng: None. S. Stensen: None. M. Jakobsen: None. B. Hartmann: None. M.B. Christensen: None. J.J. Holst: Advisory Panel; Self; Novo Nordisk A/S. Board Member; Self; Zealand Pharma A/S. Speaker's Bureau; Self; Merck Sharp & Dohme Corp., AstraZeneca. Research Support; Self; Danish Diabetes Academy, Novo Nordisk Foundation. Other Relationship; Self; Antag Therapeutics. Other Relationship; Spouse/Partner; Antag Therapeutics. T. Vilsbøll: Advisory Panel; Self; Amgen Inc., Boehringer Ingelheim GmbH, Eli Lilly and Company, AstraZeneca, MSD K.K., Sanofi, Novo Nordisk A/S. Consultant; Self; Amgen Inc., Boehringer Ingelheim GmbH, Eli Lilly and Company, AstraZeneca, MSD K.K., Sanofi, Novo Nordisk A/S. Speaker's Bureau; Self; Amgen Inc., Boehringer Ingelheim GmbH, Eli Lilly and Company, AstraZeneca, MSD K.K., Sanofi, Novo Nordisk A/S. Research Support; Self; Eli Lilly and Company, Novo Nordisk A/S. M.M. Rosenkilde: Other Relationship; Self; Antag Therapeutics. Advisory Panel; Spouse/Partner; Novo Nordisk A/S. Board Member; Spouse/Partner; Zealand Pharma A/S. Speaker's Bureau; Spouse/Partner; Merck Sharp & Dohme Corp., AstraZeneca. Research Support; Spouse/Partner; Danish Diabetes Academy, Novo Nordisk Foundation. Other Relationship; Spouse/Partner; Antag Therapeutics. F.K. Knop: Advisory Panel; Self; AstraZeneca. Consultant; Self; AstraZeneca. Research Support; Self; AstraZeneca. Speaker's Bureau; Self; AstraZeneca. Advisory Panel; Self; Eli Lilly and Company. Speaker's Bureau; Self; Eli Lilly and Company. Advisory Panel; Self; Amgen Inc.. Speaker's Bureau; Self; Merck Sharp & Dohme Corp.. Advisory Panel; Self; Novo Nordisk A/S. Consultant; Self; Novo Nordisk A/S. Speaker's Bureau; Self; Novo Nordisk A/S. Consultant; Self; Amgen Inc.. Advisory Panel; Self; MedImmune, Sanofi. Consultant; Self; Sanofi. Research Support; Self; Sanofi. Speaker's Bureau; Self; Sanofi.

Glucose-dependent insulinotropic polypeptide (GIP) is an incretin hormone secreted postprandially from enteroendocrine K cells, but despite therapeutically interesting effects, GIP physiology in humans remains incompletely understood. Progress in this field could be facilitated by a suitable GIP receptor antagonist. For the first time in humans, we investigated the antagonistic properties of the naturally occurring GIP(3-30)NHIn transiently transfected COS-7 cells, GIP(3-30)NHGIP(3-30)NHWe conclude that GIP(3-30)NHClinicalTrials.gov registration no. NCT02747472.The study was funded by Gangstedfonden, the European Foundation for the Study of Diabetes, and Aase og Ejnar Danielsens fond.