Glucose-dependent Insulinotropic Polypeptide Infusion Research Articles

GIP_HUMAN [22-51] Peptide Encoded by the Glucose-Dependent Insulinotropic Polypeptide (GIP) Gene Suppresses Insulin Expression and Secretion in INS-1E Cells and Rat Pancreatic Islets.

GIP_HUMAN [22-51] is a recently discovered peptide that shares the same precursor molecule with glucose-dependent insulinotropic polypeptide (GIP). In vivo, chronic infusion of GIP_HUMAN [22-51] in ApoE-/- mice enhanced the development of aortic atherosclerotic lesions and upregulated inflammatory and proatherogenic proteins. In the present study, we evaluate the effects of GIP_HUMAN [22-51] on insulin mRNA expression and secretion in insulin-producing INS-1E cells and isolated rat pancreatic islets. Furthermore, we characterize the influence of GIP_HUMAN [22-51] on cell proliferation and death and on Nf-kB nuclear translocation. Rat insulin-producing INS-1E cells and pancreatic islets, isolated from male Wistar rats, were used in this study. Gene expression was evaluated using real-time PCR. Cell proliferation was studied using a BrdU incorporation assay. Cell death was quantified by evaluating histone-complexed DNA fragments. Insulin secretion was determined using an ELISA test. Nf-kB nuclear translocation was detected using immunofluorescence. GIP_HUMAN [22-51] suppressed insulin (Ins1 and Ins2) in INS-1E cells and pancreatic islets. Moreover, GIP_HUMAN [22-51] promoted the translocation of NF-κB from cytoplasm to the nucleus. In the presence of a pharmacological inhibitor of NF-κB, GIP_HUMAN [22-51] was unable to suppress Ins2 mRNA expression. Moreover, GIP_HUMAN [22-51] downregulated insulin secretion at low (2.8 mmol/L) but not high (16.7 mmol/L) glucose concentration. By contrast, GIP_HUMAN [22-51] failed to affect cell proliferation and apoptosis. We conclude that GIP_HUMAN [22-51] suppresses insulin expression and secretion in pancreatic β cells without affecting β cell proliferation or apoptosis. Notably, the effects of GIP_HUMAN [22-51] on insulin secretion are glucose-dependent.

Separate and combined effects of long-term GIP and GLP-1 receptor activation in patients with type 2 diabetes: a structured summary of a study protocol for a double-blind, randomised, placebo-controlled clinical trial

IntroductionDue to reports of severely reduced insulinotropic effect of the incretin hormone glucose-dependent insulinotropic polypeptide (GIP) in type 2 diabetes (T2D), GIP has not been considered therapeutically viable. Recently, however,...

The naturally occurring GIP(1-30)NH2 is a GIP receptor agonist in humans

The gut hormone glucose-dependent insulinotropic polypeptide (GIP) is an important regulator of glucose and bone metabolism. In rodents, the naturally occurring GIP variant, GIP(1-30)NH2, has shown similar effects as full-length GIP (GIP(1-42)), but its effects in humans are unsettled. Here, we investigated the actions of GIP(1-30)NH2 compared to GIP(1-42) on glucose and bone metabolism in healthy men and in isolated human pancreatic islets. Nine healthy men completed three separate three-step glucose clamps (0-60 minutes at fasting plasma glucose (FPG) level, 60-120 minutes at 1.5× FPG, and 120-180 minutes at 2× FPG) with infusion of GIP(1-42) (4 pmol/kg/min), GIP(1-30)NH2 (4 pmol/kg/min), and saline (9 mg/mL) in randomised order. Blood was sampled for measurement of relevant hormones and bone turnover markers. Human islets were incubated with low (2 mmol/L) or high (20 mmol/L) d-glucose with or without GIP(1-42) or GIP(1-30)NH2 in three different concentrations for 30 minutes, and secreted insulin and glucagon were measured. Plasma glucose (PG) levels at FPG, 1.5× FPG, and 2× FPG were obtained by infusion of 1.45 g/kg, 0.97 g/kg, and 0.6 g/kg of glucose during GIP(1-42), GIP(1-30)NH2, and saline, respectively (P = .18), and were similar on the three experimental days. Compared to placebo, GIP(1-30)NH2 resulted in similar glucagonotropic, insulinotropic, and carboxy-terminal type 1 collagen crosslinks-suppressing effects as GIP(1-42). In vitro experiments on human islets showed similar insulinotropic and glucagonotropic effects of the two GIP variants. GIP(1-30)NH2 has similar effects on glucose and bone metabolism in healthy individuals and in human islets in vitro as GIP(1-42).

Effects of GLP-1 and GIP on Islet Function in Glucose-Intolerant, Pancreatic-Insufficient Cystic Fibrosis.

Impaired insulin and incretin secretion underlie abnormal glucose tolerance (AGT) in pancreatic insufficient cystic fibrosis (PI-CF). Whether the incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) can enhance pancreatic islet function in cystic fibrosis (CF) is not known. We studied 32 adults with PI-CF and AGT randomized to receive either GLP-1 (n = 16) or GIP (n = 16) during glucose-potentiated arginine (GPA) testing of islet function on two occasions, with either incretin or placebo infused, in a randomized, double-blind, cross-over fashion. Another four adults with PI-CF and normal glucose tolerance (NGT) and four matched control participants without CF underwent similar assessment with GIP. In PI-CF with AGT, GLP-1 substantially augmented second-phase insulin secretion but without effect on the acute insulin response to GPA or the proinsulin secretory ratio (PISR), while GIP infusion did not enhance second-phase or GPA-induced insulin secretion but increased the PISR. GIP also did not enhance second-phase insulin in PI-CF with NGT but did so markedly in control participants without CF controls. These data indicate that GLP-1, but not GIP, augments glucose-dependent insulin secretion in PI-CF, supporting the likelihood that GLP-1 agonists could have therapeutic benefit in this population. Understanding loss of GIP's insulinotropic action in PI-CF may lead to novel insights into diabetes pathogenesis.

1362-P: Endogenous Glucose-Dependent Insulinotropic Polypeptide Facilitates Postprandial Intestinal Lipid Uptake in Healthy Men, but Not in Patients with Type 2 Diabetes

The gut hormone glucose-dependent insulinotropic polypeptide (GIP) stimulates glucose-induced insulin secretion and increases triglyceride deposition in subcutaneous adipose tissue, and these effects are attenuated in both type 2 diabetes (T2D) and obesity. Using the GIP receptor antagonist GIP (3-30) NH2, we investigated the effect of endogenous GIP on circulating lipoproteins (chylomicrons, VLDL, LDL, HDL) during a meal in healthy men and patients with T2D. We measured apolipoprotein B48 (ApoB48) (as a marker of chylomicron count) and plasma lipoprotein triglyceride and cholesterol content during two liquid meal tests (1,894 kJ) with double-blind infusions of GIP (3-30) NH2 or placebo (saline) in randomized order in 12 healthy men (19-65 years, BMI 20.3-25.5 kg/m2) and in patients with T2D (44-72 years, HbA1c 6.2-11% (37-70 mmol/mol) , BMI 27.4-41.2 kg/m2) . Compared to placebo, the GIP (3-30) NH2 infusion lowered postprandial responses of ApoB48 (incremental area under the curve (iAUC0-180 min) (median (95%CI)) : 215 (156-258) vs. 4 (363-541) mg×L-1×min, P=0.0049) , chylomicron-triglyceride content (iAUC0-270 min: 32.7 (-2.32-72.1) vs. 49.5 (1.21-170) mmol× L-1×min P=0.083) and HDL-triglyceride content (iAUC0-270min: -0.90 (-1.95-0.18) vs. 0.95 (-0.72-3.95) mmol× L-1×min, P=0.016) . In patients with T2D, infusion of GIP (3-30) NH2 did not change postprandial responses of ApoB48 or lipoprotein-triglyceride content. In both groups, there were no differences in lipoprotein-cholesterol contents. Disclosure L.S.Gasbjerg: Speaker's Bureau; Eli Lilly and Company, Stock/Shareholder; Antag Therapeutics. C.Christoffersen: None. F.K.Knop: Advisory Panel; Boehringer Ingelheim International GmbH, Eli Lilly and Company, Merck Sharp & Dohme Corp., Novo Nordisk, Sanofi, ShouTi, Zucara Therapeutics, Consultant; AstraZeneca, Eli Lilly and Company, Novo Nordisk, Pharmacosmos A/S, Sanofi, ShouTi, Zealand Pharma A/S, Zucara Therapeutics, Research Support; AstraZeneca, Novo Nordisk, Sanofi, Zealand Pharma A/S, Speaker's Bureau; AstraZeneca, Bayer AG, Boehringer Ingelheim International GmbH, Eli Lilly and Company, Novo Nordisk, Sanofi, Stock/Shareholder; Antag Therapeutics. M.M.Rosenkilde: Research Support; Antag Therapeutics, Bainan Biotech, Stock/Shareholder; Antag Therapeutics, Bainan Biotech, Synklino ApS. M.M.Helsted: None. S.Stensen: Employee; Novo Nordisk A/S. L.S.L.Krogh: None. A.H.Sparre-ulrich: Other Relationship; Antag Therapeutics. B.Hartmann: Board Member; Bainan Biotech. T.Vilsbøll: Consultant; AstraZeneca, Bristol-Myers Squibb Company, Eli Lilly and Company, Gilead Sciences, Inc., GlaxoSmithKline plc., Merck Sharp & Dohme Corp., Mundipharma, Novo Nordisk, Sun Pharmaceutical Industries Ltd. M.B.Christensen: None. J.J.Holst: Advisory Panel; Novo Nordisk, Board Member; Antag Therapeutics, Bainan Biotech. Funding EFSD (no. 94815) ; Novo Nordisk Foundation (no. 13777)

Glucose-dependent insulinotropic polypeptide induces lipolysis during stable basal insulin substitution and hyperglycaemia in men with type 1 diabetes: A randomized, double-blind, placebo-controlled, crossover clinical trial.

Glucose-dependent insulinotropic polypeptide (GIP) plays an important role in the glucose and lipid metabolism. We investigated the effects of exogenous GIP on lipid metabolism during time of stable insulin levels. Ten male patients with type 1 diabetes without endogenous insulin secretion (C-peptide-negative, mean[±SD] age 26 ± 4years, body mass index 24[±2]kg/m2 , glycated haemoglobin 56[±8]mmol/mol or 7.3[±0.8]%) were studied in a randomized, double-blind, placebo-controlled, crossover study with continuous intravenous infusions of GIP (4pmol/kg/min) or placebo (saline), during two separate 90-minute hyperglycaemic (12 mmol/L) clamps with basal insulin substitution (0.1-0.2mU/kg/min). Plasma glycerol concentrations increased from baseline during GIP infusion and decreased during placebo infusion (baseline-subtracted area under the curve [bsAUC] 703 ± 407 vs. -262 ± 240 μmol/L × min, respectively; P < 0.001). Free fatty acids (FFAs) increased during GIP infusions (bsAUC 5505 ± 2170 μEq/L × min) and remained unchanged during placebo infusion (bsAUC -74 ± 2363 μEq/L × min), resulting in a significant difference between GIP and placebo infusions (P < 0.001). Plasma concentrations of glucose, insulin, glucagon-like peptide-1 and glucagon were similar during GIP and placebo infusions. GIP increased plasma glycerol and FFAs in patients with type 1 diabetes during hyperglycaemia and stable basal insulin levels. This supports a direct lipolytic effect of GIP at high glucose and low levels of plasma insulin.

The effect of 6-day subcutaneous glucose-dependent insulinotropic polypeptide infusion on time in glycaemic range in patients with type 1 diabetes: a randomised, double-blind, placebo-controlled crossover trial.

Type 1 diabetes is characterised by reduced glucagon response to hypoglycaemia, increasing the risk of insulin treatment-associated hypoglycaemia known to hamper glycaemic control. We previously reported a glucagonotropic effect of exogenous glucose-dependent insulinotropic polypeptide (GIP) during insulin-induced hypoglycaemia in individuals with type 1 diabetes. Here we investigate the effect of a 6-day s.c. GIP infusion on time in glycaemic range as assessed by continuous glucose monitoring (CGM) in individuals with type 1 diabetes. In a randomised, placebo-controlled, double-blind crossover study, time in glycaemic range (assessed by double-blinded CGM) was evaluated in 20 men with type 1 diabetes (18-75years, stable insulin treatment ≥3months, diabetes duration 2-15years, fasting plasma C-peptide below 200pmol/l, BMI 20-27kg/m2, HbA1c <69mmol/mol [8.5%]) during two × 6days of continuous s.c. GIP (6pmolkg-1min-1) and placebo (saline [154mmol/l NaCl]) infusion, respectively, with an interposed 7-day washout period. The primary outcome was glycaemic time below range, time in range and time above range. There were no significant differences in time below range (<3.9mmol/l, p = 0.53) or above range (>10mmol/l, p = 0.32) during night-time or daytime, in mean glucose, or in hypoglycaemic events as assessed by CGM. GIP altered neither self-reported hypoglycaemia nor safety measures. Compared with placebo, GIP significantly increased time in tight range (3.9-7.8mmol/l) during daytime (06:00-23:59 hours) by [mean ± SEM] 11.2 ± 5.1% [95% CI 0.41, 21.9] (p =0.02). Six-day s.c. GIP infusion in men with type 1 diabetes did not procure convincing effect on overall time in range, but increased time in tight glycaemic range during daytime by ~2h per day. ClinicalTrials.gov NCT03734718. The study was funded by grants from The Leona M. and Harry B. Helmsley Charitable Trust and Aase og Ejnar Danielsens Fond.

GIP_HUMAN[22\u201351] is a new proatherogenic peptide identified by native plasma peptidomics

We recently established a new plasma peptidomic technique and comprehensively identified a large number of low-molecular weight and low-abundance native peptides using a single drop of human plasma. To discover a novel polypeptide that potently modulates the cardiovascular system, we performed a bioinformatics analysis of the large-scale identification results, sequentially synthesized the selected peptide sequences, tested their biological activities, and identified a 30-amino-acid proatherogenic peptide, GIP_HUMAN[22–51], as a potent proatherosclerotic peptide hormone. GIP_HUMAN[22–51] has a common precursor with the glucose-dependent insulinotropic polypeptide (GIP) and is located immediately N-terminal to GIP. Chronic infusion of GIP_HUMAN[22–51] into ApoE−/− mice accelerated the development of aortic atherosclerotic lesions, which were inhibited by co-infusions with an anti-GIP_HUMAN[22–51] antibody. GIP_HUMAN[22–51] increased the serum concentrations of many inflammatory and proatherogenic proteins, whereas neutralising antibodies reduced their levels. GIP_HUMAN[22–51] induced IκB-α degradation and nuclear translocation of NF-κB in human vascular endothelial cells and macrophages. Immunoreactive GIP_HUMAN[22–51] was detected in human tissues but there was no colocalization with the GIP. The plasma GIP_HUMAN[22–51] concentration in healthy humans determined using a stable-isotope tagged peptide was approximately 0.6 nM. This study discovered a novel endogenous proatherogenic peptide by using a human plasma native peptidomic resource.

107-OR: Six-Day Subcutaneous GIP Infusion Increases Circulating Free Fatty Acids without Altering the Adipose Tissue Transcriptome, Adipocyte GIP Receptor Levels, or Circulating Inflammation Markers in Patients with Type 1 Diabetes

Glucose-dependent insulinotropic polypeptide (GIP) has been proposed to increase adipose tissue lipolysis (at low insulin levels), adipokine secretion and circulating levels of inflammation markers via the GIP receptor (GIPR) in adipose tissue. We investigated the effect of a 6-day subcutaneous (sc) GIP infusion on circulating lipids and inflammation markers, the adipose tissue transcriptome and the presence of GIPR mRNA (ISH) in adipose tissue in patients with type 1 diabetes (T1D). In a randomized, placebo-controlled, double-blind, crossover study, 20 men with T1D (age [mean± SD] 26±8 years, BMI 23.8±1.8 kg/m2, HbA1c 51±10 mmol/mol (6.8±3.1%) underwent 2 × 6 days of continuous sc GIP (6 pmol/kg/min) infusion and placebo (saline) infusion, with an interposed 7-day washout period. Fasting blood samples were drawn frequently within the initial 3 hours and after 1 and 6 days of infusion. Adipose tissue biopsies were collected before and after 6 days of infusion. During the initial 3 hours of infusion, but not at day 1 and 6, GIP increased baseline-subtracted area under the curve of plasma free fatty acids (FFA) compared to placebo (16.8±10.4 vs. 4.4±9.2 min × mmol/L, P &amp;lt;0.001) without affecting plasma glycerol and triglycerides. A panel of 23 circulating inflammation markers were unaffected by the GIP infusion. Adipose tissue transcriptomics did not show differentially expressed genes after 6 days of GIP infusion compared to placebo. In situ hybridization (ISH) localized the GIPR mRNA in the adipocyte and not in connective tissue. ISH verified GIPR mRNA levels were not altered by 6 days of GIP infusion. In patients with T1D, a 6-day sc GIP infusion temporarily increases circulating levels of FFA without altering the adipose tissue transcriptome, GIPR mRNA levels in adipocytes or circulating inflammation markers. Disclosure S. M. Nguyen heimbürger: Speaker’s Bureau; Self; AstraZeneca. T. F. Dejgaard: Advisory Panel; Self; Novo Nordisk, Consultant; Self; Boehringer Ingelheim International GmbH, Research Support; Self; AstraZeneca, Novo Nordisk, Speaker’s Bureau; Self; AstraZeneca, Boehringer Ingelheim International GmbH, Novo Nordisk. C. Pyke: Employee; Self; Novo Nordisk A/S, Stock/Shareholder; Self; Novo Nordisk A/S. M. B. Christensen: None. F. K. Knop: Advisory Panel; Self; MSD Corporation, Novo Nordisk A/S, Sanofi, Consultant; Self; AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Eli Lilly and Company, Novo Nordisk A/S, Pharmacosmos, Zealand Pharma A/S, Research Support; Self; Novo Nordisk A/S, Zealand Pharma A/S, Speaker’s Bureau; Self; AstraZeneca, Bayer AG, Boehringer Ingelheim Pharmaceuticals, Inc., Eli Lilly and Company, MSD Corporation, Novo Nordisk A/S. B. Hoe: None. C. N. Nielsen: None. B. Hartmann: None. J. J. Holst: Consultant; Self; Novo Nordisk, Other Relationship; Self; Antag Therapeutics, Bainan Biotech, MSD Corporation, Novo Nordisk, Other Relationship; Spouse/Partner; Antag Therapeutics, Bainan Biotech, Synklino ApS. F. Dela: None. A. Overgaard: Stock/Shareholder; Self; Novo Nordisk A/S. J. Størling: None. T. Vilsbøll: Consultant; Self; Amgen Inc., AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Bristol-Myers Squibb Company, Gilead Sciences, Inc., Lilly Diabetes, Merck Sharp &amp; Dohme Corp., Mundipharma International, Novo Nordisk, Sanofi, Sun Pharmaceutical Industries Ltd. Funding The Leona M. and Harry B. Helmsley Charitable Trust (2018PG-T1D037)

648-P: Glucose-Dependent Insulinotropic Polypeptide (GIP) Induces Lipolysis during Stable Basal Insulin Substitution and Hyperglycemia in Men with Type 1 Diabetes

Glucose-dependent insulinotropic polypeptide (GIP) contributes importantly to postprandial insulin secretion, and - perhaps primarily due to this insulinotropic effect - affects glucose and lipid metabolism. We investigated the effects of exogenous GIP on lipid metabolism during hyperglycemia and stable insulin levels. Ten male patients with type 1 diabetes without endogenous insulin secretion (C-peptide negative), aged [mean±SD: 26±4 years; BMI: 24±2 kg/m2; HbA1c 7.3±0.8%) were studied in a randomized, double-blind, crossover study with continuous intravenous infusions of GIP (4 pmol/kg/min) or placebo (saline), during two separate 90-minute hyperglycemic (12 mmol/L) clamps with basal insulin substitution (0.1-0.2 mU/kg/min). Plasma glycerol concentrations increased from baseline during GIP infusions and decreased during placebo infusions (baseline-subtracted area under the curve (bsAUC): 703±407 vs. -262±240 µmol/L × min, respectively, P&amp;lt;0.001). Free fatty acids increased only during GIP infusions (bsAUC: 5,431±6,393 during GIP vs. -74±2,363 µmol/l × min during placebo infusion, P&amp;lt;0.05). Plasma concentrations of glucose, insulin, and glucagon were similar during GIP and placebo infusions (P=NS). Compared to placebo, GIP increased plasma glycerol and free fatty acids in patients with type 1 diabetes during hyperglycemia and stable basal insulin levels. With this experimental design it was possible to clearly identify an important effect of GIP on lipolysis in humans. Disclosure C. N. Nielsen: None. S. M. Nguyen heimbürger: Speaker’s Bureau; Self; AstraZeneca. S. Calanna: Employee; Self; Novo Nordisk A/S. J. J. Holst: Consultant; Self; Novo Nordisk, Other Relationship; Self; Antag Therapeutics, Bainan Biotech, MSD Corporation, Novo Nordisk, Other Relationship; Spouse/Partner; Antag Therapeutics, Bainan Biotech, Synklino ApS. T. Vilsbøll: Consultant; Self; Amgen Inc., AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Bristol-Myers Squibb Company, Gilead Sciences, Inc., Lilly Diabetes, Merck Sharp &amp; Dohme Corp., Mundipharma International, Novo Nordisk, Sanofi, Sun Pharmaceutical Industries Ltd. F. K. Knop: Advisory Panel; Self; MSD Corporation, Novo Nordisk A/S, Sanofi, Consultant; Self; AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Eli Lilly and Company, Novo Nordisk A/S, Pharmacosmos, Zealand Pharma A/S, Research Support; Self; Novo Nordisk A/S, Zealand Pharma A/S, Speaker’s Bureau; Self; AstraZeneca, Bayer AG, Boehringer Ingelheim Pharmaceuticals, Inc., Eli Lilly and Company, MSD Corporation, Novo Nordisk A/S. M. B. Christensen: None.

85-LB: Glucose-Dependent Insulinotropic Polypeptide (GIP) Contributes Substantially to the Improved Beta-Cell Function during Sitagliptin Treatment in Persons with Type 2 Diabetes

In persons with type 2 diabetes (T2D), dipeptidyl peptidase 4 (DPP-4) inhibitor treatment improves glycemic control by raising the active levels of the insulinotropic gut hormones glucagon-like peptide 1 and glucose-dependent insulinotropic polypeptide (GIP). Using the GIP receptor antagonist GIP(3-30)NH2, we investigated endogenous GIP’s contribution to the insulinotropic effect of DPP-4 inhibition (assessed by insulin secretion rate (ISR) relative to plasma glucose). In a double-blind, placebo-controlled, cross-over study, 12 persons (eight men and four women) with T2D (mean ± SD; BMI 27.4 ± 2.6 kg/m2, HbA1c 7.1 ± 1.4% (54 ± 15 mmol/mol)) underwent two randomized 12-13-day treatment courses with DPP-4 inhibitor (sitagliptin 100 mg once-daily) and placebo, respectively, with an interposed 1-3-week washout period. In the end of each treatment period, two randomized 5-hour liquid mixed-meal tests with infusion of GIP(3-30)NH2 (1,200 pmol/kg/min) or saline (placebo) were performed. During placebo treatment, GIP(3-30)NH2 lowered postprandial serum C-peptide (determined as difference in baseline-subtracted area under curve (ΔbsAUC%) ± SEM: −31 ± 9%, P = 0.005) and increased postprandial plasma glucose excursions (ΔAUC% ± SEM: 7.3 ± 2.8%, P = 0.017) compared to saline. Sitagliptin increased concentrations of active GIP(1-42) (ΔAUC% ± SEM: 153 ± 21%, P &amp;lt; 0.0001) and lowered fasting plasma glucose (mean: 8.7 vs. 7.6 mmol/L, P &amp;lt; 0.0004), whereas postprandial glucose excursions were unchanged compared to placebo treatment. GIP(3-30)NH2 caused a reduction in AUCISR/AUCglucose ratio equivalent to 37 ± 12% of the increments due to sitagliptin. In conclusion, we demonstrate an insulinotropic and glucose-lowering effect of endogenous GIP in persons with T2D and show that endogenous GIP is responsible for more than one third of the improved beta cell function observed during DPP-4 inhibitor treatment. Disclosure S. Stensen: None. L. S. Gasbjerg: Stock/Shareholder; Self; Antag Therapeutics. M. M. Rosenkilde: Board Member; Self; Bainan Biotech, Synklino ApS, Board Member; Spouse/Partner; Antag Therapeutics, Bainan Biotech, Consultant; Self; Antag Therapeutics, Bainan Biotech, Synklino ApS, Stock/Shareholder; Self; Antag Therapeutics, Bainan Biotech, Synklino ApS, Stock/Shareholder; Spouse/Partner; Antag Therapeutics, Bainan Biotech. B. Hartmann: None. T. Vilsbøll: Consultant; Self; Amgen Inc., AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Bristol-Myers Squibb Company, Gilead Sciences, Inc., Lilly Diabetes, Merck Sharp &amp; Dohme Corp., Mundipharma International, Novo Nordisk, Sanofi, Sun Pharmaceutical Industries Ltd. J. J. Holst: Consultant; Self; Novo Nordisk, Other Relationship; Self; Antag Therapeutics, Bainan Biotech, MSD Corporation, Novo Nordisk, Other Relationship; Spouse/Partner; Antag Therapeutics, Bainan Biotech, Synklino ApS. M. B. Christensen: None. F. K. Knop: Advisory Panel; Self; MSD Corporation, Novo Nordisk A/S, Sanofi, Consultant; Self; AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Eli Lilly and Company, Novo Nordisk A/S, Pharmacosmos, Zealand Pharma A/S, Research Support; Self; Novo Nordisk A/S, Zealand Pharma A/S, Speaker’s Bureau; Self; AstraZeneca, Bayer AG, Boehringer Ingelheim Pharmaceuticals, Inc., Eli Lilly and Company, MSD Corporation, Novo Nordisk A/S. Funding European Foundation for the Study of Diabetes/Lilly European Diabetes Research Programme (2018); A.P. Møller Foundation

Dose-dependent efficacy of the glucose-dependent insulinotropic polypeptide (GIP) receptor antagonist GIP(3-30)NH2 on GIP actions in humans.

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.

Glucose-Dependent Insulinotropic Polypeptide (GIP) Reduces Bone Resorption in Patients With Type 2 Diabetes.

ContextIn healthy individuals, glucose-dependent insulinotropic polypeptide (GIP) enhances insulin secretion and reduces bone resorption by up to 25% estimated by absolute placebo-corrected changes in carboxy-terminal type 1 collagen crosslinks (CTX) during GIP and glucose administration. In patients with type 2 diabetes (T2D), GIP’s insulinotropic effect is impaired and effects on bone may be reduced.ObjectiveTo investigate GIP’s effect on bone biomarkers in patients with T2D.DesignRandomized, double-blinded, crossover study investigating 6 interventions.PatientsTwelve male patients with T2D.InterventionsA primed continuous 90-minute GIP infusion (2 pmol/kg/min) or matching placebo (saline) administered at 3 plasma glucose (PG) levels (i.e., paired days with “insulin-induced hypoglycemia” (PG lowered to 3 mmol/L), “fasting hyperglycemia” (mean PG ~8 mmol/L), or “aggravated hyperglycemia” (mean PG ~12 mmol/L).Main Outcome MeasuresBone biomarkers: CTX, procollagen type 1 N-terminal propeptide (P1NP) and PTH.ResultsOn days with insulin-induced hypoglycemia, CTX was suppressed by up to 40 ± 15% during GIP administration compared with 12 ± 11% during placebo infusion (P < 0.0001). On days with fasting hyperglycemia, CTX was suppressed by up to 36 ± 15% during GIP administration, compared with 0 ± 9% during placebo infusion (P < 0.0001). On days with aggravated hyperglycemia, CTX was suppressed by up to 47 ± 23% during GIP administration compared with 10 ± 9% during placebo infusion (P = 0.0005). At all glycemic levels, P1NP and PTH concentrations were similar between paired days after 90 minutes.ConclusionsShort-term GIP infusions reduce bone resorption by more than one-third (estimated by absolute placebo-corrected CTX reductions) in patients with T2DM, suggesting preserved bone effects of GIP in these patients.PrécisShort-term GIP infusions reduce the bone resorption marker CTX by one-third in patients with type 2 diabetes independent of glycemic levels.

351-OR: Six-Day Subcutaneous GIP Infusion Increases Glycemic Time-in-Range in Patients with Type 1 Diabetes

The glucagonotropic effect of glucose-dependent insulinotropic polypeptide (GIP) during insulin-induced hypoglycemia in patients with type 1 diabetes (T1D) prompted us to investigate the effect of a 6-day subcutaneous (sc) GIP infusion on glucose variability in patients with T1D. In a randomized, placebo-controlled, double-blinded, crossover study, 20 men with T1D (age [mean± SD] 26±8 years, BMI 23.8±1.8 kg/m2, HbA1c 51±10 mmol/mol), underwent 2 × 6 days of continuous sc GIP (6 pmol/kg/min) and placebo (saline) infusion, respectively, with an interposed 7-day washout period. Participants wore a continuous glucose monitoring system. GIP significantly increased daytime time in range (3.9-7.8 mmol/L) by [mean±SEM] 104±69 min/day (P=0.035) without statistically significant effects on time below range (&amp;lt;3.9 mmol/L), time above range (&amp;gt;10.1 mmol/L), mean glucose or hypoglycemic events. Compared to placebo, GIP increased hepatic fat content by 12.6±4.2 percentage points (assessed by FibroScan®) (P=0.006), decreased 24-hour systolic and diastolic blood pressure by 4.6±2.8 (P=0.001) and 2.6±1.3 mmHg (P=0.028), respectively, and increased heart rate by 4.4±2.0 beats per minute (P=0.002) (Figure). Compared to placebo, a 6-day sc GIP infusion in patients with T1D increased glycemic time in range and hepatic fat content and reduced systolic and diastolic blood pressure while increasing heart rate. Disclosure S.M. Nguyen Heimbürger: None. B. Hoe: None. C.N. Nielsen: None. N.C. Bergmann: Employee; Self; Zealand Pharma A/S. B. Hartmann: None. J.J. Holst: Advisory Panel; Self; AstraZeneca, Merck Sharp &amp; Dohme Corp., Novo Nordisk A/S, Zealand Pharma A/S. Other Relationship; Spouse/Partner; Antag Therapeutics. J. Størling: None. T. Vilsbøll: Advisory Panel; Self; AstraZeneca, Mundipharma International, Novo Nordisk A/S, Sun Pharmaceutical Industries Ltd. Consultant; Self; Boehringer Ingelheim Pharmaceuticals, Inc., Lilly Diabetes, Medscape, Merck Sharp &amp; Dohme Corp., Sanofi. T.F. Dejgaard: Advisory Panel; Self; Novo Nordisk A/S. Consultant; Self; Boehringer Ingelheim International GmbH, Novo Nordisk A/S. Speaker’s Bureau; Self; AstraZeneca, Boehringer Ingelheim International GmbH, Novo Nordisk A/S. M.B. Christensen: None. F.K. Knop: Advisory Panel; Self; AstraZeneca, Merck Sharp &amp; Dohme Corp., Mundipharma International, Novo Nordisk A/S, Sanofi. Consultant; Self; Carmot Therapeutics, Inc., Eli Lilly and Company, Novo Nordisk A/S. Research Support; Self; AstraZeneca, Gubra, Novo Nordisk A/S, Sanofi, Zealand Pharma A/S. Speaker’s Bureau; Self; AstraZeneca, Lupin Pharmaceuticals, Inc., Merck Sharp &amp; Dohme Corp., Norgine B.V., Novo Nordisk A/S. Funding The Leona M. and Harry B. Helmsley Charitable Trust (2018PG-T1D037)

89-LB: The Effect of GIP on Plasma Glucose in a Setting of Prandial Insulin Overdose and Physical Activity after Meal Intake in Patients with Type 1 Diabetes

Gluco-regulatory effects of the insulinotropic and glucagonotropic gut hormone glucose-dependent insulinotropic polypeptide (GIP) in type 1 diabetes (T1D) are unclear. We evaluated the effects of exogenous and endogenous GIP on plasma glucose excursions in a setting of prandial insulin over-dose and physical activity after meal ingestion. In a randomized, placebo-controlled, double-blinded, crossover study, 12 men with T1D (age [mean±SD]: 26±6.6 years; BMI: 23±2.3 kg/m2; HbA1c: 6.5±2.7% (48.4±6.3 mmol/mol); diabetes duration: 11.3±5.5 years; plasma C-peptide &amp;lt;200 pmol/L) underwent three separate study days involving a liquid mixed meal test with 125% of regular prandial insulin dose, 30 minutes of intermediate bicycling (60 minutes after mixed-meal), and 270 minute infusions of GIP, the GIP receptor antagonist GIP(3-30)NH2 and placebo, respectively. The GIP infusion attenuated postprandial plasma glucose excursions (Cmax-Cmin) by [mean±SEM] 1.5±0.5 mmol/L and 0.92±0.56 mmol/L compared to GIP(3-30)NH2 and placebo, respectively (P=0.03). Infused glucose needed to avoid plasma glucose &amp;lt;2.5 mmol/L was similar on all 3 study days (P=0.13). In conclusion, GIP infusion seems to attenuate postprandial plasma glucose excursions without significantly increasing the need of glucose to avoid hypoglycemia in patients with T1D. Disclosure B. Hoe: None. S.M. Nguyen Heimbürger: None. L.S. Gasbjerg: Stock/Shareholder; Self; Antag Therapeutics. M.B. Lynggaard: None. B. Hartmann: None. J.J. Holst: Advisory Panel; Self; AstraZeneca, Merck Sharp &amp; Dohme Corp., Novo Nordisk A/S, Zealand Pharma A/S. Other Relationship; Spouse/Partner; Antag Therapeutics. T. Vilsbøll: Advisory Panel; Self; AstraZeneca, Mundipharma International, Novo Nordisk A/S, Sun Pharmaceutical Industries Ltd. Consultant; Self; Boehringer Ingelheim Pharmaceuticals, Inc., Lilly Diabetes, Medscape, Merck Sharp &amp; Dohme Corp., Sanofi. A. Lund: Speaker’s Bureau; Self; AstraZeneca, Novo Nordisk A/S, Sanofi. S. Engberg: None. T.F. Dejgaard: Advisory Panel; Self; Novo Nordisk A/S. Consultant; Self; Boehringer Ingelheim International GmbH, Novo Nordisk A/S. Speaker’s Bureau; Self; AstraZeneca, Boehringer Ingelheim International GmbH, Novo Nordisk A/S. M.B. Christensen: None. F.K. Knop: Advisory Panel; Self; AstraZeneca, Merck Sharp &amp; Dohme Corp., Mundipharma International, Novo Nordisk A/S, Sanofi. Consultant; Self; Carmot Therapeutics, Inc., Eli Lilly and Company, Novo Nordisk A/S. Research Support; Self; AstraZeneca, Gubra, Novo Nordisk A/S, Sanofi, Zealand Pharma A/S. Speaker’s Bureau; Self; AstraZeneca, Lupin Pharmaceuticals, Inc., Merck Sharp &amp; Dohme Corp., Norgine B.V., Novo Nordisk A/S. Funding The Leona M. and Harry B. Helmsley Charitable Trust (2018PG-T1D037)

No Acute Effects of Exogenous Glucose-Dependent Insulinotropic Polypeptide on Energy Intake, Appetite, or Energy Expenditure When Added to Treatment With a Long-Acting Glucagon-Like Peptide 1 Receptor Agonist in Men With Type 2 Diabetes.

Dual incretin receptor agonists in clinical development have shown reductions in body weight and hemoglobin A1c (HbA1c) in patients with type 2 diabetes, but the impact of glucose-dependent insulinotropic polypeptide (GIP) receptor activation remains unclear. Here, we evaluated the effects of high-dose exogenous GIP on energy intake, energy expenditure, plasma glucose, and glucose-regulating hormones in patients with type 2 diabetes treated with a long-acting glucagon-like peptide 1 receptor (GLP-1R) agonist. In a randomized, double-blind design, men with type 2 diabetes (n = 22, mean ± SEM HbA1c 6.8 ± 0.1% [51 ± 1.5 mmol/mol]) treated with metformin and long-acting GLP-1R agonists were subjected to two 5-h continuous infusions (separated by a washout period of ≥3 days): one with GIP (6 pmol/kg/min) and another with saline (placebo). After 60 min of infusion, a liquid mixed-meal test was performed, and after 270 min of infusion, an ad libitum meal was served for evaluation of energy intake (primary end point). Energy intake was similar during GIP and placebo infusion (648 ± 74 kcal vs. 594 ± 55 kcal, respectively; P = 0.480), as were appetite measures and energy expenditure. Plasma glucagon and glucose were higher during GIP infusion compared with placebo infusion (P = 0.026 and P = 0.017) as assessed by area under the curve. In patients with type 2 diabetes, GIP infusion on top of treatment with metformin and a long-acting GLP-1R agonist did not affect energy intake, appetite, or energy expenditure but increased plasma glucose compared with placebo. These results indicate no acute beneficial effects of combining GIP and GLP-1.

No evidence of tachyphylaxis for insulinotropic actions of glucose-dependent insulinotropic polypeptide (GIP) in subjects with type 2 diabetes, their first-degree relatives, or in healthy subjects

Background, aimsIn patients with type 2 diabetes, the lost insulinotropic effect of the incretin hormone glucose-dependent insulinotropic polypeptide (GIP) is more apparent after continuous versus bolus administration. To test whether the difference might be explained by rapid tachyphylaxis in response to elevated concentrations of GIP, and whether patients with type 2 diabetes and their relatives are more susceptible to tachyphylaxis than healthy subjects. Patients and MethodsIn a two-way crossover design, insulinotropic responses to repeated bolus injection (50 pmol/kg body weight at 30 and 120 min) and continuous infusion of GIP (2 pmol.kg-1.min-1 from 30 to 180 min) under hyperglycaemic clamp conditions (8.5 mmol/l) was compared in age- gender- and weight-matched patients with type 2 diabetes, first degree relatives of such patients, and healthy subjects. ResultsInsulin secretory responses to the first and second GIP bolus were not significantly different in any of the subject groups. Subjects with type 2 diabetes had a significant relative impairment versus healthy subjects with continuous (C-peptide, −13.2 %, p < 0.05), but not with repeated bolus administration of GIP (+11.1 %, n.s.). First-degree relatives tended to hyper-secrete insulin with bolus or continuous administrations of GIP. ConclusionsRapid tachyphylaxis in response to continuous exposure to slightly supraphysiological concentrations of GIP does not explain the reduced insulinotropic response to GIP infusions in patients with type 2 diabetes or their first-degree relatives.

Effect of the Incretin Hormones on the Endocrine Pancreas in End-Stage Renal Disease.

The insulin-stimulating and glucagon-regulating effects of the 2 incretin hormones, glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), contribute to maintain normal glucose homeostasis. Impaired glucose tolerance occurs with high prevalence among patients with end-stage renal disease (ESRD). To evaluate the effect of the incretin hormones on endocrine pancreatic function in patients with ESRD. Twelve ESRD patients on chronic hemodialysis and 12 matched healthy controls, all with normal oral glucose tolerance test, were included. On 3 separate days, a 2-hour euglycemic clamp followed by a 2-hour hyperglycemic clamp (3 mM above fasting level) was performed with concomitant infusion of GLP-1 (1 pmol/kg/min), GIP (2 pmol/kg/min), or saline administered in a randomized, double-blinded fashion. A 30% lower infusion rate was used in the ESRD group to obtain comparable incretin hormone plasma levels. During clamps, comparable plasma glucose and intact incretin hormone concentrations were achieved. The effect of GLP-1 to increase insulin concentrations relative to placebo levels tended to be lower during euglycemia in ESRD and was significantly reduced during hyperglycemia (50 [8-72]%, P = 0.03). Similarly, the effect of GIP relative to placebo levels tended to be lower during euglycemia in ESRD and was significantly reduced during hyperglycemia (34 [13-50]%, P = 0.005). Glucagon was suppressed in both groups, with controls reaching lower concentrations than ESRD patients. The effect of incretin hormones to increase insulin release is reduced in ESRD, which, together with elevated glucagon levels, could contribute to the high prevalence of impaired glucose tolerance among ESRD patients.

GIP's effect on bone metabolism is reduced by the selective GIP receptor antagonist GIP(3-30)NH2.

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.

2118-P: Evidence of GIP-Induced Regulation of Fatty Acid Desaturase 2 (FADS2) Gene Expression in Subcutaneous Adipose Tissue

The incretin glucose-dependent insulinotropic polypeptide (GIP) is an important regulator of postprandial metabolism by stimulating insulin secretion and inhibiting lipolysis in the adipocytes. GIP is also involved in the development of the low-grade tissue inflammation upon high-fat and high-sucrose diet, but complete mechanisms of this action remain poorly understood. Fatty acid (FA) composition affects the obesity-associated low-grade inflammation. Recently human studies showed that fatty acid desaturase 2 (FADS2) gene polymorphism is associated with FA metabolism and adipose tissue inflammation. Here we aimed to investigate the effect on GIP infusion on the FADS2 gene expression in subcutaneous adipose tissue (SAT) and FA composition in humans. Eleven male subjects without diabetes (age: 36.9 ± 1.9 years; body mass index 32.2 ± 1.0 kg/m2) underwent saline infusion (0.9% NaCl), GIP infusion at an infusion rate of 2.0 pmol kg−1min−1, lipid infusion (Intralipid 20% emulsion for infusion) or combined GIP and lipid infusion of 4 hours duration. SAT biopsies were taken at −40 min and 240 min of infusions and FADS2 mRNA levels were detected by real-time PCR. FA compositions were measured in plasma at 0 and 240 minutes of each test by LCMS. FADS2 desaturating activity was calculated as a ratio of 18:3n-6 to 18:2n-6 FA, 20:3n-6 to 20:2n-6 FA, 22:4n-5 to 22:4n-6 FA and C22:6n-3 to C22:5n3 FA. FADS2 gene expression was increased after GIP, lipid and combined GIP and lipid infusion (p&amp;lt;0.01) compared to saline infusion. 18:3n-6 to 18:2n-6 FA ratio was significantly down-regulated at the end of GIP+lipid and lipid infusion but did not change after the GIP infusion alone. The observed GIP-dependent upregulation of FADS2 gene in adipose tissue may influence regulation of adipose tissue inflammation in postprandial state and in obesity. The observed down-regulation of 18:3n-6 to 18:2n-6 ratio reflects the saturation of enzyme capacity by substrate overload during the experiments Disclosure O. Ramich: None. A.F. Pfeiffer: Advisory Panel; Self; Abbott, Berlin-Chemie AG, Novo Nordisk A/S. Speaker's Bureau; Self; Lilly Diabetes, Novartis AG, Sanofi-Aventis Deutschland GmbH. N.N. Rudovich: None.