What Is the Mechanism Driving the Reduction of Cardiovascular Events from Glucagon-like Peptide-1 Receptor Agonists?-A Mini Review

Exendin-4, a glucagon-like peptide-1 receptor agonist, regulates ductus arteriosus by vasodilation and anti-remodeling through the PKA pathway

The mechanisms of ductus arteriosus (DA) closure involve vasoconstriction and vascular remodeling. Previous findings indicate that the glucagon-like peptide-1 receptor agonist (GLP-1RA) exhibits antihypertensive and anti-remodeling effects in the pulmonary circulation. However, its role in the DA remains unknown. This study aimed to investigate whether exendin-4 (Ex-4), a GLP-1RA, can regulate DA patency and elucidate its mechanisms. After confirming the presence of GLP-1R in neonatal rat DA tissue in vivo, the effects of Ex-4 on DA patency in neonatal rats were sequentially examined. Two hours after birth, we observed spontaneous closure of the DA in control rats. In contrast, Ex-4 prevented the closure of DA, accompanied by reduced intimal thickening. Ex-4 attenuated oxygen-induced vasoconstriction in isolated DA rings ex vivo. This effect was diminished in the presence of H89, a PKA inhibitor. In vitro, Ex-4 inhibited platelet-derived growth factor (PDGF)-BB-induced proliferation and migration of DA smooth muscle cells. Additionally, Ex-4 inhibited PDGF-BB-induced reactive oxygen species (ROS) production, calcium mobilization, and signal transduction of MAPK and Akt pathways. Furthermore, Ex-4 preserved the nuclear expression of Nrf2 attenuated by PDGF-BB. Similarly, all these in vitro effects of Ex-4 were blunted by H89. In conclusion, Ex-4 maintains postnatal DA patency through vasodilatation and anti-remodeling via the PKA pathway. The GLP-1R/PKA pathway emerges as a promising target of DA patency in clinical management.

Prevalent Metformin Use in Adults With Diabetes and the Incidence of Long COVID: An EHR-Based Cohort Study From the RECOVER Program

OBJECTIVE

Studies show metformin use before and during SARS-CoV-2 infection reduces severe COVID-19 and postacute sequelae of SARS-CoV-2 (PASC) in adults. Our objective was to describe the incidence of PASC and possible associations with prevalent metformin use in adults with type 2 diabetes mellitus (T2DM).

RESEARCH DESIGN AND METHODS

This is a retrospective cohort analysis using the National COVID Cohort Collaborative (N3C) and Patient-Centered Clinical Research Network (PCORnet) electronic health record (EHR) databases with an active comparator design that examined metformin-exposed individuals versus nonmetformin-exposed individuals who were taking other diabetes medications. T2DM was defined by HbA1c ≥6.5 or T2DM EHR diagnosis code. The outcome was death or PASC within 6 months, defined by EHR code or computable phenotype.

RESULTS

In the N3C, the hazard ratio (HR) for death or PASC with a U09.9 diagnosis code (PASC-U09.0) was 0.79 (95% CI 0.71-0.88; P < 0.001), and for death or N3C computable phenotype PASC (PASC-N3C) was 0.85 (95% CI 0.78-0.92; P < 0.001). In PCORnet, the HR for death or PASC-U09.9 was 0.87 (95% CI 0.66-1.14; P = 0.08), and for death or PCORnet computable phenotype PASC (PASC-PCORnet) was 1.04 (95% CI 0.97-1.11; P = 0.58). Incident PASC by diagnosis code was 1.6% metformin vs. 2.0% comparator in the N3C, and 2.1% metformin vs. 2.5% comparator in PCORnet. By computable phenotype, incidence was 4.8% metformin and 5.2% comparator in the N3C and 24.7% metformin vs. 26.1% comparator in PCORnet.

CONCLUSIONS

Prevalent metformin use is associated with a slightly lower incidence of death or PASC after SARS-CoV-2 infection. PASC incidence by computable phenotype is higher than by EHR code, especially in PCORnet. These data are consistent with other observational analyses showing prevalent metformin is associated with favorable outcomes after SARS-CoV-2 infection in adults with T2DM.

Metabolomic Effects of Liraglutide Therapy on the Plasma Metabolomic Profile of Patients with Obesity

BACKGROUND

Liraglutide, a long-acting glucagon-like peptide-1 receptor agonist (GLP1RA), is a well-established anti-diabetic drug, has also been approved for the treatment of obesity at a dose of 3 mg. There are a limited number of studies in the literature that have looked at changes in metabolite levels before and after liraglutide treatment in patients with obesity. To this end, in the present study we aimed to explore the changes in the plasma metabolomic profile, using liquid chromatography-high resolution mass spectrometry (LC-HRMS) in patients with obesity.

METHODS

A single-center prospective study was undertaken to evaluate the effectiveness of 3 mg liraglutide therapy in twenty-three patients (M/F: 8/15) with obesity, mean BMI 40.81 ± 5.04 kg/m2, and mean age of 36 ± 10.9 years, in two groups: at baseline (pre-treatment) and after 12 weeks of treatment (post-treatment). An untargeted metabolomic profiling was conducted in plasma from the pre-treatment and post-treatment groups using LC-HRMS, along with bioinformatics analysis using ingenuity pathway analysis (IPA).

RESULTS

The metabolomics analysis revealed a significant (FDR p-value ≤ 0.05, FC 1.5) dysregulation of 161 endogenous metabolites (97 upregulated and 64 downregulated) with distinct separation between the two groups. Among the significantly dysregulated metabolites, the majority of them were identified as belonging to the class of oxidized lipids (oxylipins) that includes arachidonic acid and its derivatives, phosphorglycerophosphates, N-acylated amino acids, steroid hormones, and bile acids. The biomarker analysis conducted using MetaboAnalyst showed PGP (a21:0/PG/F1alpha), an oxidized lipid, as the first metabolite among the list of the top 15 biomarkers, followed by cysteine and estrone. The IPA analysis showed that the dysregulated metabolites impacted the pathway related to cell signaling, free radical scavenging, and molecular transport, and were focused around the dysregulation of NF-κB, ERK, MAPK, PKc, VEGF, insulin, and pro-inflammatory cytokine signaling pathways.

CONCLUSIONS

The findings suggest that liraglutide treatment reduces inflammation and modulates lipid metabolism and oxidative stress. Our study contributes to a better understanding of the drug's multifaceted impact on overall metabolism in patients with obesity.

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.

Glucagon-like peptide-1 receptor agonists: new strategies and therapeutic targets to treat atherosclerotic cardiovascular disease

Atherosclerotic cardiovascular disease (ASCVD) is a leading cause of cardiovascular mortality and is increasingly prevalent in our population. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) can safely and effectively lower glucose levels while concurrently managing the full spectrum of ASCVD risk factors and improving patients' long-term prognosis. Several cardiovascular outcome trials (CVOTs) have been carried out to further investigate the cardiovascular benefits of GLP-1RAs. Analyzing data from CVOTs can provide insights into the pathophysiologic mechanisms by which GLP-1RAs are linked to ASCVD and define the use of GLP-1RAs in clinical practice. Here, we discussed various mechanisms hypothesized in previous animal and preclinical human studies, including blockade of the production of adhesion molecules and inflammatory factors, induction of endothelial cells' synthesis of nitric oxide, protection of mitochondrial function and restriction of oxidative stress, suppression of NOD-like receptor thermal protein domain associated protein three inflammasome, reduction of foam cell formation and macrophage inflammation, and amelioration of vascular smooth muscle cell dysfunction, to help explain the cardiovascular benefits of GLP-1RAs in CVOTs. This paper provides an overview of the clinical research, molecular processes, and possible therapeutic applications of GLP-1RAs in ASCVD, while also addressing current limitations in the literature and suggesting future research directions.

GLP-1RAs and cardiovascular disease: is the endothelium a relevant platform?

Hyperglycemia strongly affects endothelial function and activation, which in turn increases the risk of atherosclerotic cardiovascular disease. Among pharmacotherapies aimed at lowering blood glucose levels, glucagon-like peptide 1 receptor agonists (GLP-1RA) represent a class of drugs involved in the improvement of the endothelium damage and the progression of cardiovascular diseases. They show antihypertensive and antiatherosclerotic actions due at least in part to direct favorable actions on the coronary vascular endothelium, such as oxidative stress reduction and nitric oxide increase. However, cumulative peripheral indirect actions could also contribute to the antiatherosclerotic functions of GLP-1/GLP-1R agonists, including metabolism and gut microbiome regulation. Therefore, further research is necessary to clarify the specific role of this drug class in the management of cardiovascular disease and to identify specific cellular targets involved in the protective signal transduction. In the present review, we provide an overview of the effects of GLP-1RAs treatment on cardiovascular disease with particular attention on potential molecular mechanisms involving endothelium function on formation and progression of atherosclerotic plaque.

Influence of chronic kidney disease and its severity on the efficacy of semaglutide in type 2 diabetes patients: a multicenter real-world study

Objectives

Semaglutide is a glucagon-like peptide 1 receptor agonist that improves glycemic control and achieves weight loss in type 2 diabetes (T2D) patients. Subcutaneous (s.c.) semaglutide at 1 mg once weekly (OW) is safe in T2D patients with chronic kidney disease (CKD). Whether or not CKD and its severity influence treatment response remains undetermined.

Method

This is an observational, ambispective, multicenter, nationwide, real-world study designed to compare safety/efficacy of OW s.c. 1 mg semaglutide in T2D patients with or without CKD. The influence of CKD severity was also addressed. Patients were followed up for 12 months. Primary end-points were glycosylated hemoglobin (HbA1c), weight, and renal outcomes. Secondary end-points included insulin resistance, atherogenic and hepatic steatosis indexes, and changes in antihyperglycemic medications.

Results

A total of 296 and 190 T2D patients without or with CKD, respectively, were recruited. Baseline CKD risk was moderate, high, or very high in 82, 53, and 45 patients, respectively. Treatment reduced HbA1c by 0.90%-1.20%. Relevant differences were seen neither between non-CKD and CKD patients nor among CKD subgroups. Notable weight losses were achieved in both non-CKD and CKD patients. The median reduction was higher in the former at 6 months (5.90 kg vs. 4.50 kg, P = 0.008) and at end of study (6.90 kg vs. 5.00 kg, P = 0.087). A trend toward slightly lower weight losses as CKD severity increased was observed. CKD markers improved across all CKD subgroups. Relevant differences were not observed for other variables, either between non-CKD and CKD patients, or among CKD subgroups. Safety concerns were not reported.

Conclusion

The safety/efficacy of OW s.c. semaglutide to improve glycemic control and weight in T2D patients with CKD is not notably lower than that in T2D patients without renal failure. CKD severity barely influences treatment response. OW s.c. semaglutide can be useful to manage T2D patients with CKD in daily clinical practice.

Glucagon-Like Peptide 1 Therapy: From Discovery to Type 2 Diabetes and Beyond

The therapeutic benefits of the incretin hormone, glucagon-like peptide 1 (GLP1), for people with type 2 diabetes and/or obesity, are now firmly established. The evidence-base arising from head-to-head comparative effectiveness studies in people with type 2 diabetes, as well as the recommendations by professional guidelines suggest that GLP1 receptor agonists should replace more traditional treatment options such as sulfonylureas and dipeptidyl-peptidase 4 (DPP4) inhibitors. Furthermore, their benefits in reducing cardiovascular events in people with type 2 diabetes beyond improvements in glycaemic control has led to numerous clinical trials seeking to translate this benefit beyond type 2 diabetes. Following early trial results their therapeutic benefit is currently being tested in other conditions including fatty liver disease, kidney disease, and Alzheimer's disease.

The Effect of Semaglutide on Blood Pressure in Patients without Diabetes: A Systematic Review and Meta-Analysis

(1) Background: Recent advances in the pharmacological treatment of obesity with glucagon-like peptide-1 receptor agonists (GLP-1 RA) highlight the potential to target excess body weight to improve blood pressure (BP). This review aimed to determine the BP reduction in trials of semaglutide for weight reduction in patients without diabetes. (2) Methods: Relevant studies were identified via a search of research databases. Studies were screened to include randomized controlled trials (RCTs) of semaglutide versus a placebo in adults. Pooled and sensitivity analyses were performed, and risk of bias was assessed. (3) Results: six RCTs, with 4744 participants, were included in the final analysis. At baseline, the cohorts in these studies had a mean BP in the normotensive range. The mean difference in systolic BP was -4.83 mmHg (95% CI: -5.65 to -4.02), while that for diastolic BP was -2.45 mmHg (95% CI: -3.65 to -1.24). All included studies were of a high methodological quality. (4) Conclusions: A clinically significant reduction in BP was evident following semaglutide treatment in normotensive populations without diabetes. The effect of semaglutide in those with obesity and hypertension is as yet undetermined. Targeting excess body weight may be a novel therapeutic strategy for these patients.

Efficacy and safety outcomes of dulaglutide by baseline HbA1c: A post hoc analysis of the REWIND trial

AIM

To assess cardiovascular, glycaemic, weight and safety outcomes of long-term treatment with dulaglutide 1.5 mg compared with placebo in patients with a baseline HbA1c of less than 7% versus 7% or higher.

MATERIALS AND METHODS

Intention-to-treat analyses were performed on REWIND participants with a baseline HbA1c measurement, using Cox proportional hazards regression and mixed model for repeated measures. Subgroup analyses with factors for baseline HbA1c categories and their interaction with treatment group, as well as analyses within the HbA1c subgroups, were conducted. Additionally, sensitivity analyses were performed for baseline HbA1c subgroups of 6.5% or less and more than 6.5%.

RESULTS

Of the 9876 eligible participants, 3921 and 5955 had a baseline HbA1c of less than 7% and 7% or higher, respectively. Mean baseline HbA1c was 6.3% and 8.0% and the mean duration of diabetes was 9.0 and 11.6 years in the respective subgroups. The less than 7% subgroup was slightly older and less frequently insulin-treated. There was no evidence of a differential dulaglutide treatment effect on body mass index (BMI) reduction, cardiovascular or safety outcomes of interest between the baseline HbA1c subgroups. Treatment-by-baseline HbA1c group interaction was significant for HbA1c change from baseline (P < .001), with a greater reduction in the subgroup with higher baseline HbA1c values. Sensitivity analyses by baseline HbA1c subgroups of 6.5% or less and more than 6.5% showed similar results.

CONCLUSIONS

The reduced incidence of cardiovascular events, and the reduction in BMI in participants treated with once-weekly dulaglutide, were independent of the baseline HbA1c level. Conversely, participants with a higher baseline HbA1c level had greater reductions in HbA1c. Dulaglutide has a positive benefit-risk profile and can be considered in patients with comparatively well-controlled HbA1c levels seeking optimal metabolic control and cardiovascular benefits.

Current and emerging drugs for the treatment of atherosclerosis: the evidence to date

INTRODUCTION

Atherosclerosis can be considered a chronic inflammatory process that stands out as a dominant cause of cardiovascular disease (CVD). Since blood lipids are the leading risk factor for atherosclerosis development, lowering low-density lipoprotein cholesterol (LDL-C) and other apolipoprotein B-containing lipoproteins reduces the risk of future cardiovascular events. However, there has been significant progress in developing lipid-lowering drugs for aggressive management of dyslipidemia, the rates of CVD events remain unacceptably high, so there is great need to identify novel therapeutic pathways targeting the atherosclerosis process.

AREAS COVERED

We discussed the current guidelines on CVD prevention, the role of novel lipid-lowering drugs, as well as emerging drugs for atherosclerosis, emphasizing the current data on compounds targeting inflammatory and oxidant pathways.

EXPERT OPINION

Although novel lipid-lowering drugs all showed their therapeutic efficacy in LDL-C lowering, data regarding their impact on cardiovascular outcomes is still inconclusive. On the other hand, some of the agents targeting inflammatory pathways, especially colchicine, showed promising results in terms of reducing CVD events. In contrast, those pointed at oxidant pathways failed to do so. Finally, exploring ways of targeting new therapeutic venues, such as adaptive immunity and clonal hematopoiesis, is a goal in the future.

Mitochondrial Dysfunction in Cardiovascular Diseases: Potential Targets for Treatment

Cardiovascular diseases (CVDs) are serious public health issues and are responsible for nearly one-third of global deaths. Mitochondrial dysfunction is accountable for the development of most CVDs. Mitochondria produce adenosine triphosphate through oxidative phosphorylation and inevitably generate reactive oxygen species (ROS). Excessive ROS causes mitochondrial dysfunction and cell death. Mitochondria can protect against these damages via the regulation of mitochondrial homeostasis. In recent years, mitochondria-targeted therapy for CVDs has attracted increasing attention. Various studies have confirmed that clinical drugs (β-blockers, angiotensin-converting enzyme inhibitors/angiotensin receptor-II blockers) against CVDs have mitochondrial protective functions. An increasing number of cardiac mitochondrial targets have shown their cardioprotective effects in experimental and clinical studies. Here, we briefly introduce the mechanisms of mitochondrial dysfunction and summarize the progression of mitochondrial targets against CVDs, which may provide ideas for experimental studies and clinical trials.

Metabolic, structural and biochemical changes in diabetes and the development of heart failure

Diabetes contributes to the development of heart failure through various metabolic, structural and biochemical changes. The presence of diabetes increases the risk for the development of cardiovascular disease (CVD), and since the introduction of cardiovascular outcome trials to test diabetic drugs, the importance of improving our understanding of the mechanisms by which diabetes increases the risk for heart failure has come under the spotlight. In addition to the coronary vasculature changes that predispose individuals with diabetes to coronary artery disease, diabetes can also lead to cardiac dysfunction independent of ischaemic heart disease. The hyperlipidaemic, hyperglycaemic and insulin resistant state of diabetes contributes to a perturbed energy metabolic milieu, whereby the heart increases its reliance on fatty acids and decreases glucose oxidative rates. In addition to changes in cardiac energy metabolism, extracellular matrix remodelling contributes to the development of cardiac fibrosis, and impairments in calcium handling result in cardiac contractile dysfunction. Lipotoxicity and glucotoxicity also contribute to impairments in vascular function, cardiac contractility, calcium signalling, oxidative stress, cardiac efficiency and lipoapoptosis. Lastly, changes in protein acetylation, protein methylation and DNA methylation contribute to a myriad of gene expression and protein activity changes. Altogether, these changes lead to decreased cardiac efficiency, increased vulnerability to an ischaemic insult and increased risk for the development of heart failure. This review explores the above mechanisms and the way in which they contribute to cardiac dysfunction in diabetes.

Old and Novel Therapeutic Approaches in the Management of Hyperglycemia, an Important Risk Factor for Atherosclerosis

Hyperglycemia is considered one of the main risk factors for atherosclerosis, since high glucose levels trigger multiple pathological processes, such as oxidative stress and hyperproduction of pro-inflammatory mediators, leading to endothelial dysfunction. In this context, recently approved drugs, such as glucagon-like-peptide-1 receptor agonists (GLP-1RAs) and sodium-glucose cotransporter-2 inhibitors (SGLT2i), could be considered a powerful tool for to reduce glucose concentration and cardiovascular risk. Interestingly, many patients with type 2 diabetes mellitus (T2DM) and insulin resistance have been found to be deficient in vitamin D. Recent studies pointed out the unfavorable prognostic values of T2DM and vitamin D deficiency in patients with cardiac dysfunction, either when considered individually or together, which shed light on the role of vitamin D in general health status. New evidence suggests that SGLT2i could adversely affect the production of vitamin D, thereby increasing the risk of fractures, which are common in patients with T2DM. Therefore, given the biological effects of vitamin D as an anti-inflammatory mediator and a regulator of endothelial function and calcium equilibrium, these new findings should be taken into consideration as well. The aim of this review is to gather the latest advancements regarding the use of antidiabetic and antiplatelet drugs coupled with vitamin D supplementation to control glucose levels, therefore reducing the risk of coronary artery disease (CAD).