Total Glucagon-like Peptide-1 Research Articles

Activation of TLRs Triggers GLP-1 Secretion in Mice.

The gastrointestinal tract constitutes a large interface with the inner body and is a crucial barrier against gut microbiota and other pathogens. As soon as this barrier is damaged, pathogen-associated molecular patterns (PAMPs) are recognized by immune system receptors, including toll-like receptors (TLRs). Glucagon-like peptide 1 (GLP-1) is an incretin that was originally involved in glucose metabolism and recently shown to be rapidly and strongly induced by luminal lipopolysaccharides (LPS) through TLR4 activation. In order to investigate whether the activation of TLRs other than TLR4 also increases GLP-1 secretion, we used a polymicrobial infection model through cecal ligation puncture (CLP) in wild-type and TLR4-deficient mice. TLR pathways were assessed by intraperitoneal injection of specific TLR agonists in mice. Our results show that CLP induces GLP-1 secretion both in wild-type and TLR4-deficient mice. CLP and TLR agonists increase gut and systemic inflammation. Thus, the activation of different TLRs increases GLP-1 secretion. This study highlights for the first time that, in addition to an increased inflammatory status, CLP and TLR agonists also strongly induce total GLP-1 secretion. Microbial-induced GLP-1 secretion is therefore not only a TLR4/LPS-cascade.

Enhancing endogenous levels of GLP1 dampens acute olanzapine induced perturbations in lipid and glucose metabolism.

Olanzapine is a second-generation antipsychotic (SGA) used in the treatment of schizophrenia and several on- and off-label conditions. While effective in reducing psychoses, acute olanzapine treatment causes rapid hyperglycemia, insulin resistance, and dyslipidemia and these perturbations are linked to an increased risk of developing cardiometabolic disease. Pharmacological agonists of the glucagon-like peptide-1 (GLP1) receptor have been shown to offset weight-gain associated with chronic SGA administration and mitigate the acute metabolic side effects of SGAs. The purpose of this study was to determine if increasing endogenous GLP1 is sufficient to protect against acute olanzapine-induced impairments in glucose and lipid homeostasis. Male C57BL/6J mice were treated with olanzapine, in the absence or presence of an oral glucose tolerance test (OGTT), and a combination of compounds to increase endogenous GLP1. These include the non-nutritive sweetener allulose which acts to induce GLP1 secretion but not other incretins, the DPPiv inhibitor sitagliptin which prevents degradation of active GLP1, and an SSTR5 antagonist which relieves inhibition on GLP1 secretion. We hypothesized that this cocktail of agents would increase circulating GLP1 to supraphysiological concentrations and would protect against olanzapine-induced perturbations in glucose and lipid homeostasis. We found that 'triple treatment' increased both active and total GLP1 and protected against olanzapine-induced perturbations in lipid and glucose metabolism under glucose stimulated conditions and this was paralleled by an attenuation in the olanzapine induced increase in the glucagon:insulin ratio. Our findings provide evidence that pharmacological approaches to increase endogenous GLP1 could be a useful adjunct approach to reduce acute olanzapine-induced perturbations in lipid and glucose metabolism.

Incretins play an important role in FFA4/GPR120 regulation of glucose metabolism by GW-9508

AimsTo assess the role of GPR120 in glucose metabolism and incretin regulation from enteroendocrine L- and K-cells with determination of the cellular localisation of GPR120 in intestinal tissue and clonal Glucagon-Like Peptide-1 (GLP-1)/Gastric Inhibitory Polypeptide (GIP) cell lines. Main methodsAnti-hyperglycaemic, insulinotropic and incretin secreting properties of the GPR120 agonist, GW-9508 were explored in combination with oral and intraperitoneal glucose tolerance tests (GTT) in lean, diabetic and incretin receptor knockout mice. Cellular localisation of GPR120 was assessed by double immunofluorescence. Key findingsCompared to intraperitoneal injection, oral administration of GW-9508 (0.1 μmol/kg body weight) together with glucose reduced the glycaemic excursion by 22–31 % (p < 0.05-p < 0.01) and enhanced glucose-induced insulin release by 30 % (p < 0.01) in normal mice. In high fat fed diabetic mice, orally administered GW-9508 lowered plasma glucose by 17–27 % (p < 0.05-p < 0.01) and augmented insulin release by 22–39 % (p < 0.05-p < 0.001). GW-9508 had no effect on the responses of GLP-1 receptor knockout mice and GIP receptor knockout mice. Consistent with this, oral GW-9508 increased circulating total GLP-1 release by 39–44 % (p < 0.01) and total GIP by 37–47 % (p < 0.01-p < 0.001) after 15 and 30 min in lean NIH Swiss mice. Immunocytochemistry demonstrated GPR120 expression on mouse enteroendocrine L- and K-cells, GLUTag cells and pGIP/Neo STC-1 cells. SignificanceGPR120 is expressed on intestinal L- and K-cells and stimulates GLP-1/GIP secretory pathways involved in mediating enhanced insulin secretion and improved glucose tolerance, following oral GW-9508. These novel data strongly support the development of potent and selective GPR120 agonists as an effective therapeutic approach for diabetes.

Altered chronic glycemic control in a clinically relevant model of rat thoracic spinal contusion.

The lifetime risk for Type 2 diabetes mellitus remains higher in people with spinal cord injuries (SCIs) than in the able-bodied population. However, the mechanisms driving this disparity remain poorly understood. The goal of the present study was to evaluate the impact of a palatable high-fat diet (HFD) on glycemic regulation using a rodent model of moderate thoracic contusion. Animals were placed on either Chow or HFD and tolerance to glucose, insulin, and ENSURE mixed meal were investigated. Important targets in the gut-brain axis were investigated. HFD consumption equally induced weight gain in SCI and naïve rats over chow (CH) rats. Elevated blood glucose was observed during intraperitoneal glucose tolerance test in HFD-fed rats over CH-fed rats. Insulin tolerance test (ITT) was unremarkable among the three groups. Gavage of ENSURE resulted in high glucagon-like peptide 1 (GLP-1) release from SCI rats over naïve controls. An elevation in terminal total GLP-1 was measured, with a marked reduction in circulating dipeptidyl peptidase 4, the GLP-1 cleaving enzyme, in SCI rats, compared with naïve. Increased glucagon mRNA in the pancreas and reduced immunoreactive glucagon-positive staining in the pancreas in SCI rats compared with controls suggested increased glucagon turnover. Finally, GLP-1 receptor gene expression in the ileum, the primary source of GLP-1 production and release, in SCI rats suggests the responsivity of the gut to altered circulating GLP-1 in the body. In conclusion, the actions of GLP-1 and its preprohormone, glucagon, are markedly uncoupled from their actions on glucose control in the SCI rat. More work is required to understand GLP-1 in the human.

Gastrointestinal hormones and appetite ratings after weight loss induced by diet or bariatric surgery.

The aim of this study was to compare changes in gastrointestinal hormones and appetite ratings after a similar weight loss induced by a very low-energy diet alone or in combination with sleeve gastrectomy (SG) or Roux-en-Y gastric bypass (RYGB). Patients with severe obesity scheduled for SG (n=15) and RYGB (n=14) and 15 controls (very low-energy diet alone) were recruited. Body weight/composition, plasma concentrations of ß-hydroxybutyric acid, acylated ghrelin, total glucagon-like peptide-1, total peptide YY, cholecystokinin, and ratings of hunger, fullness, desire to eat, and prospective food consumption were measured pre- and postprandially, before and after 10 weeks of intervention. Changes in body weight/composition and level of ketosis were similar across groups. In SG and RYGB, basal and postprandial acylated ghrelin declined, and postprandial glucagon-like peptide-1increased, both significantly more compared with controls. Postprandial peptide YY increased in all groups. Overall, postprandial hunger decreased, and postprandial fullness increased. But ratings of desire to eat and prospective food consumption were more favorable after both surgeries compared with controls. Weight loss with SG and RYGB leads to more favorable changes in gastrointestinal hormones compared with diet alone, although ratings of appetite were reduced across all groups.

Circulating GLP-1 Levels in Patients with Pheochromocytoma/Paraganglioma.

The sympathoadrenal system has been shown to stimulate the secretory activity of enteroendocrine cells, although the response is transient. Our aim was to investigate the effects of long-term catecholamine excess on circulating glucagon-likepeptide-1 (GLP-1) levels in patients with pheochromocytoma/paraganglioma (PPGL). Thirty patients diagnosed with PPGL were analyzed. A significant negative association was observed between fasting plasma GLP-1 levels and elevated plasma-free metanephrine (r = -0.407, p = 0.026). After adjustment for age, sex, body mass index (BMI), serum creatinine, and the presence of hyperglycemia, the negative association between plasma GLP-1 and metanephrine persisted by multiple linear regression analysis (β = -0.493, p = 0.013). Positive correlations between fasting glucose and plasma metanephrine (r = 0.380, p = 0.038) and normetanephrine levels (r = 0.450, p = 0.013) were also found. Mean fasting levels of total GLP-1 increased significantly from 25.81 to 39.01 pmol/L (p = 0.017) after PPGL resection. In conclusion, long-term overproduction of catecholamines appears to induce suppression of GLP-1 production compared to an acute response to a stress stimulus. Further studies are required to elucidate the mechanism of GLP-1 secretion with chronic exposure to catecholamine.

Fasting and stimulated glucagon-like peptide-1 exhibit a compensatory adaptive response in diabetes and pre-diabetes states: A multi-ethnic comparative study.

BackgroundImpaired secretion of glucagon-like peptide-1 (GLP-1) among Caucasians contributes to reduced incretin effect in type 2 diabetes mellitus (T2DM) patients. However, studies emanating from East Asia suggested preserved GLP-1 levels in pre-diabetes (pre-DM) and T2DM. We aimed to resolve these conflicting findings by investigating GLP-1 levels during oral glucose tolerance test (OGTT) among Malay, Chinese, and Indian ethnicities with normal glucose tolerance (NGT), pre-DM, and T2DM. The association between total GLP-1 levels, insulin resistance, and insulin sensitivity, and GLP-1 predictors were also analyzed.MethodsA total of 174 subjects were divided into NGT (n=58), pre-DM (n=54), and T2DM (n=62). Plasma total GLP-1 concentrations were measured at 0, 30, and 120 min during a 75-g OGTT. Homeostasis model assessment of insulin resistance (HOMA-IR), HOMA of insulin sensitivity (HOMA-IS), and triglyceride–glucose index (TyG) were calculated.ResultsTotal GLP-1 levels at fasting and 30 min were significantly higher in T2DM compared with pre-DM and NGT (27.18 ± 11.56 pmol/L vs. 21.99 ± 10.16 pmol/L vs. 16.24 ± 7.79 pmol/L, p=0.001; and 50.22 ± 18.03 pmol/L vs. 41.05 ± 17.68 pmol/L vs. 31.44 ± 22.59 pmol/L, p<0.001; respectively). Ethnicity was a significant determinant of AUCGLP-1, with the Indians exhibiting higher GLP-1 responses than Chinese and Malays. Indians were the most insulin resistant, whereas Chinese were the most insulin sensitive. The GLP-1 levels were positively correlated with HOMA-IR and TyG but negatively correlated with HOMA-IS. This relationship was evident among Indians who exhibited augmented GLP-1 responses proportionately to their high insulin-resistant states.ConclusionThis is the first study that showed GLP-1 responses are augmented as IR states increase. Fasting and post-OGTT GLP-1 levels are raised in T2DM and pre-DM compared to that in NGT. This raises a possibility of an adaptive compensatory response that has not been reported before. Among the three ethnic groups, the Indians has the highest IR and GLP-1 levels supporting the notion of an adaptive compensatory secretion of GLP-1.

The alpha-7 nicotinic acetylcholine receptor agonist GTS-21 does not affect food intake in rats

Obesity is a prevalent disease, but effective treatments remain limited. Agonists of the alpha-7 nicotinic acetylcholine receptor (α7nAChR) promote negative energy balance in mice, but these effects are not well-studied in rats. We tested the hypothesis that the α7nAChR agonist GTS-21 would decrease food intake and body weight in adult male Sprague Dawley rats. Contrary to our hypothesis, acute systemic administration of GTS-21 produced no significant effects on chow or high-fat diet (HFD) intake. Acute intracerebroventricular (ICV) GTS-21 also had no impact on chow intake, and actually increased body weight at the highest dose tested. Previous studies suggest that GTS-21 engages the food intake-suppressive glucagon-like peptide-1 (GLP-1) system in mice. As there are known species differences in GLP-1 physiology between mice and rats, we tested the ability of GTS-21 to elicit GLP-1 secretion in rats. Our results showed that plasma levels of total GLP-1 in rats were not significantly altered by peripheral GTS-21 injection. These results represent an advance in understanding how α7nAChR activation impacts energy balance control in rodents and suggest that there may be important differences between rats and mice in the ability of GTS-21/α7nAChR activation to increase secretion of GLP-1.

A Pilot Study to Assess Glucose, Insulin, and Incretin Responses Following Novel High Resistant Starch Rice Ingestion in Healthy Men.

IntroductionA newly developed resistant starch (RS) rice line with double mutation of starch synthase IIIa and branching enzyme IIb (ss3a/be2b) exhibits a tenfold greater percentage RS value than the wild-type rice line. Currently, the effects of cooked rice with such high RS content on secretion and action of glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are unclear. Therefore, we conducted a pilot study to assess postprandial responses of GLP-1 and GIP along with glucose and insulin and also gastric emptying after ingestion of the high-RS cooked rice with ss3a/be2b in healthy subjects.MethodsIn a non-randomized crossover design, five healthy men ingested two test foods, control (low-RS) and high-RS cooked rice, with at least 1-week washout period between testing days. Plasma glucose, serum insulin, plasma total GLP-1, plasma total GIP, and also gastric emptying rate were measured after ingestion of each test food, and the incremental area under the curves (iAUC) was calculated for each biochemical parameter using the values from 0 to 180 min after ingestion.ResultsThe high-RS cooked rice ingestion tended to reduce iAUC-glucose (p = 0.06) and significantly reduced iAUC-insulin (p < 0.01) and iAUC-GLP-1 (p < 0.05) but not iAUC-GIP (p = 0.21) relative to control cooked rice ingestion. In addition, the high-RS cooked rice ingestion did not affect gastric emptying.ConclusionsThe present results indicate that the suppressive effects of the high-RS cooked rice ingestion on postprandial responses of glucose and insulin may be provided through attenuation in GLP-1 secretion along with its low digestibility into glucose. We suggest that the high-RS rice with ss3a/be2b may serve as a better carbohydrate source and also as a novel functional food for dietary interventions to improve postprandial hyperglycemia and hyperinsulinemia without both enhancing GLP-1 secretion and affecting gastric emptying in patients with diabetes.

GDF15 and Cortisol Response to Meal Tolerance Test in Post-Sleeve Gastrectomy Patients with Weight Regain.

Hormonal factors behind weight regain (WR) after surgical weight loss remain inadequately understood. Growth/differentiation factor 15 (GDF15) has emerged as a potential therapeutic target in obesity treatment. Cortisol, another stress hormone, has also been associated with weight gain at both low and high circulating concentrations. We aimed to compare meal-stimulated GDF15 and cortisol response in adults with and without WR after sleeve gastrectomy (SG). We hypothesized that GDF15 and cortisol response to meal tolerance test (MTT) will be lower in those with versus without WR after SG. Cross-sectional study comprised 21 adults without diabetes, who underwent SG. WR was defined as 100 × (current weight - nadir)/(preoperative weight - nadir) > 10%. GDF15, cortisol, insulin, glucose, and incretins (total glucagon-like peptide (GLP)-1 and glucose-dependent insulinotropic polypeptide (GIP) circulating concentrations) were measured during MTT (0-240min) after 3-6years post-bariatric surgery. All participants were 48% White, 85% female, with mean (SD) age: 43(10) years, and BMI: 36.2(7.6) kg/m2. Compared to the non-WR group (n = 6), the WR group (n = 15) had significantly higher BMI (WR: 38.6 ± 7.6kg/m2, non-WR: 30.3 ± 3.5kg/m2, p = 0.02) and showed lower GDF15 response (WR AUC vs non-WR AUC (116143 ± 13973 vs 185798 ± 38884ng*min/L, p = 0.047)) and lower cortisol response (WR AUC vs non-WR AUC (3492 ± 210 vs 4880 ± 655µg*min/dL, p = 0.015)). Incretin response did not differ between the groups. GDF15 and cortisol responses to MTT were lower in those who regained the weight after SG compared to those who did not, suggesting that dysregulation in GDF15 and cortisol response following bariatric surgery.

1385-P: Impact of Preanalytical and Analytical Factors on Glucagon and GLP-1 Levels in Humans

Glucagon and glucagon-like peptide-1 (GLP-1) have important roles in the development and treatment of diabetes. Their plasma concentrations are currently being measured in more than 500 clinical studies according to clinicaltrial.gov. As glucagon and total GLP-1 (reflecting the secretion and action of GLP-1 and is analytically independent of DPP-4 activity) circulate in the low picomolar range it has been troublesome to accurately measure their plasma concentrations. Equally important are so-called preanalytical considerations including the use of enzyme inhibitors. The latter may also depend on the analytical approach, for example single-antibody assay versus sandwich ELISA. To provide guidelines for measurement of glucagon and GLP-1 in clinical trials we obtained blood samples using four different blood-containers (with either neprilysin inhibitor: sacubitrilat 25 µg/mL; trasylol 500KIU/mL; P800 tubes; or vehicle) from healthy individuals (male/female; 7/4; mean ± SD; age: 32 ± 12 years, BMI; 26 ± 4 kg/m2) after an overnight fast and following an intravenous amino acid (AA) infusion (14 g/L; 331 mg/min/kg body weight. Plasma concentrations of glucagon increased significantly during the AA-infusion independent of blood containers and assays. The sandwich ELISA showed significant lower levels of glucagon with addition of neprilysin inhibitor whereas both trasylol and P800 tubes resulted in increased levels during the AA-infusion. Glucagon levels measured by the two radioimmunoassays (RIA) did not depend on the containers. Levels of total GLP-1 did not depend on the containers using a sandwich ELISA (Mercodia) but increased by a factor of a 2.5 when plasma from P800 containers was assayed using a C-terminal specific RIA. In summary, levels of glucagon and GLP-1 depend on both preanalytical and analytical factors that should be standardized for future clinical studies. Disclosure S. Kjeldsen: None. N.J. Jensen: None. N. Heinz: None. B. Hartmann: Board Member; Bainan Biotech. J.J. Holst: Advisory Panel; Novo Nordisk. Board Member; Antag Therapeutics, Bainan Biotech. N.J. Wewer Albrechtsen: Research Support; Mercodia AB, Novo Nordisk, Regeneron Pharmaceuticals Inc. Speaker's Bureau; Merck &amp; Co., Inc., Mercodia AB. Funding Nicolai J. Wewer Albrechtsen were financed by NNF Excellence Emerging Investigator Grant – Endocrinology and Metabolism (Application No. NNF19OC0055001) , EFSD Future Leader Award (NNF21SA0072746) and DFF Sapere Aude.

1038-P: Exposures to Hyperglycemia in the Embryonic Period and to Breast Milk from Mothers with Hyperglycemia Affect Glucose Tolerance with Higher Glucagon-Like Peptide-1 Secretion

Exposure to hyperglycemia during pregnancy results in diabetes in offspring. However, its underlying mechanisms are unclear. We therefore focused on the glucose metabolism of the offspring who were exposed to hyperglycemia in uterus or who were breast-fed from mothers with hyperglycemia. ICR female mice received single intraperitoneal injection (i.p.) of streptozotocin at six weeks old as the model of mother with diabetes (MD) . An additional group of mice received citric acid buffer injection, instead, as the model of mother with normal glycemia (MNG) . We established the model exposed to hyperglycemia in the uterus (EHU) by switching offspring from MD to MNG right after birth. As the model exposed to the breast milk of mothers with hyperglycemia (EBM) , the offspring from MNG were moved to MD right after birth. To eliminate the effects of cross fostering, offspring from MNG were fostered by another MNG as the control group. In intraperitoneal glucose tolerance test (IPGTT) at P60, EHU and EBM didn’t show increase of blood glucose level (BG) nor decrease of plasma insulin level but showed in oral glucose tolerance test (OGTT) at P50 (AUC of BG: p &amp;lt; 0.in EHU, p &amp;lt; 0.00in EBM, AUC of plasma insulin level per BG: &amp;lt;0.00in EHU and EBM) . From these conflicting results, we suspected the participation of glucagon-like peptide-1 (GLP-1) . However, the AUC of plasma total GLP-1 and active GLP-1 levels were higher in OGTT. Since we didn’t observe any difference in beta cell area per whole pancreas section by immunostaining, EHU and EBM might have GLP-1 resistance. Disclosure K.Ishii: None. M.Odawara: Other Relationship; Astellas Pharma Inc., AstraZeneca, Daiichi Sankyo, Daiichi Sankyo, Dainippon Pharmaceutical Co., Ltd., Eli Lilly Japan K.K., Kowa Company, Ltd., Kyowa Kirin Co., Ltd., Merck &amp; Co., Inc., Mitsubishi Tanabe Pharma Corporation, Nippon Boehringer Ingelheim Co. Ltd., Novartis Pharma K.K., Novo Nordisk, Omnipod, ONO PHARMACEUTICAL CO., LTD., Sanofi K.K., Taisho Pharmaceutical Holdings Co., Ltd., Takeda Pharmaceutical Co.,Ltd., Teijin Pharma Limited. R.Suzuki: Consultant; Novo Nordisk A/S, Other Relationship; Daiichi Sankyo, Eli Lilly Japan K.K., MSD K.K., Ono Pharmaceutical Co., Ltd., Sanofi K.K., Sumitomo Dainippon Pharma Co., Ltd., Research Support; Boehringer Ingelheim Japan, Inc., LifeScan, Mitsubishi Tanabe Pharma Corporation. J.Sasaki: None. K.Sugai: None. M.Ito: None. H.Iwasaki: None. N.Hara: None. M.Aierken: n/a. G.Li: None. H.Suwanai: None.

Whey protein supplementation improves postprandial glycemia in persons with type 2 diabetes mellitus: A systematic review and meta-analysis of randomized controlled trials

Whey protein (WP) can increase insulin secretion, produce an incretin effect, delay gastric emptying, and regulate appetite, resulting in improved glycemic control. We hypothesized that WP supplementation is associated with postprandial glycemia regulation in persons with type 2 diabetes mellitus (T2DM) and conducted a quantitative meta-analysis of randomized controlled trials (RCTs) to test this hypothesis. We searched PubMed, Embase, Cochrane Library, Scopus databases, and the ClinicalTrials.gov registry for relevant RCTs published before March 2022. We assessed the pooled effects using a random-effects model on glucose and insulin levels at 60 and 120 minutes, total glucagon-like peptide-1 (tGLP-1) at 30 and 60 minutes, and the incremental area under the curve (iAUC) of glucose, insulin, tGLP-1, and glucose-dependent insulinotropic polypeptide. Five RCTs involving 134 persons were included. Postprandial glycemia was significantly lower at 60 minutes (weighted mean difference: −2.67 mmol/L; 95% confidence interval, −3.62 to −1.72 mmol/L) and 120 minutes (−1.59 mmol/L; −2.91 to −0.28 mmol/L) in WP group than in placebo group. The iAUC of insulin was significantly higher in WP group (24.66 nmol/L × min, 1.65-47.66 nmol/L × min) than in placebo group. Although other results favored the WP group, differences between the groups were not statistically significant. The present study showed that premeal WP supplementation is beneficial for postprandial glycemia in persons with mild or well-controlled T2DM without substantial adverse effects. However, the level of certainty of current evidence is not high enough. Further larger and well-designed clinical trials are warranted for evaluating optimal dose and long-term effects of WP supplementation.

Serum bile acid response to oral glucose is attenuated in patients with early type 2 diabetes and correlates with 2-hour plasma glucose in individuals without diabetes.

AimTo determine the serum bile acid (BA) response to 75‐g oral glucose in individuals without diabetes, and whether this is attenuated in patients with ‘early’ type 2 diabetes (T2D) and related to the glycaemic response at 2 hours in either group.MethodsForty newly diagnosed, treatment‐naïve Han Chinese T2D subjects and 40 age‐, gender‐, and body mass index‐matched controls without T2D ingested a 75‐g glucose drink after an overnight fast. Plasma glucose and serum concentrations of total and individual BAs, fibroblast growth factor‐19 (FGF‐19), total glucagon‐like peptide‐1 (GLP‐1), and insulin, were measured before and 2 hours after oral glucose.ResultsFasting total BA levels were higher in T2D than control subjects (P < .05). At 2 hours, the BA profile exhibited a shift from baseline in both groups, with increases in conjugated BAs and/or decreases in unconjugated BAs. There were increases in total BA and FGF‐19 levels in control (both P < .05), but not T2D, subjects. Plasma glucose concentrations at 2 hours related inversely to serum total BA levels in control subjects (r = −0.42, P = .006). Total GLP‐1 and the insulin/glucose ratio were increased at 2 hours in both groups, and the magnitude of the increase was greater in control subjects.ConclusionsThe serum BA response to a 75‐g oral glucose load is attenuated in patients with ‘early’ T2D, as is the secretion of FGF‐19 and GLP‐1, while in individuals without T2D it correlates with 2‐hour plasma glucose levels. These observations support a role for BAs in the regulation of postprandial glucose metabolism.

Hyperglucagonemia in Pediatric Adiposity Associates With Cardiometabolic Risk Factors but Not Hyperglycemia.

ContextIn adults, hyperglucagonemia is associated with type 2 diabetes, impaired glucose tolerance, and obesity. The role of glucagon in pediatric overweight/obesity remains unclear.ObjectiveWe examined whether fasting concentrations of glucagon are elevated in youth with overweight/obesity and whether this associates with cardiometabolic risk profiles.MethodsAnalyses were based on the cross-sectional HOLBAEK study, including children and adolescents 6 to 19 years of age, with overweight/obesity from an obesity clinic group (n = 2154) and with normal weight from a population-based group (n = 1858). Fasting concentrations of plasma glucagon and cardiometabolic risk outcomes were assessed, and multiple linear and logistic regressions models were performed.ResultsThe obesity clinic group had higher glucagon concentrations than the population-based group (P < 0.001). Glucagon positively associated with body mass index (BMI) standard deviation score (SDS), waist, body fat %, liver fat %, alanine transaminase (ALT), high-sensitivity C-reactive protein, homeostasis model assessment of insulin resistance, insulin, C-peptide, LDL-C, triglycerides, SDS of diastolic and systolic blood pressure, and was inversely associated with fasting glucose. The inverse relationship between glucagon and glucose was attenuated in individuals with high BMI SDS and high fasting insulin. Glucagon was associated with a higher prevalence of insulin resistance, increased ALT, dyslipidemia, and hypertension, but not with hyperglycemia. Glucagon was positively associated with fasting total glucagon-like peptide-1.ConclusionCompared with normal weight peers, children and adolescents with overweight/obesity had elevated concentrations of fasting glucagon, which corresponded to worsened cardiometabolic risk outcomes, except for hyperglycemia. This suggests hyperglucagonemia in youth may precede impairments in glucose regulation.

Incretin Hypersecretion in Gestational Diabetes Mellitus.

Incretins are crucial stimulators of insulin secretion following food intake. Data on incretin secretion and action during pregnancy are sparse. The aim of the study was to investigate the incretin response during an oral glucose tolerance test (OGTT) in pregnant women with and without gestational diabetes mellitus (GDM). We analyzed data from the ongoing observational PREG study (NCT04270578). The study was conducted at the University Hospital Tübingen. We examined 167 women (33 with GDM) during gestational week 27 ± 2.2. Subjects underwent 5-point OGTT with a 75-g glucose load. We assessed insulin secretion and levels of total glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), glicentin, and glucagon during OGTT. Linear regression was used to analyze the relation of GLP-1 and glucose with insulin secretion and the association of incretin levels on birth outcome. Insulin secretion was significantly lower in women with GDM (P < 0.001). Postload GLP-1 and GIP were ~20% higher in women with GDM (all P < 0.05) independent of age, body mass index, and gestational age. GLP-1 increase was associated with insulin secretion only in GDM, but not in normal glucose tolerance. Postprandial GLP-1 levels were negatively associated with birth weight. The more pronounced GLP-1 increase in women with GDM could be part of a compensatory mechanism counteracting GLP-1 resistance. Higher GLP-1 levels might be protective against fetal overgrowth.

Plasma concentrations of glucagon and glucagon-like peptide-1 are reduced in dogs with aminoaciduric canine hypoaminoacidemic hepatopathy syndrome versus healthy dogs: a preliminary study.

To compare plasma concentrations of glucagon and glucagon-like peptide-1 (GLP-1) between healthy dogs and dogs with aminoaciduric canine hypoaminoacidemic hepatopathy syndrome (ACHES) dogs. Privately owned healthy (n = 5) control (CON) and ACHES (8; including 3 with diabetes mellitus) dogs enrolled between October 2, 2019, and March 4, 2020. This was a prospective case-control study. Fasting and 15-minute postprandial plasma glucagon total GLP-1 concentrations were measured with commercial immunoassays. Dogs with ACHES had lower fasting (median, 0.5; mean difference, 3.8; 95% CI, 0.52 to 7.0 pmol/L; P = .021) and postprandial (median, 0.35; mean difference, 5.0; 95% CI, 1.8 to 8.3 pmol/L; P = .002) plasma glucagon concentrations than CON (fasting and postprandial medians, 3.5 and 4.6 pmol/L, respectively). ACHES dogs had significantly (median, 4.15; mean difference, 12.65; 95% CI, 2.0 to 16.3 pg/ml; P = .011) lower postprandial plasma GLP-1 concentrations than CON (median, 16.8 pg/ml). There was no significant difference between fasting GLP-1 levels between the 2 groups. Lower postprandial plasma GLP-1 concentrations may contribute to the propensity of diabetes mellitus in ACHES. Lower glucagon concentrations may reflect an appropriate physiologic response to hypoaminoacidemia.

Associations between Postprandial Gut Hormones and Markers of Bone Remodeling.

Gut-derived hormones have been suggested to play a role in bone homeostasis following food intake, although the associations are highly complex and not fully understood. In a randomized, two-day cross-over study on 14 healthy individuals, we performed postprandial time-course studies to examine the associations of the bone remodeling markers carboxyl-terminal collagen type I crosslinks (CTX) and procollagen type 1 N-terminal propeptide (P1NP) with the gut hormones glucose-dependent insulinotropic polypeptide (GIP), glucagon-like peptide 1 (GLP-1), and peptide YY (PYY) using two different meal types—a standardized mixed meal (498 kcal) or a granola bar (260 kcal). Plasma concentrations of total GIP, total GLP-1, total PYY, CTX, and P1NP were measured up to 240 min after meal intake, and the incremental area under the curve (iAUC) for each marker was calculated. The iAUC of CTX and P1NP were used to assess associations with the iAUC of GIP, GLP-1, and PYY in linear mixed effect models adjusted for meal type. CTX was positively associated with GIP and GLP-1, and it was inversely associated with PYY (all p < 0.001). No associations of P1NP with GIP or GLP-1 and PYY were found. In conclusion, the postprandial responses of the gut hormones GIP, GLP-1, and PYY are associated with the bone resorption marker CTX, supporting a link between gut hormones and bone homeostasis following food intake.

Enzymatically-Synthesized Glycogen Induces Cecal Glucagon-Like Peptide-1 Production and Suppresses Food Intake in Mice.

It is well known that dietary fiber stimulates the release of satiety hormones such as glucagon-like peptide-1 (GLP-1), which in turn suppresses appetite. In order to evaluate appetite regulating role of enzymatically synthesized glycogen (ESG, one of the resistant starch), we examined the effects of dietary supplementation of ESG on food intake and cecal proglucagon gene expression in normal and high fat diet-fed mice. Twenty four male ICR mice were weighed and assigned to four groups: normal diet group; normal diet containing 25% ESG group; high-fat diet (HFD) group; HFD containing 25% ESG group. Each group was fed the relevant diets for 3 wk. All data were analyzed by a two-way ANOVA with the main effects of HFD and ESG. ESG significantly decreased food intake and increased the weight of the cecum and cecal content. Plasma total short chain fatty acids concentration was significantly elevated by ESG. The mRNA levels of proglucagon in the cecum and plasma total GLP-1 concentration were significantly increased by ESG. The mRNA levels of appetite regulating neuropeptides such as neuropeptide Y, agouti-related protein, proopiomelanocortin, and cocain- and amphetamine-regulating transcript in the hypothalamus were not influenced by ESG. There is no significant interaction between diet and ESG in any parameters. These results suggest that ESG-induced upregulation of GLP-1 production in the cecum suppresses food intake in mice and that fecal fermentation may be involved in the anorexigenic effect.

995-P: Glucagon-Like Peptide-1 (GLP-1) Levels following OGTT Mirror Insulin Resistant States (IRS) in Prediabetes Subjects: A Multi-Ethnic Comparative Study

Introduction: IRS is a precursor to the development of prediabetes which manifests itself in the form of compensatory insulin secretion. The role of GLP-1 in this compensatory mechanism has not been well studied especially among various ethnic groups.Aim: To assess differences in GLP-1 responses to OGTT and its relationship to insulin resistance indices (HOMA-IR) among 3 major ethnic groups with prediabetes.Methods: Fifty-four prediabetes subjects (21 Malays, 17 Chinese and 16 Indians) matched for age, gender, BMI and waist circumference underwent a 75-g OGTT. Plasma glucose and total GLP-1 concentrations were measured at 0, 30 and 120 minutes. Fasting glucose and insulin were obtained for the HOMA analyses.Results: Indians were the most insulin resistant. This is mirrored by Indians having the highest GLP-1 levels at 0, 30 and 120 minutes. Similarly, the area under the curve for GLP-1 was 59% higher in Indians and 50% higher in Chinese compared to the Malays. GLP-1 level was positively correlated with HOMA-IR (r=0.576, p<0.001). Ethnicity was a significant determinant of GLP-1 level with Indians exhibiting the strongest positive correlation (B=7.02, p<0.001).Conclusions: In prediabetes, GLP-1 responses post-OGTT increased proportionately to IRS, evidenced by the augmented GLP-1 responses in the Indians who possessed the highest HOMA-IR indices.View largeDownload slideView largeDownload slide DisclosureS. C. Chong: None. N. Sukor: None. S. Robert: None. K. F. Ng: None. N. A. Kamaruddin: None.FundingNational University of Malaysia Medical Centre (GUP-2017-066); Malaysian Endocrine & Metabolic Society (L12-MEMS6)