Institutional experience on the impact of glucagon-like peptide-1 agonists (GLP-1) on glycemic control and weight loss in patients with type 2 diabetes at the Dubai Diabetes Center, United Arab Emirates.

AIMS: To describe the effect of three classes of GLP1 analogues on HbA1c and weight over one year in a homogenous group of patients at the Dubai Diabetes Center in Dubai, United Arab Emirates. The specific objectives are to study the extent of change in HbA1c and weight loss on these medications as well as the sustainability of change over one year. METHODS: A retrospective audit of patients diagnosed Type 2 diabetes receiving one of the three following GLP-1 agonists (Exenatide LA 2 mg weekly, liraglutide 1.8 mg once daily, Dulaglutide 1.5 mg) over one year and documenting changes in HbA1c and weight at 3-, 6-, 9-, and 12-months intervals. RESULTS: The study shows that while there was significant reduction in HbA1c and weight in the first 3 months, this change was not clinically significant. Also, the change was not maintained at the end of the year. By the final quarter, the effect of the medication diminishes, accompanied by a partial regain of weight. CONCLUSION: GLP1 agonists favorable initial effect on HbA1c and weight may not be sustainable beyond a certain period. The exact reason and factors contributing to this need further exploration.

Prescribing of evidence-based diabetes pharmacotherapy in patients with metabolic dysfunction-associated steatohepatitis.

INTRODUCTION: Metabolic dysfunction-associated steatohepatitis (MASH) is highly prevalent in type 2 diabetes (T2D). Pioglitazone and glucagon-like peptide-1 receptor agonists (GLP-1RA) are medications used in T2D that can resolve MASH and should be considered in all patients with T2D and MASH. We assessed prescription rates of evidence-based T2D pharmacotherapy (EBP) in MASH, and ascertained racial/ethnic disparities in prescribing. RESEARCH DESIGN AND METHODS: We conducted a cross-sectional study on patients in Duke University Health System with diagnosis codes for T2D and MASH between January 2019 and January 2021. Only patients with ≥1 primary care or endocrinology encounter were included. The primary outcome was EBP, defined as ≥1 prescription for pioglitazone and/or a GLP-1RA during the study period. A multivariable logistic regression model was used to examine the primary outcome. RESULTS: A total of 847 patients with T2D and MASH were identified; mean age was 59.7 (SD 12) years, 61.9% (n=524) were female, and 11.9% (n=101) and 4.6% (n=39) were of Black race and Latino/a/x ethnicity, respectively. EBP was prescribed in 34.8% (n=295). No significant differences were noted in the rates of EBP use across racial/ethnic groups (Latino/a/x vs White patients: adjusted OR (aOR) 1.82, 95% CI 0.78 to 4.28; Black vs White patients: aOR 0.76, 95% CI 0.44 to 1.33, p=0.20). CONCLUSIONS: EBP prescriptions, especially pioglitazone, are low in patients with T2D and MASH, regardless of race/ethnicity. These data underscore the need for interventions to close the gap between current and evidence-based care.

Optimization of a Glucagon-Like Peptide 1 Receptor Antagonist Antibody for Treatment of Hyperinsulinism.

Congenital hyperinsulinism (HI) is a genetic disorder in which pancreatic ß-cell insulin secretion is excessive and results in hypoglycemia that, without treatment, can cause brain damage or death. Most patients with loss-of-function mutations in ABCC8 and KCNJ11, the genes encoding the ß-cell ATP-sensitive potassium channel (KATP), are unresponsive to diazoxide, the only U.S. Food and Drug Administration-approved medical therapy and require pancreatectomy. The glucagon-like peptide 1 receptor (GLP-1R) antagonist exendin-(9-39) is an effective therapeutic agent that inhibits insulin secretion in both HI and acquired hyperinsulinism. Previously, we identified a highly potent antagonist antibody, TB-001-003, which was derived from our synthetic antibody libraries that were designed to target G protein-coupled receptors. Here, we designed a combinatorial variant antibody library to optimize the activity of TB-001-003 against GLP-1R and performed phage display on cells overexpressing GLP-1R. One antagonist, TB-222-023, is more potent than exendin-(9-39), also known as avexitide. TB-222-023 effectively decreased insulin secretion in primary isolated pancreatic islets from a mouse model of hyperinsulinism, Sur1-/- mice, and in islets from an infant with HI, and increased plasma glucose levels and decreased the insulin to glucose ratio in Sur1-/- mice. These findings demonstrate that targeting GLP-1R with an antibody antagonist is an effective and innovative strategy for treatment of hyperinsulinism. ARTICLE HIGHLIGHTS: Patients with the most common and severe form of diazoxide-unresponsive congenital hyperinsulinism (HI) require a pancreatectomy. Other second-line therapies are limited in their use because of severe side effects and short half-lives. Therefore, there is a critical need for better therapies. Studies with the glucagon-like peptide 1 receptor (GLP-1R) antagonist, avexitide (exendin-(9-39)), have demonstrated that GLP-1R antagonism is effective at lowering insulin secretion and increasing plasma glucose levels. We have optimized a GLP-1R antagonist antibody with more potent blocking of GLP-1R than avexitide. This antibody therapy is a potential novel and effective treatment for HI.

Sodium-glucose cotransporter-2 inhibitors use and the risk of gout: a systematic review and meta-analysis.

Objective: To assess the relationship between use of sodium-glucose cotransporter-2 inhibitors (SGLT2i) and the risk of gout among patients with type 2 diabetes mellitus (T2DM). Methods: A systemic review and meta-analysis were designed by reviewing articles published between 2000 January 1 and 2022 December 31 using PubMed system and Web of Science system based on the PRISMA 2020 guidelines. The end point of interest was gout (including gout flares, gout events, starting uric-acid lowering therapy and starting anti-gout drugs use) among patients with T2DM using SGLT2i versus not using SGLT2i. A random-effects model was utilized to measure the pooled hazard ratio (HR) with 95% confidence interval (CI) for the risk of gout associated with SGLT2i use. Results: Two prospective post-hoc analyses of randomized controlled trials and 5 retrospective electronic medical record-linkage cohort studies met the inclusion criteria. The meta-analysis demonstrated that there was a decreased risk of developing gout for SGLT2i use as comparing with non-use of SGLT2i among patients with T2DM (pooled HR=0.66 and 95%CI=0.57-0.76). Conclusions: This meta-analysis demonstrates that SGLT2i use is associated with a 34% decreased risk of developing gout among patients with T2DM. SGLT2i may be the treatment options for patients with T2DM who are at high risk of gout. More randomized controlled trials and real-world data are needed to confirm whether there is a class effect of SGLT2i for the risk reduction of gout among patients with T2DM.

Design, synthesis, and biological evaluation of a small molecule oral agonist of the glucagon-like-peptide-1 receptor.

An absolute or relative deficiency of pancreatic ß-cells mass and functionality is a crucial pathological feature common to type 1 diabetes mellitus and type 2 diabetes mellitus. Glucagon-like-peptide-1 receptor (GLP1R) agonists have been the focus of considerable research attention for their ability to protect ß-cell mass and augment insulin secretion with no risk of hypoglycemia. Presently commercially available GLP1R agonists are peptides that limit their use due to cost, stability, and mode of administration. To address this drawback, strategically designed distinct sets of small molecules were docked on GLP1R ectodomain and compared with previously known small molecule GLP1R agonists. One of the small molecule PK2 (6-((1-(4-nitrobenzyl)-1H-1,2,3-triazol-4-yl)methyl)-6H-indolo[2,3-b]quinoxaline) displays stable binding with GLP1R ectodomain and induces GLP1R internalization and increasing cAMP levels. PK2 also increases insulin secretion in the INS-1 cells. The oral administration of PK2 protects against diabetes induced by multiple low-dose streptozotocin administration by lowering high blood glucose levels. Similar to GLP1R peptidic agonists, treatment of PK2 induces ß-cell replication and attenuate ß-cell apoptosis in STZ-treated mice. Mechanistically, this protection was associated with decreased thioredoxin-interacting protein expression, a potent inducer of diabetic ß-cell apoptosis and dysfunction. Together, this report describes a small molecule, PK2, as an orally active nonpeptidic GLP1R agonist that has efficacy to preserve or restore functional ß-cell mass.

Comparable Cardiorenal Benefits of SGLT2 Inhibitors and GLP-1RAs in Asian and White Populations: An Updated Meta-analysis of Results From Randomized Outcome Trials.

BACKGROUND: Whether the cardiorenal benefits of sodium-glucose cotransporter 2 (SGLT2) inhibitors and glucagon-like peptide 1 receptor agonists (GLP-1RAs) are comparable between White and Asian populations remains unclear. PURPOSE: To compare the cardiorenal benefits of SGLT2 inhibitors and GLP-1RAs between White and Asian populations and to compare the cardiorenal benefits between the two agents in Asian patients. DATA SOURCES: Electronic databases were searched up to 28 March 2021. STUDY SELECTION: We included the cardiovascular (CV) and renal outcome trials of SGLT2 inhibitors and GLP-1RAs where investigators reported major adverse CV events (MACE), CV death/hospitalization for heart failure (HHF), or composite renal outcomes with stratification by race. DATA EXTRACTION: We extracted the hazard ratio of each outcome stratified by race (Asian vs. White populations). DATA SYNTHESIS: In 10 SGLT2 inhibitor trials, there was no significant difference between Asian and White populations for MACE (P = 0.55), CV death/HHF (P = 0.87), or composite renal outcomes (P = 0.97). In seven GLP-1RA trials, we observed a similar MACE benefit between Asian and White populations (P = 0.10). In our networkmeta-analysis we found a comparable benefit for MACE between SGLT2 inhibitors and GLP-1RAs in Asian patients. LIMITATIONS: The data were from stratified analyses. CONCLUSIONS: There appear to be comparable cardiorenal benefits of SGLT2 inhibitors and GLP-1RAs between Asian and White participants enrolled in CV and renal outcome trials; the two therapies seem to have similar CV benefits for Asian participants.

Liraglutide, a glucagon-like peptide-1 receptor agonist, induces ADAM10-dependent ectodomain shedding of RAGE via AMPK activation in human aortic endothelial cells.

AIMS: Glucagon-like peptide-1 alleviates the deleterious effects of advanced glycation end products (AGEs), but the underlying mechanisms are not fully understood. In this study, we investigated the protective mechanism using liraglutide, a glucagon-like peptide-1 receptor agonist, in cultured human aortic endothelial cells (HAECs). MAIN METHODS: Following liraglutide treatment in HAECs, the receptor for AGEs (RAGE) was measured in both cell lysate and culture supernatant, the cytosolic free Ca2+ level was monitored using Fluo-4 AM, the phosphorylation of adenosine monophosphate-activated protein kinase (AMPK) was analyzed, and immunofluorescence staining was used to visualize a disintegrin and metalloprotease 10 (ADAM10) on the cell surface. KEY FINDINGS: Liraglutide (100 nM) induced ectodomain shedding of RAGE within 30 min and inhibited the expression of intercellular adhesion molecule-1 (ICAM-1) induced by AGEs of bovine serum albumin (AGE-BSA). Further experiments revealed that liraglutide rapidly increases extracellular Ca2+ influx through L-type calcium channels and activates AMPK, resulting in the translocation of ADAM10 to the cell surface, whereas siRNA-mediated ADAM10 depletion prevents liraglutide-induced ectodomain shedding of RAGE and eliminates liraglutide's inhibitory effect on AGE-BSA-induced ICAM-1 expression. Moreover, compound C-mediated AMPK inhibition and siRNA-mediated AMPK depletion both prevented ADAM10 translocation to the cell surface and ADAM10-mediated ectodomain shedding of RAGE. SIGNIFICANCE: Liraglutide reduces the number of intact RAGE on the cell surface by inducing ADAM10-mediated ectodomain shedding, which decreases the inflammatory effects of AGEs. AMPK activated by extracellular Ca2+ influx is critically involved in the translocation of ADAM10 to the cell surface, where it cleaves RAGE.

Clinical Impact of GLP-1 receptor agonists in veterans receiving basal-bolus insulin.

BACKGROUND: In 2017, an estimated 7.4 million Americans used insulin to treat diabetes. Insulin is proven to lower A1c but can result in hypoglycemia and weight gain. Combining insulin with a glucagon-like peptide-1 receptor agonist (GLP-1-RA) may provide additional blood glucose control while limiting undesirable effects including weight gain. OBJECTIVE: To characterize the clinical impact of adding a GLP-1-RA to a basal-bolus insulin regimen in patients with type 2 diabetes. METHODS: This retrospective observational study used national Veteran's Health Administration data to identify patients with an existing basal-bolus insulin regimen who initiated a GLP-1-RA between January 1, 2005 and December 31, 2017. A1c, insulin total daily dose (TDD), and weight were collected at GLP-1-RA initiation (baseline), 3-, 6-, and 12-month time points and then analyzed using an intent-to-treat approach with the last observation carried forward. Decreases in A1c ≥ 0.5% and weight ≥2 kg were deemed clinically significant. RESULTS: Among 7651 patients initiating GLP-1-RA therapy, mean A1c had a clinically significant decline at 3, 6, and 12 months by -0.5%, -0.7%, and -0.7%, respectively, from a mean baseline of 9%. Patients with lower baseline A1c levels did not have clinically significant changes in A1c, whereas patients with baseline A1c ≥9% had more clinically significant declines. Insulin TDD decreased by -32, -38, and -42 units/day at 3, 6, and 12 months, respectively, where the mean decrease in insulin TDD at 12 months was 79 units/day among patients who discontinued bolus insulin (52.3%) compared with a mean decrease of 2 units/day among those who continued bolus insulin. Mean weight reductions at 3, 6, and 12 months were -1.2, -2.3, and -2.9 kg, respectively, from a mean baseline of 120.6 kg. CONCLUSION: Combining a GLP-1-RA with basal-bolus insulin had a clinically significant improvement on blood glucose control, lowered insulin TDD, and reduced weight. These outcomes were achieved within 3 to 6 months following GLP-1-RA initiation and were maintained through 1 year.

Perceptions of injectable therapies with cardiovascular benefit: an ACNAP survey of healthcare professionals to explore facilitators and barriers.

AIMS: Injectable medicines are increasingly used to manage risk factors for cardiovascular (CV) events, such as dyslipidaemia and diabetes. These include proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors and glucagon-like peptide-1 (GLP-1) receptor agonists. Little is known about perceptions of injectable therapies among CV healthcare professionals (HCPs). This study explores their views to identify relevant facilitators and barriers to the use of injectables with CV benefit. METHODS AND RESULTS: A 22-question survey was distributed internationally via online channels. In total, 192 anonymous responses were received (43.7% physicians, 32.6% nurses, 16.8% pharmacists, 6.8% others). Among respondents with experience of these medicines, 69.1% had used an injectable PCSK9 inhibitor and 67.0% had used an injectable GLP-1 receptor agonist. Commonly raised issues were resource problems (36.5%), lack of knowledge among colleagues (32.3%), paperwork (32.3%), and lack of patient knowledge (28.1%). Key barriers respondents felt made patients decline these treatments were fear of injection (56.6%), lack of awareness or education (26.4%), and administration issues (15.1%); potential reasons for discontinuation included side effects (46.4%), perceived lack of benefit (28.6%), and local reactions (21.4%). The main topics around injectables requiring further support included managing non-adherent patients (16.2%), troubleshooting with patients (16.2%), and educating colleagues about injectables (12.2%). Preferred educational methods to support HCPs were face-to-face training (43.5%) and online learning (26.1%); favoured formats were based on role playing and case studies. CONCLUSION: Healthcare professionals highlighted various potential barriers to initiation, continuation, and adherence with injectable therapies in CV medicine. Although some require healthcare system changes, many could be addressed through simple measures based primarily on enhanced training and support for patients and HCPs.

Obese mice weight loss role on nonalcoholic fatty liver disease and endoplasmic reticulum stress treated by a GLP-1 receptor agonist.

BACKGROUND/OBJECTIVES: The weight loss following Semaglutide treatment, a GLP-1 receptor agonist, might be responsible for some effects observed on the nonalcoholic fatty liver disease of obese mice. SUBJECTS/METHODS: Two groups of C57BL/6 male mice (n = 30/group) were fed the diets Control (C) or high-fat (HF) for 16 weeks. Then, separated into six new groups for an additional four weeks (n = 10/group) and treated with Semaglutide (S, 40 µg/kg) or paired feeding (PF) with S groups (C; C-S; C-PF; HF; HF-S; HF-PF). RESULTS: Semaglutide reduced energy consumption leading to weight loss. Simultaneously it improved glucose intolerance, glycated hemoglobin, insulin resistance/sensitivity, plasma lipids, and gastric inhibitory polypeptide. Semaglutide and paired feeding mitigated liver steatosis and adipose differentiation-related protein (Plin2) expression. Semaglutide also improved hormones and adipokines, reduced lipogenesis and inflammation, and increased beta-oxidation. Semaglutide lessened liver glucose uptake and endoplasmic reticulum (ER) stress. Among the 14 genes analyzed, 13 were modified by Semaglutide (93 %, six genes were changed exclusively by Semaglutide, and seven other genes were affected by the combination of Semaglutide and paired feeding). In seven genes, the paired diet showed no effect (50% of the genes tested). No marker was affected exclusively by paired feeding. CONCLUSIONS: Semaglutide and the consequent weight loss reduced obese mice liver inflammation, insulin resistance, and ER stress. However, weight loss alone did show few or no action on some significant study findings, like liver steatosis, leptin, insulin, resistin, and amylin. Furthermore, hepatic inflammation mediated by MCP-1 and partially by TNF-alpha and IL6 were also not reduced by weight loss. Furthermore, weight loss alone did not lessen hepatic lipogenesis as determined by the findings of SREBP-1c, CHREBP, PPAR-alpha, and SIRT1. Semaglutide was implicated in improving glucose uptake and lessening ER stress by reducing GADD45, independent of weight loss.

Development of novel radioiodinated exendin-4 derivatives targeting GLP-1 receptor for detection of ß-cell mass.

In subjects with type 2 diabetes mellitus (T2DM), pancreatic ß-cell mass decreases; however, it is unknown to what extent this decrease contributes to the pathophysiology of T2DM. Therefore, the development of a method for noninvasive detection of ß-cell mass is underway. We previously reported that glucagon-like peptide-1 receptor (GLP-1R) is a promising target molecule for ß-cell imaging. In this study, we attempted to develop a probe targeting GLP-1R for ß-cell imaging using single-photon emission computed tomography (SPECT). For this purpose, we selected exendin-4 as the lead compound and radiolabeled lysine at residue 12 in exendin-4 or additional lysine at the C-terminus using [123I]iodobenzoylation. To evaluate in vitro receptor specificity, binding assay was performed using dispersed mouse islet cells. Biodistribution study was performed in normal ddY mice. Ex vivo autoradiography was performed in transgenic mice expressing green fluorescent protein under control of the mouse insulin I gene promoter. Additionally, SPECT imaging was performed in normal ddY mice. The affinity of novel synthesized derivatives toward pancreatic ß-cells was not affected by iodobenzoylation. The derivatives accumulated in the pancreas after intravenous administration specifically via GLP-1R expressed on the pancreatic ß-cells. Extremely high signal-to-noise ratio was observed during evaluation of biodistribution of [123I]IB12-Ex4. SPECT images using normal mice showed that [123I]IB12-Ex4 accumulated in the pancreas with high contrast between the pancreas and background. These results indicate that [123I]IB12-Ex4 for SPECT is useful for clinical applications because of its preferable kinetics in vivo.

Beneficial effects of glucagon-like peptide 1 receptor agonists on glucose control, cardiovascular risk profile, and non-alcoholic fatty liver disease. An expert opinion of the Italian diabetes society.

Patients with type 2 diabetes mellitus (T2DM) show an increased risk of cardiovascular diseases (CVD) and mortality. Many factors are implicated in the pathogenesis of CVD in patients with T2DM. Among the factors involved, chronic hyperglycemia and the cluster of CVD risk factors, such as dyslipidemia, hypertension, and obesity, play a major role. For many years, the control of hyperglycemia has been complicated by the fact that the use of many available drugs was associated with an increased risk of hypoglycemia. Paradoxically, hypoglycemia per se represents a risk factor for CVD. Recently, new drugs for the control of hyperglycemia have become available: many of them can determine a good control of hyperglycemia with minor risks of hypoglycemia. Among these new classes of drugs, glucagon-like peptide-1 receptor agonists (GLP-1RAs) offer many advantages. In addition to a strong anti-hyperglycemic action, they possess the ability to act on body weight and other relevant risk factors for CVD. Consistently, some of the GLP-1RAs have demonstrated, in RCT designed to assess their safety, to reduce the risk of major adverse cardiovascular events. Furthermore, GLP-1RAs possess properties useful to treat additional conditions, as the capability of improving liver damage in patients with NAFLD or NASH, highly prevalent conditions in people with T2DM. In this document, written by experts of the Italian diabetes society (SID), we will focus our attention on the therapy with GLP-1RAs in patients with T2DM, particularly on the effects on hyperglycemia, cardiovascular disease risk factors, NAFLD/NASH and CVD prevention.

Changes in markers of hepatic steatosis and fibrosis in patients with type 2 diabetes during treatment with glucagon-like peptide-1 receptor agonists. A multicenter retrospective longitudinal study.

AIMS: Metabolic dysfunction-associated fatty liver disease (MAFLD) is common in people with type 2 diabetes (T2D) and can progress to advanced fibrosis and cirrhosis. In this retrospective study, we explored the longitudinal changes in markers of hepatic steatosis and fibrosis during T2D treatment with glucagon-like peptide-1 receptor agonists (GLP-1RAs). METHODS: We analysed observational data from six diabetes outpatient clinics. In the whole T2D population, we calculated the hepatic steatosis index (HSI), which we previously validated against liver ultrasonography, and the Fibrosis (Fib)-4 index. We then identified patients who initiated a GLP-1RA from 2010 to 2018 and for whom data were available to evaluate changes in both HSI and Fib-4 scores over 24 months. RESULTS: From 83,116 outpatients with T2D, 41,302 (49.7%) had complete data for calculating HSI and Fib-4. Most of these T2D patients (∼70%) had MAFLD (defined as HSI>36), 9.7% of whom had advanced fibrosis based on Fib-4 thresholds. Patients with low compared to high risk of advanced fibrosis were 5-times more likely to be treated with GLP-1RA. In 535 patients who initiated a GLP-1RA, the prevalence of MAFLD based on HSI declined significantly at 6 and 24 months, but Fib-4 categories did not. HSI improved significantly only in patients receiving human-based but not exendin-based GLP-1RA, while patients concomitantly receiving metformin had less worsening in Fib-4 categories. CONCLUSIONS: MAFLD is very common among outpatients with T2D (∼70%) and the estimated prevalence of advanced fibrosis was ∼10%. Treatment with GLP-1RAs significantly improved MAFLD, but not MAFLD-associated advanced fibrosis.

Mechanisms underlying the prokinetic effects of endogenous glucagon-like peptide-1 in the rat proximal colon.

Glucagon-like peptide-1 (GLP-1), a well-known insulin secretagogue, is released from enteroendocrine L cells both luminally and basolaterally to exert different effects. Basolaterally released GLP-1 increases epithelial ion transport by activating CGRP-containing enteric afferent neurons. Although bath-applied GLP-1 reduced the contractility of colonic segments, GLP-1-induced stimulation of afferent neurons could also accelerate peristaltic contractions. Here, the roles of endogenous GLP-1 in regulating colonic peristalsis were investigated using isolated colonic segments. Isolated segments of rat proximal colon were placed in an organ bath, serosally perfused with oxygenated physiological salt solution, and luminally perfused with degassed 0.9% saline. Colonic wall motion was recorded using a video camera and converted into spatiotemporal maps. Intraluminal administration of GLP-1 (100 nM) stimulating the secretion of GLP-1 from L cells increased the frequency of oro-aboral propagating peristaltic contractions. The acceleratory effect of GLP-1 was blocked by luminally applied exendin-3 (9-39) (100 nM), a GLP-1 receptor antagonist. GLP-1-induced acceleration of peristaltic contractions was also prevented by bath-applied BIBN4069 (1 µM), a CGRP receptor antagonist. In colonic segments that had been exposed to bath-applied capsaicin (100 nM) that desensitizes extrinsic afferents, GLP-1 was still capable of exerting its prokinetic effect. Stimulation of endogenous GLP-1 secretion with a luminally applied cocktail of short-chain fatty acids (1 mM) increased the frequency of peristaltic waves in an exendin-3 (9-39)-sensitive manner. Thus, GLP-1 activates CGRP-expressing intrinsic afferents to accelerate peristalsis in the proximal colon. Short-chain fatty acids appear to stimulate endogenous GLP-1 secretion from L cells resulting in the acceleration of colonic peristalsis.NEW & NOTEWORTHY Glucagon-like peptide-1 (GLP-1) activates CGRP-containing intrinsic afferent neurons resulting in the acceleration of colonic peristalsis. Short-chain fatty acids stimulate the secretion of endogenous GLP-1 from L cells that accelerates colonic peristalsis. Thus, besides the well-known humoral insulinotropic action, GLP-1 exerts a local action via the activation of the enteric nervous system to accelerate colonic motility. Such a prokinetic action of GLP-1 could underlie the mechanisms causing diarrhea in patients with type-2 diabetes treated with GLP-1 analogs.

Glucagon-like Peptide-1 Receptor Agonists and Cardioprotective Benefit in Patients with Type 2 Diabetes Without Baseline Metformin: A Systematic Review and Update Meta-analysis.

INTRODUCTION: Sodium Glucose Co-transporter 2 inhibitors and glucagon-like peptide 1 receptor agonists (GLP-1RAs) were associated with a reduction in cardiovascular disease events in cardiovascular outcomes trials (CVOTs) in type 2 diabetes. Most of the patients included in these trials received metformin as background therapy. AIM: To evaluate the effect of glucagon-like peptide 1 receptor agonists on major cardiovascular events (MACE) and mortality in metformin-naïve patients with type 2 diabetes. METHODS: A systematic review and meta-analysis of randomized controlled clinical trials of GLP-1RAs on type 2 diabetes population was performed, after searching the PubMed/MEDLINE, Embase, Scielo, Google Scholar and Cochrane Controlled Trials databases. The primary endpoint was MACE. The secondary endpoints were cardiovascular death and all-cause mortality. A meta-analysis of time-to-event outcomes was performed. This meta-analysis was registered in PROSPERO (CRD42021260040) RESULTS: Seven trials, including 11510 patients, were identified and considered eligible for the analyses. GLP-1RAs were associated with a significant reduction in MACE incidence (HR: 0.86, 95% confidence interval: 0.79-0.94; I2: 0%). The secondary endpoints analysis showed a non-significant reduction in all-cause mortality (HR: 0.86, 95% confidence interval: 0.73-1.00 I2: 0%) and cardiovascular mortality (HR: 0.81, 95% confidence interval: 0.63-1.05; I2: 0%). CONCLUSIONS: In this meta-analysis, GLP-1RAs reduced the incidence of MACE in patients with type 2 diabetes without metformin at baseline, without significant reduction in all-cause mortality and cardiovascular mortality. These results support the fact that when a GLP-1RAs is administered, the benefit on cardiovascular outcomes is independent of the use of metformin.

Glucagon Potentiates Insulin Secretion Via ß-Cell GCGR at Physiological Concentrations of Glucose.

Incretin-potentiated glucose-stimulated insulin secretion (GSIS) is critical to maintaining euglycemia, of which GLP-1 receptor (GLP-1R) on ß-cells plays an indispensable role. Recently, α-cell-derived glucagon but not intestine-derived GLP-1 has been proposed as the critical hormone that potentiates GSIS via GLP-1R. However, the function of glucagon receptors (GCGR) on ß-cells remains elusive. Here, using GCGR or GLP-1R antagonists, in combination with glucagon, to treat single ß-cells, α-ß cell clusters and isolated islets, we found that glucagon potentiates insulin secretion via ß-cell GCGR at physiological but not high concentrations of glucose. Furthermore, we transfected primary mouse ß-cells with RAB-ICUE (a genetically encoded cAMP fluorescence indicator) to monitor cAMP level after glucose stimulation and GCGR activation. Using specific inhibitors of different adenylyl cyclase (AC) family members, we revealed that high glucose concentration or GCGR activation independently evoked cAMP elevation via AC5 in ß-cells, thus high glucose stimulation bypassed GCGR in promoting insulin secretion. Additionally, we generated ß-cell-specific GCGR knockout mice which glucose intolerance was more severe when fed a high-fat diet (HFD). We further found that ß-cell GCGR activation promoted GSIS more than GLP-1R in HFD, indicating the critical role of GCGR in maintaining glucose homeostasis during nutrient overload.

Primary care management of type 2 diabetes: a comparison of the efficacy and safety of glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors.

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) and dipeptidyl peptidase-4 inhibitors (DPP4is) exert their effects via the incretin system, which augments glucose-dependent insulin secretion in response to nutrient intake (the 'incretin effect'). Both classes are well-established pharmacologic options for the management of glycemic control in individuals with type 2 diabetes (T2D) after failure of first-line metformin; however, they have inherent differences in their mechanisms of action that are reflected in their clinical safety and efficacy profiles. GLP-1RAs have high glycemic efficacy and are associated with weight loss and, in some cases, cardioprotective effects, with a side-effect profile of predominantly transient gastrointestinal adverse events. Most GLP-1RAs are administered as subcutaneous injection, although an oral formulation of one GLP-1RA, semaglutide, has recently become available. DPP4is provide moderate glycemic control, are weight-neutral, and do not offer any cardiovascular benefits, but are generally well tolerated. DPP4is are all administered orally. This narrative review aims to provide guidance for a primary care audience on the similarities and differences between GLP-1RA and DPP4i therapies, with a focus on their mechanism of action, clinical safety, efficacy, and real-world effectiveness. The role of incretin-based therapies in the T2D treatment paradigm, including key considerations for guiding treatment decisions, will also be discussed.

Comparative efficacy of 5 sodium glucose cotransporter 2 inhibitor and 7 glucagon-like peptide 1 receptor agonists interventions on cardiorenal outcomes in type 2 diabetes patients: A network meta-analysis based on cardiovascular or renal outcome trials.

BACKGROUND: Sodium glucose cotransporter 2 (SGLT2) inhibitors and glucagon-like peptide 1 receptor agonists (GLP-1 RAs) have been demonstrated to be able to improve the cardiovascular and renal prognosis in patients with type 2 diabetes (T2D). However, the relative efficacy of various SGLT2 inhibitors and GLP-1 RAs on cardiorenal outcomes is unestablished. METHODS: We searched PubMed and Embase for relevant cardiovascular or renal outcome trials (CVOTs). Endpoints of interest were major adverse cardiovascular events (MACE), stroke, myocardial infarction (MI), cardiovascular death (CVD), all-cause death (ACD), kidney function progression (KFP), and hospitalization for heart failure (HHF). Bayesian network meta-analysis was conducted to produce pooled hazard ratio (HR) and 95% confidence interval (CI). We calculated the probability values of surface under the cumulative ranking curve to rank active and placebo interventions. RESULTS: Fourteen COVTs were included in analysis. Sotagliflozin (HR 0.76, 95% CI 0.61-0.94), subcutaneous semaglutide, and albiglutide lowered MACE versus lixisenatide among others. Sotagliflozin (HR 0.59, 95% CI 0.40-0.89), canagliflozin, and empagliflozin lowered HHF versus subcutaneous semaglutide among others. Dapagliflozin and empagliflozin lowered KFP versus exenatide among others. Empagliflozin and oral semaglutide lowered CVD versus dapagliflozin among others. Sotagliflozin (HR 0.65, 95% CI 0.47-0.91) and albiglutide lowered MI versus ertugliflozin among others. Sotagliflozin (HR 0.56, 95% CI 0.37-0.85) and subcutaneous semaglutide lowered stroke versus empagliflozin among others. Oral semaglutide and empagliflozin lowered ACD versus subcutaneous semaglutide among others. The maximum surface under the cumulative ranking curve values followed sotagliflozin, subcutaneous semaglutide, and albiglutide in lowering MACE; sotagliflozin, canagliflozin, and empagliflozin in lowering HHF; dapagliflozin and empagliflozin in lowering KFP; empagliflozin and oral semaglutide in lowering CVD; sotagliflozin and albiglutide in lowering MI; sotagliflozin and subcutaneous semaglutide in lowering stroke; and oral semaglutide and empagliflozin in lowering ACD. CONCLUSIONS: This updated network meta-analysis reproduced the findings in the first network meta-analysis, and moreover revealed that sotagliflozin was one of the most effective drugs as for lowering MI, stroke, MACE, and HHF, whereas ertugliflozin was not. These findings will provide the according evidence regarding the usage of specific SGLT2 inhibitors and GLP-1 RAs in T2D patients for prevention of specific cardiorenal endpoints.

Regional variation of effects of new antidiabetic medications in cardiovascular outcome trials.

BACKGROUND: In international trials, glucagon-like protein-1 receptor agonists (GLP-1RAs) and sodium-glucose cotransporter-2 inhibitors (SGLT2Is) were effective in improving cardiovascular (CV) outcomes. METHODS: We assessed the effect of GLP-1RAs and SGLT2Is treatment effect on CV endpoints by geographical region in multiple international trials using random effects weighted least squares meta-regressions. RESULTS: The estimated effects of both SGLT2Is and GLP-1RAs on major adverse CV events (MACE) in North America (SGLT2Is n = 12,399, HR 0.90, 95% CI 0.81-1.01; GLP-1RAs n = 12,515, HR 0.95, 95% CI 0.83- 1.09) and in Europe (SGLT2Is n = 19,435, HR 0.93, 95% CI 0.85-1.02; GLP-1RAs n = 22,812, HR 0.88, 95% CI 0.79-0.99) were numerically lower but not statistically different to the rest of the world (ROW) (SGLT2Is n = 15,127, HR 0.83, 95% CI 0.75-0.92, p-value for interaction 0.26; GLP-1RAs n = 17,494, HR 0.82, 95% CI 0.73-0.92, p-value for interaction 0.28). Effects of SGLT2Is on heart failure readmission or CV death varied significantly by region (P = 0.0094). The effect of SGLT2Is was significantly smaller in Europe (n = 18,653, HR 0.86, 95% CI 0.78-0.95) than in the ROW (n = 12,463, HR 0.68, 95% CI 0.61-0.76, P = 0.0024). The smaller effect in North America (n = 9776, HR 0.76, 95% CI 0.66-0.87) did not differ significantly from that in the ROW (P = 0.2370). CONCLUSION: The effects of SGLT2Is on HF events are larger in the ROW. Further analyses and studies are needed to better elucidate the differential effects of SGLTIs and GLP-1RAs by geographical regions.