Cardioprotective and vasodilatory actions of glucagon-like peptide 1 receptor are mediated through both glucagon-like peptide 1 receptor-dependent and -independent pathways

Risk of Retinal Vein Occlusion between Glucagon-Like Peptide-1 Receptor Agonists and Dipeptidyl Peptidase-4 Inhibitors in Type 2 Diabetes: A Retrospective Cohort Study

Objective

To evaluate whether glucagon-like peptide-1 receptor agonists (GLP-1RAs) are associated with reduced retinal vein occlusion (RVO) risk compared with dipeptidyl peptidase-4 (DPP-4) inhibitors in patients with type 2 diabetes mellitus (T2DM).

Design

A multinational, retrospective cohort study.

Participants

Adults with T2DM newly prescribed GLP-1RAs or DPP-4 inhibitors between 2006 and 2023 were included in our analysis.

Methods

This study leveraged data from populations across 21 countries. Propensity score matching at a 1:1 ratio balanced age, sex, race, glycated hemoglobin (HbA1c), body mass index (BMI), estimated glomerular filtration rate, medications, and comorbidities between GLP-1RA and DPP4 inhibitor users.

Main Outcomes Measures

We observed the occurrence of incident RVO and branch RVO (BRVO) in the overall population and in subpopulations stratified by age, sex, race, GLP-1RA type, baseline HbA1c, BMI, and diabetes duration.

Results

Among 79 486 matched participants, GLP-1RA use is associated with a lower risk of RVO (hazard ratio [HR], 0.73; 95% confidence interval [CI], 0.54-0.98) and BRVO (HR, 0.62; 95% CI, 0.41-0.95) over 5 years compared with DPP-4 inhibitor use. This association is consistent among patients aged ≥50 years, Blacks, those prescribed human-analog GLP-1RAs, and those with baseline HbA1c ≥8%, BMI ≥30 kg/m2, and diabetes duration ≥3 years.

Conclusions

Glucagon-like peptide-1 receptor agonist use was linked to reduced RVO and BRVO risks in patients with T2DM when compared with DPP-4 inhibitor use, particularly in high-risk populations, suggesting potential benefits of GLP-1RAs over DPP-4 inhibitors in managing ocular complications in T2DM.

Financial Disclosures

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Obesity accelerates cardiovascular ageing

A global obesity pandemic, coupled with an increasingly ageing population, is exacerbating the burden of cardiovascular disease. Indeed, clinical and experimental evidence underscores a potential connection between obesity and ageing in the pathogenesis of various cardiovascular disorders. This is further supported by the notion that weight reduction not only effectively reduces major cardiovascular events in elderly individuals but is also considered the gold standard for lifespan extension, in obese and non-obese model organisms. This review evaluates the intricate interplay between obesity and ageing from molecular mechanisms to whole organ function within the cardiovascular system. By comparatively analysing their characteristic features, shared molecular and cell biological signatures between obesity and ageing are unveiled, with the intent to shed light on how obesity accelerates cardiovascular ageing. This review also elaborates on how emerging metabolic interventions targeting obesity might protect from cardiovascular diseases largely through antagonizing key molecular mechanisms of the ageing process itself. In sum, this review aims to provide valuable insight into how understanding these interconnected processes could guide the development of novel and effective cardiovascular therapeutics for a growing aged population with a concerning obesity problem.

ANMCO statement: semaglutide in the cardio-nephro-metabolic continuum

Semaglutide, a glucagon-like peptide-1 receptor agonist, has emerged as a pivotal therapeutic agent in the management of the cardio-renal-metabolic continuum. Initially developed for glycaemic control in Type 2 diabetes mellitus, its benefits extend far beyond glucose regulation. Clinical trials have demonstrated semaglutide's potential to reduce major adverse cardiovascular events, particularly in overweight/obese patients with high cardiovascular risk, as well as improving functional capacity in patients suffering from heart failure with preserved left ventricular function. Additionally, it has shown promise in improving renal outcomes, such as slowing the progression of albuminuria and reducing the risk of chronic kidney disease in diabetic populations. These effects are likely due to its multifaceted mechanisms, including anti-inflammatory properties, weight reduction, blood pressure lowering, and direct renal protection. This review synthesizes current evidence on semaglutide's role in the interrelated domains of cardiovascular, renal, and metabolic health.

Epicardial adipose tissue as target of the incretin-based therapies in cardio-metabolic pathologies: a narrative review

The epicardial adipose tissue (EAT) serves in physiological conditions as a mechanical and thermal myocardial protective layer, as well as a readily available lipid-storage unit. In pathological conditions, EAT expansion becomes deleterious and is currently recognized as an independent risk factor for the progression of cardiovascular diseases. The EAT phenotypic shift from protective to pro-inflammatory/pro-oxidant is facilitated by the presence of metabolic diseases (obesity, metabolic syndrome, and diabetes), which further increase its expansion and dysregulation, favor the occurrence of complications (mainly atrial fibrillation), and promote progression towards heart failure. Glucagon-like peptide-1 (GLP-1) receptor agonists are novel antidiabetic medications belonging to the incretin class that have demonstrated efficacy beyond glycemic control, in terms of weight reduction and cardiorenal protection in patients with type 2 diabetes mellitus. The GLP-1 receptors and glucose-dependent insulinotropic polypeptide (GIP) receptors are expressed in the human EAT and are targeted by an increasing number of pharmacological agonists, with pleiotropic protective effects on EAT structure and function. Herein we review the literature characterizing the benefits of GLP-1 and GIP receptors activation by single and dual agonists with particular emphasis on their effects on EAT and highlight the role of incretin-based therapy for the management of cardiometabolic pathologies.

Advances in incretin therapies for targeting cardiovascular disease in diabetes

The global prevalence of obesity is skyrocketing at an alarming rate, with recent data estimating that one-in-eight people are now living with the disease. Obesity is a chronic metabolic disorder that shares underlying pathophysiology with other metabolically-linked diseases such as type 2 diabetes mellitus, cardiovascular disease and diabetic cardiomyopathy. There is a distinct correlation between type 2 diabetes status and the likelihood of heart failure. Of note, there is an apparent sexual dimorphism, with women disproportionately affected with respect to the degree of severity of the cardiac phenotype of diabetic cardiomyopathy that results from diabetes. The current pharmacotherapies available for the attenuation of hyperglycaemia in type 2 diabetes are not always effective, and have varying degrees of efficacy in the setting of heart failure. Insulin can worsen heart failure prognosis whereas metformin, sodium-glucose cotransporter 2 inhibitors (SGLT2i) and more recently, glucagon-like peptide-1 receptor agonists (GLP-1RAs), have demonstrated cardioprotection with their administration. This review will highlight the advancement of incretin therapies for individuals with diabetes and heart failure and explore newly-reported evidence of the clinical usefulness of GLP-1R agonists in this distinct phenotype of heart failure.

Modulation of GLP-1 signalling as an innovative strategy counteracting the onset of heart failure: Potential for natural compound supplementation

The clinical continuum of heart failure (HF) is commonly divided into four stages (A, B, C and D), but despite the identification of its staging, to date, the management of the early phases remains an unmet need. In fact, the incomplete knowledge of the molecular mechanisms associated with the comorbidities leading to HF onset represents an obstacle to a targeted therapy. Recently, stages A and B have been further typified and, starting from this novel characterization, the aim of our review was to propose an alternative criterion to appropriately use GLP-1 RA in association with plant-derived polyphenolic extracts. This alternative approach is based on the selection of the main molecular mechanisms underlying the early and asymptomatic HF onset that might be further prevented or antagonized through the administration of natural extracts.

Impact of glucagon-like peptide-1 receptor agonists on hypertension management: a narrative review

PURPOSE OF REVIEW

The increasing prevalence of hypertension, alongside the growing use of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) for conditions beyond type 2 diabetes, underscores the need for understanding if there is a role for these medications in blood pressure management. This review addresses the timely opportunity to assess how GLP-1 RAs could influence blood pressure control, potentially broadening therapeutic strategies for cardiovascular risk management.

RECENT FINDINGS

Emerging literature indicates that GLP-1 RAs influence blood pressure through various mechanisms, such as sympathetic nervous modulation, vasodilation, and diuretic effects. Clinical trials demonstrate modest yet statistically significant reductions in systolic blood pressure (SBP), with less consistent effects on diastolic blood pressure (DBP). The advent of dual GLP-1 and glucose-dependent insulinotropic polypeptide (GIP) receptor agonists presents enhanced possibilities for managing hypertension.

SUMMARY

The implications of these findings suggest that GLP-1 RAs have potential as adjunctive therapies for hypertension, especially in patients already receiving these agents for other cardiometabolic conditions. The blood pressure-lowering effects, often independent of weight loss or glucose control, warrant further investigation to determine their precise role within hypertension treatment algorithms and encourage integration into clinical practice.

Endothelial dysfunction in the kidney transplant population: Current evidence and management strategies

The endothelium modulates vascular homeostasis owing to a variety of vasoconstrictors and vasodilators. Endothelial dysfunction (ED), characterized by impaired vasodilation, inflammation, and thrombosis, triggers future cardiovascular (CV) diseases. Chronic kidney disease, a state of chronic inflammation caused by oxidative stress, metabolic abnormalities, infection, and uremic toxins damages the endothelium. ED is also associated with a decline in estimated glomerular filtration rate. After kidney transplantation, endothelial functions undergo immediate but partial restoration, promising graft longevity and enhanced CV health. However, the anticipated CV outcomes do not happen due to various transplant-related and unrelated risk factors for ED, culminating in poor CV health and graft survival. ED in kidney transplant recipients is an under-recognized and poorly studied entity. CV diseases are the leading cause of death among kidney transplant candidates with functioning grafts. ED contributes to the pathogenesis of many of the CV diseases. Various biomarkers and vasoreactivity tests are available to study endothelial functions. With an increasing number of transplants happening every year, and improved graft rejection rates due to the availability of effective immunosuppressants, the focus has now shifted to endothelial protection for the prevention, early recognition, and treatment of CV diseases.

Decoding TGR5: A comprehensive review of its impact on cerebral diseases

Currently, unraveling the enigmatic realm of drug targets for cerebral disorders poses a formidable challenge. Takeda G protein-coupled receptor 5 (TGR5), also known as G protein-coupled bile acid receptor 1, is a specific bile acid receptor. Widely distributed across various tissues, TGR5 orchestrates a myriad of biological functions encompassing inflammation, energy metabolism, fatty acid metabolism, immune responses, cellular proliferation, apoptosis, and beyond. Alongside its well-documented implications in liver diseases, obesity, type 2 diabetes, tumors, and cardiovascular diseases, a growing body of evidence accentuates the pivotal role of TGR5 in cerebral diseases. Thus, this comprehensive review aimed to scrutinize the current insights into the pathological mechanisms involving TGR5 in cerebral diseases, while contemplating its potential as a promising therapeutic target for cerebral diseases.

Linking Cardiovascular Disease and Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD): The Role of Cardiometabolic Drugs in MASLD Treatment

The link between cardiovascular disease (CVD) and metabolic dysfunction-associated steatotic liver disease (MASLD) is well-established at both the epidemiological and pathophysiological levels. Among the common pathophysiological mechanisms involved in the development and progression of both diseases, oxidative stress and inflammation, insulin resistance, lipid metabolism deterioration, hepatokines, and gut dysbiosis along with genetic factors have been recognized to play a pivotal role. Pharmacologic interventions with drugs targeting common modifiable cardiometabolic risk factors, such as T2DM, dyslipidemia, and hypertension, are a reasonable strategy to prevent CVD development and progression of MASLD. Recently, a novel drug for metabolic dysfunction-associated steatohepatitis (MASH), resmetirom, has shown positive effects regarding CVD risk, opening new opportunities for the therapeutic approach of MASLD and CVD. This review provides current knowledge on the epidemiologic association of MASLD to CVD morbidity and mortality and enlightens the possible underlying pathophysiologic mechanisms linking MASLD with CVD. The role of cardiometabolic drugs such as anti-hypertensive drugs, hypolipidemic agents, glucose-lowering medications, acetylsalicylic acid, and the thyroid hormone receptor-beta agonist in the progression of MASLD is also discussed. Metformin failed to prove beneficial effects in MASLD progression. Studies on the administration of thiazolinediones in MASLD suggest effectiveness in improving steatosis, steatohepatitis, and fibrosis, while newer categories of glucose-lowering agents such as GLP-1Ra and SGLT-2i are currently being tested for their efficacy across the whole spectrum of MASLD. Statins alone or in combination with ezetimibe have yielded promising results. The conduction of long-duration, large, high-quality, randomized-controlled trials aiming to assess by biopsy the efficacy of cardiometabolic drugs to reverse MASLD progression is of great importance.

Liraglutide and GLP-1(9-37) alleviated hepatic ischemia-reperfusion injury by inhibiting ferroptosis via GSK3β/Nrf2 pathway and SMAD159/Hepcidin/FTH pathway

Ferroptosis plays a pivotal role in the pathogenesis of ischemia-reperfusion injury (IRI). Liraglutide, as a GLP-1 receptor (GLP-1R) agonist, has exhibited extensive biological effects beyond its hypoglycemic action. Recent studies have shed light on the regulatory influence of Liraglutide on ferroptosis, yet the precise underlying mechanism remains elusive. GLP-1(9-37), as a metabolite of GLP-1, has a low affinity to GLP-1R. Its effect on ferroptosis remains unknown. In this study, we investigated the effects of Liraglutide and GLP-1(9-37) on the ferroptosis during hepatic ischemia-repferfusion (I/R), as well as the underlying specific mechanisms. We found that the administration of Liraglutide alleviated I/R-induced liver injury with less iron accumulation and lower lipid peroxidation, which was not entirely dependent on the presence of GLP-1R. Similarly, GLP-1(9-37) also exhibited these effects. Besides, both of them increased GPX4 expression and decreased COX2 expression. These effects were reversed by a High-Iron Diet. In vitro study showed similar results. In mechanism study, we found that both Liraglutide and GLP-1(9-37) treatment promoted the nuclear translocation of Nrf2 by inhibiting GSK-3β, thereby reducing lipid peroxides. Furthermore, they increased FTH and FTL expression via the SMAD159/Hepcidin pathway, which contributed to the decreased iron accumulation. In conclusion, this study determined that both Liraglutide and GLP-1(9-37) alleviated hepatic ischemia-reperfusion injury (HIRI) by suppressing ferroptosis via the activation of the GSK3β/Nrf2 pathway and the SMAD159/Hepcidin/FTH pathway.

Interactions between antidiabetes medications and heart-brain axis

PURPOSE OF REVIEW

The heart - brain axis (HBA) is the physiological interactions between the cardiovascular and nervous systems through autonomic nerves, hormones, and cytokines. Patients diagnosed with diabetes mellitus have an increased risk of the cardiovascular and neurological diseases. However, recent evidence demonstrated that different antidiabetic drugs may delay cognitive impairment and improve cardiovascular outcomes. This review examines the impact of antidiabetic drugs on the HBA in patients with diabetes.

RECENT FINDINGS

Metformin improves the cardiovascular and cognitive outcomes through adenosine 5'-monophosphate-activated protein kinase activation. Sodium-glucose cotransporter-2 inhibitors reduce inflammation, oxidative stress by inhibiting the NLRP3 inflammasome thereby reducing the incidence of heart failure and formation of beta-amyloid and neurofibrillary tangles in the brain. Dipeptidyl peptidase-4 inhibitors exhibit neuroprotective effects in Alzheimer's disease by reducing amyloid-beta and tau pathology and inflammation but may exacerbate heart failure risk due to increased sympathetic activity and prolonged β-adrenergic stimulation. Glucagon-like peptide-1 receptor agonists exhibit neuroprotective effects in Alzheimer's and Parkinson's diseases by reducing neuroinflammation, but may increase sympathetic activity, potentially elevating heart rate and blood pressure, despite their cardioprotective benefits.

SUMMARY

Antidiabetes medications have the potential to improve cardiovascular and cognitive outcomes; however, additional studies are required to substantiate these effects.

Glucagon-Like Peptide-1 Links Ingestion, Homeostasis, and the Heart

Glucagon-like peptide-1 (GLP-1), a hormone released from enteroendocrine cells in the distal small and large intestines in response to nutrients and other stimuli, not only controls eating and insulin release, but is also involved in drinking control as well as renal and cardiovascular functions. Moreover, GLP-1 functions as a central nervous system peptide transmitter, produced by preproglucagon (PPG) neurons in the hindbrain. Intestinal GLP-1 inhibits eating by activating vagal sensory neurons directly, via GLP-1 receptors (GLP-1Rs), but presumably also indirectly, by triggering the release of serotonin from enterochromaffin cells. GLP-1 enhances glucose-dependent insulin release via a vago-vagal reflex and by direct action on beta cells. Finally, intestinal GLP-1 acts on the kidneys to modulate electrolyte and water movements, and on the heart, where it provides numerous benefits, including anti-inflammatory, antiatherogenic, and vasodilatory effects, as well as protection against ischemia/reperfusion injury and arrhythmias. Hindbrain PPG neurons receive multiple inputs and project to many GLP-1R-expressing brain areas involved in reward, autonomic functions, and stress. PPG neuron-derived GLP-1 is involved in the termination of large meals and is implicated in the inhibition of water intake. This review details GLP-1's roles in these interconnected systems, highlighting recent findings and unresolved issues, and integrating them to discuss the physiological and pathological relevance of endogenous GLP-1 in coordinating these functions. As eating poses significant threats to metabolic, fluid, and immune homeostasis, the body needs mechanisms to mitigate these challenges while sustaining essential nutrient intake. Endogenous GLP-1 plays a crucial role in this "ingestive homeostasis."

Syringaldehyde Alleviates Cardiac Hypertrophy Induced by Hyperglycemia in H9c2 Cells Through GLP-1 Receptor Signals

Background: Cardiac hypertrophy is a significant complication of diabetes, often triggered by hyperglycemia. Glucagon-like peptide-1 (GLP-1) receptor agonists alleviate cardiac hypertrophy, but their efficacy diminishes under GLP-1 resistance. Syringaldehyde (SA), a natural phenolic compound, may activate GLP-1 receptors and mitigate hypertrophy. This study explores SA's therapeutic potential in hyperglycemia-induced cardiac hypertrophy in H9c2 cardiomyocytes. Methods: H9c2 cells were exposed to high glucose to induce hypertrophy. Cells were treated with varying SA concentrations, and hypertrophic biomarkers were analyzed using ELISA, qPCR, and Western blot. Results: SA reduced cell size and hypertrophic biomarkers in a dose-dependent manner while increasing GLP-1 receptor expression and cAMP levels. These effects were attenuated in GLP-1-resistant cells, highlighting the role of GLP-1 receptor activation. AMPK activation was essential, as its inhibition abolished SA's effects. SA also decreased O-linked N-acetylglucosamine transferase (OGT) expression via AMPK activation, contributing to reduced hypertrophy. Conclusions: SA alleviates hyperglycemia-induced cardiac hypertrophy in H9c2 cells by activating the GLP-1 receptor and AMPK signaling pathway.

The Beneficial Effects of GLP-1 Receptor Agonists Other than Their Anti-Diabetic and Anti-Obesity Properties

As an incretin hormone, Glucagon-like peptide-1 (GLP-1) has obvious effects on blood glucose regulation and weight loss. GLP-1 receptor (GLP-1R) agonists are synthetic products that have similar effects to GLP-1 but are less prone to degradation, and they are widely used in the treatment of type 2 diabetes and obesity. In recent years, different beneficial effects of GLP-1R agonists were discovered, such as reducing ischemia-reperfusion injury, improving the function of various organs, alleviating substance use disorder, affecting tumorigenesis, regulating bone metabolism, changing gut microbiota composition, and prolonging graft survival. Therefore, GLP-1R agonists have great potential for clinical application in various diseases. Here, we briefly summarized the beneficial effects of GLP-1R agonists other than the anti-diabetic and anti-obesity effects.

Pharmacologic Treatment of Obesity in adults and its impact on comorbidities: 2024 Update and Position Statement of Specialists from the Brazilian Association for the Study of Obesity and Metabolic Syndrome (Abeso) and the Brazilian Society of Endocrinology and Metabolism (SBEM)

Pharmacological treatment of obesity is passing through many changes in the last decades; different agents have been approved, and newer options are leaning towards higher efficacy and a more favourable safety profile; however, medications approved for a longer time are still available and useful for many patients. This document is an 2024 Update Position Statement of Specialists from the Brazilian Association for the Study of Obesity and Metabolic Syndrome (Abeso) and the Brazilian Society of Endocrinology and Metabolism (SBEM), with the aim of reviewing all the approved medications for the management of obesity in Brazil (sibutramine, orlistat, liraglutide, semaglutide and bupropion/naltrexone fixed dose), with the addition of tirzepatide, that is approved in other countries and likely approved soon in Brazil. The review is focused on efficacy, safety profile and the impact of drugs (based on existing studies) on different comorbidities.

Roseburia intestinalis: A possible target for vascular calcification

With the advancement of metagenomics and metabolomics techniques, the crucial role of the gut microbiome in intestinal, cardiovascular, and metabolic disorders has been extensively explored. Vascular calcification (VC) is common in atherosclerosis, hypertension, diabetes mellitus, and chronic kidney disease. Moreover, it is a significant cause of cardiovascular diseases and mortality. Roseburia intestinalis, as a promising candidate for the next generation of probiotics, plays a substantial role in inhibiting the systemic inflammatory response and holds great potential in the treatment of intestinal diseases, cardiovascular diseases, and metabolic disorders. Its primary metabolite, butyrate, acts on specific receptors (GPR43, GPR41, GPR109a). It enters cells via transporters (MCT1, SMCT1), affecting gene expression through HDACs, PPARγ and Nrf2, promoting energy metabolism and changing the concentration of other metabolites (including AGEs, LPS, BHB) in the circulation to affect the body's life activities. In this paper, we focus on the possible mechanism of the primary metabolite butyrate of Roseburia intestinalis in inhibiting VC, which may become a potential therapeutic target for the treatment of VC and the ways to enhance its effect.

A Comprehensive Review of Clinical Studies Applying Flow-Mediated Dilation

Flow-mediated dilation (FMD) is a noninvasive method to evaluate vascular endothelial function, which manifests the vascular inflammatory response, cell proliferation, and autoregulation. Since FMD is noninvasive and assesses commonly in the brachial artery by ultrasound, compared to other invasive methods such as optical coherence tomography (OCT) and intravascular ultrasound (IVUS), it is widely used to evaluate endothelial function and allows serial assessment. In this review, we present the currently accepted mechanisms and methods of FMD measurement with the studies applied in the current clinical practice using FMD. After all, the association with cardiovascular diseases is of substance, and so we introduce clinical studies of FMD related to cardiovascular disease such as diabetes, hyperlipidemia, chronic kidney disease, coronary artery disease, and peripheral vascular disease. In addition, studies related to pregnancy and COVID-19 were also inspected. Yet, endothelial examination is not endorsed as a cardiovascular prevention measure, for the lack of a clear standardized value methodology. Still, many studies recommend practicable FMD and would be a better prognostic value in the cardiovascular prognosis in future clinical research.

Association of sodium-glucose cotransporter 2 inhibitors with risk of incident dementia and all-cause mortality in older patients with type 2 diabetes: A retrospective cohort study using the TriNetX US collaborative networks

BACKGROUND

Limited evidence exists to support any specific medication over others to prevent dementia in older patients with type 2 diabetes (T2D). We investigated whether treatment with sodium-glucose cotransporter 2 (SGLT-2) inhibitors is associated with a lower risk of incident dementia and all-cause mortality, relative to dipeptidyl peptidase-4 (DPP-4) inhibitors and glucagon-like peptide-1 receptor agonists (GLP-1 RA).

METHODS

In this retrospective, active-comparator cohort study, we used data from the TriNetX electronic health records network. Our primary cohort comprised patients with T2D aged ≥50 years, registered between January 2012 and December 2022. Patients with a history of dementia were excluded. We used Kaplan-Meier survival analysis to estimate the incidence of dementia and all-cause mortality in our cohort after they had used glucose-lowering drugs for at least 12 months. Propensity score matching was performed to balance the SGLT-2 inhibitor, DPP-4 inhibitor and GLP-1 RA cohorts. Subgroup analyses for sex and age were also conducted.

RESULTS

Our first cohort comprised 193 948 patients treated with metformin and SGLT-2 inhibitors and an equal number of patients treated with metformin and DPP-4 inhibitors. In this cohort, the risk of dementia and all-cause mortality was lower in patients treated with SGLT-2 inhibitors than in those treated with DPP-4 inhibitors (hazard ratio [HR]: 0.62, 95% confidence interval [CI]: 0.59-0.65, for dementia; HR: 0.54, 95% CI: 0.52-0.56, for all-cause mortality). Our second cohort comprised 165 566 patients treated with metformin and SGLT-2 inhibitors and an equal number of patients treated with metformin and GLP-1 RAs. In this cohort, the risk of dementia and all-cause mortality was lower in those treated with SGLT-2 inhibitors than in those treated with GLP-1 RAs (HR: 0.92, 95% CI: 0.87-0.98, for dementia; HR: 0.88, 95% CI: 0.85-0.91, for all-cause mortality).

CONCLUSIONS

The use of SGLT-2 inhibitor was associated with a lower risk of incident dementia and all-cause mortality in older adults with T2D compared to DPP-4 inhibitor and GLP-1 RA.

Gut Hormones in Heart Failure

Heart failure (HF) is a syndrome affecting all organ systems. While some organ interactions have been studied intensively in HF (such as the cardiorenal interaction), the endocrine gut has to some degree been overlooked. However, there is growing evidence of direct cardiac effects of several hormones secreted from the gastrointestinal tract. For instance, GLP-1 (glucagon-like peptide-1), an incretin hormone secreted from the distal intestine following food intake, has notable effects on the heart, impacting heart rate and contractility. GLP-1 may even possess cardioprotective abilities, such as inhibition of myocardial ischemia and cardiac remodeling. While other gut hormones have been less studied, there is evidence suggesting cardiostimulatory properties of several hormones. Moreover, it has been reported that patients with HF have altered bioavailability of numerous gastrointestinal hormones, which may have prognostic implications. This might indicate an important role of gut hormones in cardiac physiology and pathology, which may be of particular importance in the failing heart. We present an overview of the current knowledge on gut hormones in HF, focusing on HF with reduced ejection fraction, and discuss how these hormones may be regulators of cardiac function and central hemodynamics. Potential therapeutic perspectives are discussed, and knowledge gaps are highlighted herein.

Glucagon-like peptide-1 increases heart rate by a direct action on the sinus node

AIMS

Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are increasingly used to treat type 2 diabetes and obesity. Albeit cardiovascular outcomes generally improve, treatment with GLP-1 RAs is associated with increased heart rate, the mechanism of which is unclear.

METHODS AND RESULTS

We employed a large animal model, the female landrace pig, and used multiple in vivo and ex vivo approaches including pharmacological challenges, electrophysiology, and high-resolution mass spectrometry to explore how GLP-1 elicits an increase in heart rate. In anaesthetized pigs, neither cervical vagotomy, adrenergic blockers (alpha, beta, or combined alpha-beta blockade), ganglionic blockade (hexamethonium), nor inhibition of hyperpolarization-activated cyclic nucleotide-gated (HCN) channels (ivabradine) abolished the marked chronotropic effect of GLP-1. GLP-1 administration to isolated perfused pig hearts also increased heart rate, which was abolished by GLP-1 receptor blockade. Electrophysiological characterization of GLP-1 effects in vivo and in isolated perfused hearts localized electrical modulation to the atria and conduction system. In isolated sinus nodes, GLP-1 administration shortened the action potential cycle length of pacemaker cells and shifted the site of earliest activation. The effect was independent of HCN blockade. Collectively, these data support a direct effect of GLP-1 on GLP-1 receptors within the heart. Consistently, single nucleus RNA sequencing showed GLP-1 receptor expression in porcine pacemaker cells. Quantitative phosphoproteomics analyses of sinus node samples revealed that GLP-1 administration leads to phosphorylation changes of calcium cycling proteins of the sarcoplasmic reticulum, known to regulate heart rate.

CONCLUSION

GLP-1 has direct chronotropic effects on the heart mediated by GLP-1 receptors in pacemaker cells of the sinus node, inducing changes in action potential morphology and the leading pacemaker site through a calcium signalling response characterized by PKA-dependent phosphorylation of Ca2+ cycling proteins involved in pacemaking. Targeting the pacemaker calcium clock may be a strategy to lower heart rate in people treated with GLP-1 RAs.

Exploring the clinical effectiveness of glucagon-like peptide-1 receptor agonists in managing cardiovascular complications: an updated comprehensive review and future directives

The possible cardiovascular advantages of glucagon-like peptide-1 receptor agonists (GLP-1RAs), a class of drugs predominantly used to treat type 2 diabetes (T2D), have garnered increasing attention in recent years. Clinical trials have looked into the possibility that GLP-1RAs have extra cardioprotective benefits in addition to their ability to manage T2D, demonstrating significant major adverse cardiovascular events (MACE) reduction and a favorable safety profile. GLP-1 RAs improve cardiovascular outcomes, especially in those with existing cardiovascular disease. MACE has been steadily declining with this class of drugs, which results in a noticeable rise in cardiovascular outcome trials (CVOTs). GLP-1 RAs have a variety of impacts on the cardiovascular system beyond their function in glycemic control. They offer direct cardioprotection, vasodilation, promotion of salt excretion, reduction of weight, improved lipid profile, and anti-inflammatory qualities through a variety of mechanisms. Thus, this review focuses on GLP-1RAs, its mechanism of action, its clinical effectiveness in CVOTs, the mechanism behind its cardiovascular benefits, its potential role in heart failure, cardiovascular outcomes, its underutilization, and future directives. In conclusion, GLP-1 RAs shows potential in controlling T2D while also lowering cardiovascular risk, but warrants further study into long-term results and real-world data to optimize treatment regimens, ultimately increasing patient outcomes and lowering the burden of cardiovascular disease in T2D populations.

Glucagon-like peptide-1 receptor: mechanisms and advances in therapy

The glucagon-like peptide-1 (GLP-1) receptor, known as GLP-1R, is a vital component of the G protein-coupled receptor (GPCR) family and is found primarily on the surfaces of various cell types within the human body. This receptor specifically interacts with GLP-1, a key hormone that plays an integral role in regulating blood glucose levels, lipid metabolism, and several other crucial biological functions. In recent years, GLP-1 medications have become a focal point in the medical community due to their innovative treatment mechanisms, significant therapeutic efficacy, and broad development prospects. This article thoroughly traces the developmental milestones of GLP-1 drugs, from their initial discovery to their clinical application, detailing the evolution of diverse GLP-1 medications along with their distinct pharmacological properties. Additionally, this paper explores the potential applications of GLP-1 receptor agonists (GLP-1RAs) in fields such as neuroprotection, anti-infection measures, the reduction of various types of inflammation, and the enhancement of cardiovascular function. It provides an in-depth assessment of the effectiveness of GLP-1RAs across multiple body systems-including the nervous, cardiovascular, musculoskeletal, and digestive systems. This includes integrating the latest clinical trial data and delving into potential signaling pathways and pharmacological mechanisms. The primary goal of this article is to emphasize the extensive benefits of using GLP-1RAs in treating a broad spectrum of diseases, such as obesity, cardiovascular diseases, non-alcoholic fatty liver disease (NAFLD), neurodegenerative diseases, musculoskeletal inflammation, and various forms of cancer. The ongoing development of new indications for GLP-1 drugs offers promising prospects for further expanding therapeutic interventions, showcasing their significant potential in the medical field.

The role of glucagon-like peptide-1 receptor agonists (GLP1-RAs) in the management of the hypertensive patient with metabolic syndrome: a position paper from the Korean society of hypertension

Obesity is the one of the most important components of metabolic syndrome. Because obesity related hypertension accounts for two thirds of essential hypertension, managing obesity and metabolic syndrome is a crucial task in the management of hypertension. However, the current non-pharmacological therapies have limitations for achieving or maintaining ideal body weight. Recently, glucagon-like peptide-1 receptor agonists (GLP1-RAs) have demonstrated excellent weight control effects, accompanied by corresponding reductions in blood pressure. GLP1-RAs have shown cardiovascular and renal protective effects in cardiovascular outcome trials both in primary and secondary prevention. In this document, the Korean Society of Hypertension intends to remark the current clinical results of GLP1-RAs and recommend the government and health-policy makers to define obesity as a disease and to establish forward-looking policies for GLP1-RA treatment for obesity treatment, including active reimbursement policies.

Glucagon-like peptide 1 agonist and effects on reward behaviour: A systematic review

INTRODUCTION

The roles of metabolic signals, including Glucagon-like peptide 1 (GLP-1), have been implicated in multiple domains outside metabolic regulation. There is a growing interest in repurposing Glucagon-like peptide 1 receptor agonists (GLP-1RAs) as therapeutics for motivation and reward-related behavioural disturbances. Herein, we aim to systematically review the extant evidence on the potential effects of GLP-1RAs on the reward system.

METHODS

The study followed PRISMA guidelines using databases such as OVID, PubMed, Scopus, and Google Scholar. The search focused on "Reward Behavior" and "Glucagon Like Peptide 1 Receptor Agonists" and was restricted to human studies. Quality assessment achieved by the NIH's Quality Assessment of Controlled Intervention Studies RESULTS: GLP-1RAs consistently reduced energy intake and influenced reward-related behaviour. These agents have been associated with decreased neurocortical activation in response to higher rewards and food cues, particularly high-calorie foods, and lowered caloric intake and hunger levels.

DISCUSSION

GLP-1RAs show promise in addressing reward dysfunction linked to food stimuli, obesity, and T2DM. They normalize insulin resistance, and might also modulate dopaminergic signalling and reduce anhedonia. Their effects on glycemic variability and cravings suggest potential applications in addiction disorders.

Curbing the Obesity Epidemic: Should GLP-1 Receptor Agonists Be the Standard of Care for Obesity?

PURPOSE OF REVIEW

This article summarizes the medical management of obesity with an emphasis on incretin-based therapeutics that target the neuro-hormonal basis of obesity.

RECENT FINDINGS

Medications that mimic the effect of incretins, a group of peptide hormones released in response to nutrient intake that regulate appetite, result in potent and durable weight loss. Glucagon-like peptide 1 (GLP-1) agonists and glucose-dependent insulinotropic polypeptide (GIP) agonists such as semaglutide and tirzepatide are approved by the United States Food and Drug Administration (FDA) for the management of obesity. The SELECT trial demonstrated that semaglutide led to a reduction in major adverse cardiovascular events in patients without diabetes who were either overweight and had preexisting cardiovascular disease or obese.

SUMMARY

The treatment of obesity is critical to prevent the progression of cardiovascular-kidney-metabolic syndrome. Incretin-based therapies offer remarkable weight loss and reduce major cardiovascular adverse events.

Novel Metabolites Associated With Blood Pressure After Dietary Interventions

BACKGROUND

The blood pressure (BP) etiologic study is complex due to multifactorial influences, including genetic, environmental, lifestyle, and their intricate interplays. We used a metabolomics approach to capture internal pathways and external exposures and to study BP regulation mechanisms after well-controlled dietary interventions.

METHODS

In the ProBP trail (Protein and Blood Pressure), a double-blinded crossover randomized controlled trial, participants underwent dietary interventions of carbohydrate, soy protein, and milk protein, receiving 40 g daily for 8 weeks, with 3-week washout periods. We measured plasma samples collected at baseline and at the end of each dietary intervention. Multivariate linear models were used to evaluate the association between metabolites and systolic/diastolic BP. Nominally significant metabolites were examined for enriching biological pathways. Significant ProBP findings were evaluated for replication among 1311 participants of the BHS (Bogalusa Heart Study), a population-based study conducted in the same area as ProBP.

RESULTS

After Bonferroni correction for 77 independent metabolite clusters (α=6.49×10-4), 18 metabolites were significantly associated with BP at baseline or the end of a dietary intervention, of which 11 were replicated in BHS. Seven emerged as novel discoveries, which are as follows: 1-linoleoyl-GPE (18:2), 1-oleoyl-GPE (18:1), 1-stearoyl-2-linoleoyl-GPC (18:0/18:2), 1-palmitoyl-2-oleoyl-GPE (16:0/18:1), maltose, N-stearoyl-sphinganine (d18:0/18:0), and N6-carbamoylthreonyladenosine. Pathway enrichment analyses suggested dietary protein intervention might reduce BP through pathways related to G protein-coupled receptors, incretin function, selenium micronutrient network, and mitochondrial biogenesis.

CONCLUSIONS

Seven novel metabolites were identified to be associated with BP at the end of different dietary interventions. The beneficial effects of protein interventions might be mediated through specific metabolic pathways.

Contractile Effects of Semaglutide in the Human Atrium

Semaglutide is a glucagon-like peptide 1 receptor (GLP-1R) agonist. GLP-1R agonists are used to treat type 2 diabetes and obesity. It is currently unknown whether semaglutide can directly increase force of contraction (FOC) in the human heart. We tested the hypothesis that semaglutide might increase the FOC in the isolated human atrium. To this end, we conducted contraction experiments in isolated human right atrial muscle preparations (HAP). HAP were obtained during open-heart surgery. We detected a concentration- and time-dependent positive inotropic effect (PIE) of semaglutide in HAP. These PIEs were accompanied by increases in the rates of tension development and tension relaxation and a reduction in muscle relaxation time. The PIE of semaglutide in HAP was attenuated by H89, an inhibitor of the cyclic AMP-dependent protein kinase and by ryanodine, an inhibitor of sarcoplasmic Ca2+ release. Semaglutide up to 100 nM failed to exert a PIE in isolated electrically paced (1 Hz) wild-type mouse left atrial preparations studied for comparison. Our data suggest that semaglutide can increase the FOC in the atria of patients at therapeutic drug concentrations.

Beyond Glycemic Control: GLP-1 Receptor Agonists and Their Impact on Calcium Homeostasis in Real-World Patients

Background/Objectives: The effect of glucagon-like peptide-1 receptor (GLP-1R) agonists on calcium homeostasis is poorly understood. This study aimed to investigate the association between GLP-1R agonist use and the risk of hypocalcemia and/or hypercalcemia, as well as other clinical outcomes. Methods: A retrospective cohort study used de-identified patient data from the TriNetX Global Collaborative Network, including 15,655 adult patients prescribed GLP-1R agonists and 15,655 propensity-matched controls. Outcomes included hypocalcemia, hypercalcemia, emergency visits, hospitalizations, cardiovascular events, and all-cause mortality. Results: GLP-1R agonist use was associated with a reduced risk of hypocalcemia (2.7% vs. 5.5%, RR 0.49, 95% CI: 0.44-0.55) but an increased risk of hypercalcemia (2.3% vs. 1.1%, RR 2.02, 95% CI: 1.69-2.42). The effect on hypocalcemia was most pronounced during the first six months of treatment. Among individual agents, tirzepatide showed the most pronounced effect, reducing hypocalcemia risk by 63% while increasing hypercalcemia risk by 85%. Semaglutide demonstrated similar effects, while dulaglutide and liraglutide showed modest effects. Furthermore, GLP-1R agonist use was associated with reduced risks of emergency visits (RR 0.57, 95% CI: 0.54-0.60), hospitalizations (RR 0.40, 95% CI: 0.36-0.44), cardiovascular events, and all-cause mortality (HR 0.27, 95% CI: 0.21-0.36). Conclusions: GLP-1R agonists exhibit a complex influence on calcium homeostasis, reducing hypocalcemia risk while increasing hypercalcemia risk. Beyond calcium regulation, these medications significantly reduce healthcare utilization, improve cardiovascular outcomes, and decrease mortality. Further research is needed to elucidate the mechanisms behind the differential effects of individual GLP-1R agonists, particularly tirzepatide, to optimize personalized treatment approaches and long-term safety.

Cardiovascular Protective Properties of GLP-1 Receptor Agonists: More than Just Diabetic and Weight Loss Drugs

Owing to their potent glucose-lowering efficacy and substantial weight loss effects, glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are now considered part of the frontline therapeutic options to treat both type 2 diabetes mellitus and nondiabetic overweight/obesity. Stemming from successful demonstration of their cardiometabolic modulation and reduction of major adverse cardiovascular events in clinical outcome trials, GLP-1 RAs have since been validated as agents with compelling cardiovascular protective properties. Studies spanning from the bench to preclinical and large-scale randomised controlled trials have consistently corroborated the cardiovascular benefits of this pharmacological class. Most notably, there is converging evidence that they exert favourable effects on atherosclerotic ischaemic endpoints, with preclinical data indicating that they may do so by directly modifying the burden and composition of atherosclerotic plaques. This narrative review examines the underlying pharmacology and clinical evidence behind the cardiovascular benefits of GLP-1 RAs, with particular focus on atherosclerotic cardiovascular disease. It also delves into the mechanisms that underpin their putative plaque-modifying actions, addresses existing knowledge gaps and therapeutic challenges and looks to future developments in the field, including the use of combination incretin agents for diabetes and weight loss management.

Cardio-reno-vascular protection in type 2 diabetes mellitus: new insights into pharmacotherapeutic management

INTRODUCTION

From 2008 and following the withdrawal of rosiglitazone, obligatory cardiovascular outcomes trials are performed for glucose lowering drugs introduced to the market to ensure their cardiovascular (CV) safety. Paradoxically, these studies have demonstrated CV safety but also shown additional cardio-reno-vascular protection of some therapeutic agents. Additionally, nonsteroidal mineralocorticoid receptor antagonists (ns-MRA) have emerged as novel drugs for cardio - and renoprotection in type 2 diabetes (T2D) and chronic kidney disease (CKD). In addition to atherosclerotic CV disease, heart failure (HF) and CKD are important clinical problems in T2D leading to poor quality of life and premature death as such cardio-reno-vascular protection is an important clinical issue.

AREAS COVERED

We provide new insights into pharmacotherapeutic cardio-reno-vascular protection in T2D based on the new glucose lowering drugs and ns-MRA. PUB MED/CINAHL/Web of Science/Scopus were searched (May 2024).

EXPERT OPINION

The conventional glucose lowering approach alone which was implemented for decades is now replaced by the use of disease modifying drugs which lower the rates of CV events, HF decompensation, hospitalization due to HF, slow progression of CKD and all-cause mortality. Indeed, the choice of medications in T2D should be focused on underlying co-morbidities with cardio-reno-vascular protection rather than a gluco-centric approach.

The role of glucagon-like peptide-1/GLP-1R and autophagy in diabetic cardiovascular disease

Diabetes leads to a significantly accelerated incidence of various related macrovascular complications, including peripheral vascular disease and cardiovascular disease (the most common cause of mortality in diabetes), as well as microvascular complications such as kidney disease and retinopathy. Endothelial dysfunction is the main pathogenic event of diabetes-related vascular disease at the earliest stage of vascular injury. Understanding the molecular processes involved in the development of diabetes and its debilitating vascular complications might bring up more effective and specific clinical therapies. Long-acting glucagon-like peptide (GLP)-1 analogs are currently available in treating diabetes with widely established safety and extensively evaluated efficacy. In recent years, autophagy, as a critical lysosome-dependent self-degradative process to maintain homeostasis, has been shown to be involved in the vascular endothelium damage in diabetes. In this review, the GLP-1/GLP-1R system implicated in diabetic endothelial dysfunction and related autophagy mechanism underlying the pathogenesis of diabetic vascular complications are briefly presented. This review also highlights a possible crosstalk between autophagy and the GLP-1/GLP-1R axis in the treatment of diabetic angiopathy.

Impact of Selected Glucagon-like Peptide-1 Receptor Agonists on Serum Lipids, Adipose Tissue, and Muscle Metabolism-A Narrative Review

Glucagon-like peptide-1 receptor agonists (GLP-1 RA) are novel antihyperglycemic agents. By acting through the central nervous system, they increase satiety and reduce food intake, thus lowering body weight. Furthermore, they increase the secretion of insulin while decreasing the production of glucagon. However, recent studies suggest a more complex metabolic impact through the interaction with various other tissues. In our present review, we aim to provide a summary of the effects of GLP-1 RA on serum lipids, adipose tissue, and muscle metabolism. It has been found that GLP-1 RA therapy is associated with decreased serum cholesterol levels. Epicardial adipose tissue thickness, hepatic lipid droplets, and visceral fat volume were reduced in obese patients with cardiovascular disease. GLP-1 RA therapy decreased the level of proinflammatory adipokines and reduced the expression of inflammatory genes. They have been found to reduce endoplasmic reticulum stress in adipocytes, leading to better adipocyte function and metabolism. Furthermore, GLP-1 RA therapy increased microvascular blood flow in muscle tissue, resulting in increased myocyte metabolism. They inhibited muscle atrophy and increased muscle mass and function. It was also observed that the levels of muscle-derived inflammatory cytokines decreased, and insulin sensitivity increased, resulting in improved metabolism. However, some clinical trials have been conducted on a very small number of patients, which limits the strength of these observations.

Bridging the gap between GLP1-receptor agonists and cardiovascular outcomes: evidence for the role of tirzepatide

Tirzepatide is a new drug targeting glucagon-like peptide 1(GLP1) and gastric inhibitory polypeptide (GIP) receptors. This drug has demonstrated great potential in improving the clinical outcomes of patients with type 2 diabetes. It can lead to weight loss, better glycemic control, and reduced cardiometabolic risk factors. GLP1 receptor agonists have been proven effective antidiabetic medications with possible cardiovascular benefits. Even though they have been proven to reduce the risk of major adverse cardiovascular events, their effectiveness in treating heart failure is unknown. Unlike traditional GLP1 receptor agonists, tirzepatide is more selective for the GIP receptor, resulting in a more balanced activation of these receptors. This review article discusses the possible mechanisms tirzepatide may use to improve cardiovascular health. That includes the anti-inflammatory effect, the ability to reduce cell death and promote autophagy, and also its indirect effects through blood pressure, obesity, and glucose/lipid metabolism. Additionally, tirzepatide may benefit atherosclerosis and lower the risk of major adverse cardiac events. Currently, clinical trials are underway to evaluate the safety and efficacy of tirzepatide in patients with heart failure. Overall, tirzepatide's dual agonism of GLP1 and GIP receptors appears to provide encouraging cardiovascular benefits beyond glycemic control, offering a potential new therapeutic option for treating cardiovascular diseases and heart failure.

Semaglutide Concurrently Improves Vascular and Liver Indices in Patients With Type 2 Diabetes and Fatty Liver Disease

Context

The cardiovascular benefits of semaglutide are established; however, its effects on surrogate vascular markers and liver function are not known.

Objective

To investigate the effects of semaglutide on vascular, endothelial, and liver function in patients with type 2 diabetes (T2DM) and nonalcoholic fatty liver disease (NAFLD).

Methods

Overall, 75 consecutive subjects with T2DM and NAFLD were enrolled: 50 patients received semaglutide 1 mg (treatment group) and 25 patients received dipeptidyl peptidase 4 inhibitors (control group). All patients underwent a clinical, vascular, and hepatic examination with Fibroscan elastography at 4 and 12 months after inclusion in the study.

Results

Treatment with semaglutide resulted in a reduction of Controlled Attenuation Parameter (CAP) score, E fibrosis score, NAFLD fibrosis score, Fibrosis-4 (FIB-4) score and perfused boundary region (PBR) at 4 and at 12 months (P < .05), contrary to controls. Patients treated with semaglutide showed a greater decrease of central systolic blood pressure (SBP) (-6% vs -4%, P = .048 and -11% vs -9%, P = .039), augmentation index (AIx) (-59% vs -52%, P = .041 and -70% vs -57%, P = .022), and pulse wave velocity (PWV) (-6% vs -3.5%, P = .019 and -12% vs -10%, P = .036) at 4 and at 12 months, respectively. In all patients, ΔPWV and ΔPBR were correlated with a corresponding reduction of CAP, E fibrosis, NAFLD fibrosis, and FIB-4 scores.

Conclusion

Twelve-month treatment with semaglutide simultaneously improves arterial stiffness, endothelial function, and liver steatosis and fibrosis in patients with T2DM and NAFLD.

Effects of Semaglutide in Doxorubicin-Induced Cardiac Toxicity in Wistar Albino Rats

Background

Doxorubicin (DOX) is used to treat various types of cancers. However, its use is restricted by cardiotoxicity, a leading cause of morbidity and mortality. Glucagon-like peptide 1 receptor agonists (GLP-1 RAs) may be associated with cardioprotective properties.

Purpose

This study aims to determine the protective effects of different semaglutide (SEM) doses on DOX-induced cardiotoxicity in a rat model.

Methodology

Thirty-five female Wistar rats were divided into five groups. The first group received distilled water as a negative control (NC); the positive control (PC) group received distilled water plus DOX; the third group (SL) received a low dose of SEM (0.06 mg/kg) plus DOX; the fourth group (SM) received a moderate dose of SEM (0.12 mg/kg) plus DOX; and the fifth group (SH) received a high dose of SEM (0.24 mg/kg) plus DOX. Blood samples were collected on day 8 to assess serum troponin, lactate dehydrogenase (LDH), creatine phosphokinase (CPK), total lipid profile, and vascular cell adhesion molecule 1 (VCAM-1). Cardiac tissue was sent for histopathological analysis.

Results

DOX increased the total cholesterol (TC), low-density lipoprotein (LDL), triglyceride (TG), LDH, and CKP levels. Moderate and high doses of semaglutide significantly reduced serum cholesterol levels (*p = 0.0199), (**p = 0.0077), respectively. A significant reduction (***p = 0.0013) in total body weight after treatment with SEM was observed in the SL group and a highly significant reduction (****p < 0.0001) was observed in the SM and SH groups. SEM at all doses reduced CPK levels. The SL group showed a significant reduction in troponin level (*p=0.0344). Serum LDH levels were reduced by all three SEM doses. The histopathological findings support the biochemical results.

Conclusion

Semaglutide may possess cardioprotective properties against DOX-induced cardiotoxicity in a rat model by decreasing serum biochemical markers of cardiotoxicity.

Case report: Nerve fiber regeneration in children with melanocortin 4 receptor gene mutation related obesity treated with semaglutide

Melanocortin 4 receptor (MC4R) mutations are the commonest cause of monogenic obesity through dysregulation of neuronal pathways in the hypothalamus and prefrontal cortex that regulate hunger and satiety. MC4R also regulates neuropathic pain pathways via JNK signaling after nerve injury. We show evidence of corneal small fiber degeneration in 2 siblings carrying a heterozygous missense variant c.508A>G, p.Ille170Val in the MC4R gene. Both children were treated with once weekly semaglutide for 6 months with no change in weight, and only a minor improvement in HbA1c and lipid profile. However, there was evidence of nerve regeneration with an increase in corneal nerve fiber density (CNFD) [child A (13.9%), child B (14.7%)], corneal nerve branch density (CNBD) [child A (110.2%), child B (58.7%)] and corneal nerve fiber length (CNFL) [child A (21.5%), child B (44.0%)].

The Regulation of Metabolic Homeostasis by Incretins and the Metabolic Hormones Produced by Pancreatic Islets

In healthy humans, the complex biochemical interplay between organs maintains metabolic homeostasis and pathological alterations in this process result in impaired metabolic homeostasis, causing metabolic diseases such as diabetes and obesity, which are major global healthcare burdens. The great advancements made during the last century in understanding both metabolic disease phenotypes and the regulation of metabolic homeostasis in healthy individuals have yielded new therapeutic options for diseases like type 2 diabetes (T2D). However, it is unlikely that highly desirable more efficacious treatments will be developed for metabolic disorders until the complex systemic regulation of metabolic homeostasis becomes more intricately understood. Hormones produced by pancreatic islet beta-cells (insulin) and alpha-cells (glucagon) are pivotal for maintaining metabolic homeostasis; the activity of insulin and glucagon are reciprocally correlated to achieve strict control of glucose levels (normoglycaemia). Metabolic hormones produced by other pancreatic islet cells and incretins produced by the gut are also crucial for maintaining metabolic homeostasis. Recent studies highlighted the incomplete understanding of metabolic hormonal synergism and, therefore, further elucidation of this will likely lead to more efficacious treatments for diseases such as T2D. The objective of this review is to summarise the systemic actions of the incretins and the metabolic hormones produced by the pancreatic islets and their interactions with their respective receptors.

Glucagon-like peptide-1 receptor agonists rescued diabetic vascular endothelial damage through suppression of aberrant STING signaling

Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) protect against diabetic cardiovascular diseases and nephropathy. However, their activity in diabetic retinopathy (DR) remains unclear. Our retrospective cohort study involving 1626 T2DM patients revealed superior efficacy of GLP-1 RAs in controlling DR compared to other glucose-lowering medications, suggesting their advantage in DR treatment. By single-cell RNA-sequencing analysis and immunostaining, we observed a high expression of GLP-1R in retinal endothelial cells, which was down-regulated under diabetic conditions. Treatment of GLP-1 RAs significantly restored the receptor expression, resulting in an improvement in retinal degeneration, vascular tortuosity, avascular vessels, and vascular integrity in diabetic mice. GO and GSEA analyses further implicated enhanced mitochondrial gene translation and mitochondrial functions by GLP-1 RAs. Additionally, the treatment attenuated STING signaling activation in retinal endothelial cells, which is typically activated by leaked mitochondrial DNA. Expression of STING mRNA was positively correlated to the levels of angiogenic and inflammatory factors in the endothelial cells of human fibrovascular membranes. Further investigation revealed that the cAMP-responsive element binding protein played a role in the GLP-1R signaling pathway on suppression of STING signaling. This study demonstrates a novel role of GLP-1 RAs in the protection of diabetic retinal vasculature by inhibiting STING-elicited inflammatory signals.

Cyclic Adenosine Monophosphate in Cardiac and Sympathoadrenal GLP-1 Receptor Signaling: Focus on Anti-Inflammatory Effects

Glucagon-like peptide-1 (GLP-1) is a multifunctional incretin hormone with various physiological effects beyond its well-characterized effect of stimulating glucose-dependent insulin secretion in the pancreas. An emerging role for GLP-1 and its receptor, GLP-1R, in brain neuroprotection and in the suppression of inflammation, has been documented in recent years. GLP-1R is a G protein-coupled receptor (GPCR) that couples to Gs proteins that stimulate the production of the second messenger cyclic 3',5'-adenosine monophosphate (cAMP). cAMP, acting through its two main effectors, protein kinase A (PKA) and exchange protein directly activated by cAMP (Epac), exerts several anti-inflammatory (and some pro-inflammatory) effects in cells, depending on the cell type. The present review discusses the cAMP-dependent molecular signaling pathways elicited by the GLP-1R in cardiomyocytes, cardiac fibroblasts, central neurons, and even in adrenal chromaffin cells, with a particular focus on those that lead to anti-inflammatory effects by the GLP-1R. Fully elucidating the role cAMP plays in GLP-1R's anti-inflammatory properties can lead to new and more precise targets for drug development and/or provide the foundation for novel therapeutic combinations of the GLP-1R agonist medications currently on the market with other classes of drugs for additive anti-inflammatory effect.

Glucagon-Like Peptide-1: New Regulator in Lipid Metabolism

Glucagon-like peptide-1 (GLP-1) is a 30-amino acid peptide hormone that is mainly expressed in the intestine and hypothalamus. In recent years, basic and clinical studies have shown that GLP-1 is closely related to lipid metabolism, and it can participate in lipid metabolism by inhibiting fat synthesis, promoting fat differentiation, enhancing cholesterol metabolism, and promoting adipose browning. GLP-1 plays a key role in the occurrence and development of metabolic diseases such as obesity, nonalcoholic fatty liver disease, and atherosclerosis by regulating lipid metabolism. It is expected to become a new target for the treatment of metabolic disorders. The effects of GLP-1 and dual agonists on lipid metabolism also provide a more complete treatment plan for metabolic diseases. This article reviews the recent research progress of GLP-1 in lipid metabolism.

GLP-1 receptor agonists and atherosclerosis protection: the vascular endothelium takes center stage

Atherosclerotic cardiovascular disease is a chronic condition that often copresents with type 2 diabetes and obesity. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are incretin mimetics endorsed by major professional societies for improving glycemic status and reducing atherosclerotic risk in people living with type 2 diabetes. Although the cardioprotective efficacy of GLP-1RAs and their relationship with traditional risk factors are well established, there is a paucity of publications that have summarized the potentially direct mechanisms through which GLP-1RAs mitigate atherosclerosis. This review aims to narrow this gap by providing comprehensive and in-depth mechanistic insight into the antiatherosclerotic properties of GLP-1RAs demonstrated across large outcome trials. Herein, we describe the landmark cardiovascular outcome trials that triggered widespread excitement around GLP-1RAs as a modern class of cardioprotective agents, followed by a summary of the origins of GLP-1RAs and their mechanisms of action. The effects of GLP-1RAs at each major pathophysiological milestone of atherosclerosis, as observed across clinical trials, animal models, and cell culture studies, are described in detail. Specifically, this review provides recent preclinical and clinical evidence that suggest GLP-1RAs preserve vessel health in part by preventing endothelial dysfunction, achieved primarily through the promotion of angiogenesis and inhibition of oxidative stress. These protective effects are in addition to the broad range of atherosclerotic processes GLP-1RAs target downstream of endothelial dysfunction, which include systemic inflammation, monocyte recruitment, proinflammatory macrophage and foam cell formation, vascular smooth muscle cell proliferation, and plaque development.

Effect of GLP-1 Receptor Agonist on Ischemia Reperfusion Injury in Rats with Metabolic Syndrome

Metabolic syndrome (MetS) represents an important factor that increases the risk of myocardial infarction, and more severe complications. Glucagon Like Peptide-1 Receptor Agonists (GLP-1RAs) exhibit cardioprotective potential, but their efficacy in MetS-related myocardial dysfunction has not been fully explored. Therefore, we aimed to assess the effects of exenatide and dulaglutide on heart function and redox balance in MetS-induced rats. Twenty-four Wistar albino rats with induced MetS were divided into three groups: MetS, exenatide-treated (5 µg/kg), dulaglutide-treated (0.6 mg/kg). After 6 weeks of treatment, in vivo heart function was assessed via echocardiography, while ex vivo function was evaluated using a Langendorff apparatus to simulate ischemia-reperfusion injury. Heart tissue samples were analyzed histologically, and oxidative stress biomarkers were measured spectrophotometrically from the coronary venous effluent. Both exenatide and dulaglutide significantly improved the ejection fraction by 3% and 7%, respectively, compared to the MetS group. Histological analyses corroborated these findings, revealing a reduction in the cross-sectional area of cardiomyocytes by 11% in the exenatide and 18% in the dulaglutide group, indicating reduced myocardial damage in GLP-1RA-treated rats. Our findings suggest strong cardioprotective potential of GLP-1RAs in MetS, with dulaglutide showing a slight advantage. Thus, both exenatide and dulaglutide are potentially promising targets for cardioprotection and reducing mortality in MetS patients.

Glucagon-Like Peptide-1 Based Therapies: A New Horizon in Obesity Management

Obesity is a significant risk factor for health issues like type 2 diabetes and cardiovascular disease. It often proves resistant to traditional lifestyle interventions, prompting a need for more precise therapeutic strategies. This has led to a focus on signaling pathways and neuroendocrine mechanisms to develop targeted obesity treatments. Recent developments in obesity management have been revolutionized by introducing novel glucagon-like peptide-1 (GLP-1) based drugs, such as semaglutide and tirzepatide. These drugs are part of an emerging class of nutrient-stimulated hormone-based therapeutics, acting as incretin mimetics to target G-protein-coupled receptors like GLP-1, glucose-dependent insulinotropic polypeptide (GIP), and glucagon. These receptors are vital in regulating body fat and energy balance. The development of multiagonists, including GLP-1-glucagon and GIP-GLP-1-glucagon receptor agonists, especially with the potential for glucagon receptor activation, marks a significant advancement in the field. This review covers the development and clinical efficacy of various GLP-1-based therapeutics, exploring the challenges and future directions in obesity management.

Renal tubule-specific Atgl deletion links kidney lipid metabolism to glucagon-like peptide 1 and insulin secretion independent of renal inflammation or lipotoxicity

OBJECTIVE

Lipotoxic injury from renal lipid accumulation in obesity and type 2 diabetes (T2D) is implicated in associated kidney damage. However, models examining effects of renal ectopic lipid accumulation independent of obesity or T2D are lacking. We generated renal tubule-specific adipose triglyceride lipase knockout (RT-SAKO) mice to determine if this targeted triacylglycerol (TAG) over-storage affects glycemic control and kidney health.

METHODS

Male and female RT-SAKO mice and their control littermates were tested for changes in glycemic control at 10-12 and 16-18 weeks of age. Markers of kidney health and blood lipid and hormone concentrations were analyzed. Kidney and blood lysophosphatidic acid (LPA) levels were measured, and a role for LPA in mediating impaired glycemic control was evaluated using the LPA receptor 1/3 inhibitor Ki-16425.

RESULTS

All groups remained insulin sensitive, but 16- to 18-week-old male RT-SAKO mice became glucose intolerant, without developing kidney inflammation or fibrosis. Rather, these mice displayed lower circulating insulin and glucagon-like peptide 1 (GLP-1) levels. Impaired first-phase glucose-stimulated insulin secretion was detected and restored by Exendin-4. Kidney and blood LPA levels were elevated in older male but not female RT-SAKO mice, associated with increased kidney diacylglycerol kinase epsilon. Inhibition of LPA-mediated signaling restored serum GLP-1 levels, first-phase insulin secretion, and glucose tolerance.

CONCLUSIONS

TAG over-storage alone is insufficient to cause renal tubule lipotoxicity. This work is the first to show that endogenously derived LPA modulates GLP-1 levels in vivo, demonstrating a new mechanism of kidney-gut-pancreas crosstalk to regulate insulin secretion and glucose homeostasis.

Maternal GLP-1 receptor activation inhibits fetal growth

Glucagon-like peptide 1 (GLP-1) regulates food intake, insulin production, and metabolism. Our recent study demonstrated that pancreatic α-cells-secreted (intraislet) GLP-1 effectively promotes maternal insulin secretion and metabolic adaptation during pregnancy. However, the role of circulating GLP-1 in maternal energy metabolism remains largely unknown. Our study aims to investigate systemic GLP-1 response to pregnancy and its regulatory effect on fetal growth. Using C57BL/6 mice, we observed a gradual decline in maternal blood GLP-1 concentrations. Subsequent administration of the GLP-1 receptor agonist semaglutide (Sem) to dams in late pregnancy revealed a modest decrease in maternal food intake during initial treatment. At the same time, no significant alterations were observed in maternal body weight or fat mass. Notably, Sem-treated dams exhibited a significant decrease in fetal body weight, which persisted even following the restoration of maternal blood glucose levels. Despite no observable change in placental weight, a marked reduction in the placenta labyrinth area from Sem-treated dams was evident. Our investigation further demonstrated a substantial decrease in the expression levels of various pivotal nutrient transporters within the placenta, including glucose transporter one and sodium-neutral amino acid transporter one, after Sem treatment. In addition, Sem injection led to a notable reduction in the capillary area, number, and surface densities within the labyrinth. These findings underscore the crucial role of modulating circulating GLP-1 levels in maternal adaptation, emphasizing the inhibitory effects of excessive GLP-1 receptor activation on both placental development and fetal growth.NEW & NOTEWORTHY Our study reveals a progressive decline in maternal blood glucagon-like peptide 1 (GLP-1) concentration. GLP-1 receptor agonist injection in late pregnancy significantly reduced fetal body weight, even after restoration of maternal blood glucose concentration. GLP-1 receptor activation significantly reduced the placental labyrinth area, expression of some nutrient transporters, and capillary development. Our study indicates that reducing maternal blood GLP-1 levels is a physiological adaptation process that benefits placental development and fetal growth.

Semaglutide modulates prothrombotic and atherosclerotic mechanisms, associated with epicardial fat, neutrophils and endothelial cells network

BACKGROUND

Obesity has increased in recent years with consequences on diabetes and other comorbidities. Thus, 1 out of 3 diabetic patients suffers cardiovascular disease (CVD). The network among glucose, immune system, endothelium and epicardial fat has an important role on pro-inflammatory and thrombotic mechanisms of atherogenesis. Since semaglutide, long-acting glucagon like peptide 1- receptor agonist (GLP-1-RA), a glucose-lowering drug, reduces body weight, we aimed to study its effects on human epicardial fat (EAT), aortic endothelial cells and neutrophils as atherogenesis involved-cardiovascular cells.

METHODS

EAT and subcutaneous fat (SAT) were collected from patients undergoing cardiac surgery. Differential glucose consumption and protein cargo of fat-released exosomes, after semaglutide or/and insulin treatment were analyzed by enzymatic and TripleTOF, respectively. Human neutrophils phenotype and their adhesion to aortic endothelial cells (HAEC) or angiogenesis were analyzed by flow cytometry and functional fluorescence analysis. Immune cells and plasma protein markers were determined by flow cytometry and Luminex-multiplex on patients before and after 6 months treatment with semaglutide.

RESULTS

GLP-1 receptor was expressed on fat and neutrophils. Differential exosomes-protein cargo was identified on EAT explants after semaglutide treatment. This drug increased secretion of gelsolin, antithrombotic protein, by EAT, modulated CD11b on neutrophils, its migration and endothelial adhesion, induced by adiposity protein, FABP4, or a chemoattractant. Monocytes and neutrophils phenotype and plasma adiposity, stretch, mesothelial, fibrotic, and inflammatory markers on patients underwent semaglutide treatment for 6 months showed a 20% reduction with statistical significance on FABP4 levels and an 80% increase of neutrophils-CD88.

CONCLUSION

Semaglutide increases endocrine activity of epicardial fat with antithrombotic properties. Moreover, this drug modulates the pro-inflammatory and atherogenic profile induced by the adiposity marker, FABP4, which is also reduced in patients after semaglutide treatment.

Liraglutide Improves Diabetic Cardiomyopathy by Downregulation of Cardiac Inflammatory and Apoptosis Markers

BACKGROUND

Diabetic cardiomyopathy is one of the leading causes of mortality for people with diabetes worldwide. The majority of the formalistic alterations in the heart associated with diabetic cardiomyopathy have been found to be primarily caused by the ongoing oxidative stress brought on by hyperglycemia, which leads to the dysfunctional reactions of apoptosis and inflammation. Liraglutide, a long-acting counterpart of glucagon-like peptide-1, has been demonstrated to have a number of therapeutic applications in medicine and other biological processes.

METHODS

The PubMed database was searched using the terms liraglutide, DCM, and all associated inflammatory markers.

RESULTS

There has been a lot of research on liraglutide's potential to protect the heart from cardiomyopathy brought on by diabetes. Liraglutide's therapeutic actions as an antioxidant, antihyperglycemic, anti-apoptotic, and anti-inflammatory medicine may help to lessen diabetic cardiomyopathy.

CONCLUSION

The most recent studies on the effects of liraglutide therapy on DCM are presented in this review, along with an explanation of the underlying mechanisms.

Glucagon-Like Peptide Receptor Agonist Inhibits Angiotensin II-Induced Proliferation and Migration in Vascular Smooth Muscle Cells and Ameliorates Phosphate-Induced Vascular Smooth Muscle Cells Calcification

BACKGRUOUND

Glucagon-like peptide-1 receptor agonist (GLP-1RA), which is a therapeutic agent for the treatment of type 2 diabetes mellitus, has a beneficial effect on the cardiovascular system.

METHODS

To examine the protective effects of GLP-1RAs on proliferation and migration of vascular smooth muscle cells (VSMCs), A-10 cells exposed to angiotensin II (Ang II) were treated with either exendin-4, liraglutide, or dulaglutide. To examine the effects of GLP-1RAs on vascular calcification, cells exposed to high concentration of inorganic phosphate (Pi) were treated with exendin-4, liraglutide, or dulaglutide.

RESULTS

Ang II increased proliferation and migration of VSMCs, gene expression levels of Ang II receptors AT1 and AT2, proliferation marker of proliferation Ki-67 (Mki-67), proliferating cell nuclear antigen (Pcna), and cyclin D1 (Ccnd1), and the protein expression levels of phospho-extracellular signal-regulated kinase (p-Erk), phospho-c-JUN N-terminal kinase (p-JNK), and phospho-phosphatidylinositol 3-kinase (p-Pi3k). Exendin-4, liraglutide, and dulaglutide significantly decreased the proliferation and migration of VSMCs, the gene expression levels of Pcna, and the protein expression levels of p-Erk and p-JNK in the Ang II-treated VSMCs. Erk inhibitor PD98059 and JNK inhibitor SP600125 decreased the protein expression levels of Pcna and Ccnd1 and proliferation of VSMCs. Inhibition of GLP-1R by siRNA reversed the reduction of the protein expression levels of p-Erk and p-JNK by exendin-4, liraglutide, and dulaglutide in the Ang II-treated VSMCs. Moreover, GLP-1 (9-36) amide also decreased the proliferation and migration of the Ang II-treated VSMCs. In addition, these GLP-1RAs decreased calcium deposition by inhibiting activating transcription factor 4 (Atf4) in Pi-treated VSMCs.

CONCLUSION

These data show that GLP-1RAs ameliorate aberrant proliferation and migration in VSMCs through both GLP-1Rdependent and independent pathways and inhibit Pi-induced vascular calcification.