Heterogeneity and Similarities in GLP-1 Receptor Agonist Cardiovascular Outcomes Trials

The benefits of oral glucose-lowering agents: GLP-1 receptor agonists, DPP-4 and SGLT-2 inhibitors on myocardial ischaemia/reperfusion injury

Myocardial infarction (MI) is a life-threatening cardiovascular disease that, on average, results in 8.5 million deaths worldwide each year. Timely revascularization of occluded vessels is a critical method of myocardial salvage. However, reperfusion paradoxically leads to the worsening of myocardial damage known as myocardial ischaemia/reperfusion injury (MI/RI). Therefore, reducing the size of myocardial infarction after reperfusion is critical and remains an important therapeutic goal. The susceptibility of the myocardium to MI/RI may be increased by diabetes. Currently, some traditional antidiabetic agents such as metformin reduce MI/RI by decreasing inflammation, inhibiting oxidative stress, and improving vascular endothelial function. This appears to be a new direction for the treatment of MI/RI. Recent cardiovascular outcome trials have shown that several oral antidiabetic agents, including glucagon-like peptide-1 receptor agonists (GLP-1RAs), dipeptidyl peptidase-4 inhibitors (DPP-4is), and sodium-glucose-linked transporter-2 inhibitors (SGLT-2is), not only have good antidiabetic effects but also have a protective effect on myocardial protection. This article aims to discuss the mechanisms and effects of oral antidiabetic agents, including GLP-1RAs, DPP-4is, and SGLT-2is, on MI/RI to facilitate their clinical application.

The current landscape for diabetes treatment: Preventing diabetes-associated CV risk

Despite the risk of atherosclerosis has progressively declined over the past few decades, subjects with type 2 diabetes mellitus (T2DM) continue to experience substantial excess of atherosclerotic cardiovascular disease (ASCVD)-related events. Therefore, there is urgent need to treat ASCVD disease in T2DM earlier, more intensively, and with greater precision. Many factors concur to increase the risk of atherosclerosis, and multifactorial intervention remains the basis for effective prevention or reduction of atherosclerotic events. The role of anti-hyperglycemic medications in reducing the risk of ASCVD in subjects with T2DM has evolved over the past few years. Multiple cardiovascular outcome trials (CVOTs) with new and emerging glucose-lowering agents, namely SGLT2 inhibitors (SGLT2i) and GLP-1 receptor agonists (GLP1-RA), have demonstrated significant reductions of major cardiovascular events and additional benefits. This robust evidence has changed the landscape for managing people with T2DM. In addition to glycemic and ancillary extra-glycemic properties, SGLT2i and GLP1-RA might exert favorable effects on subclinical and clinical atherosclerosis. Therefore, the objective of this review is to discuss the available evidence supporting anti-atherosclerotic properties of SGLT2i and GLP1-RA, with a quick nod to sotagliflozin and tirzepatide.

Renal effects of GLP-1 receptor agonists and tirzepatide in individuals with type 2 diabetes: seeds of a promising future

PURPOSE

Chronic kidney disease (CKD) is one of the most common complications of type 2 diabetes (T2D), and CKD-related disability and mortality are increasing despite the recent advances in diabetes management. The dual GIP/GLP-1 receptor agonist tirzepatide is among the furthest developed multi-agonists for diabetes care and has so far displayed promising nephroprotective effects. This review aims to summarize the evidence regarding the nephroprotective effects of glucagon-like peptide-1 receptor agonists (GLP-1RA) and tirzepatide and the putative mechanisms underlying the favorable renal profile of tirzepatide.

METHODS

A comprehensive literature search was performed from inception to July 31st 2023 to select research papers addressing the renal effects of GLP-1RA and tirzepatide.

RESULTS

The pathogenesis of CKD in patients with T2D likely involves many contributors besides hyperglycemia, such as hypertension, obesity, insulin resistance and glomerular atherosclerosis, exerting kidney damage through metabolic, fibrotic, inflammatory, and hemodynamic mechanisms. Tirzepatide displayed an unprecedented glucose and body weight lowering potential, presenting also with the ability to increase insulin sensitivity, reduce systolic blood pressure and inflammation and ameliorate dyslipidemia, particularly by reducing triglycerides levels.

CONCLUSION

Tirzepatide is likely to counteract most of the pathogenetic factors contributing to CKD in T2D, potentially representing a step forward in incretin-based therapy towards nephroprotection. Further evidence is needed to understand its role in renal hemodynamics, fibrosis, cell damage and atherosclerosis, as well as to conclusively show reduction of hard renal outcomes.

GLP-1-ra and heart failure-related outcomes in patients with and without history of heart failure: an updated systematic review and meta-analysis

AIMS

Glucagon-like peptide-1 receptor agonists (GLP1-ra) have shown to reduce cardiovascular (CV) events in patients with diabetes, including heart failure (HF) hospitalizations. However, whether such benefit consistently occurs in patients with history of HF remains uncertain. We performed a systematic review and meta-analysis to assess the impact of GLP1-ra on CV outcomes in patients with and without HF history.

METHODS AND RESULTS

All randomized, placebo-controlled trials evaluating GLP1-ra and reporting CV outcomes stratified by HF history were searched in Pubmed from inception to November 12th, 2023. The primary outcome was HF hospitalizations. Secondary outcomes included CV death, the composite of CV death and hospitalizations for HF, and major adverse cardiovascular events (MACE). Hazard ratio (HR) and 95% confidence interval (CIs) were used as effect estimates and calculated with a random-effects model. 68,653 patients (GLP1-ra = 34,301, placebo = 34,352) from 10 trials were included. GLP1-ra reduced HF hospitalization (no HF: HR = 0.79, 95% CI 0.63-0.98; HF: HR = 1.00, 95% CI 0.82-1.24, pinteraction = 0.12), CV death (no HF: HR = 0.81, 95% CI 0.71-0.92; HF: HR = 0.97, 95% CI 0.81-1.15, pinteraction = 0.11), and the composite of HF hospitalizations and CV death (no HF: HR = 0.80, 95% CI 0.72-0.89; HF: HR = 1.00 95% CI 0.88-1.15, pinteraction = 0.010) only in patients without history of HF, despite a significant interaction between HF history and treatment effect was detected only for the latter. MACE were reduced in both subgroups without significant interaction between HF history and treatment effect (no HF: HR = 0.86, 95% CI 0.78-0.96; HF: HR = 0.83, 95% CI 0.72-0.95, pinteraction = 0.69).

CONCLUSION

GLP1-ra do not decrease HF-hospitalization risk, despite a potential benefit in patients without history of HF, but are effective in reducing ischemic events irrespective of the presence of HF. PROSPERO-registered (CRD42022371264).

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.

Anti-inflammatory role of glucagon-like peptide 1 receptor agonists and its clinical implications

Glucagon-like peptide 1 receptor agonists (GLP-1RAs) have emerged as promising therapeutic agents with potent anti-inflammatory properties and diverse clinical implications. This in-depth review article explores the mechanisms behind the anti-inflammatory actions of GLP-1RAs and assesses their prospective applicability in a wide range of disease scenarios. The current review establishes the significance of comprehending the anti-inflammatory role of GLP-1RAs and identifies pertinent research gaps. A concise overview of inflammation and its clinical consequences underscores the critical need for effective anti-inflammatory interventions. Subsequently, the article elucidates the intricate mechanisms through which GLP-1RAs modulate immune cell signaling and regulate the nuclear factor-kappa B (NF-κB) pathway. Detailed discussions encompass their impact on inflammatory responses, cytokine production, and attenuation of oxidative stress. The exposition is substantiated by a collection of pertinent examples and an extensive array of references from both preclinical and clinical investigations. The historical trajectory of GLP-1RA drugs, including exenatide, lixisenatide, liraglutide, and semaglutide, is traced to delineate their development as therapeutic agents. Moreover, the review emphasizes the therapeutic potential of GLP-1RAs in specific disease contexts like type 2 diabetes, a neurodegenerative disorder, and inflammatory bowel disease (IBD), shedding light on their anti-inflammatory effects through rigorous examination of preclinical and clinical studies. The article also provides an outlook on future perspectives for GLP-1RAs, encompassing the domains of diabetes, neurodegenerative diseases, and IBD. In conclusion, GLP-1RAs exhibit substantial anti-inflammatory effects, rendering them promising therapeutic agents with broad clinical implications. They are very useful in a wide variety of diseases because they regulate immunological responses, block NF-κB activation, and decrease production of pro-inflammatory cytokines. Ongoing research endeavors aim to optimize their therapeutic use, delineate patient-specific treatment paradigms, and explore novel therapeutic applications. GLP-1RAs represent a significant breakthrough in anti-inflammatory therapy, offering novel treatment options, and improved patient outcomes.

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.

Is the steady-state concentration, duration of action, or molecular weight of GLP-1RA associated with cardiovascular and renal outcomes in type 2 diabetes?

IMPORTANCE

Disparities were found in the cardiovascular and renal outcomes among different glucagon-like peptide 1 receptor agonist (GLP-1RA) subtypes. However, whether the characteristics of GLP-1RA itself are associated with these disparities remains unclear.

OBJECTIVE

To assess the association between the steady-state concentration, duration of action, or molecular weight of GLP-1RA and the risks of cardiovascular and renal outcomes in patients with type 2 diabetes (T2D).

DATA SOURCES

PubMed, MEDLINE, EMBASE, Cochrane and Clinicaltrial.gov from inception to April 2022.

STUDY SELECTION

Randomized controlled trials (RCTs) investigating GLP-1RAs in patients with T2D were included.

DATA EXTRACTION AND SYNTHESIS

Literature screening and data extraction were performed independently by 2 researchers. The outcomes were computed as odds ratio (OR) and its 95% confidence interval (CI). Subgroup analyses were conducted according to steady-state concentration, duration of action and molecular weight of GLP-1RAs.

MAIN OUTCOMES AND MEASURES

Primary outcomes were major adverse cardiovascular events (MACE), composite renal outcome and all-cause mortality.

RESULTS

In all, 61 RCTs were included. When compared with non-GLP-1RA agents, GLP-1RAs with high steady-state concentration were associated with greater risk reduction in MACE (p for subgroup difference = 0.01) and the composite renal outcome (p for subgroup difference = 0.008) in patients with T2D. Greater risk reductions in MACE between GLP-1RA users versus non-GLP-RA users were observed in long acting stratum when compared with short acting stratum (p for subgroup difference = 0.04) in patients with T2D. The molecular weight of GLP-1RAs was not associated with the risk of cardiovascular and renal outcomes.

CONCLUSIONS AND RELEVANCE

GLP-1RAs with high steady-state concentrations might be associated with greater risk reductions in cardiovascular and renal outcomes in patients with T2D. Long acting GLP-1RAs might outperform short acting ones in reducing the risk of cardiovascular outcomes. These findings provided new insights for guiding the clinical applications of GLP-1RAs in patients with T2D.

The correlations between steady-state concentration, duration of action and molecular weight of GLP-1RAs and their efficacy and gastrointestinal side effects in patients with type 2 diabetes mellitus: a systematic review and meta-analysis

BACKGROUND

To assess the influence of steady-state concentration, duration of action and molecular weight of glucagon-like peptide-1 receptor (GLP-1RA) on efficacy and gastrointestinal (GI) side effects in patients with type 2 diabetes mellitus (T2DM).

METHODS

PubMed, EMBASE, the Cochrane Center Register of Controlled Trials for Studies and Clinicaltrial.gov were searched from inception to April 2022. Randomized controlled trials (RCTs) comparing GLP-1RA versus non-GLP-1RA agents in patients with T2DM were included. Sensitivity analyses on steady-state concentration, duration of action and molecular weight of GLP-1RA were conducted.

RESULTS

113 RCTs were included. Greater HbA1c reduction between GLP-1RA users versus non-GLP-1RA users was observed in the high-steady-state-concentration stratum and long-acting stratum compared with the low-steady-state-concentration stratum (P_{subgroup difference} = 0.0004) and short-acting stratum (P_{subgroup difference}<0.0001). The risk of GI adverse events in GLP-1RA users versus non-GLP-1RA users was decreased in the high-steady-state-concentration stratum, long-acting stratum and heavy-molecular-weight stratum compared with low-steady-state-concentration stratum (P_{subgroup difference}<0.0001), short-acting stratum (P_{subgroup difference} = 0.002) and light-molecular-weight stratum (P_{subgroup difference} = 0.0008).

CONCLUSION

GLP-1RA with high steady-state concentration and long duration of action showed better hypoglycemic effect. GLP-1RA with high steady-state concentration, long duration of action and heavy molecular weight was associated with lower risk of GI adverse events.

Endogenous incretin levels and risk of first incident cancer: a prospective cohort study

Concerns have been raised regarding a potentially increased risk of cancer associated with treatment with glucagon-like peptide-1 (GLP-1) receptor agonists. Here, we explored whether fasting and oral glucose tolerance test post-challenge glucose-dependent insulinotropic peptide (GIP) and GLP-1 levels were associated with incident first cancer. Within the cardiovascular re-examination arm of the population-based Malmö Diet Cancer study (n = 3734), 685 participants with a previous cancer diagnosis were excluded, resulting in 3049 participants (mean age 72.2 ± 5.6 years, 59.5% women), of whom 485 were diagnosed with incident first cancer (median follow-up time 9.9 years). Multivariable Cox-regression and competing risk regression (death as competing risk) were used to explore associations between incretin levels and incident first cancer. Higher levels of fasting GLP-1 (462 incident first cancer cases/2417 controls) showed lower risk of incident first cancer in competing risk regression (sub-hazard ratio 0.90; 95% confidence interval 0.82-0.99; p = 0.022). No association was seen for fasting GIP, post-challenge GIP, or post-challenge GLP-1 and incident first cancer. In this prospective study, none of the fasting and post-challenge levels of GIP and GLP-1 were associated with higher risk of incident first cancer; by contrast, higher levels of fasting GLP-1 were associated with lower risk of incident first cancer.

Revisiting 'intensive' blood glucose control: A causal directed acyclic graph-guided systematic review of randomized controlled trials

AIM

To clarify the importance of HbA1c reduction and antidiabetic drug use in preventing major adverse cardiovascular events (MACE) for patients with type 2 diabetes (T2D).

MATERIALS AND METHODS

We conducted an updated systematic review of contemporary large randomized controlled trials assessing the relative efficacy and safety of antidiabetic drugs with less hypoglycaemia risk in adult T2D patients. Mixed-effects meta-regression was performed to examine the associations of HbA1c reduction with subsequent risk of macrovascular and microvascular events. We evaluated the potential mediating role of HbA1c reduction in the relationship between antidiabetic drugs and MACE.

RESULTS

Eighteen placebo-controlled trials comprising 155 610 participants were included. The effects of treatment differed among antidiabetic drug classes for most adverse outcomes with high heterogeneity (I2 : 63.7%-95.8%). Mean HbA1c reduction was lowest with dipeptidyl peptidase-4 inhibitors (0.30%), followed by sodium-glucose co-transporter-2 inhibitors (0.46%), and was highest with glucagon-like peptide-1 receptor agonists (0.58%) and thiazolidinediones (0.60%). Lower relative risks of MACE were significantly associated with larger reductions in achieved HbA1c (β -0.3182; 95% CI: -0.5366 to -0.0998; P = .0043), even after adjusting for drug classes. When considering HbA1c lowering as a mediator to be controlled, beneficial effects owing to specific antidiabetic treatment for MACE were not observed (χ2  = 1.4494; P = .6940). The proportion mediated by HbA1c reduction was 50.0%-63.5% for these antidiabetic agents.

CONCLUSIONS

The main benefits of antidiabetic agents might result from the reduction in blood sugar levels and are generally independent of drugs used. Risk reduction in MACE was proportional to the magnitude of HbA1c decrease conferred by antidiabetic agents with less hypoglycaemic hazard.

Effects of glucagon-like peptide-1 receptor agonists on cardiovascular and renal outcomes: A meta-analysis and meta-regression analysis

AIM

To evaluate the cardiovascular and renal outcomes of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and the associations between these outcomes and HbA1c or weight reduction.

MATERIALS AND METHODS

We searched PubMed/MEDLINE, EMBASE, and CENTRAL databases for randomized, placebo-controlled trials of GLP-1 RAs reporting major adverse cardiovascular events (MACE; a composite of cardiovascular mortality, stroke, and myocardial infarction) as the primary outcome. We conducted a meta-regression analysis of primary and secondary outcomes with HbA1c or weight reduction following a meta-analysis with a random-effects model for these outcomes.

RESULTS

We extracted data of 60 800 individuals from eight eligible studies (ELIXA, LEADER, SUSTAIN-6, EXSCEL, HARMONY, PIONEER 6, REWIND, and AMPLITUDE-O). GLP-1 RAs reduced MACE (hazard ratio [HR] 0.86; 95% CI: 0.80-0.93; P < .001) and secondary outcomes including the composite renal outcome (0.80; 0.73-0.87; P < .001). In meta-regression analysis, every 1% reduction in HbA1c was associated with 26% and 35% decreases in the logarithm of HR of MACE (P = .044; R²  = 0.65) and the composite renal outcome (P = .040; R²  = 0.85), respectively. On the contrary, weight reduction was not associated with any outcome, including MACE (P = .390).

CONCLUSIONS

The reduction in HbA1c, but not body weight, is associated with cardiovascular and renal outcomes. The magnitude of HbA1c reduction can be a surrogate for the cardiovascular and renal benefits of treatment with GLP-1 RAs.

Cardiovascular and Renal Effectiveness of GLP-1 Receptor Agonists vs. Other Glucose-Lowering Drugs in Type 2 Diabetes: A Systematic Review and Meta-Analysis of Real-World Studies

Cardiovascular outcome trials (CVOT) showed that treatment with glucagon-like peptide-1 receptor agonists (GLP-1RA) is associated with significant cardiovascular benefits. However, CVOT are scarcely representative of everyday clinical practice, and real-world studies could provide clinicians with more relatable evidence. Here, literature was thoroughly searched to retrieve real-world studies investigating the cardiovascular and renal outcomes of GLP-1RA vs. other glucose-lowering drugs and carry out relevant meta-analyses thereof. Most real-world studies were conducted in populations at low cardiovascular and renal risk. Of note, real-world studies investigating cardio-renal outcomes of GLP-1RA suggested that initiation of GLP-1RA was associated with a greater benefit on composite cardiovascular outcomes, MACE (major adverse cardiovascular events), all-cause mortality, myocardial infarction, stroke, cardiovascular death, peripheral artery disease, and heart failure compared to other glucose-lowering drugs with the exception of sodium-glucose transporter-2 inhibitors (SGLT-2i). Initiation of SGLT-2i and GLP-1RA yielded similar effects on composite cardiovascular outcomes, MACE, stroke, and myocardial infarction. Conversely, GLP-1RA were less effective on heart failure prevention compared to SGLT-2i. Finally, the few real-world studies addressing renal outcomes suggested a significant benefit of GLP-1RA on estimated glomerular filtration rate (eGFR) reduction and hard renal outcomes vs. active comparators except SGLT-2i. Further real-world evidence is needed to clarify the role of GLP-1RA in cardio-renal protection among available glucose-lowering drugs.

Use of Lipid-, Blood Pressure-, and Glucose-Lowering Pharmacotherapy in Patients With Type 2 Diabetes and Atherosclerotic Cardiovascular Disease

IMPORTANCE

Based on contemporary estimates in the US, evidence-based therapies for cardiovascular risk reduction are generally underused among patients with type 2 diabetes and atherosclerotic cardiovascular disease (ASCVD).

OBJECTIVE

To determine the use of evidence-based cardiovascular preventive therapies in a broad US population with diabetes and ASCVD.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter cohort study used health system-level aggregated data within the National Patient-Centered Clinical Research Network, including 12 health systems. Participants included patients with diabetes and established ASCVD (ie, coronary artery disease, cerebrovascular disease, and peripheral artery disease) between January 1 and December 31, 2018. Data were analyzed from September 2020 until January 2021.

EXPOSURES

One or more health care encounters in 2018.

MAIN OUTCOMES AND MEASURES

Patient characteristics by prescription of any of the following key evidence-based therapies: high-intensity statin, angiotensin-converting enzyme inhibitor (ACEI) or angiotensin-receptor blocker (ARB) and sodium glucose cotransporter-2 inhibitors (SGLT2I) or glucagon-like peptide-1 receptor agonist (GLP-1RA).

RESULTS

The overall cohort included 324 706 patients, with a mean (SD) age of 68.1 (12.2) years and 144 169 (44.4%) women and 180 537 (55.6%) men. A total of 59 124 patients (18.2% ) were Black, and 41 470 patients (12.8%) were Latinx. Among 205 885 patients with specialized visit data from the prior year, 17 971 patients (8.7%) visited an endocrinologist, 54 330 patients (26.4%) visited a cardiologist, and 154 078 patients (74.8%) visited a primary care physician. Overall, 190 277 patients (58.6%) were prescribed a statin, but only 88 426 patients (26.8%) were prescribed a high-intensity statin; 147 762 patients (45.5%) were prescribed an ACEI or ARB, 12 724 patients (3.9%) were prescribed a GLP-1RA, and 8989 patients (2.8%) were prescribed an SGLT2I. Overall, 14 918 patients (4.6%) were prescribed all 3 classes of therapies, and 138 173 patients (42.6%) were prescribed none. Patients who were prescribed a high-intensity statin were more likely to be men (59.9% [95% CI, 59.6%-60.3%] of patients vs 55.6% [95% CI, 55.4%-55.8%] of patients), have coronary atherosclerotic disease (79.9% [95% CI, 79.7%-80.2%] of patients vs 73.0% [95% CI, 72.8%-73.3%] of patients) and more likely to have seen a cardiologist (40.0% [95% CI, 39.6%-40.4%] of patients vs 26.4% [95% CI, 26.2%-26.6%] of patients).

CONCLUSIONS AND RELEVANCE

In this large cohort of US patients with diabetes and ASCVD, fewer than 1 in 20 patients were prescribed all 3 evidence-based therapies, defined as a high-intensity statin, either an ACEI or ARB, and either an SGLT2I and/or a GLP-1RA. These findings suggest that multifaceted interventions are needed to overcome barriers to the implementation of evidence-based therapies and facilitate their optimal use.

Mini Review: Effect of GLP-1 Receptor Agonists and SGLT-2 Inhibitors on the Growth Hormone/IGF Axis

Accumulating evidence supports the early use of glucagon-like peptide-1 receptor agonists (GLP-1RAs) and sodium glucose transporter-2 inhibitors (SGLT-2is) for the treatment of type 2 diabetes. Indeed, these compounds exert numerous pleiotropic actions that favorably affect metabolism and diabetes comorbidities, showing an additional effect beyond glucose control. Although a substantial amount of knowledge has been generated regarding the mechanism of action of both drug classes, much remains to be understood. Growth hormone (GH) is an important driver for multiple endocrine responses involving changes in glucose and lipid metabolism, and affects several tissues and organs (e.g., bone, heart). It acts directly on several target tissues, including skeletal muscle and bone, but several effects are mediated indirectly by circulating (liver-derived) or locally produced IGF-1. In consideration of the multiple metabolic and cardiovascular effects seen in subjects treated with GLP-1RAs and SGLT-2is (e.g., reduction of hyperglycemia, weight loss, free/fat mass and bone remodeling, anti-atherosclerosis, natriuresis), it is reasonable to speculate that GH and IGF-1 may play a about a relevant role in this context. This narrative mini-review aims to describe the involvement of the GH/IGF-1/IGF-1R axis in either mediating or responding to the effects of each of the two drug classes.

Exposure-Response Analysis of Cardiovascular Outcome Trials With Incretin-Based Therapies

Our study aimed to evaluate the exposure-response relationship between incretin-based medications and the risk of major adverse cardiovascular events (MACE) using cardiovascular outcome trials (CVOTs). Eleven CVOTs with incretin-based medications were included. The median follow-up time, percentage of time exposure, and hazard ratio (HR) of MACE were obtained from each CVOT. The pharmacokinetic parameters of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and dipeptidyl peptidase-4 inhibitor (DPP-4) were obtained from published studies. Regression analysis was performed to assess the relationship between drug exposure and MACE HR. Cutoff values were determined from the ROC curves. The linear regression results indicated that log C_max, log AUC_0-24h, and log AUC_CVOT are negatively correlated with MACE HR (R² = 0.8494, R² = 0.8728, and R² = 0.8372, respectively; all p < 0.0001). The relationship between drug exposure (log C_max, log AUC_0-24h, and log AUC_CVOT) and MACE HR strongly corresponded with the log (inhibitor) vs. response curve (R² = 0.8383, R² = 0.8430, and R² = 0.8229, respectively). The cutoff values in the ROC curves for log C_max, log AUC_0-24h, and log AUC_CVOT, were 2.556, 3.868, and 6.947, respectively (all p = 0.007). A Fisher's exact test revealed that these cutoff values were significantly related to cardiovascular benefits (all p < 0.05). Our study revealed a linear exposure-response relationship between drug exposure and MACE HR. We conclude that the cardiovascular benefits of incretin-based therapies may occur with higher doses of GLP-1 RAs and with increased exposure.

Role of a Dual Glucose-Dependent Insulinotropic Peptide (GIP)/Glucagon-like Peptide-1 Receptor Agonist (Twincretin) in Glycemic Control: From Pathophysiology to Treatment

Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are two gut hormones, defined incretins, responsible for the amplification of insulin secretion after oral glucose intake. Unlike GLP-1, GIP has little acute effect on insulin secretion and no effect on food intake; instead it seems that the GIP may be an obesity-promoting hormone. In patients with type2 diabetes mellitus (T2DM) some studies found a downregulation of GIP receptors on pancreatic β cells caused by hyperglycemic state, but the glucagonotropic effect persisted. Agonists of the receptor for the GLP-1 have proven successful for the treatment of diabetes, since they reduce the risk for cardiovascular and renal events, but the possible application of GIP as therapy for T2DM is discussed. Moreover, the latest evidence showed a synergetic effect when GIP was combined with GLP-1 in monomolecular co-agonists. In fact, compared with the separate infusion of each hormone, the combination increased both insulin response and glucagonostatic response. In accordance with theseconsiderations, a dual GIP/GLP-1receptor agonist, i.e., Tirzepatide, known as a "twincretin" had been developed. In the pre-clinical trials, as well as Phase 1-3 clinical trials, Tirzepatideshowedpotent glucose lowering and weight loss effects within an acceptable safety.

Liraglutide blocks the proliferation, migration and phenotypic switching of Homocysteine (Hcy)-induced vascular smooth muscle cells (VSMCs) by suppressing proprotein convertase subtilisin kexin9 (PCSK9)/ low-density lipoprotein receptor (LDLR)

Liraglutide, a glucagon-like peptide 1 (GLP1) receptor agonist, is known to inhibit the atherosclerosis of apoE mice and suppress the cellular behaviors of VSMCs induced by AngII. This study aimed to explore whether liraglutide can reduce the proliferation, invasion and phenotypic transformation of VSMCs induced by Hcy and the underlying mechanism. Hcy was used to induce the proliferation of VSMCs, and liraglutide was then used to expose the cells for assessing cell proliferation. Afterward, the cell migration and phenotypic switch were evaluated to observe the effects of liraglutide. Meanwhile, the expression of PCSK9 and LDLR was detected. After overexpressing PCSK9, the changes in proliferation, cell migration and phenotypic switch were estimated again. Hcy promoted cell proliferation of VSMCs, whereas liraglutide blocked the proliferation, migration and phenotypic switch of Hcy-induced VSMCs. Furthermore, the expression of PCSK9 was downregulated and LDLR expression was upregulated after liraglutide administration in Hcy-induced VSMCs. After overexpressing PCSK9, the proliferation, migration and phenotypic switch of Hcy-induced VSMCs were enhanced. Liraglutide blocked the proliferation, migration and phenotypic switching of Hcy-induced VSMCs by suppressing PCSK9/LDLR. This finding provided the basis for the future application of liraglutide as an effective drug for therapeutic strategy in targeting AS.

Lower risk of death and cardiovascular events in patients with diabetes initiating glucagon-like peptide-1 receptor agonists or sodium-glucose cotransporter-2 inhibitors: A real-world study in two Italian cohorts

AIM

To examine the efficacy and safety of glucagon-like peptide-1 receptor agonists (GLP-1RAs) and sodium-glucose cotransporter-2 (SGLT2) inhibitors compared with other antihyperglycaemic agents (AHAs) in large and unselected populations of the Lombardy and Apulia regions in Italy.

MATERIALS AND METHODS

An observational cohort study of first-time users of GLP-1RAs, SGLT2 inhibitors or other AHAs was conducted from 2010 to 2018. Death and cardiovascular (CV) events were evaluated using conditional Cox models in propensity-score-matched populations. Adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated for each region and in a meta-analysis for pooled risks.

RESULTS

After propensity-score matching, the Lombardy cohort included 18 716 and 11 683 patients and the Apulia cohort 9772 and 6046 patients for the GLP-1RA and SGLT2 inhibitor groups, respectively. Use of GLP-1RAs was associated with lower rates of death (HR 0.61, CI 0.56-0.65, Lombardy; HR 0.63, CI 0.55-0.71, Apulia), cerebrovascular disease and ischaemic stroke (HR 0.70, CI 0.63-0.79; HR 0.72, CI 0.60-0.87, Lombardy), peripheral vascular disease (HR 0.72, CI 0.64-0.82, Lombardy; HR 0.80, CI 0.67-0.98, Apulia), and lower limb complications (HR 0.67, CI 0.56-0.81, Lombardy; HR 0.69, CI 0.51-0.93, Apulia). Compared with other AHAs, SGLT2 inhibitor use decreased the risk of death (HR 0.47, CI 0.40-0.54, Lombardy; HR 0.43, CI 0.32-0.57, Apulia), cerebrovascular disease (HR 0.75, CI 0.61-0.91, Lombardy; HR 0.72, CI 0.54-0.96, Apulia), and heart failure (HR 0.56, CI 0.46-0.70, Lombardy; HR 0.57, CI 0.42-0.77, Apulia). In the pooled cohorts, a reduction in heart failure was also observed with GLP-1RAs (HR 0.89, 95% CI 0.82-0.97). Serious adverse events were quite low in frequency.

CONCLUSION

Our findings from real-world practice confirm the favourable effect of GLP-1RAs and SGLT2 inhibitors on death and CV outcomes across both regions consistently. Thus, these drug classes should be preferentially considered in a broad type 2 diabetes population beyond those with CV disease.

GLP-1 receptor agonists (GLP-1RAs): cardiovascular actions and therapeutic potential

Type 2 diabetes mellitus (T2DM) is closely associated with cardiovascular diseases (CVD), including atherosclerosis, hypertension and heart failure. Some anti-diabetic medications are linked with an increased risk of weight gain or hypoglycemia which may reduce the efficacy of the intended anti-hyperglycemic effects of these therapies. The recently developed receptor agonists for glucagon-like peptide-1 (GLP-1RAs), stimulate insulin secretion and reduce glycated hemoglobin levels without having side effects such as weight gain and hypoglycemia. In addition, GLP1-RAs demonstrate numerous cardiovascular protective effects in subjects with or without diabetes. There have been several cardiovascular outcomes trials (CVOTs) involving GLP-1RAs, which have supported the overall cardiovascular benefits of these drugs. GLP1-RAs lower plasma lipid levels and lower blood pressure (BP), both of which contribute to a reduction of atherosclerosis and reduced CVD. GLP-1R is expressed in multiple cardiovascular cell types such as monocyte/macrophages, smooth muscle cells, endothelial cells, and cardiomyocytes. Recent studies have indicated that the protective properties against endothelial dysfunction, anti-inflammatory effects on macrophages and the anti-proliferative action on smooth muscle cells may contribute to atheroprotection through GLP-1R signaling. In the present review, we describe the cardiovascular effects and underlying molecular mechanisms of action of GLP-1RAs in CVOTs, animal models and cultured cells, and address how these findings have transformed our understanding of the pharmacotherapy of T2DM and the prevention of CVD.

GLP-1 receptor agonists in the treatment of type 2 diabetes - state-of-the-art

BACKGROUND

GLP-1 receptor agonists (GLP-1 RAs) with exenatide b.i.d. first approved to treat type 2 diabetes in 2005 have been further developed to yield effective compounds/preparations that have overcome the original problem of rapid elimination (short half-life), initially necessitating short intervals between injections (twice daily for exenatide b.i.d.).

SCOPE OF REVIEW

To summarize current knowledge about GLP-1 receptor agonist.

MAJOR CONCLUSIONS

At present, GLP-1 RAs are injected twice daily (exenatide b.i.d.), once daily (lixisenatide and liraglutide), or once weekly (exenatide once weekly, dulaglutide, albiglutide, and semaglutide). A daily oral preparation of semaglutide, which has demonstrated clinical effectiveness close to the once-weekly subcutaneous preparation, was recently approved. All GLP-1 RAs share common mechanisms of action: augmentation of hyperglycemia-induced insulin secretion, suppression of glucagon secretion at hyper- or euglycemia, deceleration of gastric emptying preventing large post-meal glycemic increments, and a reduction in calorie intake and body weight. Short-acting agents (exenatide b.i.d., lixisenatide) have reduced effectiveness on overnight and fasting plasma glucose, but maintain their effect on gastric emptying during long-term treatment. Long-acting GLP-1 RAs (liraglutide, once-weekly exenatide, dulaglutide, albiglutide, and semaglutide) have more profound effects on overnight and fasting plasma glucose and HbA1c, both on a background of oral glucose-lowering agents and in combination with basal insulin. Effects on gastric emptying decrease over time (tachyphylaxis). Given a similar, if not superior, effectiveness for HbA1c reduction with additional weight reduction and no intrinsic risk of hypoglycemic episodes, GLP-1RAs are recommended as the preferred first injectable glucose-lowering therapy for type 2 diabetes, even before insulin treatment. However, GLP-1 RAs can be combined with (basal) insulin in either free- or fixed-dose preparations. More recently developed agents, in particular semaglutide, are characterized by greater efficacy with respect to lowering plasma glucose as well as body weight. Since 2016, several cardiovascular (CV) outcome studies have shown that GLP-1 RAs can effectively prevent CV events such as acute myocardial infarction or stroke and associated mortality. Therefore, guidelines particularly recommend treatment with GLP-1 RAs in patients with pre-existing atherosclerotic vascular disease (for example, previous CV events). The evidence of similar effects in lower-risk subjects is not quite as strong. Since sodium/glucose cotransporter-2 (SGLT-2) inhibitor treatment reduces CV events as well (with the effect mainly driven by a reduction in heart failure complications), the individual risk of ischemic or heart failure complications should guide the choice of treatment. GLP-1 RAs may also help prevent renal complications of type 2 diabetes. Other active research areas in the field of GLP-1 RAs are the definition of subgroups within the type 2 diabetes population who particularly benefit from treatment with GLP-1 RAs. These include pharmacogenomic approaches and the characterization of non-responders. Novel indications for GLP-1 RAs outside type 2 diabetes, such as type 1 diabetes, neurodegenerative diseases, and psoriasis, are being explored. Thus, within 15 years of their initial introduction, GLP-1 RAs have become a well-established class of glucose-lowering agents that has the potential for further development and growing impact for treating type 2 diabetes and potentially other diseases.

Cardiovascular Outcomes in Trials of New Antidiabetic Drug Classes

Type 2 diabetes is among the most prevalent chronic diseases worldwide and the prevention of associated cardiovascular complications is an important treatment goal. Sodium–glucose co-transporter 2 (SGLT2) inhibitors, glucagon-like peptide 1 (GLP-1) receptor agonists and dipeptidyl peptidase-4 (DPP-4) inhibitors are second-line options after metformin, while cardiovascular outcome trials have been conducted to establish the cardiovascular safety of these antidiabetic drug classes. SGLT2 inhibitors have been shown to have the best overall mortality, renal and cardiovascular outcomes. Reduction in hospitalisation for heart failure is particularly consistent. GLP-1 receptor agonists have also showed some benefits, especially in stroke prevention. DPP-4 inhibitors showed neutral effects on cardiovascular outcomes, but may increase the incidence of heart failure. Favourable outcomes observed in trials of SGLT2 inhibitors mean that these should be the preferred second-line option. DPP-4 inhibitors are useful for patients with diabetes at low cardiovascular risk.

Irisin and Incretin Hormones: Similarities, Differences, and Implications in Type 2 Diabetes and Obesity

Incretins are gut hormones that potentiate glucose-stimulated insulin secretion (GSIS) after meals. Glucagon-like peptide-1 (GLP-1) is the most investigated incretin hormone, synthesized mainly by L cells in the lower gut tract. GLP-1 promotes β-cell function and survival and exerts beneficial effects in different organs and tissues. Irisin, a myokine released in response to a high-fat diet and exercise, enhances GSIS. Similar to GLP-1, irisin augments insulin biosynthesis and promotes accrual of β-cell functional mass. In addition, irisin and GLP-1 share comparable pleiotropic effects and activate similar intracellular pathways. The insulinotropic and extra-pancreatic effects of GLP-1 are reduced in type 2 diabetes (T2D) patients but preserved at pharmacological doses. GLP-1 receptor agonists (GLP-1RAs) are therefore among the most widely used antidiabetes drugs, also considered for their cardiovascular benefits and ability to promote weight loss. Irisin levels are lower in T2D patients, and in diabetic and/or obese animal models irisin administration improves glycemic control and promotes weight loss. Interestingly, recent evidence suggests that both GLP-1 and irisin are also synthesized within the pancreatic islets, in α- and β-cells, respectively. This review aims to describe the similarities between GLP-1 and irisin and to propose a new potential axis-involving the gut, muscle, and endocrine pancreas that controls energy homeostasis.

Efficacy and safety of polyethylene glycol loxenatide monotherapy in type 2 diabetes patients: A multicentre, randomized, double-blind, placebo-controlled phase 3a clinical trial

AIM

To evaluate the efficacy and safety of polyethylene glycol loxenatide (PEX168) monotherapy in type 2 diabetes (T2D) patients in China.

MATERIALS AND METHODS

In a multicentred, randomized, double-blinded, placebo-controlled phase 3a clinical trial, 361 patients with inadequate glycaemic control (HbA1c 7.0%-10.5%, fasting plasma glucose <13.9 mmol/L) were randomized (1:1:1) for weekly subcutaneous injections: placebo, PEX168/100 μg or PEX168/200 μg. The 24-week treatment was followed by a 28-week extension, during which placebo-treated patients were randomly assigned to PEX168/100 μg or PEX168/200 μg. The primary efficacy endpoint was the HbA1c change from baseline to week 24.

RESULTS

The three groups had similar demographics and baseline characteristics. The HbA1c least-square mean (95% CI) change from baseline to week 24 was greater for PEX168/100 μg (-1.02% [-1.21%, -0.83%]) and PEX168/200 μg (-1.34% [-1.54%, -1.15%]) than for placebo (-0.17% [-0.36%, 0.02%]); (superiority: P < .0001). The proportions of patients with less than 7% HbA1c in the placebo, PEX168/100 μg and PEX168/200 μg groups were 15.7%, 34.7% and 46.6%, respectively. Common gastrointestinal adverse events (AEs) were nausea (5.6%, 10.0% and 0% for PEX168/100 μg, PEX168/200 μg and placebo, respectively) and vomiting (2.4%, 8.3% and 0% for PEX168/100 μg, PEX168/200 μg and placebo, respectively). Six (1.6%) patients (PEX168/100 μg: N = 2 [1.6%], PEX168/200 μg: N = 3 [2.5%] and placebo: N = 1 [0.8%]) discontinued treatment because of AEs. Four (1.2%) patients (PEX168/100 μg: N = 3 [2.5%] and PEX168/200 μg: N = 1 [0.9%]) developed PEX168 antidrug antibodies.

CONCLUSION

PEX168 monotherapy significantly improved glycaemic control in T2D patients with a safety profile resembling that of other glucagon-like peptide-1 receptor agonists.

Clinical Perspectives on the Use of Subcutaneous and Oral Formulations of Semaglutide

Early and effective glycemic control can prevent or delay the complications associated with type 2 diabetes (T2D). The benefits of glucagon-like peptide-1 receptor agonists (GLP-1RAs) are becoming increasingly recognized and they now feature prominently in international T2D treatment recommendations and guidelines across the disease continuum. However, despite providing effective glycemic control, weight loss, and a low risk of hypoglycemia, GLP-1RAs are currently underutilized in clinical practice. The long-acting GLP-1RA, semaglutide, is available for once-weekly injection and in a new once-daily oral formulation. Semaglutide is an advantageous choice for the treatment of T2D since it has greater efficacy in reducing glycated hemoglobin and body weight compared with other GLP-1RAs, has demonstrated benefits in reducing major adverse cardiovascular events, and has a favorable profile in special populations (e.g., patients with hepatic impairment or renal impairment). The oral formulation represents a useful option to help improve acceptance and adherence compared with injectable formulations for patients with a preference for oral therapy, and may lead to earlier and broader use of GLP-1RAs in the T2D treatment trajectory. Oral semaglutide should be taken on an empty stomach, which may influence the choice of formulation. As with most GLP-1RAs, initial dose escalation of semaglutide is required for both formulations to mitigate gastrointestinal adverse events. There are also specific dose instructions to follow with oral semaglutide to ensure sufficient gastric absorption. The evidence base surrounding the clinical use of semaglutide is being further expanded with trials investigating effects on diabetic retinopathy, cardiovascular outcomes, and on the common T2D comorbidities of obesity, chronic kidney disease, and non-alcoholic steatohepatitis. These will provide further information about whether the benefits of semaglutide extend to these other indications.

Glucose-Dependent Insulinotropic Peptide in the High-Normal Range Is Associated With Increased Carotid Intima-Media Thickness

OBJECTIVE

While existing evidence supports beneficial cardiovascular effects of glucagon-like peptide 1 (GLP-1), emerging studies suggest that glucose-dependent insulinotropic peptide (GIP) and/or signaling via the GIP receptor may have untoward cardiovascular effects. Indeed, recent studies show that fasting physiological GIP levels are associated with total mortality and cardiovascular mortality, and it was suggested that GIP plays a role in pathogenesis of coronary artery disease. We investigated the associations between fasting and postchallenge GIP and GLP-1 concentrations and subclinical atherosclerosis as measured by mean intima-media thickness in the common carotid artery (IMT_meanCCA) and maximal intima-media thickness in the carotid bifurcation (IMT_maxBulb).

RESEARCH DESIGN AND METHODS

Participants at reexamination within the Malmö Diet and Cancer-Cardiovascular Cohort study (n = 3,734, mean age 72.5 years, 59.3% women, 10.8% subjects with diabetes, fasting GIP available for 3,342 subjects, fasting GLP-1 available for 3,299 subjects) underwent oral glucose tolerance testing and carotid ultrasound.

RESULTS

In linear regression analyses, each 1-SD increment of fasting GIP was associated with increased (per mm) IMT_meanCCA (β = 0.010, P = 0.010) and IMT_maxBulb (β = 0.014; P = 0.040) in models adjusted for known risk factors and glucose metabolism. In contrast, each 1-SD increment of fasting GLP-1 was associated with decreased IMT_maxBulb (per mm, β = -0.016, P = 0.014). These associations remained significant when subjects with diabetes were excluded from analyses.

CONCLUSIONS

In a Swedish elderly population, physiologically elevated levels of fasting GIP are associated with increased IMT_meanCCA, while GLP-1 is associated with decreased IMT_maxBulb, further emphasizing diverging cardiovascular effects of these two incretin hormones.

Cardiovascular outcomes trials with glucagon-like peptide-1 receptor agonists: A comparison of study designs, populations and results

Despite treatment advances leading to improved outcomes over the past 2 decades, cardiovascular (CV) disease (CVD) remains the leading cause of morbidity and mortality in people with diabetes. People with type 2 diabetes (T2D) have a 2- to 4-fold increased risk of CVD and CV death. Individuals with T2D have not seen the same improvements in CV morbidity and mortality as those without T2D. Given this, it is important to understand the CV impact of drugs used to treat T2D. In patients with T2D, glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have shown a reduction in HbA1c and body weight regardless of their differences in chemical structure and pharmacokinetic variables. Glycaemic efficacy, accompanied by the potential for weight reduction and a low risk of hypoglycaemia, has moved GLP-1 RAs to the first treatment of choice following metformin monotherapy in the latest American Diabetes Association treatment guidelines. Additionally, all GLP-1 RAs have shown CV safety and several have proven CV benefit. GLP-1 RAs have been evaluated in cardiovascular outcomes trials (CVOTs) of varying sizes, designs and patient populations with differing reported effects on CV outcomes. The purpose of this article is to review the completed GLP-1 RA CVOTs with special attention to how their design, size, patient populations and conduct may influence the interpretation of results.

Structural basis for GLP-1 receptor activation by LY3502970, an orally active nonpeptide agonist

Glucagon-like peptide-1 receptor agonists have become established as a leading class of diabetes medications. However, these peptide-based drugs are administered by subcutaneous injection or, in one case, by a complex oral dosing regimen. We now report the discovery of LY3502970, a potent and selective small-molecule GLP-1R agonist. LY3502970 exhibits preclinical pharmacology equivalent to a marketed injectable GLP-1R agonist and possesses pharmacokinetic properties compatible with oral dosing in humans. Cryoelectron microscopy (cryo-EM) studies reveal an ECD-driven receptor binding mode for LY3502970 that provides a favorable pharmacological profile.

Glucagon-like peptide-1 receptor (GLP-1R) agonists are efficacious antidiabetic medications that work by enhancing glucose-dependent insulin secretion and improving energy balance. Currently approved GLP-1R agonists are peptide based, and it has proven difficult to obtain small-molecule activators possessing optimal pharmaceutical properties. We report the discovery and mechanism of action of LY3502970 (OWL833), a nonpeptide GLP-1R agonist. LY3502970 is a partial agonist, biased toward G protein activation over β-arrestin recruitment at the GLP-1R. The molecule is highly potent and selective against other class B G protein–coupled receptors (GPCRs) with a pharmacokinetic profile favorable for oral administration. A high-resolution structure of LY3502970 in complex with active-state GLP-1R revealed a unique binding pocket in the upper helical bundle where the compound is bound by the extracellular domain (ECD), extracellular loop 2, and transmembrane helices 1, 2, 3, and 7. This mechanism creates a distinct receptor conformation that may explain the partial agonism and biased signaling of the compound. Further, interaction between LY3502970 and the primate-specific Trp33 of the ECD informs species selective activity for the molecule. In efficacy studies, oral administration of LY3502970 resulted in glucose lowering in humanized GLP-1R transgenic mice and insulinotropic and hypophagic effects in nonhuman primates, demonstrating an effect size in both models comparable to injectable exenatide. Together, this work determined the molecular basis for the activity of an oral agent being developed for the treatment of type 2 diabetes mellitus, offering insights into the activation of class B GPCRs by nonpeptide ligands.

Cardiovascular effectiveness of human-based vs. exendin-based glucagon like peptide-1 receptor agonists: a retrospective study in patients with type 2 diabetes

AIMS

Glucagon like peptide-1 (GLP-1) receptor agonists (GLP-1RA) are effective to control type 2 diabetes (T2Ds) and can protect from adverse cardiovascular outcomes. GLP-1RA are based on the human GLP-1 or the exendin-4 sequence. We compared cardiovascular outcomes of patients with T2D who received human-based or exendin-based GLP-1RA in routine clinical practice.

METHODS AND RESULTS

We performed a retrospective study on the administrative database of T2D patients from the Veneto Region (North-East Italy). We identified patients who initiated a human-based or exendin-based GLP-1RA from 2011 to 2018. The primary outcome was occurrence of major adverse cardiovascular events (MACE). Secondary outcomes were individual MACE components, revascularization, hospitalization for heart failure, or for cardiovascular causes. From 330 193 patients with diabetes, 6620 were new users of GLP-1RA. After propensity score matching, we analysed 1098 patients in each group, who were on average 61 years old, 59.5% males, 13% with established cardiovascular disease, had an estimated diabetes duration of 8.4 years, and a baseline HbA1c of 7.9%. During a median follow-up of 18 months, patients treated with human-based GLP-1RA as compared to those treated with exendin-based GLP-1RA, showed lower rates of MACE [hazard ratio 0.61; 95% confidence interval (CI) 0.39-0.95], myocardial infarction (0.51; 95% CI 0.28-0.94), and hospitalization for cardiovascular causes (0.66; 95% CI 0.47-0.92).

CONCLUSION

We observed better cardiovascular outcomes among patients treated with human-based vs. exendin-based GLP-1RA under routine care. In the absence of comparative trials and in view of the limitations of retrospective studies, this finding provides a moderate level of evidence to guide clinical decision.

Cardiovascular outcomes trials with incretin-based medications: a critical review of data available on GLP-1 receptor agonists and DPP-4 inhibitors

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) and dipeptidyl peptidase-4 (DPP-4) inhibitors are so called "incretin-based therapies" (IBTs) that represent innovative therapeutic approaches and are commonly used in clinical practice for the treatment of type 2 diabetes mellitus (T2DM). The cardiovascular outcome trials (CVOTs) have provided useful information that has helped to shape changes in clinical practice guidelines for the management of T2DM. At the same time, the mechanisms that may explain the nonglycemic and cardiovascular (CV) benefits of these medications are still being explored. A summary of the main findings from CVOTs performed to-date with particular emphasis on various outcomes and inconsistencies observed in the trials is provided. Overall, available data is favourable to the early deployment of GLP-1RAs in clinical practice, fully in line with recommendations from international scientific guidelines, and based on their effects on glucose metabolism parameters, body weight reduction and CV outcomes. Evidence further suggest that the CV benefits of GLP-1RAs may not be a class effect, with GLP-1 analogues having a greater benefit rather than exendin-based agents.

2020 Consensus of Taiwan Society of Cardiology on the pharmacological management of patients with type 2 diabetes and cardiovascular diseases

The global incidence and prevalence of type 2 diabetes have been escalating in recent decades. The total diabetic population is expected to increase from 415 million in 2015 to 642 million by 2040. Patients with type 2 diabetes have an increased risk of atherosclerotic cardiovascular disease (ASCVD). About two-thirds of patients with type 2 diabetes died of ASCVD. The association between hyperglycemia and elevated cardiovascular (CV) risk has been demonstrated in multiple cohort studies. However, clinical trials of intensive glucose reduction by conventional antidiabetic agents did not significantly reduce macrovascular outcomes.In December 2008, U.S. Food and Drug Administration issued a mandate that every new antidiabetic agent requires rigorous assessments of its CV safety. Thereafter, more than 200,000 patients have been enrolled in a number of randomized controlled trials (RCTs). These trials were initially designed to prove noninferiority. It turned out that some of these trials demonstrated superiority of some new antidiabetic agents versus placebo in reducing CV endpoints, including macrovascular events, renal events, and heart failure. These results are important in clinical practice and also provide an opportunity for academic society to formulate treatment guidelines or consensus to provide specific recommendations for glucose control in various CV diseases.In 2018, the Taiwan Society of Cardiology (TSOC) and the Diabetes Association of Republic of China (DAROC) published the first joint consensus on the "Pharmacological Management of Patients with Type 2 Diabetes and Cardiovascular Diseases." In 2020, TSOC appointed a new consensus group to revise the previous version. The updated 2020 consensus was comprised of 5 major parts: (1) treatment of diabetes in patients with multiple risk factors, (2) treatment of diabetes in patients with coronary heart disease, (3) treatment of diabetes in patients with stage 3 chronic kidney disease, (4) treatment of diabetes in patients with a history of stroke, and (5) treatment of diabetes in patients with heart failure. The members of the consensus group thoroughly reviewed all the evidence, mainly RCTs, and also included meta-analyses and real-world evidence. The treatment targets of HbA1c were finalized. The antidiabetic agents were ranked according to their clinical evidence. The consensus is not mandatory. The final decision may need to be individualized and based on clinicians' discretion.

How May GIP Enhance the Therapeutic Efficacy of GLP-1?

Glucagon-like peptide-1 (GLP-1) receptor agonists improve glucose homeostasis, reduce bodyweight, and over time benefit cardiovascular health in type 2 diabetes mellitus (T2DM). However, dose-related gastrointestinal effects limit efficacy, and therefore agents possessing GLP-1 pharmacology that can also target alternative pathways may expand the therapeutic index. One approach is to engineer GLP-1 activity into the sequence of glucose-dependent insulinotropic polypeptide (GIP). Although the therapeutic implications of the lipogenic actions of GIP are debated, its ability to improve lipid and glucose metabolism is especially evident when paired with the anorexigenic mechanism of GLP-1. We review the complexity of GIP in regulating adipose tissue function and energy balance in the context of recent findings in T2DM showing that dual GIP/GLP-1 receptor agonist therapy produces profound weight loss, glycemic control, and lipid lowering.

Use of incretin-based medications: what do current international recommendations suggest with respect to GLP-1 receptor agonists and DPP-4 inhibitors?

In recent years guidelines for the treatment of type 2 diabetes (T2DM) have evolved substantially. Initially limited to a few glucose lowering agents, early guidelines predicated strict glycemic control as a main goal in the attempt to reduce the risk of long-term diabetic complications. Nowadays, guidelines are not limited to such a goal but include cardiovascular (and renal) protection. This rapid evolution was made possible by the introduction of new glucose lowering agents, which have been extensively tested in randomized clinical studies including large cardiovascular outcome trials (CVOTs). In this review we will specifically consider the use of incretin-based medications in T2DM as recommended in the recent ADA/EASD consensus, and other international guidelines, with special consideration of their glucose-lowering efficacy, their cardiovascular (and renal) benefit, their effect on body weight and risk of hypoglycemia, as well as the economic implications for their use.

Trend 2010-2018 in the clinical use of GLP-1 receptor agonists for the treatment of type 2 diabetes in routine clinical practice: an observational study from Northeast Italy

AIMS

Several GLP-1 receptor agonists (GLP-1RA) have become available for the treatment of type 2 diabetes (T2D), and evidence on their beneficial effects has evolved. We evaluated how the clinical phenotype of patients initiating GLP-1RA changed from 2010 to 2018.

METHODS

This was a retrospective study conducted at six diabetes outpatient clinics in Northeast Italy. We collected data of T2D patients who initiated new GLP-1RA between 2010 and 2018. We recorded baseline characteristics, including demographics, anthropometrics, cardiovascular risk factors, glucose control, lipid profile, liver enzymes, renal function and concomitant medications. We recorded updated HbA1c and body weight at follow-up.

RESULTS

There were 83,116 T2D patients from a general population of ~ 1,380,000 inhabitants. Among 6167 cases of GLP-1RA initiation, 5408 were analyzed after excluding intra-class switchers. Prescription of GLP-1RA increased exponentially, and the change in the type of GLP-1RA reflected waves of their entering the market. From 2010 to 2018, there were significant increases in baseline age, diabetes duration and prevalence of male sex, of cardiovascular disease and of insulin users. Blood pressure and cholesterol levels decreased concomitantly with increasing use of medications for the control of cardiovascular risk. Baseline average HbA1c (8.3% [67 mmol/mol]) and BMI (34 kg/m²) and their improvement after GLP-1RA initiation did not change over time.

CONCLUSIONS

Despite the early positioning of GLP-1RA in T2D treatment algorithms, GLP-1RA have been prescribed in patients with progressively more advanced disease stage and especially in the presence of cardiovascular disease. Optimization of GLP-1RA use in routine clinical practice is still needed.

Differential indication for SGLT-2 inhibitors versus GLP-1 receptor agonists in patients with established atherosclerotic heart disease or at risk for congestive heart failure

SGLT-2 inhibitors and most GLP-1 receptor agonists demonstrated cardiovascular superiority and reduction of cardiovascular and overall mortality. These results stand as a turning point in the management of diabetes, shifting the focus from controlling glucose levels to mastering the extra-glycemic effects of these new drugs. This narrative review will discuss recent CVOT with focus on SGLT-2 inhibitors and GLP-1 receptor agonists to distinguish relevant patients' characteristics as potential predictors for therapeutic efficacy. It will also examine their efficacy and safety, the differences in their cardiovascular and renal benefits, aiming to convey clinical suggestions for everyday practice.

Semaglutide (SUSTAIN and PIONEER) reduces cardiovascular events in type 2 diabetes across varying cardiovascular risk

AIM

To investigate the effects of semaglutide versus comparators on major adverse cardiovascular events (MACE: cardiovascular [CV] death, nonfatal myocardial infarction [MI] and nonfatal stroke) and hospitalization for heart failure (HF) in the SUSTAIN (subcutaneous semaglutide) and PIONEER (oral semaglutide) trials across subgroups of varying CV risk.

METHODS

Post hoc analyses of individual patient-level data combined from SUSTAIN 6 and PIONEER 6 were performed to assess MACE and HF. MACE were analysed in subjects with and without: established CV disease and/or chronic kidney disease; prior MI or stroke; and prior HF. MACE in the SUSTAIN and PIONEER glycaemic efficacy trials were also assessed.

RESULTS

In SUSTAIN 6 and PIONEER 6 combined, the hazard ratio (HR) for effect of semaglutide versus placebo on overall MACE was 0.76 (95% CI 0.62, 0.92), which was mainly driven by the effect on nonfatal stroke (HR 0.65 [95% CI 0.43, 0.97]). The HR for hospitalization for HF was 1.03 (95% CI 0.75, 1.40). The HRs for MACE were <1.0 in all subgroups, except for those with prior HF (HR 1.06 [95% CI 0.72, 1.57]); P-values for interaction of subgroup on treatment effect were >0.05, except for HF (0.046). In the combined glycaemic efficacy trials, the HR for effect of semaglutide versus comparators on MACE was 0.85 (95% CI 0.55, 1.33).

CONCLUSIONS

In SUSTAIN and PIONEER combined, glucagon-like peptide-1 analogue semaglutide showed consistent effects on MACE versus comparators across varying CV risk. No effect of semaglutide on MACE was observed in subjects with prior HF.

Incretin therapy for diabetes mellitus type 2

PURPOSE OF REVIEW

Among the gastrointestinal hormones, the incretins: glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 have attracted interest because of their importance for the development and therapy of type 2 diabetes and obesity. New agonists and formulations of particularly the GLP-1 receptor have been developed recently showing great therapeutic efficacy for both diseases.

RECENT FINDINGS

The status of the currently available GLP-1 receptor agonists (GLP-1RAs) is described, and their strengths and weaknesses analyzed. Their ability to also reduce cardiovascular and renal risk is described and analysed. The most recent development of orally available agonists and of very potent monomolecular co-agonists for both the GLP-1 and GIP receptor is also discussed.

SUMMARY

The GLP-1RAs are currently the most efficacious agents for weight loss, and show potential for further efficacy in combination with other food-intake-regulating peptides. Because of their glycemic efficacy and cardiorenal protection, the GLP-1 RAs will be prominent elements in future diabetes therapy.