Cardiovascular Actions and Clinical Outcomes With Glucagon-Like Peptide-1 Receptor Agonists and Dipeptidyl Peptidase-4 Inhibitors

Glucagon-like Peptide 1 Receptor Agonist use and the effect on diabetic retinopathy: An uncertain relationship

Glucagon-like Peptide 1 Receptor Agonists (GLP-1 RAs) are a group of relatively novel medications for the treatment of diabetes mellitus. These medications can mimic the naturally occurring incretins of the body, which promote the release of insulin in response to hyperglycaemia. The anti-glycaemic effects of these medications can be profound and carry other metabolic benefits such as promoting weight loss. Clinical trials have shown GLP-1 RAs are safe to use from a cardiovascular perspective. However, some trials have suggested a link between GLP-1 RA use and worsening diabetic retinopathy. The conclusions surrounding this link are poorly established as data is drawn primarily from cardiovascular outcome trials. If an association does exist, a possible explanation might be the observed phenomenon of early worsening diabetic retinopathy with rapid correction of hyperglycaemic states. Trials which look at diabetic retinopathy as a primary outcome in relation to use of GLP-1 RAs are sparse and warrant investigation given the growing use of this group of medications. Therefore currently, it is uncertain what effect, beneficial or adverse, GLP-1 RA use has on diabetic retinopathy. This article provides an overview of GLP-1 RA use as a treatment for diabetes mellitus and the current understanding of their relationship with diabetic retinopathy.

Prevention and treatment of ischaemic and haemorrhagic stroke in people with diabetes mellitus: a focus on glucose control and comorbidities

Diabetes mellitus is a significant risk factor for both ischaemic and haemorrhagic stroke, affecting up to a third of individuals with cerebrovascular diseases. Beyond being a risk factor for stroke, diabetes and hyperglycaemia have a negative impact on outcomes after ischaemic and haemorrhagic stroke. Hyperglycaemia during the acute ischaemic stroke phase is associated with a higher risk of haemorrhagic transformation and poor functional outcome, with evidence in favour of early intervention to limit and manage severe hyperglycaemia. Similarly, intensive glucose control nested in a broader bundle of care, including blood pressure, coagulation and temperature control, can provide substantial benefit for clinical outcomes after haemorrhagic stroke. As micro- and macrovascular complications are frequent in people with diabetes, cardiovascular prevention strategies also need to consider tailored treatment. In this regard, the broader availability of sodium-glucose cotransporter 2 inhibitors and glucagon-like peptide 1 receptor agonists can allow tailored treatments, particularly for those with heart failure and chronic kidney disease as comorbidities. Here, we review the main concepts of hyperacute stroke management and CVD prevention among people with diabetes, capitalising on results from large studies and RCTs to inform clinicians on preferred treatments.

Emerging therapeutic landscape: Incretin agonists in chronic kidney disease management

The increasing incidence of chronic kidney disease (CKD) poses a significant public health concern, prompting heightened attention to its treatment. Incretins, including glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide, are intestinal peptides released after nutrient intake, known for their hypoglycemic effects in diabetes management. Recent advancements highlight the promising outcomes of GLP-1 receptor agonists in reducing CKD risk factors and improving renal outcomes. The multifaceted functions of GLP-1, such as its anti-obesity, anti-hypertensive, anti-hyperglycemic, anti-lipid, anti-inflammatory, and endothelial function protective properties, contribute to its potential as a therapeutic agent for CKD. Although experiments suggest the potential benefits of incretin in CKD, a comprehensive understanding of its specific mechanisms is still lacking. This review aims to provide a detailed examination of current evidence and potential future directions, emphasizing the promising yet evolving landscape of incretin agonists in the context of CKD.

Effect of liraglutide on thigh muscle fat and muscle composition in adults with overweight or obesity: Results from a randomized clinical trial

BACKGROUND

Excess muscle fat is observed in obesity and associated with greater burden of cardiovascular risk factors and higher risk of mortality. Liraglutide reduces total body weight and visceral fat but its effect on muscle fat and adverse muscle composition is unknown.

METHODS

This is a pre-specified secondary analysis of a randomized, double-blind, placebo-controlled trial that examined the effects of liraglutide plus a lifestyle intervention on visceral adipose tissue and ectopic fat among adults without diabetes with body mass index ≥30 kg/m2 or ≥27 kg/m2 and metabolic syndrome. Participants were randomly assigned to a once-daily subcutaneous injection of liraglutide (target dose 3.0 mg) or matching placebo for 40 weeks. Body fat distribution and muscle composition was assessed by magnetic resonance imaging at baseline and 40-week follow-up. Muscle composition was described by the combination of thigh muscle fat and muscle volume. Treatment difference (95% confidence intervals [CI]) was calculated by least-square means adjusted for baseline thigh muscle fat. The association between changes in thigh muscle fat and changes in body weight were assessed using Spearman correlation coefficients. The effect of liraglutide versus placebo on adverse muscle composition, denoted by high thigh muscle fat and low thigh muscle volume, was explored.

RESULTS

Among the 128 participants with follow-up imaging (92.2% women, 36.7% Black), median muscle fat at baseline was 7.8%. The mean percent change in thigh muscle fat over median follow-up of 36 weeks was -2.87% among participants randomized to liraglutide (n = 73) and 0.05% in the placebo group (absolute change: -0.23% vs. 0.01%). The estimated treatment difference adjusted for baseline thigh muscle fat was -0.24% (95% CI, -0.41 to -0.06, P-value 0.009). Longitudinal change in thigh muscle fat was significantly associated with change in body weight in the placebo group but not the liraglutide group. The proportion of participants with adverse muscle composition decreased from 11.0% to 8.2% over follow-up with liraglutide, but there was no change with placebo.

CONCLUSIONS

In a cohort of predominantly women with overweight or obesity in the absence of diabetes, once-daily subcutaneous liraglutide was associated with a reduction in thigh muscle fat and adverse muscle composition compared with placebo. The contribution of muscle fat improvement to the cardiometabolic benefits of liraglutide requires further study.

The effect of glucagon-like peptide-1 receptor agonists on cardiac function and structure in patients with or without type 2 diabetes mellitus: An updated systematic review and meta-analysis

AIMS

To conduct an updated systematic review and meta-analysis to evaluate the efficacy of glucagon-like peptide-1 receptor agonists (GLP-1RAs) with regard to cardiac function and structure in people with or without type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

We conducted a systematic search using the PubMed, Embase and ClinicalTrials.gov online databases. The primary outcome of interest was changes in mitral inflow E-velocity to tissue Doppler e' velocity (E/e') ratio. Secondary outcomes included other indicators of cardiac reverse remodelling and functional capacity comprising changes in left ventricular mass (LVM), left ventricular global longitudinal strain, left ventricular end-diastolic volume, left ventricular end-systolic volume, left ventricular ejection fraction (LVEF), early to atrial mitral inflow velocity ratio, left atrial volume (LAV), N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels and 6-min walk test (6MWT) results.

RESULTS

A total of 15 trials involving 898 patients were included in this analysis. GLP-1RAs significantly improved E/e' ratio (mean difference [MD] = -0.73; 95% confidence interval [CI] -1.34, -0.13), LVM (MD = -3.86 g; 95% CI -7.60, -0.12), LAV (MD = -8.20 mL; 95% CI -12.37, -4.04), NT-proBNP level (standardized MD = -0.27; 95% CI -0.47, -0.06), and 6MWT result (MD = +22.31 m; 95% CI 1.64, 42.99). However, GLP-1RAs had no effect on LVEF (MD = +0.31%; 95% CI -1.02, 1.64).

CONCLUSIONS

In this systematic review and meta-analysis, GLP-1RAs were found to have a positive impact on left ventricle diastolic function, hypertrophy, and exercise capacity, but had no effect on systolic function.

Glucagon-like peptide-1 receptor agonists modestly reduced blood pressure among patients with and without diabetes mellitus: A meta-analysis and meta-regression

AIM

The cardiovascular benefits provided by glucagon-like peptide-1 receptor agonists (GLP-1RAs) extend beyond weight reduction and glycaemic control. One possible mechanism may relate to blood pressure (BP) reduction. We aim to quantify the BP-lowering effects of GLP1-RAs.

METHODS

A comprehensive database search for placebo-controlled randomized controlled trials on GLP-1RA treatment was conducted until December 2023. Data extraction and quality assessment were carried out, employing a robust statistical analysis using a random effects model to determine outcomes with a mean difference (MD) in mmHg and 95% confidence intervals (CIs). The primary endpoint was the mean difference in systolic BP (SBP) and diastolic BP. Subgroup analyses and meta-regressions were done to account for covariates.

RESULTS

Compared with placebo, GLP-1RAs modestly reduced SBP [semaglutide: MD -3.40 (95% CI -4.22 to -2.59, p < .001); liraglutide: MD -2.61 (95% CI -3.48 to -1.74, p < .001); dulaglutide: MD -1.46 (95% CI -2.20 to -0.72, p < .001); and exenatide: MD -3.36 (95% CI -3.63 to -3.10, p < .001)]. This benefit consistently increased with longer treatment durations. Diastolic BP reduction was only significant in the exenatide group [MD -0.94 (95% CI -1.78 to -0.1), p = .03]. Among semaglutide cohorts, mean changes in glycated haemoglobin and mean changes in body mass index were directly associated with SBP reduction.

CONCLUSION

Patients on GLP-1RA experienced modest SBP lowering compared with placebo. This observed effect was associated with weight/body mass index reduction and better glycaemic control, which suggests that BP-lowering is an indirect effect of GLP-1RA and unlikely to be responsible for the benefits.

Contemporary management of obesity: A comparison of bariatric metabolic surgery and novel incretin mimetic drugs

The global prevalence of obesity has risen sharply during the past half-century, reaching pandemic proportions and creating a public health crisis. Obesity is a recognized risk factor for the development of diabetes, atherosclerosis, hypertension, hepatic steatosis, and many other cardiometabolic disorders with significant resultant morbidity and mortality. Though treatment of obesity can prevent or slow the progression of these aforementioned illnesses, efforts to help patients achieve reliable and sustainable weight loss have had limited success. While improving nutrition and increasing physical activity results in a host of health benefits, the weight loss achieved with lifestyle interventions alone is modest and difficult to sustain. Early attempts at medical and surgical treatment of obesity were plagued with adverse effects and complications. Moreover, these approaches failed to demonstrate long-term health benefits, even when weight loss was achieved. Recently, novel incretin-based therapies targeting glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) receptors have gained popularity due to their effectiveness in achieving substantial weight loss in patients both with and without diabetes. After many successful clinical trials, there are now multiple GLP-1 and one dual GLP-1-GIP receptor agonists FDA approved for chronic weight management. Advancements in laparoscopic surgical technique and refinements in procedure selection have similarly improved the safety and efficacy of bariatric metabolic surgery for achieving weight reduction in overweight and obese patients. In this review, we discuss the advantages and disadvantages of contemporary pharmacologic and surgical weight management strategies. We review the data regarding expected weight loss, glycemic control, cardiometabolic benefits, and potential adverse effects of various treatment approaches. As obesity rates continue to rise worldwide, it is imperative that clinicians keep these considerations in mind in order to better care for patients.

Effects of Glucagon-Like Peptide-1 Receptor Agonist (GLP-1RA) on Cardiac Structure and Function: A Systematic Review and Meta-Analysis of Randomized-Controlled Trials

PURPOSE

Recent trials suggest glucagon-like peptide-1 receptor agonists (GLP-1RAs) may have a cardioprotective role by reducing major adverse cardiac events, stroke mortality and heart failure-related hospitalisations. We examined whether and how GLP-1RAs affect cardiac function in cardiovascular and metabolic diseases including type 2 diabetes, heart failure and post-myocardial infarction.

METHODS

In this PRISMA-adherent systematic review and meta-analysis, three databases were searched from inception to July 2021 and registered on PROSPERO (CRD42021259661).

RESULTS

20 reports of 19 randomized placebo-controlled trials including 2062 participants were meta-analyzed. Among type 2 diabetes patients, GLP-1RA resulted in improved systolic function measured by circumferential strain (mean difference [MD]= -5.48; 95% CI: -10.47 to -0.49; P= 0.03; I2= 89%) and diastolic dysfunction measured by E / A (MD= -0.15; 95% CI: -0.25 to -0.05; P= 0.003; I2= 0%). For post-myocardial infarction patients, GLP-1RA reduced infarct size (g) (MD= -5.36; 95% CI: -10.68 to -0.04; P= 0.05; I2= 78%). Liraglutide, but not exenatide, demonstrated improved systolic function, by increasing left ventricular ejection fraction (MD= 4.89; 95% CI: 3.62 to 6.16; P< 0.00001; I2= 0%) and reducing left ventricular end-systolic volume (MD= -4.15; 95% CI: -7.49 to -0.81; P = 0.01; I2= 0%). Among heart failure patients, no significant changes were noted.

CONCLUSION

GLP-1RA drugs may improve systolic and diastolic function in type 2 diabetes and reduce infarct size post-acute myocardial infarction with no demonstrable effect on cardiac function in heart failure. Tailored recommendations for the use of GLP-1RAs for cardioprotection should be considered for each patient's condition.

Effect of Single Oral Coingestion of GABA and Malic Acid on Postprandial GLP-1, Glucose, and Insulin Responses in Healthy Volunteers: A Randomized, Double-Blind, Placebo-Controlled, Crossover Study

SCOPE

This study examines whether coingestion of γ-aminobutyric acid (GABA) and malic acid (MA) before meals enhances glucagon-like peptide-1 (GLP-1) secretion, and which affects subsequent insulin and glycemic responses in humans.

METHODS AND RESULTS

Initially, a murine enteroendocrine STC-1 cell line is used to verify coadministration of GABA and MA synergistically induces GLP-1 secretion. Next, 22 healthy adults are given water (50 mL) containing 400 mg GABA and 400 mg MA (Test), or only 400 mg citric acid (CA) (Placebo) 20 min before meal tolerance test (MTT). Interval blood samples are taken postprandially over 180 min to determine GLP-1, insulin, and glucose responses. By comparison to preload of Placebo, preload of Test significantly increases plasma GLP-1 (total/active) levels (incremental area under the curve by 1.2- and 1.6-fold), respectively. However, there are no significant differences in postprandial blood glucose and insulin.

CONCLUSION

Coingestion of GABA and MA before meals enhances postprandial GLP-1 secretion. Future studies should explore optimal dosage regimens to find the efficacy of the mixture on insulin and glycemic response.

Two years with GIOIA 'Effects of gliflozins and gliptins on markers of cardiovascular damage in type 2 diabetes': A prospective, multicentre, quasi-experimental study on sodium-glucose cotransporter 2 and dipeptidyl peptidase-4 inhibitors in diabetes clinical practice

AIM

To assess and compare the metabolic and vascular effectiveness of sodium-glucose cotransporter 2 inhibitors (SGLT-2i) and dipeptidyl peptidase-4 inhibitors (DPP-4i) in the clinical practice of patients with type 2 diabetes in Italy.

MATERIALS AND METHODS

GIOIA is a 2-year prospective, multicentre, quasi-experimental study that enrolled patients with type 2 diabetes initiating SGLT-2i or DPP-4i for inadequate glycaemic control [glycated haemoglobin (HbA1c) >7%] between March 2018 and March 2021. The primary endpoints were changes in markers of organ damage [carotid intima-media thickness (CIMT), albuminuria, myocardial function] and HbA1c from baseline to year 2.

RESULTS

In total, 1150 patients were enrolled in the study (SGLT-2i n = 580, DPP-4i n = 570). Patients initiated on SGLT-2i were younger (about 6 years) and heavier (about 11 kg), had higher HbA1c level (1% more), more albuminuria and cardiovascular events (16% more) than patients initiated on DPP-4i. CIMT and echocardiographic parameters were not significantly different. Propensity score matching yielded two groups, each consisting of 155 patients with diabetes with similar baseline characteristics. Despite a significant similar reduction in HbA1c levels in both groups (-0.8%), more patients on SGLT-2i had regression of CIMT and albuminuria (22% and 10%, respectively, p < .001 vs. DPP-4i); more patients on DPP-4i had progression of CIMT and albuminuria (23% and 28%, respectively, p < .001 vs. SGLT-2i). Left ventricular ejection fraction improved slightly (3%, p = .043) on SGLT-2i only.

CONCLUSIONS

In a real-world setting, both SGLT-2i and DPP-4i improve glycaemic control persisting after 2 years of treatment, with a robust effect on both CIMT and albuminuria regression for SGLT-2i as compared with DPP-4i in the propensity score matching.

Effects of glucose-lowering drugs on cardiovascular outcomes in patients with type 2 diabetes: an update

INTRODUCTION

Over the last few years, there has been a substantial increase in the data available about the benefits of sodium-glucose cotransporter-2 (SGLT2) inhibitors and glucagon-like peptide-1 receptor agonists (GLP-1 RAs) in improving cardiovascular and renal outcomes in patients with type 2 diabetes (T2D). Very little new information is available for the other groups of glucose-lowering drugs.

AREAS COVERED

This brief report summarizes the recent information about the respective benefits of the two newer groups of glucose-lowering drugs and the effects on cardiovascular risk factors that may be involved in these benefits. The articles reviewed were identified by a Medline search.

EXPERT OPINION

Recent guidelines recommend SGLT2 inhibitors or GLP-1 RAs with proven cardiovascular disease benefits as potential first line treatment for patients with T2D and established atherosclerotic cardiovascular disease (ASCVD) or those with high risk of ASCVD or with chronic kidney disease or heart failure. Both groups of drugs have been shown to reduce major adverse cardiovascular events, but the mechanisms vary between them. SGLT2 inhibitors are preferred for the treatment and prevention of heart failure and chronic kidney disease, whereas GLP-1 RAs are more effective in reducing body weight and improving glycemic control in patients with T2D.

Practical guide: Glucagon-like peptide-1 and dual glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 receptor agonists in diabetes mellitus

In 2005, exenatide became the first approved glucagon-like peptide-1 receptor agonist (GLP-1 RA) for type 2 diabetes mellitus (T2DM). Since then, numerous GLP-1 RAs have been approved, including tirzepatide, a novel dual glucose-dependent insulinotropic polypeptide (GIP)/GLP-1 RA, which was approved in 2022. This class of drugs is considered safe with no hypoglycemia risk, making it a common second-line choice after metformin for treating T2DM. Various considerations can make selecting and switching between different GLP-1 RAs challenging. Our study aims to provide a comprehensive guide for the usage of GLP-1 RAs and dual GIP and GLP-1 RAs for the management of T2DM.

Underlying mechanisms and cardioprotective effects of SGLT2i and GLP-1Ra: insights from cardiovascular magnetic resonance

Originally designed as anti-hyperglycemic drugs, Glucagon-Like Peptide-1 receptor agonists (GLP-1Ra) and Sodium-glucose cotransporter-2 inhibitors (SGLT2i) have demonstrated protective cardiovascular effects, with significant impact on cardiovascular morbidity and mortality. Despite several mechanisms have been proposed, the exact pathophysiology behind these effects is not yet fully understood. Cardiovascular imaging is key for the evaluation of diabetic patients, with an established role from the identification of early subclinical changes to long-term follow up and prognostic assessment. Among the different imaging modalities, CMR may have a key-role being the gold standard for volumes and function assessment and having the unique ability to provide tissue characterization. Novel techniques are also implementing the possibility to evaluate cardiac metabolism through CMR and thereby further increasing the potential role of the modality in this context. Aim of this paper is to provide a comprehensive review of changes in CMR parameters and novel CMR techniques applied in both pre-clinical and clinical studies evaluating the effects of SGLT2i and GLP-1Ra, and their potential role in better understanding the underlying CV mechanisms of these drugs.

Implications of Atrial Fibrillation for Guideline-Directed Therapy in Patients With Heart Failure: JACC State-of-the-Art Review

Atrial fibrillation (AF) and heart failure (HF) are common cardiovascular conditions that frequently coexist. Among patients with HF, more than one-half also have AF. Both are associated with significant morbidity and mortality. Moreover, the prevalence of each is increasing globally, and this trend is expected to continue owing to an aging population and increased life expectancy. Diagnosis of AF in a patient with HF is associated with greater symptom burden, more frequent hospitalizations, and a worse prognosis. Guideline-directed medical therapy (GDMT) for HF can affect the incidence of AF. Once present, AF can influence the efficacy of some components of GDMT for HF. In this review, we discuss the effect of GDMT for HF across the spectrum of ejection fraction on prevention of AF as well as the benefit of GDMT in patients with vs without AF.

Liraglutide for Lower Limb Perfusion in People With Type 2 Diabetes and Peripheral Artery Disease: The STARDUST Randomized Clinical Trial

Importance

Peripheral artery disease (PAD) in diabetes may lead to diabetic foot ulcer and lower-extremities amputation. Glucagon-like peptide 1 receptor agonists have proven cardiovascular benefits in trials of people with type 2 diabetes at high cardiovascular risk.

Objective

To examine the effect of liraglutide on peripheral perfusion measured as peripheral transcutaneous oxygen pressure (TcPo2) in individuals with type 2 diabetes and PAD.

Design, Setting, and Participants

This open-label randomized clinical trial was conducted between February 1, 2021, and June 30, 2022, with a final follow-up on December 30, 2022, at University of Campania "Luigi Vanvitelli," Naples, Italy. Fifty-five individuals with type 2 diabetes, PAD, and TcPo2 between 30 and 49 mm Hg were included.

Interventions

Patients were randomized to receive 1.8 mg of subcutaneous liraglutide or conventional treatment of cardiovascular risk factors (control group) for 6 months.

Main Outcomes and Measures

Coprimary outcomes were the change from baseline of peripheral perfusion between groups and the comparison of the proportion of individuals who reached 10% increase of TcPo2 from baseline in each group.

Results

Fifty-five participants (mean [SD] age, 67.5 [8.5] years; 43 [78%] male) were randomized (27 to the liraglutide group and 28 to the control group) and analyzed. Participants had a median (IQR) hemoglobin A1c level of 6.9% (6.5%-7.8%) and a mean (SD) TcPo2 of 40.3 (5.7) mm Hg. Transcutaneous Po2 increased over time in both groups, with significant differences favoring the liraglutide group after 6 months (estimated treatment difference, 11.2 mm Hg; 95% CI, 8.0-14.5 mm Hg; P < .001). The 10% increase of TcPo2 occurred in 24 participants (89%) in the liraglutide group and 13 (46%) in the control group (relative risk, 1.91; 95% CI, 1.26-2.90; P < .001). Compared with the control group, individuals in the liraglutide group had a significant reduction of C-reactive protein (-0.4 mg/dL; 95% CI, -0.7 to -0.07 mg/dL; P = .02), urinary albumin to creatinine ratio (-119.4 mg/g; 95% CI, -195.0 to -43.8 mg/g; P = .003), and improvement of 6-minute walking distance (25.1 m; 95% CI, 21.8-28.3 m; P < .001).

Conclusions and Relevance

In this randomized clinical trial of people with type 2 diabetes and PAD, liraglutide increased peripheral perfusion detected by TcPo2 measurement during 6 months of treatment. These results support the use of liraglutide to prevent the clinical progression of PAD in individuals with type 2 diabetes.

Trial Registration

ClinicalTrials.gov Identifier: NCT04881110.

Recent advances in the treatment of type 2 diabetes mellitus using new drug therapies

Several recent advances provide multiple health benefits to individuals with type 2 diabetes mellitus (T2DM). Pharmacological therapy is governed by person-centered factors, including comorbidities and treatment goals. Adults with T2DM who have an established/high risk of atherosclerotic cardiovascular disease, heart failure, and/or chronic kidney disease, require a treatment regimen that includes agents that are proven to reduce cardiorenal risk. Weight management plays a key role in reducing glucose for patients with T2DM. A glucose-reduction treatment regimen must consider weight management. Sodium glucose co-transporter 2 (SGLT2) inhibitors reduce the risk of heart failure, cardiovascular and renal events. Glucagon-like peptide-1 (GLP-1) receptor agonists allow better control of glycemia, promote weight loss and reduce the risk of cardiovascular events. Newer Glucose-dependent insulinotropic polypeptide (GIP) and GLP-1 dual agonist, which activate GIP and GLP-1 receptors improve glycemic control and promote greater weight loss than GLP-1 receptor agonists. Several novel drugs are in the clinical development phase. This review pertains to recent advances in pharmacological management of type 2 diabetes.

Increased A1 astrocyte activation-driven hippocampal neural network abnormality mediates delirium-like behavior in aged mice undergoing cardiac surgery

Delirium is the most common neurological complication after cardiac surgery with adverse impacts on surgical outcomes. Advanced age is an independent risk factor for delirium occurrence but its underlying mechanisms are not fully understood. Although increased A1 astrocytes and abnormal hippocampal networks are involved in neurodegenerative diseases, whether A1 astrocytes and hippocampal network changes are involved in the delirium-like behavior of aged mice remains unknown. In the present study, a mice model of myocardial ischemia-reperfusion mimicking cardiac surgery and various assessments were used to investigate the different susceptibility of the occurrence of delirium-like behavior between young and aged mice and the underlying mechanisms. The results showed that surgery significantly increased hippocampal A1 astrocyte activation in aged compared to young mice. The high neuroinflammatory state induced by surgery resulted in glutamate accumulation in the extrasynaptic space, which subsequently decreased the excitability of pyramidal neurons and increased the PV interneurons inhibition through enhancing N-methyl-D-aspartate receptors' tonic currents in the hippocampus. These further induced the abnormal activities of the hippocampal neural networks and consequently contributed to delirium-like behavior in aged mice. Notably, the intraperitoneal administration of exendin-4, a glucagon-like peptide-1 receptor agonist, downregulated A1 astrocyte activation and alleviated delirium-like behavior in aged mice, while IL-1α, TNF-α, and C1q in combination administered intracerebroventricularly upregulated A1 astrocyte activation and induced delirium-like behavior in young mice. Therefore, our study suggested that cardiac surgery increased A1 astrocyte activation which subsequently impaired the hippocampal neural networks and triggered delirium development.

Preoperative Patient Evaluation: Newer Hypoglycemic Agents

New medications in the treatment of diabetes are an active area of research and drug development. Although many hypoglycemic therapies have been in use for decades, new evidence continues to emerge highlighting benefits of these medications for other indications. In this article, the authors review the classes of newer hypoglycemic agents and summarize medications currently in phase 2 and 3 clinical trials. The literature to support specific recommendations for perioperative management is scant, however, where it exists, we have included it. In other instances, the authors have noted a reasonable approach based on pharmacokinetics and principles of perioperative medication management.

Diabetes: a potential mediator of associations between polycyclic aromatic hydrocarbon exposure and stroke

Epidemiological evidence suggests associations between exposure to polycyclic aromatic hydrocarbons (PAHs) and cardiovascular diseases (CVD), while diabetes is a common risk factor for CVD. The present study aims to clarify the effect of high PAH exposure on diabetes and stroke in general population. A total of 7849 individuals aged 20 years or older from the National Health and Nutrition Examination Survey 2007-2016 were included in the study. The logistic regression analysis modeled the association between PAH exposure and diabetes as well as stroke. The analysis yielded odds ratios (ORs) and 95% confidence intervals (CIs). The study also evaluated the potential mediating role of diabetes in the relation between PAH exposure and stroke via mediating effect analyses. Of the 7849 eligible participants, 1424 cases of diabetes and 243 cases of stroke were recorded. After adjusting for covariates including age, gender, smoking status, drinking status, education level, marital status, physical activity, hypertension, low-density lipoprotein cholesterol, and BMI, the ORs for stroke in the highest quartile (Q4) of total urinary PAHs were 1.97 (95% CI 1.11-3.52, P = 0.022) as compared to the lowest quartile (Q1) of total urinary PAHs. The ORs for diabetes in the Q4 of total urinary PAHs were 1.56 (95% CI 1.15-2.12, P = 0.005), while the ORs between Q4 and Q1 for stroke and diabetes concerning exposure to 2-hydroxynaphthalene were 2.23 (95% CI 1.17-4.25, P = 0.016) and 1.40 (95% CI 1.07-1.82, P = 0.015), respectively. The mediation analysis found that diabetes accounted for 5.00% of the associations between urinary PAHs and the prevalence of stroke. Urinary metabolites of PAH have been linked to stroke and diabetes. Increasing the risk of diabetes may play a significant role in mediating the association between exposure to PAHs and increased risk of stroke. Monitoring and improving glucose metabolism in individuals with high exposure to PAHs may aid in reducing the prevalence of stroke.

Poly-Agonist Pharmacotherapies for Metabolic Diseases: Hopes and New Challenges

The use of glucagon-like peptide-1 (GLP-1) receptor-based multi-agonists in the treatment of type 2 diabetes and obesity holds great promise for improving glycaemic control and weight management. Unimolecular dual and triple agonists targeting multiple gut hormone-related pathways are currently in clinical trials, with recent evidence supporting their efficacy. However, significant knowledge gaps remain regarding the biological mechanisms and potential adverse effects associated with these multi-target agents. The mechanisms underlying the therapeutic efficacy of GLP-1 receptor-based multi-agonists remain somewhat mysterious, and hidden threats may be associated with the use of gut hormone-based polyagonists. In this review, we provide a critical analysis of the benefits and risks associated with the use of these new drugs in the management of obesity and diabetes, while also exploring new potential applications of GLP-1-based pharmacology beyond the field of metabolic disease.

Therapeutic effects of anti-diabetic drugs on traumatic brain injury

AIMS

In this narrative review, we have analyzed and synthesized current studies relating to the effects of anti-diabetic drugs on traumatic brain injury (TBI) complications.

METHODS

Eligible studies were collected from Scopus, Google Scholar, PubMed, and Cochrane Library for clinical, in-vivo, and in-vitro studies published on the impact of anti-diabetic drugs on TBI.

RESULTS

Traumatic brain injury (TBI) is a serious brain disease that is caused by any type of trauma. The pathophysiology of TBI is not yet fully understood, though physical injury and inflammatory events have been implicated in TBI progression. Several signaling pathways are known to play pivotal roles in TBI injuries, including Nuclear factor erythroid 2-related factor 2 (Nrf2), High mobility group box 1 protein/Nuclear factor kappa B (HMGB1/NF-κB), Adiponectin, Mammalian Target of Rapamycin (mTOR), Toll-Like Receptor (TLR), Wnt/β-catenin, Janus Kinase/Signal Transducers and Activators of Transcription (JAK/STAT), Nod-like receptor protein3 (NLRP3) inflammasome, Phosphoglycerate kinase 1/Kelch-like ECH-associated protein 1 (PGK1/KEAP1)/Nrf2, and Mitogen-activated protein kinase (MAPK) . Recent studies suggest that oral anti-diabetic drugs such as biguanides, thiazolidinediones (TZDs), sulfonylureas (SUs), sodium-glucose cotransporter-2 inhibitors (SGLT2is), dipeptidyl peptidase-4 inhibitors (DPPIs), meglitinides, and alpha-glucosidase inhibitors (AGIs) could have beneficial effects in the management of TBI complications. These drugs may downregulate the inflammatory pathways and induce antioxidant signaling pathways, thus alleviating complications of TBI.

CONCLUSION

Based on this comprehensive literature review, antidiabetic medications might be considered in the TBI treatment protocol. However, evidence from clinical trials in patients with TBI is still warranted.

A diabetic patient increased premature ventricular contractions after using liraglutide: a case report

The common adverse reactions of liraglutide are hypoglycemia and gastrointestinal reactions. This case reports a patient with type 2 diabetes mellitus who had an increase in ventricular premature beats after using liraglutide and a decrease in ventricular premature beats after stopping liraglutide, suggesting that clinicians should rule out the possibility of drug-related adverse reactions when using liraglutide in the treatment of diabetes mellitus complicated with coronary heart disease and arrhythmia.

Unlocking the miRNA-34a-5p/TGF-β and HMGB1/PI3K/Akt/mTOR crosstalk participate in the enhanced cardiac protection of liraglutide against isoproterenol-induced acute myocardial injury rat model

Liraglutide (LIRA), a drug used to treat type 2 diabetes mellitus that belongs to the glucagon-like peptide-1 class, has recently drawn attention for its potential cardioprotective properties because of its anti-oxidative and anti-inflammatory properties. This current investigation was designed to assess the impact of LIRA on myocardial injury induced by isoproterenol (ISO). The experiment included 24 male Wistar rats in total, and they were divided into four groups: Control, LIRA (200 µg/kg/12 hrs., S.C.), ISO (85 mg/kg, S.C.), and ISO + LIRA. To assess the results, various biochemical and histopathological analyses were carried out. The findings showed elevated serum enzyme levels, a sign of cardiac injury. ISO-treated rats showed an upregulation of oxidative stress and inflammatory biomarkers like MDA, MPO, nitrites, NADPH oxidase, TNF-α, IL-1β, IL-6, 8-Hydroxyguanosine (8-OHdG), and TGF-β, as well as altered gene expressions like TLR-1 and miRNA-34a-5p. According to western blotting analysis, protein levels of AKT, PI3K, and mTOR were obviously enhanced. Additionally, ISO-treated samples showed altered tissue morphology, elevated caspase 3, and decreased Bcl2 concentrations. The levels of these dysregulated parameters were significantly normalized by LIRA therapy, demonstrating its cardioprotective function against ISO-induced myocardial injury in rats. This protective mechanism was linked to anti-inflammatory properties, redox balance restoration, and modulation of the miRNA-34a-5p/TGF-β pathway.

Research Advances in Fusion Protein-Based Drugs for Diabetes Treatment

Diabetes mellitus (DM) is a chronic metabolic disease characterized by elevated blood glucose levels, resulting in multi-organ dysfunction and various complications. Fusion proteins can form multifunctional complexes by combining the target proteins with partner proteins. It has significant advantages in improving the performance of the target proteins, extending their biological half-life, and enhancing patient drug compliance. Fusion protein-based drugs have emerged as promising new drugs in diabetes therapeutics. However, there has not been a systematic review of fusion protein-based drugs for diabetes therapeutics. Hence, we conducted a comprehensive review of published literature on diabetic fusion protein-based drugs for diabetes, with a primary focus on immunoglobulin G (IgG) fragment crystallizable (Fc) region, albumin, and transferrin (TF). This review aims to provide a reference for the subsequent development and clinical application of fusion protein-based drugs in diabetes therapeutics.

The Role of GLP-1, GIP, MCP-1 and IGFBP-7 Biomarkers in the Development of Metabolic Disorders: A Review and Predictive Analysis in the Context of Diabetes and Obesity

Metabolic illnesses, including obesity and type 2 diabetes, have become worldwide epidemics that have an effect on public health. Clinical investigations and further exploration of these mechanisms could lead to innovative, effective, and personalized treatment strategies for individuals. It is important to screen biomarkers in previous studies to discover what is missing. Glucagon-like peptide-1's role in insulin secretion and glucose control highlights its diagnostic and therapeutic potential. Glucose-dependent insulinotropic peptide's influence on postprandial satiety and weight management signifies its importance in understanding metabolic processes. Monocyte chemoattractant protein-1's involvement in inflammation and insulin resistance underlines its value as a diagnostic marker. Insulin-like growth factor-binding protein-7's association with insulin sensitivity and kidney function presents it as a potential target for these diseases' management. In validating these biomarkers, it will be easier to reflect pathophysiological processes, and clinicians will be able to better assess disease severity, monitor disease progression, and tailor treatment strategies. The purpose of the study was to elucidate the significance of identifying novel biomarkers for type 2 diabetes mellitus and obesity, which can revolutionize early detection, risk assessment, and personalized treatment strategies. Standard literature searches of PubMed (MEDLINE), EMBASE, and Cochrane Library were conducted in the year 2023 to identify both original RCTs and recent systematic reviews that have explored the importance of identifying novel biomarkers for T2D and obesity. This search produced 1964 results, and then was reduced to randomized controlled trial and systematic reviews, producing 145 results and 44 results, respectively. Researchers have discovered potential associations between type 2 diabetes mellitus and obesity and the biomarkers glucagon-like peptide-1, glucose-dependent insulinotropic peptide, monocyte chemoattractant protein-1, and insulin-like growth factor-binding protein-7. Understanding the role of those biomarkers in disease pathogenesis offers hope for improving diagnostics, personalized treatment, and prevention strategies.

MASLD and the Development of HCC: Pathogenesis and Therapeutic Challenges

Metabolic-dysfunction-associated steatotic liver disease (MASLD, previously known as non-alcoholic fatty liver disease (NAFLD)) represents a rapidly increasing cause of chronic liver disease and hepatocellular carcinoma (HCC), mirroring increasing rates of obesity and metabolic syndrome in the Western world. MASLD-HCC can develop at an earlier stage of fibrosis compared to other causes of chronic liver disease, presenting challenges in how to risk-stratify patients to set up effective screening programmes. Therapeutic decision making for MASLD-HCC is also complicated by medical comorbidities and disease presentation at a later stage. The response to treatment, particularly immune checkpoint inhibitors, may vary by the aetiology of the disease, and, in the future, patient stratification will be key to optimizing the therapeutic pathways.

Associations of antidiabetic drugs with diabetic retinopathy in people with type 2 diabetes: an umbrella review and meta-analysis

Background

Diabetic retinopathy (DR) is the most frequent complication of type 2 diabetes and remains the leading cause of preventable blindness. Current clinical decisions regarding the administration of antidiabetic drugs do not sufficiently incorporate the risk of DR due to the inconclusive evidence from preceding meta-analyses. This umbrella review aimed to systematically evaluate the effects of antidiabetic drugs on DR in people with type 2 diabetes.

Methods

A systematic literature search was undertaken in Medline, Embase, and the Cochrane Library (from inception till 17th May 2022) without language restrictions to identify systematic reviews and meta-analyses of randomized controlled trials or longitudinal studies that examined the association between antidiabetic drugs and DR in people with type 2 diabetes. Two authors independently extracted data and assessed the quality of included studies using the AMSTAR-2 (A MeaSurement Tool to Assess Systematic Reviews) checklist, and evidence assessment was performed using the GRADE (Grading of recommendations, Assessment, Development and Evaluation). Random-effects models were applied to calculate relative risk (RR) or odds ratios (OR) with 95% confidence intervals (CI). This study was registered with PROSPERO (CRD42022332052).

Results

With trial evidence from 11 systematic reviews and meta-analyses, we found that the use of glucagon-like peptide-1 receptor agonists (GLP-1 RA), sodium-glucose cotransporter-2 inhibitors (SGLT-2i), or dipeptidyl peptidase-4 inhibitors (DPP-4i) was not statistically associated with the risk of DR, compared to either placebo (RR: GLP-1 RA, 0.98, 0.89-1.08; SGLT-2i, 1.00, 95% CI 0.79-1.27; DPP-4i, 1.17, 0.99-1.39) or other antidiabetic drugs. Compared to other antidiabetic drugs, meglitinides (0.34, 0.01-8.25), SGLT-2i (0.73, 0.10-5.16), thiazolidinediones (0.92, 0.67-1.26), metformin (1.15, 0.81-1.63), sulphonylureas (1.24, 0.93-1.65), and acarbose (4.21, 0.44-40.43) were not statistically associated with the risk of DR. With evidence from longitudinal studies only, insulin was found to have a higher risk of DR than other antidiabetic drugs (OR: 2.47, 95% CI: 2.04-2.99).

Conclusion

Our results indicate that antidiabetic drugs are generally safe to prescribe regarding the risk of DR among people with type 2 diabetes. Further robust and large-scale trials investigating the effects of insulin, meglitinides, and acarbose on DR are warranted.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=332052, identifier CRD42022332052.

Discovery of non-peptide GLP-1r natural agonists for enhancing coronary safety in type 2 diabetes patients

This study explores the computational discovery of non-peptide agonists targeting the Glucagon-Like Peptide-1 Receptor (GLP-1R) to enhance the safety of major coronary outcomes in individuals affected by Type 2 Diabetes. The objective is to identify novel compounds that can activate the GLP-1R pathway without the limitations associated with peptide agonists. Type 2 diabetes mellitus (T2DM) is associated with an increased risk of cardiovascular disease (CVD) and mortality, which is attributed to the accumulation of fat in organs, including the heart. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are frequently used to manage T2DM and could potentially offer cardiovascular benefits. Therefore, this study examines non-peptide agonists of GLP-1R to improve coronary safety in type 2 diabetes patients. After rigorous assessments, two standout candidates were identified, with natural compound 12 emerging as the most promising. This study represents a notable advancement in enhancing the management of coronary outcomes among individuals with type 2 diabetes. The computational methodology employed successfully pinpointed potential GLP-1R natural agonists, providing optimism for the development of safer and more effective therapeutic interventions. Although computational methodologies have provided crucial insights, realizing the full potential of these compounds requires extensive experimental investigations, crucial in advancing therapeutic strategies for this critical patient population.Communicated by Ramaswamy H. Sarma.

Weight Loss-Independent Effect of Liraglutide on Insulin Sensitivity in Individuals With Obesity and Prediabetes

Metabolic effects of glucagon-like peptide 1 (GLP-1) receptor agonists are confounded by weight loss and not fully recapitulated by increasing endogenous GLP-1. We tested the hypothesis that GLP-1 receptor (GLP-1R) agonists exert weight loss-independent, GLP-1R-dependent effects that differ from effects of increasing endogenous GLP-1. Individuals with obesity and prediabetes were randomized to receive for 14 weeks the GLP-1R agonist liraglutide, a hypocaloric diet, or the dipeptidyl peptidase 4 (DPP-4) inhibitor sitagliptin. The GLP-1R antagonist exendin(9-39) and placebo were administered in a two-by-two crossover study during mixed-meal tests. Liraglutide and diet, but not sitagliptin, caused weight loss. Liraglutide improved insulin sensitivity measured by HOMA for insulin resistance (HOMA-IR), the updated HOMA model (HOMA2), and the Matsuda index after 2 weeks, prior to weight loss. Liraglutide decreased fasting and postprandial glucose levels, and decreased insulin, C-peptide, and fasting glucagon levels. In contrast, diet-induced weight loss improved insulin sensitivity by HOMA-IR and HOMA2, but not the Matsuda index, and did not decrease glucose levels. Sitagliptin increased endogenous GLP-1 and GIP values without altering insulin sensitivity or fasting glucose levels, but decreased postprandial glucose and glucagon levels. Notably, sitagliptin increased GIP without altering weight. Acute GLP-1R antagonism increased glucose levels in all groups, increased the Matsuda index and fasting glucagon level during liraglutide treatment, and increased endogenous GLP-1 values during liraglutide and sitagliptin treatments. Thus, liraglutide exerts rapid, weight loss-independent, GLP-1R-dependent effects on insulin sensitivity that are not achieved by increasing endogenous GLP-1.

ARTICLE HIGHLIGHTS

Metabolic benefits of glucagon-like peptide 1 (GLP-1) receptor agonists are confounded by weight loss and are not fully achieved by increasing endogenous GLP-1 through dipeptidyl peptidase 4 (DPP-4) inhibition. We investigated weight loss-independent, GLP-1 receptor (GLP-1R)-dependent metabolic effects of liraglutide versus a hypocaloric diet or the DPP-4 inhibitor sitagliptin. GLP-1R antagonism with exendin(9-39) was used to assess GLP-1R-dependent effects during mixed meals. Liraglutide improved insulin sensitivity and decreased fasting and postprandial glucose prior to weight loss, and these benefits were reversed by exendin(9-39). GLP-1R agonists exert rapid, weight loss-independent, GLP-1R-dependent effects on insulin sensitivity not achieved by increasing endogenous GLP-1.

G protein-coupled receptors and obesity

G protein-coupled receptors (GPCRs) have emerged as important drug targets for various chronic diseases, including obesity and diabetes. Obesity is a complex chronic disease that requires long term management predisposing to type 2 diabetes, heart disease, and some cancers. The therapeutic landscape for GPCR as targets of anti-obesity medications has undergone significant changes with the approval of semaglutide, the first peptide glucagon like peptide 1 receptor agonist (GLP-1RA) achieving double digit weight loss (≥10%) and cardiovascular benefits. The enhanced weight loss, with the expected beneficial effect on obesity-related complications and reduction of major adverse cardiovascular events (MACE), has propelled the commercial opportunity for the obesity market leading to new players entering the space. Significant progress has been made on approaches targeting GPCRs such as single peptides that simultaneously activate GIP and/or GCGR in addition to GLP1, oral tablet formulation of GLP-1, small molecules nonpeptidic oral GLP1R and fixed-dose combination as well as add-on therapy for patients already treated with a GLP-1 agonist.

Blockbuster Medications for Obesity: A Primer for Nephrologists

The prevalence of obesity in the United States and across the world continues to climb, imparting increased risk of chronic disease. This impact is doubly felt in nephrology because obesity not only increases the risk of chronic kidney disease (CKD) but also exacerbates existing cardiovascular morbidity and mortality. The role of medical weight loss therapy in CKD has been debated, but increasing evidence suggests that intentional weight loss is protective against adverse kidney and cardiovascular outcomes. This may be particularly true with the advent of novel pharmacotherapies taking advantage of the incretin system, resulting in weight loss approaching that seen with surgical interventions. Moreover, these novel therapies have repeatedly demonstrated protective effects on the cardiovascular system. Here, we review the impact of obesity and weight loss on CKD, and the biological basis and clinical evidence for incretin therapy. This perspective provides recommended prescribing practices as a practical tool to engage nephrologists and patients with CKD in the treatment of obesity-related morbidity.

Biology and Clinical Use of Glucagon-Like Peptide-1 Receptor Agonists in Vascular Protection

Glucagon-like peptide-1 receptor agonists (GLP1RA) are incretin agents initially designed for the treatment of type 2 diabetes mellitus but because of pleiotropic actions are now used to reduce cardiovascular disease in people with type 2 diabetes mellitus and in some instances as approved treatments for obesity. In this review we highlight the biology and pharmacology of GLP1RA. We review the evidence for clinical benefit on major adverse cardiovascular outcomes in addition to modulation of cardiometabolic risk factors including reductions in weight, blood pressure, improvement in lipid profiles, and effects on kidney function. Guidance is provided on indications and potential adverse effects to consider. Finally, we describe the evolving landscape of GLP1RA and including novel glucagon-like peptide-1-based dual/polyagonist therapies that are being evaluated for weight loss, type 2 diabetes mellitus, and cardiorenal benefit.

Postmarket safety profile of suicide/self-injury for GLP-1 receptor agonist: a real-world pharmacovigilance analysis

BACKGROUND

Recent reports of individuals experiencing suicidal and/or self-injurious behaviors while using liraglutide and semaglutide have heightened the concerns regarding neuropsychiatric safety of Glucagon-like peptide-1 agonists (GLP-1RAs). As real-world evidence is very limited, we explored the association between GLP-1RA and suicide/self-injury by mining the FDA Adverse Event Reporting System (FAERS) database.

METHODS

The FAERS database was queried from 2005 Q2 to 2023 Q2. The Reporting Odds Ratio (ROR) and Empirical Bayes Geometric Mean (EBGM) were used to conduct the disproportionality analysis.

RESULTS

A total of 534 GLP-1RA-associated suicide/self-injury cases were reported in the FAERS during the study period. GLP-1RA did not cause a disproportionate increase in overall suicidal and self-injurious cases (ROR: 0.16, 95%CI 0.15-0.18, P < 0.001; EBGM05: 0.15). Stratified analyses found no safety signal of suicide/injury for GLP-1RA in both females and males. The ROR for suicide/self-injury with GLP-1RA was slightly elevated (ROR: 2.50, 95%CI 1.02-6.13, P = 0.05) in children, while the EBGM05 was < 2 in this population. No significant signal value was observed in other age groups. No over-reporting of suicide/self-injury was identified for GLP-1RA before or after the COVID-19 pandemic outbreak.

CONCLUSIONS

The cases of suicide or self-injury reported to FAERS do not indicate any overall safety signal attributable to GLP-1RA at this time. Subgroup analysis revealed a marginal elevation of ROR for suicide and self-injury with GLP-1RA in children, but no safety signal was detected by EBGM05 in this population. Further large-scale prospective investigations are still warranted to further confirm this finding.

Diagnosis and treatment of post-cholecystectomy diarrhoea

The incidence of cholecystitis is relatively high in developed countries and may usually be attributed to gallstones, the treatment for which involves complete surgical removal of the gallbladder (cholecystectomy). Bile acids produced following cholecystectomy continue to flow into the duodenum but are poorly absorbed by the colon. Excessive bile acids in the colon stimulate mucosal secretion of water and electrolytes leading, in severe cases, to diarrhoea. Bile acid diarrhoea (BAD) is difficult to diagnose, requiring a comprehensive medical history and physical examination in combination with laboratory evaluation. The current work reviews the diagnosis and treatment of BAD following cholecystectomy.

Role of TRPV4 on vascular tone regulation in pathophysiological states

Vascular tone regulation is a key event in controlling blood flow in the body. Endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) help regulate the vascular tone. Abnormal vascular responsiveness to various stimuli, including constrictors and dilators, has been observed in pathophysiological states although EC and VSMC coordinate to maintain the exquisite balance between contraction and relaxation in vasculatures. Thus, investigating the mechanisms underlying vascular tone abnormality is very important in maintaining vascular health and treating vasculopathy. Increased intracellular free Ca2+ concentration ([Ca2+]i) is one of the major triggers initiating each EC and VSMC response. Transient receptor potential vanilloid family member 4 (TRPV4) is a Ca2+-permeable non-selective ion channel, which is activated by several stimuli, and is presented in both ECs and VSMCs. Therefore, TRPV4 plays an important role in vascular responses. Emerging evidence indicates the role of TRPV4 on the functions of ECs and VSMCs in various pathophysiological states, including hypertension, diabetes, and obesity. This review focused on the link between TRPV4 and the functions of ECs/VSMCs, particularly its role in vascular tone and responsiveness to vasoactive substances.

Targeting cluster of differentiation 26 / dipeptidyl peptidase 4 (CD26/DPP4) in organ fibrosis

Cluster of differentiation 26 (CD26)/dipeptidyl peptidase 4 (DPP4) is an exopeptidase that is expressed as a transmembrane protein in many organs but also present in a circulating soluble form. Beyond its enzymatic and costimulatory activity, CD26/DPP4 is involved in the pathogenesis of chronic fibrotic diseases across many organ types, such as liver cirrhosis, kidney fibrosis and lung fibrosis. Organ fibrosis is associated with a high morbidity and mortality, and there are no causative therapies that can effectively attenuate the progress of the disease. Growing evidence suggests that inhibiting CD26/DPP4 can modulate the profibrotic tissue microenvironment and thus reduce fibrotic changes within affected organs. This review summarizes the role of CD26/DPP4 in fibroproliferative disorders and highlights new opportunities for an antifibrotic treatment by CD26/DPP4 inhibition. As a major advantage, CD26/DPP4 inhibitors have been in safe and routine clinical use in type 2 diabetes for many years and thus qualify for repurposing to repurpose as a promising therapeutic against fibrosis. LINKED ARTICLES: This article is part of a themed issue on Translational Advances in Fibrosis as a Therapeutic Target. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v180.22/issuetoc.

Chronic kidney outcomes associated with GLP-1 receptor agonists versus long-acting insulins among type 2 diabetes patients requiring intensive glycemic control: a nationwide cohort study

BACKGROUND

Effectiveness of glucagon-like peptide-1 receptor agonists (GLP-1RAs) versus long-acting insulins (LAIs) on preventing progressive chronic kidney outcomes is uncertain for type 2 diabetes (T2D) patients requiring intensive glycemic control. This study aimed to evaluate comparative effectiveness of GLP-1RA versus LAI therapies on progressive chronic kidney outcomes among patients having poor glycemic control and requiring these injectable glucose-lowering agents (GLAs).

METHODS

7279 propensity-score-matched pairs of newly stable GLP-1RA and LAI users in 2013-2018 were identified from Taiwan's National Health Insurance Research Database and followed until death or 12/31/2019 (intention-to-treat). Subdistributional hazard model was utilized to assess the comparative effectiveness on a composite renal outcome (i.e., renal insufficiency [eGFR < 15 mL/min/1.73 m2], dialysis-dependent end-stage renal disease [ESRD], or renal death) and its individual components. Sensitivity analyses with the as-treated scenario, PS weighting, high-dimensional PS techniques, using cardiovascular diseases (CVDs) as positive control outcomes, and interaction testing were performed.

RESULTS

In primary analyses, subdistribution hazard ratios (95% CIs) for initiating GLP-1RAs versus LAIs for the composite renal outcome, renal insufficiency, dialysis-dependent ESRD, and renal death were 0.39 (0.30-0.51), 0.43 (0.32-0.57), 0.29 (0.20-0.43), and 0.28 (0.15-0.51), respectively. Sensitivity analysis results were consistent with the primary findings. CVD history and the medication possession ratio of prior oral GLAs possessed modification effects on GLP-1RA-associated kidney outcomes.

CONCLUSION

Using GLP-1RAs versus LAIs was associated with kidney benefits in T2D patients requiring intensive glycemic control and potentially at high risk of kidney progression. GLP-1RAs should be prioritized to patients with CVDs or adherence to prior oral GLAs to maximize kidney benefits.

Beyond Blood Sugar: Investigating the Cardiovascular Effects of Antidiabetic Drugs

Cardiovascular disease is a major comorbidity associated with diabetes mellitus. Various antidiabetic drugs are currently used to treat type 2 diabetes mellitus and have varying effects on the cardiovascular system. Some drugs, such as glucagon-like peptide 1 (GLP-1) agonists and sodium-glucose cotransporter 2 (SGLT-2) inhibitors, are cardioprotective, whereas others, such as insulin, have deleterious effects on the cardiovascular system. This narrative review assessed the impact of antidiabetic drugs on cardiovascular health in the management of diabetes mellitus. It critically examines various classes of these medications, including conventional options such as metformin and newer agents such as incretin-based therapies and SGLT-2.

DPP-4 Inhibitors Suppress Tau Phosphorylation and Promote Neuron Autophagy through the AMPK/mTOR Pathway to Ameliorate Cognitive Dysfunction in Diabetic Mellitus

Dipeptidyl peptidase-4 (DPP-4) inhibitors have been considered as incretin-based agents that signal through GLP-1R. Our high-throughput RNA sequencing (RNA-seq) and bioinformatics methods indicated that GLP-1R, downregulated in diabetes mellitus (DM), was a potential target of DPP-4 inhibitors, which was further confirmed in DM rats. Thus, this study illuminated the alleviatory mechanism of DPP-4 on cognitive dysfunction in diabetes mellitus (DM), which may be associated with GLP-1R signaling. DM rats were administered with DPP-4 inhibitors, Chloroquine (an autophagy inhibitor), Exendin 9-39 (a GLP-1R antagonist), or Compound C (a specific inhibitor of AMPK). An in vitro model of DM was induced in rat hippocampal neuronal cell line H19-7 by exposure to high glucose (HG) and high fat (HF), followed by treatment with the above inhibitors and antagonists. It was found that cognitive dysfunction was promoted, and LC3 expression was lowered in DM rats by an autophagy inhibitor. The DPP-4 inhibitors decreased cognitive dysfunction, repressed Tau phosphorylation, and enhanced GLP-1R protein level, LC3 expression, and AMPK and mTOR phosphorylation in DM rats, while GLP-1R antagonist, an autophagy inhibitor, or AMPK inhibitor counteracted these effects. Such effects were also observed in HG/HF-induced neurons. In conclusion, our data elucidated the alleviatory mechanism of DPP-4 inhibitors in the cognitive dysfunction of DM rats via the AMPK/mTOR pathway.

Effects of Incretin-Based Treatment on the Diastolic (Dys)Function in Patients with Uncontrolled Type 2 Diabetes Mellitus: A Prospective Study with 1-Year Follow-Up

Left ventricular diastolic dysfunction (DD) is a subclinical cardiac abnormality in patients with type 2 diabetes mellitus (T2DM) that can progress to heart failure (HF) and increase cardiovascular risk. This prospective study evaluated the DD in T2DM patients without atherosclerotic cardiovascular disease after one year of incretin-based drugs added to standard treatment. Of the 138 enrolled patients (49.30% male, mean age 57.86 ± 8.82, mean T2DM history 5 years), 71 were started on dipeptidyl peptidase-4 inhibitor sitagliptin/saxagliptin, 21 on glucagon-like peptide-1 receptor agonist exenatide, and 46 formed the control group (metformin and sulphonylurea/acarbose). At baseline, 71 patients had grade 1 DD, another 12 had grade 2 and 3 DD, and 15 had indeterminate DD. After one year, DD was evidenced in 50 cases. Diastolic function improved in 9 cases, and 27 patients went from grade 1 to indeterminate DD. The active group benefited more, especially patients treated with exenatide; their metabolic and inflammation profiles also improved the most. An in-depth analysis of echocardiographic parameters and paraclinical results in the context of literature data justifies the conclusion that early assessment of diastolic function in T2DM patients is necessary and the benefits of affordable incretin-based treatment may extend to subclinical cardiovascular manifestations such as DD.

The Impact of Glucagon-Like Peptide-1 Receptor Agonist on the Cardiovascular Outcomes in Patients With Type 2 Diabetes Mellitus: A Meta-Analysis and Systematic Review

BACKGROUND

Since 2005, the cardioprotective effects of glucagon-like peptide 1 receptor agonists (GLP-1 RAs) have garnered attention. The cardioprotective effect could be an added benefit to the use of GLP-1 RA. This systematic review and meta-analysis aimed at summarizing observational studies that recruited type 2 diabetes individuals with fewer cardiovascular (CV) events before enrolling in the research.

METHODS

Systematically, the databases were searched for observational studies reporting compound CV events and deaths in type 2 diabetics without having the risk of cardiovascular diseases (CVDs) compared to other glucose-lowering agents. A meta-analysis was carried out using random effects model to estimate the overall hazard ratio (HR) with a 95% confidence interval (CI). Five studies were found eligible for the systematic review including a total of 64,452 patients receiving either liraglutide (three studies) or exenatide (two studies).

RESULTS

The pooled HR for major adverse cardiac event (MACE) and extended MACE was 0.72 (95% CI: 0.65 - 0.93, I2 = 68%) and 0.93 (95% CI: 0.89 - 0.98, I2 = 29%), respectively. The pooled HR for hospitalization due to heart failure (HHF) and occurrence of HF was 0.84 (95% CI: 0.77 - 0.91, I2 = 79%) and 0.83 (95% CI: 0.75 - 0.94, I2 = 95%), respectively. For stroke, GLP-1 RA was associated with a significant risk reduction of 0.86 (95% CI: 0.75 - 0.98, I2 = 81%). There was no significant myocardial infarction (MI) risk reduction with GLP-1 RA. As for all-cause mortality, the pooled HR for the occurrence of all-cause mortality was 0.82 (95% CI: 0.76 - 0.88, I2 = 0%). The pooled HR for the occurrence of CV death was 0.75 (95% CI: 0.65 - 0.85, I2 = 38%). GLP-1 RA therapy was associated with a significantly low risk of MACE, extended MACE, all-cause mortality, and CV mortality. Except for MACE, the heterogenicity among the studies was low.

CONCLUSION

We conclude that GLP-1 RA is associated with a low risk of CV events composites and mortality. The findings support the cardioprotective effect of GLP-1 RA.

Glucagon-Like Peptide-1 Protects Against Atrial Fibrillation and Atrial Remodeling in Type 2 Diabetic Mice

Atrial fibrillation (AF) is highly prevalent in type 2 diabetes where it increases morbidity and mortality. Glucagon-like peptide (GLP)-1 receptor agonists are used in the treatment of type 2 diabetes (T2DM), but their effects on AF in T2DM are poorly understood. The present study demonstrates type 2 diabetic db/db mice are highly susceptible to AF in association with atrial electrical and structural remodeling. GLP-1, as well as the long-acting GLP-1 analogue liraglutide, reduced AF and prevented atrial remodeling in db/db mice. These data suggest that GLP-1 and related analogues could protect against AF in patients with T2DM.

Therapies for patients with coexisting heart failure with reduced ejection fraction and non-alcoholic fatty liver disease

Heart failure with reduced ejection fraction (HFrEF) and nonalcoholic fatty liver disease (NAFLD) are two common comorbidities that share similar pathophysiological mechanisms. There is a growing interest in the potential of targeted therapies to improve outcomes in patients with coexisting HFrEF and NAFLD. This manuscript reviews current and potential therapies for patients with coexisting HFrEF and NAFLD. Pharmacological therapies, including angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, mineralocorticoids receptor antagonist, and sodium-glucose cotransporter-2 inhibitors, have been shown to reduce fibrosis and fat deposits in the liver. However, there are currently no data showing the beneficial effects of sacubitril/valsartan, ivabradine, hydralazine, isosorbide nitrates, digoxin, or beta blockers on NAFLD in patients with HFrEF. This study highlights the importance of considering HFrEF and NAFLD when developing treatment plans for patients with these comorbidities. Further research is needed in patients with coexisting HFrEF and NAFLD, with an emphasis on novel therapies and the importance of a multidisciplinary approach for managing these complex comorbidities.

Endothelial Function in Patients with Multiple Sclerosis: The Role of GLP-1 Agonists, Lipoprotein Subfractions, and Redox Balance

INTRODUCTION

Epidemiological studies have suggested an increased vascular risk in patients with multiple sclerosis (MS). There is increasing evidence of the beneficial effects of GLP-1 agonists (GLP-1a) in preventing vascular complications and slowing the progression of neurodegeneration. Our objective was to explore the changes in the endothelial function of MS patients after 12 months of GLP-1a therapy. We also explored the role of lipoprotein subfractions and the antioxidant capacity of plasma.

METHODS

MS patients were enrolled in a prospective, unicentric study. GLP-1a (dulaglutide) was administered to 13 patients. The control population consisted of 12 subjects. Endothelial function was determined by peripheral arterial tonometry and expressed as reperfusion hyperemia index (RHI). Trolox equivalent antioxidant capacity (TEAC) was used to assess the total antioxidant capacity of the plasma. The levels of lipoprotein subfractions were evaluated.

RESULTS

The GLP-1a group did not have a significant change in their RHIs after 12 months (2.1 ± 0.6 vs. 2.1 ± 0.7; p = 0.807). However, a significant increase in their TEACs was observed (4.1 ± 1.4 vs. 5.2 ± 0.5 mmol/L, p = 0.010). On the contrary, the subjects in the control group had a significant worsening of their RHIs (2.1 ± 0.5 vs. 1.8 ± 0.6; p = 0.030), without significant changes in their TEACs. Except for a significant decrease in very-low-density lipoprotein (VLDL) (30.8 ± 10.2 vs. 22.6 ± 8.3 mg/dL, p = 0.043), no other significant changes in the variables were observed in the control group. VLDL levels (beta = -0.637, p = 0.001), the use of GLP-1a therapy (beta = 0.560, p = 0.003), and small LDL (beta = 0.339, p = 0.043) were the only significant variables in the model that predicted the follow-up RHI.

CONCLUSION

Our results suggest that the application of additional GLP-1a therapy may have atheroprotective and antioxidant effects in MS patients with high MS activity and thus may prospectively mitigate their vascular risk. However, the lipoprotein profile may also play an important role in the atherogenic risk of MS subjects.

Is it time to repurpose geroprotective diabetes medications for prevention of dementia?

See related Editorial by Tang et al. in this issue.

Glucagon-like peptide 1(GLP-1) receptor agonists in the management of the patient with type 2diabetes mellitus and chronic kidney disease: an approach for the nephrologist

Diabetic kidney disease, a common complication in patients with type 2 diabetes mellitus, is associated with a markedly increased morbidity and mortality, especially of cardiovascular origin, and faster progression to end-stage renal disease. To date, reducing cardiovascular and renal risk in this population was based on strict control of cardiovascular risk factors and the renin-angiotensin system blockade. More recently, sodium-glucose cotransporter type 2 inhibitors have demonstrated to offer cardiovascular and renal protection, but the residual risk remains high and their antihyperglycemic efficacy is limited in moderate-severe CKD. Therefore, drugs with a potent antihyperglycemic effect, independent of the glomerular filtration rate, with a low risk of hypoglycemia, that reduce weight in overweight/obese patients and that provide cardiovascular and renal protection, such as GLP-1 receptor agonists, are needed. However, these drugs require subcutaneous administration, which may limit their early use. The recent availability of oral semaglutide may facilitate the early introduction of this family with proven cardiovascular and renal benefits and excellent safety profile. In this review the family is analyzed as well as their cardiovascular and renal effects.

Effect of Liraglutide on Cardiac Function in Individuals With Type 2 Diabetes: A Meta-Analysis

The aim of this study was to determine the effect of liraglutide on cardiac function in individuals with type 2 diabetes. The present meta-analysis aimed to identify studies testing liraglutide in individuals with type 2 diabetes. We included observational and randomized controlled trials comparing liraglutide with placebo or any other drug alone or in combination with other drugs. A comprehensive search was carried out using online databases including PubMed, Google Scholar, and Cochrane Library to find relevant studies from inception to June 30, 2023, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Key terms used to search for relevant studies included "liraglutide," "cardiac function," and "type 2 diabetes," along with their synonyms and Medical Subject Heading (MeSH) terms. The outcomes assessed in the present meta-analysis included diastolic cardiac function and systolic cardiac function. For diastolic cardiac function, we assessed the E to A (E/A) ratio and the E to Ea (E/Ea) ratio. To assess the impact of liraglutide on systolic function, we assessed stroke volume in mL, left ventricular ejection fraction (LVEF) in %, cardiac output in L/min, and cardiac index in L/min/m². A total of seven studies were included, with a pooled sample size of 307 individuals (160 in the liraglutide group and 147 in the control group). The results indicated that liraglutide significantly reduced the E/A ratio (mean difference [MD]: -0.22, 95% CI: -0.38 to -0.06, p-value: 0.008) and E/Ea ratio (MD: -0.76, 95% confidence interval (CI): -1.39 to -0.12, p-value: 0.02, suggesting a potential clinical benefit on ventricular diastolic function. However, there was no significant impact on LVEF (MD: 0.46, 95% CI: -3.13 to 4.05, p-value: 0.80), cardiac output (MD: 0.05, 95% CI: -0.39 to 0.49), cardiac index (MD: 0.07, 95% CI: -0.18 to 0.32), and stroke volume (MD: -5.34, 95% CI: -14.81 to 4.12), indicating that liraglutide did not improve systolic function.

Cardiorenal syndrome and diabetes: an evil pairing

Cardiorenal syndrome (CRS) is a pathology where the heart and kidney are involved, and the deterioration of one of them leads to the malfunction of the other. Diabetes mellitus (DM) carries a higher risk of HF and a worse prognosis. Furthermore, almost half of people with DM will have chronic kidney disease (CKD), which means that DM is the main cause of kidney failure. The triad of cardiorenal syndrome and diabetes is known to be associated with increased risk of hospitalization and mortality. Cardiorenal units, with a multidisciplinary team (cardiologist, nephrologist, nursing), multiple tools for diagnosis, as well as new treatments that help to better control cardio-renal-metabolic patients, offer holistic management of patients with CRS. In recent years, the appearance of drugs such as sodium-glucose cotransporter type 2 inhibitors, have shown cardiovascular benefits, initially in patients with type 2 DM and later in CKD and heart failure with and without DM2, offering a new therapeutic opportunity, especially for cardiorenal patients. In addition, glucagon-like peptide-1 receptor agonists have shown CV benefits in patients with DM and CV disease in addition to a reduced risk of CKD progression.

Tirzepatide: A Promising Drug for Type 2 Diabetes and Beyond

Tirzepatide is a promising drug with dual-acting glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1) receptor activation that has revolutionized the treatment of type 2 diabetes mellitus (T2DM) as an adjunct to diet and exercise. In phase 3 clinical trials (SURPASS 1-5), the dose-dependent efficacy and safety of tirzepatide were assessed by once-weekly subcutaneous injection (5 mg, 10 mg, and 15 mg), as monotherapy or combination therapy, in individuals with T2DM. Tirzepatide has been shown to achieve better glycemic control in terms of glycosylated hemoglobin reduction and improved fasting and postprandial glucose levels as compared to other diabetic medications. Moreover, the studies demonstrate a reduction in body weight (-6.2 to -12.9 kg), and other cardiovascular benefits by altering the lipid profile, reducing blood pressure, and visceral adiposity. Tirzepatide has acceptable side effects and is well tolerated, with a low risk of hypoglycemia. The SURPASS 4 clinical trial has shown positive cardiovascular outcomes in people with T2DM and elevated cardiovascular risk. Additionally, encouraging results from SURMOUNT trials and ongoing SURPASS-CVOT studies will shed more light on cardiovascular safety in the future. In this review, we have summarized the clinical trials and their respective outcomes and highlighted the potential future indications for tirzepatide in the management of obesity, heart failure, and nonalcoholic steatohepatitis.