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Follistatin is secreted from the liver and may regulate muscle growth and insulin sensitivity. Protein intake stimulates follistatin secretion, which may be mediated by increased glucagon in the context of low insulin concentrations. We investigated circulating follistatin after mixed-meals in two cohorts of patients who were part of previously published studies and had undergone bariatric surgery with either simultaneous assessment of amino acid absorption or administration of the GLP-1 receptor antagonist exendin-(9-39), which increased glucagon concentrations and impaired insulin secretion. Study 1 comprised obese matched subjects with previous Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) surgery and unoperated controls who underwent 6-hour mixed-meal tests with intravenous and oral tracers including intrinsically labelled caseinate in the meal. Study 2 comprised obese subjects with previous RYGB who underwent two 5-hour mixed-meal tests with concomitant exendin-(9-39) or saline infusion. In study 1, the secretion of follistatin as well as the amino acid absorption was accelerated after RYGB compared with SG and controls, but the glucagon-to-C-peptide ratios did not differ between the groups. In study 2, exendin-(9-39) administration increased postprandial glucagon concentrations and lowered insulin secretion, whereas the concentration of follistatin was unchanged. In conclusion, postprandial follistatin secretion is accelerated in patients after RYGB which might be explained by an accelerated protein absorption rate rather than the glucagon-to-insulin ratio.

Our combined data show that GDF15 does not increase in response to a liquid meal. Moreover, we show for the first time that ingestion of sucrose, isomaltose, glucose, fat, or protein also does not increase plasma GDF15 concentrations, questioning the role of GDF15 in regulation of food source preference. Finally, we find that neither fasting nor postprandial plasma GDF15 concentrations are increased in individuals with previous bariatric surgery compared with unoperated body mass index (BMI)-matched controls.

Enhanced secretion of glucagon-like peptide-1 (GLP-1) seems to be essential for improved postprandial β-cell function after Roux-en-Y gastric bypass (RYGB) but is less studied after sleeve gastrectomy (SG). Moreover, the role of the other major incretin hormone, glucose-dependent insulinotropic polypeptide (GIP), is relatively unexplored after bariatric surgery. We studied the effects of separate and combined GLP-1 receptor (GLP-1R) and GIP receptor (GIPR) blockade during mixed meal tests in unoperated (CON), SG-operated, and RYGB-operated people with no history of diabetes. Postprandial GLP-1 concentrations were highest after RYGB but also higher after SG compared with CON. In contrast, postprandial GIP concentrations were lowest after RYGB. The effect of GLP-1R versus GIPR blockade differed between groups. GLP-1R blockade reduced β-cell glucose sensitivity and increased or tended to increase postprandial glucose responses in the surgical groups but had no effect in CON. GIPR blockade reduced β-cell glucose sensitivity and increased or tended to increase postprandial glucose responses in the CON and SG groups but had no effect in the RYGB group. Our results support that GIP is the most important incretin hormone in unoperated people, whereas GLP-1 and GIP are equally important after SG, and GLP-1 is the most important incretin hormone after RYGB.

Follistatin is secreted from the liver and is involved in the regulation of muscle mass and insulin sensitivity via inhibition of activin A in humans. The secretion of follistatin seems to be stimulated by glucagon and inhibited by insulin, but only limited knowledge on the postprandial regulation of follistatin exists. Moreover, results on postoperative changes after Roux-en-Y gastric bypass (RYGB) are conflicting with reports of increased, unaltered, and lowered fasting concentrations of follistatin. In this study, we investigated postprandial follistatin and activin A concentrations after intake of isocaloric amounts of protein, fat, or glucose in subjects with obesity with and without previous RYGB to explore the regulation of follistatin by the individual macronutrients. Protein intake enhanced follistatin concentrations similarly in the two groups, whereas glucose and fat ingestion did not change postprandial follistatin concentrations. Concentrations of activin A were lower after protein intake compared with glucose intake in RYGB. Glucagon concentrations were also particularly enhanced by protein intake and tended to correlate with follistatin in RYGB. In conclusion, we demonstrated that protein intake, but not glucose or fat, is a strong stimulus for follistatin secretion in subjects with obesity and that this regulation is maintained after RYGB surgery.

Sacubitril/valsartan is a neprilysin-inhibitor/angiotensin II receptor blocker used for the treatment of heart failure. Recently, a post-hoc analysis of a 3-year randomized controlled trial showed improved glycaemic control with sacubitril/valsartan in patients with heart failure and type 2 diabetes. We previously reported that sacubitril/valsartan combined with a dipeptidyl peptidase-4 inhibitor increases active glucagon-like peptide-1 (GLP-1) in healthy individuals. We now hypothesized that administration of sacubitril/valsartan with or without a dipeptidyl peptidase-4 inhibitor would lower postprandial glucose concentrations (primary outcome) in patients with type 2 diabetes via increased active GLP-1.We performed a crossover trial in 12 patients with obesity and type 2 diabetes. A mixed meal was ingested following five respective interventions: (a) a single dose of sacubitril/valsartan; (b) sitagliptin; (c) sacubitril/valsartan + sitagliptin; (d) control (no treatment); and (e) valsartan alone. Glucose, gut and pancreatic hormone responses were measured.Postprandial plasma glucose increased by 57% (incremental area under the curve 0-240 min) (p = .0003) and increased peak plasma glucose by 1.7 mM (95% CI: 0.6-2.9) (p = .003) after sacubitril/valsartan compared with control, whereas postprandial glucose levels did not change significantly after sacubitril/valsartan + sitagliptin. Glucagon, GLP-1 and C-peptide concentrations increased after sacubitril/valsartan, but insulin and glucose-dependent insulinotropic polypeptide did not change.The glucose-lowering effects of long-term sacubitril/valsartan treatment reported in patients with heart failure and type 2 diabetes may not depend on changes in entero-pancreatic hormones. Neprilysin inhibition results in hyperglucagonaemia and this may explain the worsen glucose tolerance observed in this study.gov (NCT03893526).

Glucagon is a key regulator of metabolism and is used in the diagnostic of neuroendocrine tumors. Accurate measurement of glucagon requires both extreme sensitivity and specificity since several peptides are derived from the same proglucagon precursor encoding part of the glucagon sequence and given that glucagon circulates in picomolar concentrations. A sandwich ELISA was recently developed and extensively evaluated; however, this method may not be accurate when measuring glucagon in patients with an enhanced production of proglucagon-derived peptides as seen after Roux-en-Y gastric bypass (RYGB). To overcome this, a modified version of the ELISA was developed. In this study, we evaluate an unmodified and a modified version of the ELISA in healthy individuals, individuals with obesity, and finally in two cohorts of patients following RYGB surgery using different nutrient stimuli to assess glucagon dynamics. Finally, in vitro spike-in recoveries using native glucagon and proglucagon-derived peptides were performed in buffer and in plasma. Our data support that both versions of the ELISA accurately capture endogenous and exogenous glucagon in healthy individuals and in individuals with obesity. However, the unmodified version of the assay may overestimate glucagon levels in patients following RYGB in line with minimal but consistent cross-reactivity to oxyntomodulin and glicentin that both are 50-fold increased after RYGB. Importantly, we did not find any changes between the two protocols at fasted conditions and therefore diagnostics of glucagonomas is not affected by the choice of assay procedure nor the surgical history of the patient (RYGB).

Women with polycystic ovary syndrome (PCOS) have been shown to be less insulin sensitive compared with control (CON) women, independent of BMI. Training is associated with molecular adaptations in skeletal muscle, improving glucose uptake and metabolism in both healthy individuals and patients type 2 diabetes. In the current study, lean hyperandrogenic women with PCOS (n = 9) and healthy CON women (n = 9) completed 14 weeks of controlled and supervised exercise training. In CON, the training intervention increased whole body insulin action by 26% and insulin-stimulated leg glucose uptake by 53%, together with increased insulin-stimulated leg blood flow and a more oxidative muscle fiber type distribution. In PCOS, no such changes were found, despite similar training intensity and improvements in VO2max. In skeletal muscle of CON but not PCOS, training increased GLUT4 and HKII mRNA and protein expressions. These data suggest that the impaired increase in whole-body insulin action in women with PCOS with training is caused by an impaired ability to upregulate key glucose-handling proteins for insulin-stimulated glucose uptake in skeletal muscle and insulin-stimulated leg blood flow. Still, other important benefits of exercise training appeared in women with PCOS, including an improvement of the hyperandrogenic state.

Enhanced meal-related enteroendocrine secretion, particularly of glucagon-like peptide-1 (GLP-1), contributes to weight-loss and improved glycemia after Roux-en-Y gastric bypass (RYGB). Dietary glucose drives GLP-1 and glucose-dependent insulinotropic polypeptide (GIP) secretion postoperatively. Understanding how glucose triggers incretin secretion following RYGB could lead to new treatments of diabetes and obesity. In vitro, incretin release depends on glucose absorption via sodium-glucose cotransporter 1 (SGLT1). We investigated the importance of SGLT1/SGLT2 for enteropancreatic hormone concentrations and glucose metabolism after RYGB in a randomized, controlled, crossover study. Ten RYGB-operated patients ingested 50 g of oral glucose with and without acute pretreatment with 600 mg of the SGLT1/SGLT2-inhibitor canagliflozin. Paracetamol and 3- O-methyl-d-glucopyranose (3-OMG) were added to the glucose drink to evaluate rates of intestinal entry and absorption of glucose, respectively. Blood samples were collected for 4 h. The primary outcome was 4-h plasma GLP-1 (incremental area-under the curve, iAUC). Secondary outcomes included glucose, GIP, insulin, and glucagon. Canagliflozin delayed glucose absorption (time-to-peak 3-OMG: 50 vs. 132 min, P < 0.01) but did not reduce iAUC GLP-1 (6,067 vs. 7,273·min·pmol−1·L−1, P = 0.23), although peak GLP-1 concentrations were lowered (−28%, P = 0.03). Canagliflozin reduced GIP (iAUC −28%, P = 0.01; peak concentrations −57%, P < 0.01), insulin, and glucose excursions, whereas plasma glucagon (AUC 3,216 vs. 4,160 min·pmol·L−1, P = 0.02) and amino acids were increased. In conclusion, acute SGLT1/SGLT2-inhibition during glucose ingestion did not reduce 4-h plasma GLP-1 responses in RYGB-patients but attenuated the early rise in GLP-1, GIP, and insulin, whereas late glucagon concentrations were increased. The results suggest that SGLT1-mediated glucose absorption contributes to incretin hormone secretion after RYGB.

Bile acids in plasma are elevated after bariatric surgery and may contribute to metabolic improvements, but underlying changes in bile flow are poorly understood. We assessed bilio-enteric flow of bile and plasma bile concentrations in individuals with Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) surgery compared with matched non-surgical controls (CON). Fifteen RYGB, 10 SG and 15 CON underwent 99Tc-mebrofenin cholescintigraphy combined with intake of a high-fat 111In-DTPA-labelled meal and frequent blood sampling. A 75Se-HCAT test was used to assess bile acid retention. After RYGB, gallbladder filling was decreased (p = 0.045 versus CON), basal flow of bile into the small intestine increased (p = 0.005), bile acid retention augmented (p = 0.021) and basal bile acid plasma concentrations elevated (p = 0.009). During the meal, foods passed unimpeded through the gastric pouch resulting in almost instant postprandial mixing of bile and foods, but the postprandial rise in plasma bile acids was brief and associated with decreased overall release of fibroblast growth factor-19 (FGF-19) compared with CON (p = 0.033). After SG, bile flow and retention were largely unaltered (p > 0.05 versus CON), but gastric emptying was accelerated (p

BackgroundSkeletal muscle wasting is often associated with insulin resistance. A major regulator of muscle mass is the transforming growth factor β (TGF-β) superfamily, including activin A, which causes atrophy. TGF-β superfamily ligands also negatively regulate insulin-sensitive proteins, but whether this pathway contributes to insulin action remains to be determined.MethodsTo elucidate if TGF-β superfamily ligands regulate insulin action we used an adeno-associated virus gene editing approach to overexpress the activin A inhibitor, follistatin (Fst288) in mouse muscle of lean and diet-induced obese mice. We determined basal and insulin-stimulated 2 deoxy-glucose uptake using isotopic tracers in vivo. Furthermore, to evaluate whether circulating Fst and activin A concentrations are associated with obesity, insulin resistance, and weight loss in humans we analysed serum from morbidly obese subjects before, 1 week, and 1 year after Roux-en-Y gastric bypass (RYGB).ResultsFst288 muscle overexpression markedly increased in vivo insulin-stimulated (but not basal) glucose uptake (+75%, pConclusionsWe here present evidence that Fst is a potent regulator of insulin action in muscle and in addition to AKT and p70S6K, we identify TBC1D1, TBC1D4 and PAK1 as Fst targets. A possible role for Fst in regulating glycemic control is suggested because circulating Fst more than doubled post RYGB surgery, a treatment that markedly improved insulin sensitivity. These findings demonstrate the therapeutic potential of inhibiting TGF-β superfamily ligands to improve insulin action and Fst’s relevance to muscle wasting associated insulin resistant conditions in mice and humans.

Weight regain after weight loss is a major problem in the treatment of persons with obesity.In a randomized, head-to-head, placebo-controlled trial, we enrolled adults with obesity (body-mass index [the weight in kilograms divided by the square of the height in meters], 32 to 43) who did not have diabetes. After an 8-week low-calorie diet, participants were randomly assigned for 1 year to one of four strategies: a moderate-to-vigorous-intensity exercise program plus placebo (exercise group); treatment with liraglutide (3.0 mg per day) plus usual activity (liraglutide group); exercise program plus liraglutide therapy (combination group); or placebo plus usual activity (placebo group). End points with prespecified hypotheses were the change in body weight (primary end point) and the change in body-fat percentage (secondary end point) from randomization to the end of the treatment period in the intention-to-treat population. Prespecified metabolic health-related end points and safety were also assessed.After the 8-week low-calorie diet, 195 participants had a mean decrease in body weight of 13.1 kg. At 1 year, all the active-treatment strategies led to greater weight loss than placebo: difference in the exercise group, -4.1 kg (95% confidence interval [CI], -7.8 to -0.4; P = 0.03); in the liraglutide group, -6.8 kg (95% CI, -10.4 to -3.1; P0.001); and in the combination group, -9.5 kg (95% CI, -13.1 to -5.9; P0.001). The combination strategy led to greater weight loss than exercise (difference, -5.4 kg; 95% CI, -9.0 to -1.7; P = 0.004) but not liraglutide (-2.7 kg; 95% CI, -6.3 to 0.8; P = 0.13). The combination strategy decreased body-fat percentage by 3.9 percentage points, which was approximately twice the decrease in the exercise group (-1.7 percentage points; 95% CI, -3.2 to -0.2; P = 0.02) and the liraglutide group (-1.9 percentage points; 95% CI, -3.3 to -0.5; P = 0.009). Only the combination strategy was associated with improvements in the glycated hemoglobin level, insulin sensitivity, and cardiorespiratory fitness. Increased heart rate and cholelithiasis were observed more often in the liraglutide group than in the combination group.A strategy combining exercise and liraglutide therapy improved healthy weight loss maintenance more than either treatment alone. (Funded by the Novo Nordisk Foundation and others; EudraCT number, 2015-005585-32; ClinicalTrials.gov number, NCT04122716.).

Neurotensin (NT) is released from enteroendocrine cells and lowers food intake in rodents. We evaluated postprandial NT secretion in humans after surgeries associated with accelerated small intestinal nutrient delivery, and after Roux-en-Y gastric bypass (RYGB) when glucagon-like peptide-1 (GLP-1) signalling and dipeptidyl peptidase 4 (DPP-4) were inhibited, and during pharmacological treatments influencing entero-pancreatic functions.We measured NT concentrations in plasma from meal studies: (I) after truncal vagotomy with pyloroplasty (TVP), cardia resection +TVP (CTVP), and matched controls (n = 10); (II) after RYGB, sleeve gastrectomy (SG), and in matched controls (n = 12); (III) after RYGB (n = 11) with antagonism of GLP-1 signalling using exendin(9-39) and DPP-4 inhibition using sitagliptin; (IV) after RYGB (n = 11) during a run-in period and subsequent treatment with, sitagliptin, liraglutide (GLP-1 receptor agonist), verapamil (calcium antagonist), acarbose (alpha glucosidase inhibitor), and pasireotide (somatostatin analogue), respectively.(I) NT secretion was similar after TVP/CTVP (p = 0.9), but increased vs. controls (p 0.0001). (II) NT secretion was increased after RYGB vs. SG and controls (p 0.0001). NT responses were similar in SG and controls (p = 0.3), but early postprandial NT concentrations were higher after SG (p 0.05). (III) Exendin (9-39) and sitagliptin did not change NT responses vs placebo (p 0.2), but responses were lower during sitagliptin vs. exendin(9-39) (p = 0.03). (IV) Pasireotide suppressed NT secretion (p = 0.004). Sitagliptin tended to lower NT secretion (p = 0.08). Liraglutide, verapamil, and acarbose had no effect (p 0.9).Neurotensin secretion is increased after surgeries associated with accelerated gastric emptying and lowered by pasireotide.

The worldwide prevalence of obesity and type 2 diabetes (T2D) constitutes an epidemic that is a threat to public health. Bariatric surgery, including Roux en-Y gastric bypass (RYGB), is currently the most effective treatment to induce long-term weight loss and remission of co-morbid conditions. Surgery, however, comes with an added risk of complications, highlighting the need to understand the comparative effectiveness and risks of surgical versus conventional approaches to the treatment of obesity and T2D.Positive and negative outcomes of RYGB surgery in patients with T2D are assessed, with a primary focus on RYGB surgery versus standard non-surgical treatment of obese patients with T2D in randomized clinical trials or high-quality observational cohorts. Searches were conducted in the PubMed database up to 11 April 2019 for relevant studies.High-level evidence reveals that RYGB ameliorates the clinical manifestations of T2D to a significantly higher degree than medical therapy. Postoperative incidence of beneficial effects and complications, however, differ across subgroups of patients with different preoperative characteristics. Key knowledge gaps, particularly on long-term complications, microvascular- and macrovascular events, and mortality should be addressed, so treatment with RYGB can be applied in an individualized approach to maximize benefits and minimize complications.

Bariatric surgery results in marked body weight loss and improves type 2 diabetes in most patients with obesity. The growth differentiation factor 15 (GDF15) has recently emerged as a novel satiety factor. To begin to understand whether GDF15 is involved in mediating the effects of bariatric surgery on body weight and glycemia in humans, we measured plasma GDF15 in patients with obesity ( n = 25) and in patients with obesity and diabetes ( n = 22) before and after Roux-en-Y gastric bypass (RYGB) surgery. GDF15 was increased 1 wk after RYGB compared with before surgery (689 ± 45 vs. 487 ± 28 pg/ml, P < 0.001) and GDF15 remained elevated at 3 mo (554 ± 37 pg/ml, P < 0.05), at 1 yr (566 ± 37 pg/ml, P < 0.05), and at 2.5–4 yr (630 ± 50 pg/ml, P < 0.001) after RYGB surgery. Both age and insulin sensitivity correlated with GDF15 before the surgery ( r = 0.46, P < 0.0001 and r = 0.34, P < 0.001, respectively). These correlations disappeared at 2.5–4 yr following the surgery. Conversely, weight loss magnitude correlated with GDF15, measured 2.5–4 yr postsurgery ( r = 0.21, P < 0.0055). In summary, circulating GDF15 increases and correlates with body weight loss following RYGB surgery.

Hyperinsulinemia is the hallmark of insulin resistance in obesity, and the relative importance of insulin clearance, insulin resistance, and insulin hypersecretion has been widely debated. On the basis of recent experimental evidence, we summarize existing evidence to suggest hepatic insulin clearance as a major and immediate regulator of systemic insulin concentrations responding within days to altered dietary energy and, in particular, carbohydrate intake. Hepatic insulin clearance seems to be closely associated with opposite alterations in hepatic lipid content and glucose production, providing a potential mechanistic link to hepatic insulin sensitivity. The molecular regulation of insulin clearance in the liver is likely to involve changes in insulin binding and receptor internalization in response to the dietary alterations, the molecular mechanisms of which await further research.

Accumulation of hepatic triacylglycerol (TG) is associated with obesity and metabolic syndrome, which are important pathogenic factors in the development of type 2 diabetes. In this narrative review, we summarize the effects of hepatic TG accumulation on hepatic glucose and insulin metabolism and the underlying molecular regulation in order to highlight the importance of hepatic TG accumulation for whole-body glucose metabolism. We find that liver fat accumulation is closely linked to impaired insulin-mediated suppression of hepatic glucose production and reduced hepatic insulin clearance. The resulting systemic hyperinsulinemia has a major impact on whole-body glucose metabolism and may be an important pathogenic step in the development of type 2 diabetes.

Background: Pregnancy-associated plasma protein-A (PAPP-A) is an enzyme that increases IGF-activity through cleavage of IGF-binding proteins (IGFBPs), primarily IGFBP-4, whereby bound IGF-I becomes released as a free molecule. The enzymatic activity of PAPP-A is irreversibly suppressed by the glycoprotein stanniocalcin-2 (STC2). Pre-clinical and clinical studies suggest that the STC2 – PAPP-A – IGFBP-4 axis is important in controlling local IGF-action. STC2, PAPP-A and IGFBP-4 are expressed in adipose tissue, and as bariatric surgery markedly reduces the amount of fat, we found it relevant to study the impact of Roux-en-Y gastric bypass (RYGB) on circulating concentrations of this IGF-regulatory network. Methods: Analysis of fasting blood samples from 20 obese subjects, hereof 10 with preoperative type 2 diabetes, investigated before RYGB, and 1 week, 3 months and 12 months post-surgery. Members of the IGF-system were analyzed by immunoassays, bioactive IGF by cell-based IGF-I receptor activation assay. We compared changes in IGF-system components with changes in fasting plasma insulin and glucose, and HbA1c. Results: PAPP-A remained unchanged, but STC2 decreased following RYGB (p < 0.05). The PAPP-A substrate IGFBP-4 declined (p < 0.01), whereas levels of PAPP-A specific IGFBP-4 fragments increased (p < 0.05), indicating an increased PAPP-A enzymatic activity post-RYGB. Further, the reduction in intact IGFBP-4 correlated with increased levels of bioactive IGF (p < 0.05). In multivariable regression analyses, an improved glucose metabolism correlated with reductions in STC2 and IGFBP-4, and with increases in bioactive IGF and IGF-I (p < 0.05). Conclusion: After 12 months, RYGB caused reduced serum concentrations of intact IGFBP-4 and STC2, whereas serum PAPP-A remained at pre-operative levels. However, concentrations of PAPP-A generated IGFBP-4 fragments increased, pointing to an overall increased PAPP-A enzymatic activity following RYGB. Notably, reductions in intact IGFBP-4 and STC2 associated with improvements in glucose metabolism. Therefore, we propose that STC2 and IGFBP-4 are involved in the metabolic improvement that follows RYGB.

The Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) bariatric procedures lead to remission or improvement of type 2 diabetes. A weight loss-independent augmentation of postprandial insulin secretion contributes to the improvement in glycemic control after RYGB and is associated with a ∼10-fold increase in plasma concentrations of the incretin hormone glucagon-like peptide-1 (GLP-1). However, the physiologic importance of the markedly increased postprandial GLP-1 secretion after RYGB has been much debated. The effect of GLP-1 receptor blockade after RYGB has been investigated in 12 studies. The studies indicate a shift toward a more prominent role for GLP-1 in postprandial β-cell function after RYGB. The effect of GLP-1 receptor antagonism on glucose tolerance after RYGB is more complex and is associated with important methodological challenges. The postprandial GLP-1 response is less enhanced after SG compared with RYGB. However, the effect of GLP-1 receptor blockade after SG has been examined in 1 study only and needs further investigation.

Women with polycystic ovary syndrome (PCOS) have been shown to be less insulin sensitive compared with control women, independent of BMI. Training is associated with molecular adaptations in skeletal muscle improving glucose uptake and metabolism in both healthy and type 2 diabetic individuals. In the present study, lean, hyperandrogenic women with PCOS (n=9) and healthy controls (CON, n=9) completed 14 weeks of controlled and supervised exercise training. In CON, the training intervention increased whole body insulin action by 26% and insulin-stimulated leg glucose uptake by 53%, together with increased insulin-stimulated leg blood flow and a more oxidative muscle fiber type distribution. In PCOS, no such changes were found, despite similar training intensity and improvements in maximal oxygen uptake. In skeletal muscle of CON, but not PCOS, training increased GLUT4 and HKII mRNA and protein expressions. These data suggest that the impaired increase in whole body insulin action in women with PCOS with training is caused by an impaired ability to upregulate key glucose handling proteins for insulin-stimulated glucose uptake in skeletal muscle, and insulin-stimulated leg blood flow. Still, other important benefits of exercise training appeared in women with PCOS, including an improvement of the hyperandrogenic state.

Plasma concentrations of the two pancreatic enzymes, amylase and lipase, are increased within the normal physiological range after initiation of glucagon-like peptide-1 receptor agonist (GLP-1RA) treatment. An association between the use of GLR-1RA and incidence of acute pancreatitis or pancreatic cancer has not been found - neither in rodent studies nor in preclinical studies or in the large cardiovascular outcome trials with GLP-1RAs. The increased concentrations of pancreatic enzymes have been suggested to be explained by increased DNA or protein synthesis found in rodent and acinar cell studies. However, whether this translates into humans is unknown. We therefore investigated the effect of liraglutide, a GLP-1RA, on pancreatic volume, edema and DNA synthesis reflected by 18F-flourothymidine (FLT)-uptake using state-of-the-art positron emission tomography (PET)-magnetic resonance imaging (MRI) before initiation, after four weeks during titration of liraglutide and after six weeks during steady state on maximum dose of liraglutide 3.0 mg in 14 obese men (age 38 ± 3 years, BMI 32 ± 1 kg/m2) without diabetes. Plasma concentrations of amylase and lipase were assessed in parallel. Amylase (+7 U/L [95% confidence intervals, 3 - 11] p In conclusion, six weeks of treatment with liraglutide did not affect pancreatic volume, edema or cellularity in obese individuals. Increased DNA synthesis reflected by FLT-uptake in the pancreas seen after four weeks of liraglutide treatment may be responsible for the increase in pancreatic enzymes. Disclosure M.S. Svane: None. H.H. Johannesen: None. C. Martinussen: None. K.N. Bojsen-Moller: None. M.L. Hansen: None. A.E. Hansen: None. C.F. Deacon: Employee; Spouse/Partner; Merck & Co., Inc. Stock/Shareholder; Spouse/Partner; Merck & Co., Inc. Other Relationship; Self; Boehringer Ingelheim International GmbH, Eli Lilly and Company, Merck & Co., Inc., Novartis AG, Novo Nordisk A/S. B. Hartmann: None. S.H. Keller: None. T.L. Klausen: None. A. Loft: None. A. Kjaer: None. S. Madsbad: Advisory Panel; Self; AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Merck Sharp & Dohme Corp., Novo Nordisk A/S, Sanofi-Aventis. Research Support; Self; Boehringer Ingelheim International GmbH, Novo Nordisk A/S. Speaker’s Bureau; Self; AstraZeneca, Boehringer Ingelheim International GmbH, Novo Nordisk A/S. J.O. Löfgren: None. J.J. Holst: Advisory Panel; Self; AstraZeneca, Merck Sharp & Dohme Corp., Novo Nordisk A/S, Zealand Pharma A/S. Other Relationship; Spouse/Partner; Antag Therapeutics. N.J. Wewer Albrechtsen: Research Support; Self; Mercodia, Novo Nordisk A/S, Novo Nordisk Foundation. Speaker’s Bureau; Self; Merck Sharp & Dohme Corp.

Background: Weight loss decreases energy expenditure and increases appetite, leading to weight regain. Energy expenditure can be targeted with exercise, and appetite with the glucagon-like peptide-1 (GLP-1) receptor agonist, liraglutide.The objective was to investigate 1-year weight loss maintenance and change in body composition with liraglutide, exercise, and the combination in individuals with obesity after a very low-calorie diet (VLCD). Methods: Double-blinded, randomized placebo-controlled trial. Following 8-weeks of VLCD (800 kcal/day), inducing a body weight loss of ≥ 5%, the participants were randomized to 1-year of treatment with 1) liraglutide 3.0 mg/day (LIRA), 2) exercise 150 min/week + placebo (EX), 3) exercise 150 min/week + liraglutide 3.0 mg/day (LIRA + EX), or 4) placebo (PLA). Results: Participants with obesity were included (n = 215, 64% women, age 42 years (IQR 30.7 to 51.9), BMI 36.6 kg/m2 (34.5 to 39.2)). See Table 1 for all results. Conclusion: The combination of liraglutide and exercise was superior to placebo and exercise alone, and numerically better to liraglutide, in weight loss maintenance and further weight reduction. Fat percentage loss with the combination treatment was superior to liraglutide and exercise alone, supporting the combined treatment for healthy weight loss maintenance. Disclosure C. Janus: Research Support; Spouse/Partner; Mercodia, Novo Nordisk A/S. Research Support; Self; Novo Nordisk Foundation. Research Support; Spouse/Partner; Novo Nordisk Foundation. Speaker’s Bureau; Spouse/Partner; Merck Sharp & Dohme Corp. J.R. Lundgren: None. S. Jensen: None. L.M. Olsen: None. C. Juhl: None. M.B. Blond: None. R.M. Christensen: None. K.N. Bojsen-Moller: None. M.S. Svane: None. T. Bandholm: Employee; Spouse/Partner; Novo Nordisk A/S. Stock/Shareholder; Spouse/Partner; Novo Nordisk A/S. J.B. Jensen: None. B. Stallknecht: None. J.J. Holst: Advisory Panel; Self; AstraZeneca, Merck Sharp & Dohme Corp., Novo Nordisk A/S, Zealand Pharma A/S. Other Relationship; Spouse/Partner; Antag Therapeutics. S. Madsbad: Advisory Panel; Self; AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Merck Sharp & Dohme Corp., Novo Nordisk A/S, Sanofi-Aventis. Research Support; Self; Boehringer Ingelheim International GmbH, Novo Nordisk A/S. Speaker’s Bureau; Self; AstraZeneca, Boehringer Ingelheim International GmbH, Novo Nordisk A/S. S.S. Torekov: Research Support; Self; Novo Nordisk Inc. Funding Novo Nordisk Foundation (NNF16OC0019968); Novo Nordisk Center for Metabolic Research; Helsefonden

Background: Altered meal-associated secretion of gut peptides is key for the metabolic changes and weight-loss observed after Roux-en-Y gastric bypass (RYGB). Parenteral administration of the gut peptide neurotensin (NT) reduces food intake in rodents, and, like glucagon-like peptide-1 and peptide YY, the secretion of NT is markedly increased after RYGB. We therefore investigated the effect of intravenous (IV) NT on ad libitum food intake and appetite sensations. Design: Using a double-blinded, randomized placebo-controlled design, NT (2.5pmol/kg/min) or saline was infused IV in healthy young men to obtain NT concentrations similar to NT levels observed postprandially after RYGB. Four visits were performed in random order, after an acclimatization visit, to evaluate the main outcomes - ad libitum food intake and appetite sensations (visual analogue scale (VAS) questionnaires). Blood samples were collected for plasma and serum analyses (including entero-pancreatic peptides and glucose). NT or saline was infused after a basal period (t= -60 to 0 min). On two study days (n=18), an ad libitum meal was served after one hour of infusion (t= 60 min) followed by blood sampling/VAS until t= 120 min (infusion discontinued). On two other study days (n=16), a liquid mixed meal was ingested after one hour of infusion (t = 60 min) followed by blood sampling and VAS until an ad libitum meal was served at t= 240 min (infusion discontinued at t=270min). Results: Food intake was similar on the ad libitum meal (t = 60 min) days - NT (4150 (3607-4696)kJ, mean (95% confidence interval) vs. saline (3820 (3250-4405) kJ, P=0.062 (paired t-test)) and on the LMM + ad libitum meal (t= 240 min) days - NT (4320 (3698-5008)kJ vs. saline (4250 (3739-4870)kJ, P=0.80). NT infusions did not influence appetite sensations or elicit gastrointestinal side effects. Conclusions: Despite obtaining NT concentrations similar to what is observed postprandially after RYGB, we did not observe any differences in appetite sensations or food intake. Disclosure S. Veedfald: None. C. Martinussen: None. M.S. Svane: None. T. Justinussen: None. M.G. Hindsø: None. N. Hedbäck: None. C.B. Christiansen: None. N.J. Wewer Albrechtsen: Research Support; Self; Mercodia, Novo Nordisk A/S, Novo Nordisk Foundation. Speaker’s Bureau; Self; Merck Sharp & Dohme Corp. K.N. Bojsen-Moller: None. B. Hartmann: None. M. Fenger: None. J.F. Rehfeld: None. S. Madsbad: Advisory Panel; Self; AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Merck Sharp & Dohme Corp., Novo Nordisk A/S, Sanofi-Aventis. Research Support; Self; Boehringer Ingelheim International GmbH, Novo Nordisk A/S. Speaker’s Bureau; Self; AstraZeneca, Boehringer Ingelheim International GmbH, Novo Nordisk A/S. J.J. Holst: Advisory Panel; Self; AstraZeneca, Merck Sharp & Dohme Corp., Novo Nordisk A/S, Zealand Pharma A/S. Other Relationship; Spouse/Partner; Antag Therapeutics. Funding Desirée og Niels Ydes Fond; Læge Sophus og hustru Olga Friis Legat; Beckett Fonden; Hørslev Fonden; Aase og Ejnar Danielsens Fond; Fabrikant Frands Køhler Nielsen og hustrus legat; Carl og Ellen Hertz’ Legat

Roux-en-Y gastric bypass (RYGB) surgery is a therapeutic intervention for morbid obesity and type 2 diabetes (T2D) that improves metabolic regulation. Follistatin (Fst) could be implicated in improved glycemia as it is highly regulated by RYGB. However, it is unknown if metabolic status, such as T2D, alters the Fst response to RYGB. In addition, the effect of RYGB on the Fst target, activin A, is unknown in individuals with obesity and T2D, but is needed to interpret the functional effects of altering Fst. Finally, whether Fst-regulated intracellular signaling contributes to beneficial effects of RYGB is undetermined. Circulating Fst and activin A were measured before, 1 week, and 1 year after RYGB surgery in a total of 20 individuals with obesity, 10 with normoglycemia (NGT) and 10 with preoperative T2D. Intracellular signaling downstream of the Activin receptor type IIB (ActRIIB) signaling pathway was analyzed in skeletal muscle and adipose tissue. The doubling in circulating Fst observed in subjects with NGT 1-week and 1-year post surgery was absent in T2D. After 1 week, RYGB reduced activin A by 27% (p

AIM To investigate the effect of a glucagon-like peptide-1 receptor agonist (GLP-1RA), liraglutide, on pancreatic volume, oedema, cellularity and DNA synthesis in humans. MATERIALS AND METHODS We performed an open-label study in 14 obese men (age 38 ± 11 years, body mass index 32 ± 4 kg/m2 ) without diabetes. Subjects were examined at baseline, during titration (week 4) of liraglutide towards 3.0 mg/day, and 2 weeks after steady-state treatment (week 6) of a final dose of liraglutide. The primary endpoint was pancreatic volume determined by magnetic resonance imaging. Secondary endpoints included pancreatic oedema and cellularity, positron emission tomography-based [18 F]fluorothymidine (FLT) uptake (DNA synthesis) and plasma pancreatic enzymes. RESULTS Plasma amylase (+7 U/L [95% confidence intervals 3-11], P

Postprandial gut hormone responses change after Roux-en-Y gastric bypass (RYGB), and we investigated the impact of glucose, protein, and fat (with and without pancreas lipase inhibition) on plasma responses of gut and pancreas hormones, bile acids, and fibroblast growth factor 21 (FGF-21) after RYGB and in nonoperated control subjects. In a randomized, crossover study 10 RYGB operated and 8 healthy weight-matched control subjects were administered 4 different 4-h isocaloric (200 kcal) liquid meal tests containing >90 energy (E)% of either glucose, protein (whey protein), or fat (butter with and without orlistat). The primary outcome was glucagon-like peptide-1 (GLP-1) secretion (area under the curve above baseline). Secondary outcomes included responses of peptide YY (PYY), glucose-dependent insulinotropic polypeptide (GIP), cholecystokinin (CCK), glicentin, neurotensin, ghrelin, insulin, glucagon, bile acids, and FGF-21. In the RYGB group the responses of GLP-1, GIP, glicentin, FGF-21, and C-peptide were increased after glucose compared with the other meals. The neurotensin and bile acids responses were greater after fat, while the glucagon and CCK responses were greater after protein ingestion. Furthermore, compared with control subjects, RYGB subjects had greater responses of total PYY after glucose, glucagon after glucose and fat, glicentin after glucose and protein, and GLP-1 and neurotensin after all meals, while GIP and CCK responses were lower after fat. Ghrelin responses did not differ between meals or between groups. Orlistat reduced all hormone responses to fat ingestion, except for ghrelin in the RYGB group. In conclusion, after RYGB glucose is a more potent stimulator of most gut hormones, especially for the marked increased secretion of GLP-1 compared with fat and protein. NEW & NOTEWORTHY We investigated the impact of glucose, protein, and fat meals on intestinal and pancreatic hormones, bile acid, and fibroblast growth factor 21 (FGF-21) secretion in gastric bypass-operated patients compared with matched nonoperated individuals. The fat meal was administered with and without a pancreas lipase inhibitor. We found that the impact of the different meals on gut hormones, bile, and FGF 21 secretion differ and was different from the responses observed in nonoperated control subjects.

ObjectivesGastrointestinal hormones contribute to the beneficial effects of Roux-en-Y gastric bypass surgery (RYGB) on glycemic control. Secretin is secreted from duodenal S cells in response to low luminal pH, but it is unknown whether its secretion is altered after RYGB and if secretin contributes to the postoperative improvement in glycemic control. We hypothesized that secretin secretion increases after RYGB as a result of the diversion of nutrients to more distal parts of the small intestine, and thereby affects islet hormone release.MethodsA specific secretin radioimmunoassay was developed, evaluated biochemically, and used to quantify plasma concentrations of secretin in 13 obese individuals before, 1 week after, and 3 months after RYGB. Distribution of secretin and its receptor was assessed by RNA sequencing, mass-spectrometry and in situ hybridization in human and rat tissues. Isolated, perfused rat intestine and pancreas were used to explore the molecular mechanism underlying glucose-induced secretin secretion and to study direct effects of secretin on glucagon, insulin, and somatostatin secretion. Secretin was administered alone or in combination with GLP-1 to non-sedated rats to evaluate effects on glucose regulation.ResultsPlasma postprandial secretin was more than doubled in humans after RYGB (P P P = 0.2) nor glucagon (P = 0.97) secretion. When administered to rats in vivo, insulin secretion was attenuated and glucagon secretion increased (P = 0.04), while blood glucose peak time was delayed (from 15 to 45 min) and gastric emptying time prolonged (P = 0.004).ConclusionsGlucose-sensing secretin cells located in the distal part of the small intestine may contribute to increased plasma concentrations observed after RYGB. The metabolic role of the distal S cells warrants further studies.

Bile acids in plasma are elevated after bariatric surgery and may contribute to metabolic improvements, but underlying changes in bile flow are poorly understood. We assessed bilio-enteric flow of bile and plasma bile concentrations in individuals with Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) surgery compared with matched non-surgical controls (CON).Fifteen RYGB, 10 SG and 15 CON underwentAfter RYGB, gallbladder filling was decreased (p = 0.045 versus CON), basal flow of bile into the small intestine increased (p = 0.005), bile acid retention augmented (p = 0.021) and basal bile acid plasma concentrations elevated (p = 0.009). During the meal, foods passed unimpeded through the gastric pouch resulting in almost instant postprandial mixing of bile and foods, but the postprandial rise in plasma bile acids was brief and associated with decreased overall release of fibroblast growth factor-19 (FGF-19) compared with CON (p = 0.033). After SG, bile flow and retention were largely unaltered (p 0.05 versus CON), but gastric emptying was accelerated (p 0.001) causing earlier mixture of bile and foods also in this group. Neither basal nor postprandial bile acid concentrations differed between SG and CON.Bilio-enteric bile flow is markedly altered after RYGB resulting in changes in plasma concentrations of bile acids and FGF-19, whereas bile flow and plasma concentrations are largely unaltered after SG.

To describe glucose metabolism in the late, weight stable phase after Roux-en-Y Gastric Bypass (RYGB) in patients with and without preoperative type 2 diabetes we invited 55 RYGB-operated persons from two existing cohorts to participate in a late follow-up study. 44 (24 with normal glucose tolerance (NGT)/20 with type 2 diabetes (T2D) before surgery) accepted the invitation (median follow-up 2.7 [Range 2.2–5.0 years]). Subjects were examined during an oral glucose stimulus and results compared to preoperative and 1-year (1 y) post RYGB results. Glucose tolerance, insulin resistance, beta-cell function and incretin hormone secretion were evaluated. 1 y weight loss was maintained late after surgery. Glycemic control, insulin resistance, beta-cell function and GLP-1 remained improved late after surgery in both groups. In NGT subjects, nadir glucose decreased 1 y after RYGB, but did not change further. In T2D patients, relative change in weight from 1 y to late after RYGB correlated with relative change in fasting glucose and HbA1c, whereas relative changes in glucose-stimulated insulin release correlated inversely with relative changes in postprandial glucose excursions. In NGT subjects, relative changes in postprandial nadir glucose correlated with changes in beta-cell glucose sensitivity. Thus, effects of RYGB on weight and glucose metabolism are maintained late after surgery in patients with and without preoperative T2D. Weight loss and improved beta-cell function both contribute to maintenance of long-term glycemic control in patients with type 2 diabetes, and increased glucose stimulated insulin secretion may contribute to postprandial hypoglycemia in NGT subjects.

Roux-en-Y Gastric bypass surgery (RYGB) is emerging as a powerful tool for treatment of obesity and may also cause remission of type 2 diabetes. However, the molecular mechanism of RYGB leading to diabetes remission independent of weight loss remains elusive. In this study, we profiled plasma metabolites and proteins of 10 normal glucose-tolerant obese (NO) and 9 diabetic obese (DO) patients before and 1-week, 3-months, 1-year after RYGB. 146 proteins and 128 metabolites from both NO and DO groups at all four stages were selected for further analysis. By analyzing a set of bi-molecular associations among the corresponding network of the subjects with our newly developed computational method, we defined the represented physiological states (called the edge-states that reflect the interactions among the bio-molecules), and the related molecular networks of NO and DO patients, respectively. The principal component analyses (PCA) revealed that the edge states of the post-RYGB NO subjects were significantly different from those of the post-RYGB DO patients. Particularly, the time-dependent changes of the molecular hub-networks differed between DO and NO groups after RYGB. In conclusion, by developing molecular network-based systems signatures, we for the first time reveal that RYGB generates a unique path for diabetes remission independent of weight loss., Highlights • Plasma proteomic and metabolomic datasets were collected with time-series mode in patients treated with RYGB. • Workflow to define the physiological states based on associations between biomolecules • Systems signatures reveal unique path for diabetes remission independent of weight loss.

Background Roux-en-Y gastric bypass is associated with an increased risk of postprandial hyperinsulinaemic hypoglycaemia, but the underlying pathophysiology remains poorly understood. We therefore examined the effect of re-routing of nutrient delivery on gut-islet cell crosstalk in a person with severe postprandial hypoglycaemia after Roux-en-Y gastric bypass. Case report A person with severe postprandial hypoglycaemia, who underwent surgical reversal of Roux-en-Y gastric bypass, was studied before reversal and at 2 weeks and 3 months after reversal surgery using liquid mixed meal tests and hyperinsulinaemic-euglycaemic clamps. The nadir of postprandial plasma glucose rose from 2.8 mmol/l to 4.1 mmol/l at 2 weeks and to 4.4 mmol/l at 3 months after reversal. Concomitant insulin- and glucagon-like peptide-1 secretion (peak concentrations and area under the curve) clearly decreased after reversal, while concentrations of glucose-dependent insulinotropic polypeptide and ghrelin increased. Insulin clearance declined after reversal, whereas clamp-estimated peripheral insulin sensitivity was unchanged. The person remained without symptoms of hypoglycaemia, but had experienced significant weight gain at 15- month follow-up. Discussion Accelerated nutrient absorption may be a driving force behind postprandial hyperinsulinaemic hypoglycaemia after Roux-en-Y gastric bypass. Re-routing of nutrients by reversal of the Roux-en-Y gastric bypass diminished postprandial plasma glucose excursions, alleviated postprandial insulin and glucagon-like peptide-1 hypersecretion and eliminated postprandial hypoglycaemia, which emphasizes the importance of altered gut-islet cell crosstalk for glucose metabolism after Roux-en-Y gastric bypass. This article is protected by copyright. All rights reserved.

Roux-en-Y gastric bypass (RYGB) induces weight loss and improves insulin sensitivity when evaluated by the hyperinsulinemic-euglycemic clamp (HEC). Surrogate indices of insulin sensitivity calculated from insulin and glucose concentrations at fasting or after an oral glucose tolerance test (OGTT) are frequently used, but have not been validated after RYGB. Our aim was to evaluate whether surrogate indices reliably estimate changes in insulin sensitivity after RYGB. Four fasting surrogates (inverse-HOMA-IR, HOMA2-%S, QUICKI, revised-QUICKI) and three OGTT-derived surrogates (Matsuda, Gutt, OGIS) were compared with HEC-estimated peripheral insulin sensitivity ( Rd or Rd/I, depending on how the index was originally validated) and the tracer-determined hepatic insulin sensitivity index (HISI) in patients with preoperative type 2 diabetes ( n = 10) and normal glucose tolerance ( n = 10) 1 wk, 3 mo, and 1 yr postoperatively. Post-RYGB changes in inverse-HOMA-IR and HOMA2-%S did not correlate with changes in Rd at any visit, but were comparable to changes in HISI at 1 wk. Changes in QUICKI and revised-QUICKI correlated with Rd/I after surgery. Changes in the Matsuda and Gutt indices did not correlate with changes in Rd/I and Rd, respectively, whereas OGIS changes correlated with Rd changes at 1 yr post-RYGB. In conclusion, surrogate measures of insulin sensitivity may not reflect results obtained with gold standard methodology after RYGB, underscoring the importance of critical reflection when surrogate endpoints are used. Fasting surrogate indices may be particularly affected by post-RYGB changes in insulin clearance, whereas the validity of OGTT-derived surrogates may be compromised by surgical rearrangements of the gut.

The increasing prevalence of obesity represents a huge threat to public health and the current pharmacological treatment options are limited. Bariatric surgery is by far the most effective treatment for severe obesity, highlighting the urgent need for new and improved drug therapies. Areas covered: Based on the physiological regulation of energy homeostasis, pharmacological strategies to treat obesity are evaluated with focus on drugs in phase 2 and 3 clinical development. The potential impact of these drugs on current treatment standards and the barriers for development are discussed and set in a historical perspective of previous antiobesity medications. Expert opinion: The radical effects of bariatric surgery have extended our understanding of the mechanisms controlling appetite and boosted the search for new drug targets in obesity treatment. Accordingly, several compounds targeting the central nervous system and/or periphery are in pipeline for obesity. These drugs should be evaluated over a wide array of end-points; in particular, long-term safety monitoring is necessary as serious adverse events may appear. Combination therapy targeting more than one pathway controlling energy balance might be necessary to achieve substantial weight loss while minimising side effects.

Enhanced glucagon-like peptide-1 (GLP-1) secretion is important for improved glycemic control after Roux-en-Y gastric bypass (RYGB) and higher concentrations of circulating bile acids (BA) have been suggested to be involved. The BA chenodeoxycholic acid (CDCA) stimulates GLP-1 secretion after RYGB in the absence of nutrients. In this study we investigated the effects of oral intake of CDCA or the BA sequestrant colesevelam (COL) on postprandial GLP-1 secretion in RYGB operated subjects. We hypothesized that CDCA would increase secretion and that COL would decrease secretion by reducing re-absorption of endogenous BA. Twelve participants (BMI 31±2 (mean±SEM) kg/m2, age 43±3 years, time from RYGB 4.3±0.5 years, weight loss after RYGB 34±5 kg) were studied in a single-blinded, randomised study with four experimental days: 1) A mixed meal consisting of solid/semisolid components (1523 kJ, 53E% carb, 33E% fat, 14E% prot) 2) Mixed meal added 1250 mg CDCA 3) Mixed meal added COL 3750 mg 4) Mixed meal with COL administered both as 3750 mg tablets the evening before the experiment and as 3750 mg added to the meal. Oral intake of CDCA increased GLP-1 significantly compared with mixed meal alone (p=0.03), whereas neither single (p=0.74) nor double (p=0.28) dosage of COL affected GLP-1 secretion (Incremental AUC (iAUC) GLP-1: Meal: 2792±288 pmol x min, CDCA: 4362±618, COL: 2703±330, COLx2: 3328±380). Plasma glucose and C-peptide (iAUC) decreased after CDCA but both were unchanged after COL administration vs. meal alone. Beta-cell function (AUC C-peptide/AUC plasma glucose) was equal between all study days. In summary, administration of the exogenous BA CDCA potentiated mixed-meal stimulated GLP-1 secretion after RYGB but did not affect beta-cell function. Administration of the BA sequestrant COL did not affect GLP-1 secretion, glucose concentrations or beta-cell function, suggesting a limited role for endogenous BA for regulation of postprandial glucose metabolism after RYGB. Disclosure M.S. Svane: None. I. Jonsson: None. V. Kristiansen: None. R.E. Kuhre: None. N.J. Wewer Albrechtsen: Research Support; Self; Mercodia, Novo Nordisk A/S. Speaker's Bureau; Self; Merck Sharp & Dohme Corp. J.J. Holst: Advisory Panel; Self; Novo Nordisk A/S. S. Madsbad: None. K.N. Bojsen-Moller: None. Funding European Research Council (695069)

Postprandial GLP-1 secretion is greatly enhanced after Roux-en-Y gastric bypass (RYGB) and seems important for the reduced food intake and improved insulin secretion postoperatively. Understanding the mechanisms of gut hormone release after RYGB could aid the discovery of new drugs for the treatment of diabetes and obesity. Glucose is particularly potent for stimulating the release of GLP-1 as well as GIP compared with protein and fat in RYGB operated patients. It is unclear how glucose triggers gut hormone secretion in humans, but animal studies suggest a crucial role of sodium-glucose transporter 1 (SGLT1). Our aim was to investigate secretion of GLP-1 and GIP in response to an oral glucose load (50 g) on two separate days with or without acute pretreatment of 600 mg of the dual SGLT1/SGLT2 inhibitor canagliflozin (CANA) in 10 RYGB operated patients with no history of diabetes (age 47 ± 5 years, BMI 36 ± 7 kg/m2, HbA1c 35 ± 4 mmol/mol, time from surgery 6 ± 1 years, mean ± SD). CANA lowered peak glucose (11.8 vs. 8.4 mmol/l, p0.01, and AUC above basal by 28%, p=0.01, respectively). In addition, CANA reduced the postprandial rise in lactate concentrations and pulse rate and caused marked glucosuria (0.2 vs. 11 g). SGLT1/2 inhibition by canagliflozin during glucose ingestion reduced glycemic excursions and diminished early release of GLP-1 and GIP in RYGB operated patients. The results support that glucose absorption via SGLT1 is important for incretin hormone secretion after gastric bypass. Disclosure C. Martinussen: None. S. Veedfald: None. K.N. Bojsen-Moller: None. C. Dirksen: None. M.S. Svane: None. V. Kristiansen: None. J.J. Holst: Advisory Panel; Self; Novo Nordisk A/S. S. Madsbad: None. Funding European Union Horizon 2020 Research and Innovation Program (695069-Bypass Without Surgery); Danish Diabetes Academy; Novo Nordisk Foundation (NNF15OC0017188); Research Foundation for Health Research of the Capital Region of Denmark; Hvidovre Hospital

Roux-en-Y gastric bypass (RYGB) induces large and sustained weight loss in most patients. However, a minority of patients (5-10%) never obtain a successful weight loss after RYGB. The aim of this study was to characterize the role of gut hormones for appetite regulation in patients with primary weight loss (WL) failure defined as maximal excess BMI loss (EBLmax= ΔBMIpreoperative-postoperative/ΔBMIpreoperative-25) 60%) after RYGB. Twenty women with primary WL failure (EBL 24% [9;27], median [IQR]) were matched to 20 women with successful WL (EBL 74% [70;83]) on age (51±9 vs. 51±9 years, mean ± sd), preoperative BMI (43.1±4.0 vs. 43.0±3.6 kg/m2) and time from RYGB (4.8±2.0 vs. 4.8±1.4 years). On separate days, a patient blinded subcutaneous injection of the somatostatin analogue Octreotide (Oct) 1 µg/kg bodyweight (max 100 µg) or saline (placebo) was given in randomized order followed by a mixed meal test at T=30 min and an ad libitum meal with measurement of food intake at T=270 min. The WL failure group had similar GLP-1 (tAUC, median [IQR], 4039 [3336;6018] vs. 4669 [3006;5891] pM·min, p=0.30) and PYY secretion (tAUC, 1935 [1493;2783], 1778 [1163;2756] pM·min, p=0.65) on the placebo day compared with the successful WL group. Injection of Oct diminished GLP-1 and PYY secretion in both groups. Oct had no effect on ad libitum food intake in the WL failure group (-0.5% [-13, 12], mean [95% CI]), while food intake was increased after Oct in the successful WL group (+23% [1.6, 44]) (ANOVA Group x Oct p=0.04). In conclusion, primary WL failure after RYGB was not explained by lower secretion of GLP-1 or PYY. However, inhibition of hormone secretion with octreotide increased food intake only in patients with successful WL, whereas the effect was absent in patients with primary WL failure. These results support that an impaired gut-hormone mediated suppression of appetite could contribute to primary weight loss failure after RYGB. Disclosure K.N. Bojsen-Moller: None. M.S. Svane: None. C. Martinussen: None. C. Dirksen: None. N.B. Jørgensen: Stock/Shareholder; Self; Novo Nordisk A/S. V. Kristiansen: None. B. Hartmann: None. J.J. Holst: Advisory Panel; Self; Novo Nordisk A/S. S. Madsbad: None. Funding Danish Council for Independent Research

BACKGROUND Altered meal-related gut hormone secretion seems important for weight loss and diabetes remission after Roux-en-Y gastric bypass (RYGB). Elucidating the responsible meal components and receptors could aid discovery of new treatments of obesity and diabetes. Enteroendocrine cells respond to digestion products of dietary triacylglycerol, especially long-chain fatty acids (LCFAs) and 2-oleoyl-glycerol (2-OG), but not medium-chain fatty acids (MCFAs). OBJECTIVE We examined the impact of olive oil (20 mL) and its derivates, LCFAs and 2-OG, on enteroendocrine secretions [glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), cholecystokinin (CCK), peptide YY (PYY), and neurotensin (NT)] and on glucose, lipid, and bile acid metabolism in RYGB-operated and unoperated individuals. METHODS In an exploratory randomized crossover design, 10 RYGB-operated patients and 10 matched controls ingested 3 equimolar triacylglycerol formulations on separate days: olive oil (digested to 2-OG + LCFAs), C8-dietary oil (2-OG + MCFAs), and tricaprylin (MCFAs; negative control). Hormone responses were calculated as area under the curve (AUC). RESULTS Independent of group status, olive oil had greater effects than C8-dietary oil on AUCs of plasma GLP-1 (+32%; 95% CI: 23%, 43%; P

Background Glucagon-like peptide-2 (GLP-2) and glucose-dependent insulinotropic polypeptide (GIP) both inhibit bone resorption in humans but the underlying mechanisms are poorly understood. In vitro, GLP-2 activates the GIP-receptor (GIPR). Objective Based on in vitro studies, we hypothesized that the antiresorptive effect of GLP-2 was mediated through the GIPR. This was tested using the selective GIPR-antagonist GIP(3-30)NH2. Methods The study was a randomized, single-blinded, placebo-controlled, crossover study conducted at Hvidovre University Hospital, Denmark. Eight healthy young men were included and studied on four study days: GIP (200 μg), GLP-2 (800 μg), GIP(3-30)NH2 (800 pmol/kg/min) + GLP-2 (800 μg), and placebo. The main outcomes were bone resorption measured as collagen type 1 C-terminal telopeptide (CTX) and bone formation measured as procollagen type 1 N-terminal propeptide (P1NP). Results CTX (mean ± SEM) significantly decreased after both GIP (to 55.3 ± 6.3% of baseline at t = 90 min) and GLP-2 (to 60.5 ± 5.0% of baseline at t = 180 min). The maximal reduction in CTX after GIP(3-30)NH2 + GLP-2 (to 63.2 ± 3.1% of baseline) did not differ from GLP-2 alone (p = 0.95) nor did net AUC0–240 (−6801 ± 879%*min vs −6027 ± 648%*min, p = 0.56). At t = 30 min, GIP significantly (p Conclusions GIPR antagonism did not inhibit the GLP-2-induced reduction in bone resorption (CTX) in healthy young men. In contrast to GLP-2, GIP increased P1NP despite decreasing CTX indicating an uncoupling of bone resorption from formation. Thus, GLP-2 and GIP seem to exert separate effects on bone turnover in humans. Clinical trials information ClinicalTrials.gov ( NCT03159741 ).

Exaggerated secretion of glucagon-like peptide 1 (GLP-1) is important for postprandial glucose tolerance after Roux-en-Y gastric bypass (RYGB), whereas the role of glucose-dependent insulinotropic polypeptide (GIP) remains to be resolved. We aimed to explore the relative importance of endogenously secreted GLP-1 and GIP on glucose tolerance and β-cell function after RYGB. We used DPP-4 inhibition to enhance concentrations of intact GIP and GLP-1 and the GLP-1 receptor antagonist exendin-(9–39) (Ex-9) for specific blockage of GLP-1 actions. Twelve glucose-tolerant patients were studied after RYGB in a randomized, placebo-controlled, 4-day crossover study with standard mixed-meal tests and concurrent administration of placebo, oral sitagliptin, Ex-9 infusion, or combined Ex-9-sitagliptin. GLP-1 receptor antagonism increased glucose excursions, clearly attenuated β-cell function, and aggravated postprandial hyperglucagonemia compared with placebo, whereas sitagliptin had no effect despite two- to threefold increased concentrations of intact GLP-1 and GIP. Similarly, sitagliptin did not affect glucose tolerance or β-cell function during GLP-1R blockage. This study confirms the importance of GLP-1 for glucose tolerance after RYGB via increased insulin and attenuated glucagon secretion in the postprandial state, whereas amplification of the GIP signal (or other DPP-4-sensitive glucose-lowering mechanisms) did not appear to contribute to the improved glucose tolerance seen after RYGB.

Exaggerated postprandial secretion of GLP-1 seems to contribute importantly to the metabolic effects of Roux-en-Y gastric bypass (RYGB). The surgery accelerates nutrient entry to the distal intestine, which is believed to augment GLP-1 secretion. In un-operated individuals, slowly digested carbohydrates are also absorbed in the distal intestine and may accordingly produce greater GLP-1 responses than rapidly absorbed ones. Our aim was to investigate GLP-1 secretion in response to isomolar (0.1385 mol) oral loads of glucose (glu) and fructose (fru), either given as separate monosaccharides (25 g glu and 25 g fru) or as disaccharides in the form of 47.5 g sucrose (suc) +/- alpha glucosidase inhibition (by acarbose (aca)) or 47.5 g isomaltulose (iso), which is slower digested than suc, on 4 separate days in 10 RYGB patients and 10 controls (CON) matched on BMI, age and sex. Glu/fru and suc induced similar glucose excursions and responses of C-peptide and GLP-1, the latter being 3-fold greater in RYGB compared to CON. Digestion of iso was slow in comparison with suc in both groups. Mean GLP-1 response (positive iAUC) to iso was ∼50% and ∼160% greater than to suc in RYGB (p=0.11) and CON (p=0.01), respectively. Aca effectively slowed suc digestion in both groups, resulting in lower peak concentrations of glucose (RYGB: 9.3 vs. 6.7 mmol/l, CON: 7.7 vs. 6.6 mmol/l) and C-peptide (RYGB: 2762 vs. 1341 pmol/l, CON: 2367 vs. 1520 pmol/l) compared with suc alone (p The slowly absorbed disaccharide isomaltulose elicits a greater GLP-1 response than sucrose. The same effect is not evident when digestion of sucrose is inhibited by acarbose, which in RYGB diminishes sucrose induced GLP-1 secretion. Understanding the digestive processes involved in carbohydrate induced GLP-1 release after gastric bypass is an important step towards mimicking the effects of the surgery by pharmacological means. Disclosure C. Martinussen: None. K.N. Bojsen-Moller: None. C. Dirksen: None. M.S. Svane: 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. S. Madsbad: Advisory Panel; Self; AstraZeneca. Speaker's Bureau; Self; AstraZeneca. Research Support; Self; Boehringer Ingelheim Pharmaceuticals, Inc.. Advisory Panel; Self; Boehringer Ingelheim Pharmaceuticals, Inc.. Speaker's Bureau; Self; Eli Lilly and Company, Eli Lilly and Company. Advisory Panel; Self; Merck Sharp & Dohme Corp., Sanofi-Aventis, Novo Nordisk A/S. Speaker's Bureau; Self; Novo Nordisk A/S. Research Support; Self; Novo Nordisk A/S.

Sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) induce comparable weight loss and improvements in glycemic control despite marked differences in gastrointestinal rearrangements. We hypothesized that absorption rates of oral glucose and protein derived amino acids (AA) were accelerated after both procedures resulting in comparable gut hormone responses. 12 SG and 12 RYGB operated and 12 control (C) subjects carefully matched on BMI, age, sex and post-operative weight loss received primed-continuous infusions of stable isotopes of glucose, glycerol, phenylalanine (phe), tyrosine and urea combined with a 6-hour mixed meal test (400 kcal, 50E% carb, 35E% fat, 15E% protein) containing a glucose isotope and intrinsically phe labelled casein. Peak rate of appearance (Ra) of oral glucose was higher after RYGB and SG compared with C (RYGB 36±1 µmol/kg FFM/min, SG 27±1, C 22±1; p Disclosure M.S. Svane: None. K.N. Bojsen-Moller: None. C. Martinussen: None. C. Dirksen: None. S. Reitelseder: None. L. Holm: None. V.B. Kristiansen: None. G. van Hall: 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. S. Madsbad: Advisory Panel; Self; AstraZeneca. Speaker's Bureau; Self; AstraZeneca. Research Support; Self; Boehringer Ingelheim Pharmaceuticals, Inc.. Advisory Panel; Self; Boehringer Ingelheim Pharmaceuticals, Inc.. Speaker's Bureau; Self; Eli Lilly and Company, Eli Lilly and Company. Advisory Panel; Self; Merck Sharp & Dohme Corp., Sanofi-Aventis, Novo Nordisk A/S. Speaker's Bureau; Self; Novo Nordisk A/S. Research Support; Self; Novo Nordisk A/S.

Introduction: Elevated bile acid (BA) concentrations have been suggested to partly drive metabolic improvements after bariatric surgery but the mechanisms remain poorly understood. We assessed flow of bile and foods using scintigraphy after Roux-en-Y Gastric Bypass (RYGB) and Sleeve Gastrectomy (SG). Materials and Methods: 15 RYGB, 10 SG and 15 gender, age and BMI matched controls (C) underwent a combined cholescintigraphy and fatty test-meal with frequent blood sampling, for concomitant visualization of radiolabeled bile and food markers in the GI tract. BA retention was estimated 7 days after ingestion of a radiolabeled taurine-conjugated BA analogue (75Se-HCAT). Results: Prior to meal intake, gallbladder filling was lower (mean ± SEM: RYGB 23% ± 4, SG 39 ± 4, C 36 ± 5, RYGB vs. C p = 0.04) and more bile marker had passed passively into the small intestine in RYGB but not SG (RYGB 48% ± 6, SG 21 ± 5, C 20 ± 6, RYGB vs. C p < 0.01). Postprandial gallbladder emptying was complete in all groups. Gastric retention of foods was negligible in RYGB and lower in SG at 10 min after meal intake (RYGB 12% ± 2, SG 59 ± 7, C 90 ± 4, RYGB vs. C p < 0.01, SG vs. C p < 0.01) resulting in instant mixing of food with bile in RYGB and accelerated mixing in SG (RYGB 78% ± 3, SG 35 ± 8, C 8 ± 4, RYGB vs. C p < 0.01, SG vs. C p < 0.01). BA-retention over 7 days was only increased in RYGB (RYGB 54% ± 6, SG 34 ± 4, C 33 ± 5, RYGB vs. C: p = 0.02). Peak S-cholecystokinin (CCK) was comparably increased in RYGB and SG (RYGB 13 pmol/l ± 3, SG 15 ± 3, C 6 ± 1, RYGB vs. C p = 0.03, SG vs. C p = 0.01). Conclusion: After RYGB, enteric BA appearance is altered (more hepatic less gallbladder derived) and food is instantly mixed with bile due to negligible retention of foods in the gastric pouch. BA retention is increased. In contrast, BA appearance and retention remains normal after SG, although gastric emptying is accelerated. The metabolic impact of the changes in BA circulation after RYGB needs further evaluation. Disclosure A. Eiken: None. S. Fuglsang: None. M.L. Eiken: None. M.S. Svane: 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. K.N. Bojsen-Moller: None. S. Madsbad: Advisory Panel; Self; AstraZeneca. Speaker's Bureau; Self; AstraZeneca. Research Support; Self; Boehringer Ingelheim Pharmaceuticals, Inc.. Advisory Panel; Self; Boehringer Ingelheim Pharmaceuticals, Inc.. Speaker's Bureau; Self; Eli Lilly and Company, Eli Lilly and Company. Advisory Panel; Self; Merck Sharp & Dohme Corp., Sanofi-Aventis, Novo Nordisk A/S. Speaker's Bureau; Self; Novo Nordisk A/S. Research Support; Self; Novo Nordisk A/S. J.L. Madsen: None. C. Dirksen: None.