Risk of stroke and retinopathy during GLP-1 receptor agonist cardiovascular outcome trials: An eight RCTs meta-analysis

Cardiovascular and renal outcomes of glucagon-like peptide 1 receptor agonists among patients with and without type 2 diabetes mellitus: A meta-analysis of randomized placebo-controlled trials

Background

Multiple cardiovascular outcomes trials (CVOTs) have shown the efficacy of GLP-1RAs in reducing major adverse cardiovascular events (MACEs) for high-risk patients. However, some CVOTs failed to demonstrate cardiovascular benefits.

Objectives

We analyzed the impact of GLP-1RA on cardiovascular and renal outcomes in patients with or without T2DM, with subgroup analysis based on sex, estimated glomerular filtration rate (eGFR), body mass index (BMI), and history of cardiovascular disease (CVD).

Methods

A comprehensive database search for placebo-controlled RCTs on GLP-1RA treatment was conducted until April 2024. Data extraction and quality assessment were carried out, employing a robust statistical analysis using a random effects model to determine outcomes with log odds ratios and 95 % confidence intervals (CIs).

Results

A total of 13 CVOTs comprising 83,258 patients were included. GLP-1RAs significantly reduced MACE (OR 0.86, 95 % CI: 0.80 to 0.94, p < 0.01) all-cause mortality OR 0.87, 95 % CI: 0.82 to 0.93, p < 0.001, CV mortality (OR 0.87, 95 % CI: 0.81 to 0.94, p < 0.001), stroke (fatal: OR 0.74, 95 % CI: 0.56 to 0.96, p = 0.03; non-fatal: OR 0.87, 95 % CI: 0.79 to 0.96, p = 0.005), coronary revascularization (OR 0.86, 95 % CI: 0.74 to 0.99, p = 0.023), and composite kidney outcome (OR 0.76, 95 % CI: 0.67 to 0.85, p < 0.001. GLP-1RA significantly reduced MACE in both sexes. Furthermore, GLP-1RA reduced MACE regardless of CVD history, BMI, and eGFR level.

Conclusion

Significant reductions in MACE, overall and CV mortality, stroke, coronary revascularization, and composite kidney outcome with GLP-1RA treatment were noted across all subgroups.

Diabetes and Stroke: Impact of Novel Therapies for the Treatment of Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) is a significant risk factor for stroke. Nevertheless, the evidence supporting stringent glycemic control to reduce macrovascular complications, particularly stroke, is not as clear as for microvascular complications. Presently, risk reduction strategies are based on controlling multiple risk factors, including hypertension, dyslipidemia, glycemia, smoking, and weight. Since 2008, new pharmacological therapies for treating T2DM have been required to undergo trials to ensure their cardiovascular safety. Remarkably, several novel therapies have exhibited protective effects against the combined endpoint of major cardiovascular events. Evidence from these trials, with stroke as a secondary endpoint, along with real-world data, suggests potential benefits in stroke prevention, particularly with glucagon-like peptide 1 receptor agonists. Conversely, the data on sodium-glucose cotransporter type 2 inhibitors remains more controversial. Dipeptidyl peptidase 4 inhibitors appear neutral in stroke prevention. More recent pharmacological therapies still lack significant data on this particular outcome. This article provides a comprehensive review of the evidence on the most recent T2DM therapies for stroke prevention and their impact on clinical practice.

Risk of Stroke in Real-World US Individuals with Type 2 Diabetes Receiving Semaglutide or a Dipeptidyl Peptidase 4 Inhibitor

INTRODUCTION

People with type 2 diabetes (T2D) have a higher risk of stroke and worse outcomes than those without T2D. Pooled data from randomized controlled trials indicate that the glucagon-like peptide 1 receptor agonist semaglutide is associated with stroke risk reduction in people with T2D at high cardiovascular risk. We compared real-world stroke risk in people with T2D or T2D plus atherosclerotic cardiovascular disease (ASCVD) initiating either semaglutide or a dipeptidyl peptidase 4 inhibitor (DPP4i).

METHODS

Adults (≥ 18 years old) in a US claims database with a claim indicating initiation of either semaglutide or a DPP4i (index date) during the index period (1 January 2018-30 September 2020), a diagnosis code for T2D on or before the index date and at least 12 months' continuous enrolment in the database pre-index were included and propensity score matched 1:1 on baseline demographic and clinical characteristics. The primary outcome was time to first stroke event during follow-up. Healthcare resource utilization was also compared between groups.

RESULTS

The analysis included 17,920 matched pairs with T2D and 4234 matched pairs with T2D and ASCVD. The groups were well matched on baseline characteristics. People initiating semaglutide had a lower risk of stroke over short-term follow-up than those initiating a DPP4i (T2D: hazard ratio 0.63 [95% confidence interval 0.41-0.95], p = 0.029; T2D plus ASCVD: 0.45 [0.24-0.86], p = 0.015). Semaglutide was also associated with a lower rate of inpatient, outpatient and emergency room visits compared with a DPP4i.

CONCLUSION

This proof-of-concept analysis indicates that semaglutide has the potential to reduce the risk of stroke in people with T2D when prescribed in clinical practice.

Effects of newer-generation anti-diabetics on diabetic retinopathy: a critical review

Diabetic retinopathy (DR) is the leading etiology of blindness in the working population of the USA. Its long-term management relies on effective glycemic control. Seven anti-diabetic classes have been introduced for patients with type 2 diabetes (T2D) in the past two decades, with different glucose-lowering and cardiovascular benefits. Yet, their effects specifically on DR have not been studied in detail. A systematic review of the literature was conducted to investigate this topic, focusing on the available clinical data for T2D. Published studies were evaluated based on their level of statistical evidence, as long as they incorporated at least one endpoint or adverse event pertaining to retinal health. Fifty nine articles met our inclusion criteria and were grouped per anti-diabetic class as follows: alpha-glucosidase inhibitors (1), peroxisome proliferator-activated receptor gamma (PPAR-γ) agonists (8), amylin analogs (1), glucagon-like peptide-1 (GLP-1) receptor agonists (28), dipeptidyl peptidase 4 (DPP-4) inhibitors (9), and sodium glucose co-transporter-2 (SGLT-2) inhibitors (9), plus one retrospective study and two meta-analyses evaluating more than one of the aforementioned anti-diabetic categories. We also reviewed publicly-announced results of trials for the recently-introduced class of twincretins. The available data indicates that most drugs in the newer anti-diabetic classes are neutral to DR progression; however, there are subclasses differences in specific drugs and T2D populations. In particular, there is evidence suggesting there may be worse diabetic macular edema with PPAR-gamma agonists, potential slight DR worsening with semaglutide (GLP-1 receptor agonist), and potential slight increase in the incidence of retinal vein occlusion in elderly and patients with advanced kidney disease receiving SGLT-2 inhibitors. All these warrant further investigation. Longer follow-up and systematic assessment of at least one DR-related endpoint are highly recommended for all future trials in the T2D field, to ultimately address this topic.

Incretin-based drugs and the risk of diabetic retinopathy among individuals with type 2 diabetes: A systematic review and meta-analysis of observational studies

AIM

The results from the SUSTAIN-6 trial generated some uncertainty regarding the association between incretin-based drugs [dipeptidyl peptidase-4 (DPP-4) inhibitors and glucagon-like peptide-1 receptor agonists (GLP-1 RAs)] and the risk of diabetic retinopathy. Our objective was to synthesize the available evidence from observational studies regarding the use of incretin-based drugs and the risk of diabetic retinopathy among individuals with type 2 diabetes.

MATERIALS AND METHODS

We systemically searched Cochrane Library, Embase and Medline to identify observational studies of interest. Risk of bias was assessed using the ROBINS-I tool. Data from included studies were pooled using the DerSimonian and Laird random-effect model with the Hartung-Knapp extension.

RESULTS

We included 14 studies in the systematic review, with 10 examining DPP-4 inhibitors and seven examining GLP-1 RAs. Nine studies investigated incident diabetic retinopathy, six investigated diabetic retinopathy progression and two investigated both outcomes. Seven studies were at moderate risk of bias, four at serious risk of bias and three at critical risk of bias. Data pooled across studies showed no association between the use of DPP-4 inhibitors (risk ratio: 0.98, 95% confidence interval: 0.83, 1.17) or GLP-1 RAs (risk ratio: 0.87, 95% confidence interval: 0.56, 1.34) and the risk of diabetic retinopathy.

CONCLUSION

This study suggests that the use of incretin-based drugs is not associated with the risk of diabetic retinopathy among individuals with type 2 diabetes. However, these findings should be interpreted with caution considering the limited quality of some of the available evidence.

Incretins and cardiovascular disease: to the heart of type 2 diabetes?

Major cardiovascular outcome trials and real-life observations have proven that glucagon-like peptide-1 (GLP-1) receptor agonists (GLP-1RAs), regardless of structural GLP-1 homology, exert clinically relevant cardiovascular protection. GLP-1RAs provide cardioprotective benefits through glycaemic and non-glycaemic effects, including improved insulin secretion and action, body-weight loss, blood-pressure lowering and improved lipid profile, as well as via direct effects on the heart and vasculature. These actions are likely combined with anti-inflammatory and antioxidant properties that translate into robust and consistent reductions in atherothrombotic events, particularly in people with type 2 diabetes and established atherosclerotic CVD. GLP-1RAs may also have an impact on obesity and chronic kidney disease, conditions for which cardiovascular risk-reducing options are limited. The available evidence has prompted professional and medical societies to recommend GLP-1RAs for mitigation of the cardiovascular risk in people with type 2 diabetes. This review summarises the clinical evidence for cardiovascular protection with use of GLP-1RAs and the main mechanisms underlying this effect. Moreover, it looks into how the availability of upcoming dual and triple incretin receptor agonists might expand the possibility for cardiovascular protection in people with type 2 diabetes.

Incretins and microvascular complications of diabetes: neuropathy, nephropathy, retinopathy and microangiopathy

Glucagon-like peptide-1 receptor agonists (GLP-1RAs, incretin mimetics) and dipeptidyl peptidase-4 inhibitors (DPP-4is, incretin enhancers) are glucose-lowering therapies with proven cardiovascular safety, but their effect on microvascular disease is not fully understood. Both therapies increase GLP-1 receptor agonism, which is associated with attenuation of numerous pathological processes that may lead to microvascular benefits, including decreased reactive oxygen species (ROS) production, decreased inflammation and improved vascular function. DPP-4is also increase stromal cell-derived factor-1 (SDF-1), which is associated with neovascularisation and tissue repair. Rodent studies demonstrate several benefits of these agents in the prevention or reversal of nephropathy, retinopathy and neuropathy, but evidence from human populations is less clear. For nephropathy risk in human clinical trials, meta-analyses demonstrate that GLP-1RAs reduce the risk of a composite renal outcome (doubling of serum creatinine, eGFR reduction of 30%, end-stage renal disease or renal death), whereas the benefits of DPP-4is appear to be limited to reductions in the risk of albuminuria. The relationship between GLP-1RAs and retinopathy is less clear. Many large trials and meta-analyses show no effect, but an observed increase in the risk of retinopathy complications with semaglutide therapy (a GLP-1RA) in the SUSTAIN-6 trial warrants caution, particularly in individuals with baseline retinopathy. Similarly, DPP-4is are associated with increased retinopathy risk in both trials and meta-analysis. The association between GLP-1RAs and peripheral neuropathy is unclear due to little trial evidence. For DPP-4is, one trial and several observational studies show a reduced risk of peripheral neuropathy, with others reporting no effect. Evidence in other less-established microvascular outcomes, such as microvascular angina, cerebral small vessel disease, skeletal muscle microvascular disease and autonomic neuropathies (e.g. cardiac autonomic neuropathy, gastroparesis, erectile dysfunction), is sparse. In conclusion, GLP-1RAs are protective against nephropathy, whereas DPP-4is are protective against albuminuria and potentially peripheral neuropathy. Caution is advised with DPP-4is and semaglutide, particularly for patients with background retinopathy, due to increased risk of retinopathy. Well-designed trials powered for microvascular outcomes are needed to clarify associations of incretin therapies and microvascular diseases.

Role of Glucagon-Like Peptide-1 (GLP-1) Receptor Agonists in Cardiovascular Risk Management in Patients With Type 2 Diabetes Mellitus: A Systematic Review

People with type 2 diabetes mellitus have a greater risk of developing cardiovascular problems. Since cardiovascular diseases are a major cause of mortality all over the world, we need to find more efficient measures to control this risk in the diabetes population in addition to conventional glycemic control. In this systematic review, we aim to explore the latest findings on the cardiovascular effects of glucagon-like peptide-1 (GLP-1) agonists and dual GLP-1/glucose-dependent insulinotropic peptide (GIP) agonists in patients with type 2 diabetes mellitus. We conducted a comprehensive literature search using PubMed and Google Scholar as the main sources for data collection. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 recommendations for conducting this review. The outcomes of interest included mortality due to cardiovascular causes, non-fatal myocardial infarction, stroke, effects on cardiovascular risk factors, heart failure, and development of arrhythmias. After thorough literature screening and quality analysis, 14 articles were finally included for qualitative synthesis. GLP-1 receptor agonists appeared to be effective in reducing the risk of cardiovascular mortality, myocardial infarction, and stroke. They were found to reduce the risk of composite major adverse cardiovascular event (MACE) outcomes by 12-14% when compared to placebo. Their role in preventing heart failure and arrhythmias is uncertain, and further trials are needed to confirm the same. The cardiovascular outcomes of GLP-1/GIP dual agonists are currently under investigation. Studies completed to date show that they do not increase the risk of cardiovascular disease when compared to placebo.

Glucagon-like peptide 1 receptor agonists: cardiovascular benefits and mechanisms of action

Type 2 diabetes mellitus (T2DM) and obesity are metabolic disorders characterized by excess cardiovascular risk. Glucagon-like peptide 1 (GLP1) receptor (GLP1R) agonists reduce body weight, glycaemia, blood pressure, postprandial lipaemia and inflammation - actions that could contribute to the reduction of cardiovascular events. Cardiovascular outcome trials (CVOTs) have demonstrated that GLP1R agonists reduce the rates of major adverse cardiovascular events in patients with T2DM. Separate phase III CVOTs of GLP1R agonists are currently being conducted in people living with heart failure with preserved ejection fraction and in those with obesity. Mechanistically, GLP1R is expressed at low levels in the heart and vasculature, raising the possibility that GLP1 might have both direct and indirect actions on the cardiovascular system. In this Review, we summarize the data from CVOTs of GLP1R agonists in patients with T2DM and describe the actions of GLP1R agonists on the heart and blood vessels. We also assess the potential mechanisms that contribute to the reduction in major adverse cardiovascular events in individuals treated with GLP1R agonists and highlight the emerging cardiovascular biology of novel GLP1-based multi-agonists currently in development. Understanding how GLP1R signalling protects the heart and blood vessels will optimize the therapeutic use and development of next-generation GLP1-based therapies with improved cardiovascular safety.