Protection against stroke with glucagon‐like peptide 1 receptor agonists: a systematic review and meta‐analysis

Glucagon-like peptide-1 receptor agonists and stroke: A systematic review and meta-analysis of cardiovascular outcome trials

BACKGROUND

In patients surviving stroke, approximately 15% and 60% exhibit concurrent diabetes mellitus and overweight/obesity, respectively, necessitating heightened secondary prevention efforts. Despite glucagon-like peptide-1 receptor agonists (GLP-1 RAs) demonstrating improved outcomes for those with diabetes mellitus or obesity, their underutilization persists among eligible individuals. This systematic review and meta-analysis investigated the impact of GLP-1 RAs on stroke risk. The findings aim to optimize the implementation of this therapeutic strategy in patients surviving stroke with diabetes mellitus or obesity.

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, we systematically reviewed MEDLINE and Scopus until 15 November 2023. Eligible studies included randomized cardiovascular outcome trials (CVOTs) with individuals, with or without type 2 diabetes, randomized to either GLP-1 RA or placebo. The outcomes were total strokes, non-fatal strokes, and fatal strokes. Analyses were conducted using RevMan 5.4.1.

RESULTS

Among 1369 screened studies, 11 were eligible, encompassing 82,140 participants (34.6% women) with a cumulative follow-up of 247,596 person-years. In the GLP-1 RAs group, the stroke rate was significantly lower compared to placebo (RR: 0.85, 95% CI: 0.77-0.93; NNT: 200), showing no heterogeneity or interaction with administration frequency (daily vs weekly). In addition, the GLP-1 RAs group exhibited a significantly lower rate of non-fatal strokes compared to placebo (RR: 0.87, 95% CI: 0.79-0.95; NNT: 250), with no heterogeneity or interaction based on administration frequency, route (oral vs subcutaneous), or diabetes presence.

CONCLUSION

In this meta-analysis of 11 CVOTs with 82,140 participants, GLP-1 RAs demonstrated a 16% relative reduction in stroke risk compared to placebo. This finding may increase implementation of GLP-1 RAs by stroke specialists in individuals with stroke and comorbid diabetes mellitus or obesity.

DATA ACCESS STATEMENT

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Incretin-Based Multi-Agonist Peptides Are Neuroprotective and Anti-Inflammatory in Cellular Models of Neurodegeneration

Glucagon-like peptide-1 (GLP-1)-based drugs have been approved by the United States Food and Drug Administration (FDA) and are widely used to treat type 2 diabetes mellitus (T2DM) and obesity. More recent developments of unimolecular peptides targeting multiple incretin-related receptors ("multi-agonists"), including the glucose-dependent insulinotropic polypeptide (GIP) receptor (GIPR) and the glucagon (Gcg) receptor (GcgR), have emerged with the aim of enhancing drug benefits. In this study, we utilized human and mouse microglial cell lines, HMC3 and IMG, respectively, together with the human neuroblastoma SH-SY5Y cell line as cellular models of neurodegeneration. Using these cell lines, we studied the neuroprotective and anti-inflammatory capacity of several multi-agonists in comparison with a single GLP-1 receptor (GLP-1R) agonist, exendin-4. Our data demonstrate that the two selected GLP-1R/GIPR dual agonists and a GLP-1R/GIPR/GcgR triple agonist not only have neurotrophic and neuroprotective effects but also have anti-neuroinflammatory properties, as indicated by the decreased microglial cyclooxygenase 2 (COX2) expression, nitrite production, and pro-inflammatory cytokine release. In addition, our results indicate that these multi-agonists have the potential to outperform commercially available single GLP-1R agonists in neurodegenerative disease treatment.

Thiazolidinediones Decrease the Recurrence of Intracerebral Hemorrhage in Type 2 Diabetes Mellitus Patients: A Nested Case-Control Study

INTRODUCTION

Preclinical evidence demonstrated the therapeutic potential of thiazolidinediones (TZDs) for the treatment of intracerebral hemorrhage (ICH). The present study conducted an investigation of cerebrovascular and cardiovascular outcomes following ICH in patients with type 2 diabetes mellitus (T2DM) treated with or without TZDs.

METHODS

This retrospective nested case-control study used data from the Taiwan National Health Insurance Research Database. A total of 62,515 T2DM patients who were hospitalized with a diagnosis of ICH were enrolled, including 7,603 TZD users. Data for TZD non-users were extracted using propensity score matching. Primary outcomes included death and major adverse cardiovascular events (MACEs), which were defined as a composite of ischemic stroke, hemorrhagic stroke (HS), acute myocardial infarction, and congestive heart failure. Patients aged <20 years with a history of traumatic brain injury or any prior history of MACEs were excluded.

RESULTS

TZD users had significantly lower MACE risks compared with TZD non-users following ICH (adjusted hazard ratio [aHR]: 0.90, 95% confidence interval [CI]: 0.85-0.94, p < 0.001). The most significant MACE difference reported for TZD users was HS, which possessed lower incidence than in TZD non-users, especially for the events that happened within 3 months following ICH (aHR: 0.74, 95% CI: 0.62-0.89 within 1 month, p < 0.01; aHR: 0.68, 95% CI: 0.54-0.85 between 1 and 3 month).

CONCLUSION

The use of TZD in patients with T2DM was associated with a lower risk of subsequent HS and mortality following ICH.

GLP-1 Receptor Agonists: A New Treatment in Parkinson's Disease

Parkinson's disease (PD) is one of the most common neurodegenerative diseases. Recent data highlight similarities between neurodegenerative diseases, including PD and type 2 diabetes mellitus (T2DM), suggesting a crucial interplay between the gut-brain axis. Glucagon-like peptide-1 receptor (GLP-1R) agonists, known for their use in T2DM treatment, are currently extensively studied as novel PD modifying agents. For this narrative review article, we searched PubMed and Scopus databases for peer-reviewed research, review articles and clinical trials regarding GLP-1R agonists and PD published in the English language with no time restrictions. We also screened the references of the selected articles for possible additional articles in order to include most of the key recent evidence. Many data on animal models and preclinical studies show that GLP1-R agonists can restore dopamine levels, inhibit dopaminergic loss, attenuate neuronal degeneration and alleviate motor and non-motor features of PD. Evidence from clinical studies is also very promising, enhancing the possibility of adding GLP1-R agonists to the current armamentarium of drugs available for PD treatment.

Comparative Effect of Glucose-Lowering Drugs for Type 2 Diabetes Mellitus on Stroke Prevention: A Systematic Review and Network Meta-Analysis

BACKGRUOUND

There is still a lack of research on which diabetic drugs are more effective in preventing stroke. Our network metaanalysis aimed to compare cerebrovascular benefits among glucose-lowering treatments.

METHODS

We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, and the ClinicalTrials.gov registry for clinical trials from inception through May 25, 2021. We included both prespecified cerebrovascular outcomes and cerebrovascular events reported as severe adverse events. Subgroup analyses were conducted by stroke subtype, publication type, age of patients, baseline glycosylated hemoglobin (HbA1c), duration of type 2 diabetes mellitus, and cardiovascular risks.

RESULTS

Of 2,861 reports and 1,779 trials screened, 79 randomized controlled trials comprising 206,387 patients fulfilled the inclusion criteria. In the pairwise meta-analysis, the use of glucagon-like peptide-1 (GLP-1) agonist was associated with a lower risk of total stroke compared with placebo (relative risk [RR], -0.17; 95% confidence interval [CI], -0.27 to -0.07). In the network meta- analysis, only the use of sodium-glucose cotransporter-2 (SGLT-2) inhibitor was associated with a reduction of total stroke, compared with placebo (RR, 0.81; 95% CI, 0.67 to 0.98). In the subgroup analyses, the use of SGLT-2 inhibitor and GLP-1 agonist was associated with a lower risk of stroke in those with high HbA1c (≥8.0) and low-risk of cardiovascular disease, respectively.

CONCLUSION

SGLT-2 inhibitors and GLP-1 agonists were shown to be beneficial for stroke prevention in patients with type 2 diabetes mellitus.

Glucagon-like peptide-1 (GLP-1) receptor agonists and neuroinflammation: Implications for neurodegenerative disease treatment

Chronic, excessive neuroinflammation is a key feature of neurodegenerative diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD). However, neuroinflammatory pathways have yet to be effectively targeted in clinical treatments for such diseases. Interestingly, increased inflammation and neurodegenerative disease risk have been associated with type 2 diabetes mellitus (T2DM) and insulin resistance (IR), suggesting that treatments that mitigate T2DM pathology may be successful in treating neuroinflammatory and neurodegenerative pathology as well. Glucagon-like peptide-1 (GLP-1) is an incretin hormone that promotes healthy insulin signaling, regulates blood sugar levels, and suppresses appetite. Consequently, numerous GLP-1 receptor (GLP-1R) stimulating drugs have been developed and approved by the US Food and Drug Administration (FDA) and related global regulatory authorities for the treatment of T2DM. Furthermore, GLP-1R stimulating drugs have been associated with anti-inflammatory, neurotrophic, and neuroprotective properties in neurodegenerative disorder preclinical models, and hence hold promise for repurposing as a treatment for neurodegenerative diseases. In this review, we discuss incretin signaling, neuroinflammatory pathways, and the intersections between neuroinflammation, brain IR, and neurodegenerative diseases, with a focus on AD and PD. We additionally overview current FDA-approved incretin receptor stimulating drugs and agents in development, including unimolecular single, dual, and triple receptor agonists, and highlight those in clinical trials for neurodegenerative disease treatment. We propose that repurposing already-approved GLP-1R agonists for the treatment of neurodegenerative diseases may be a safe, efficacious, and cost-effective strategy for ameliorating AD and PD pathology by quelling neuroinflammation.

The Longer-Term Benefits and Harms of Glucagon-Like Peptide-1 Receptor Agonists: a Systematic Review and Meta-Analysis

BACKGROUND

Previous meta-analyses of the benefits and harms of glucagon-like peptide-1 receptor agonists (GLP1RAs) have been limited to specific outcomes and comparisons and often included short-term results. We aimed to estimate the longer-term effects of GLP1RAs on cardiovascular risk factors, microvascular and macrovascular complications, mortality, and adverse events in patients with type 2 diabetes, compared to placebo and other anti-hyperglycemic medications.

METHODS

We searched PubMed, Scopus, and clinicaltrials.gov (inception-July 2019) for randomized controlled trials ≥ 52 weeks' duration that compared a GLP1RA to placebo or other anti-hyperglycemic medication and included at least one outcome of interest. Outcomes included cardiovascular risk factors, microvascular and macrovascular complications, all-cause mortality, and treatment-related adverse events. We performed random effects meta-analyses to give summary estimates using weighted mean differences (MD) and pooled relative risks (RR). Risk of bias was assessed using the Cochrane Collaboration risk of bias in randomized trials tool. Quality of evidence was summarized using the Grading of Recommendations, Assessment, Development, and Evaluation approach. The study was registered a priori with PROSPERO (CRD42018090506).

RESULTS

Forty-five trials with a mean duration of 1.7 years comprising 71,517 patients were included. Compared to placebo, GLP1RAs reduced cardiovascular risk factors, microvascular complications (including renal events, RR 0.85, 0.80-0.90), macrovascular complications (including stroke, RR 0.86, 0.78-0.95), and mortality (RR 0.89, 0.84-0.94). Compared to other anti-hyperglycemic medications, GLP1RAs only reduced cardiovascular risk factors. Increased gastrointestinal events causing treatment discontinuation were observed in both comparisons.

DISCUSSION

GLP1RAs reduced cardiovascular risk factors and increased gastrointestinal events compared to placebo and other anti-hyperglycemic medications. GLP1RAs also reduced MACE, stroke, renal events, and mortality in comparisons with placebo; however, analyses were inconclusive for comparisons with other anti-hyperglycemic medications. Given the high costs of GLP1RAs, the lack of long-term evidence comparing GLP1RAs to other anti-hyperglycemic medications has significant policy and clinical practice implications.

Hyperglycemia in acute ischemic stroke: physiopathological and therapeutic complexity

Diabetes mellitus and associated chronic hyperglycemia enhance the risk of acute ischemic stroke and lead to worsened clinical outcome and increased mortality. However, post-stroke hyperglycemia is also present in a number of non-diabetic patients after acute ischemic stroke, presumably as a stress response. The aim of this review is to summarize the main effects of hyperglycemia when associated to ischemic injury in acute stroke patients, highlighting the clinical and neurological outcomes in these conditions and after the administration of the currently approved pharmacological treatment, i.e. insulin. The disappointing results of the clinical trials on insulin (including the hypoglycemic events) demand a change of strategy based on more focused therapies. Starting from the comprehensive evaluation of the physiopathological alterations occurring in the ischemic brain during hyperglycemic conditions, the effects of various classes of glucose-lowering drugs are reviewed, such as glucose-like peptide-1 receptor agonists, DPP-4 inhibitors and sodium glucose cotransporter 2 inhibitors, in the perspective of overcoming the up-to-date limitations and of evaluating the effectiveness of new potential therapeutic strategies.

The metabolite GLP-1 (9-36) is neuroprotective and anti-inflammatory in cellular models of neurodegeneration

Glucagon-like peptide-1 (GLP-1) is best known for its insulinotropic action following food intake. Its metabolite, GLP-1 (9-36), was assumed biologically inactive because of low GLP-1 receptor (GLP-1R) affinity and non-insulinotropic properties; however, recent studies contradict this assumption. Increased use of FDA approved GLP-1 analogues for treating metabolic disorders and neurodegenerative diseases raises interest in GLP-1 (9-36)'s biological role. We use human SH-SY5Y neuroblastoma cells and a GLP-1R over-expressing variety (#9), in both undifferentiated and differentiated states, to evaluate the neurotrophic/neuroprotective effects of GLP-1 (9-36) against toxic glutamate exposure and other oxidative stress models (via the MTS, LDH or ROS assays). In addition, we examine GLP-1 (9-36)'s signaling pathways, including cyclic-adenosine monophosphate (cAMP), protein kinase-A (PKA), and 5' adenosine monophosphate-activated protein kinase (AMPK) via the use of ELISA, pharmacological inhibitors, or GLP-1R antagonist. Human HMC3 and mouse IMG microglial cell lines were used to study the anti-inflammatory effects of GLP-1 (9-36) against lipopolysaccharide (LPS) (via ELISA). Finally, we applied GLP-1 (9-36) to primary dissociation cultures challenged with α-synuclein or amyloid-β and assessed survival and morphology via immunochemistry. We demonstrate evidence of GLP-1R, cAMP, PKA, and AMPK-mediated neurotrophic and neuroprotective effects of GLP-1 (9-36). The metabolite significantly reduced IL-6 and TNF-α levels in HMC3 and IMG microglial cells, respectively. Lastly, we show mild but significant effects of GLP-1 (9-36) in primary neuron cultures challenged with α-synuclein or amyloid-β. These studies enhance understanding of GLP-1 (9-36)'s effects on the nervous system and its potential as a primary or complementary treatment in pathological contexts.

Usefulness of Glucagon-Like Peptide-1 Receptor Agonists to Reduce Adverse Cardiovascular Disease Events in Patients with Type 2 Diabetes Mellitus

Evidence suggests glucagon-like peptide-1 receptor agonists (GLP-1 RA) reduce cardiovascular disease (CVD) events. The objective of this study was to analyze randomized controlled trials (RCT) testing GLP-1 RA's effect on CVD events among participants with type 2 diabetes (T2DM). RCTs comparing GLP-1 RA versus placebo were identified using the PubMed and Cochrane databases. The endpoints in this study included major adverse cardiovascular events (MACE; a composite of cardiovascular death, nonfatal myocardial infarction (MI), and nonfatal stroke), and the individual components of MACE. The primary analysis calculated risk ratios (RR) and 95% confidence intervals (CI) for each endpoint. Heterogeneity for each endpoint was calculated using Chi² and I² tests. For any endpoint with significant heterogeneity, a meta-regression was performed using mean baseline hemoglobin A1C (A1C) as the moderator and a R² value was calculated. Seven RCTs (N = 56,004) were identified with 174,163 patient-years of follow-up. GLP-1 RA reduced MACE [RR 0.89, 95% CI 0.83 to 0.95], cardiovascular death [RR 0.88, 95% CI 0.81 to 0.95], and nonfatal stroke [RR 0.85, 95% CI 0.77 to 0.95]. There was no statistically significant heterogeneity among these RCTs. GLP-1 RA did not reduce nonfatal MI [RR 0.91, 95% CI 0.81 to 1.02]. However, there was significant heterogeneity among these RCTs (Chi² = 12.68, p = 0.05, I² = 53%). When accounting for baseline A1C in the regression model, there was no longer significant heterogeneity for this endpoint (p = 0.23, I² = 27%). A potential linear relationship between baseline A1C and GLP-1 RA's effect on nonfatal MI (R² = 0.64) was observed. In conclusion, GLP-1 RA reduced MACE, cardiovascular death, and nonfatal stroke; GLP-1 RA did not reduce nonfatal MI, however there may be a linear association between baseline A1C and GLP-1 RA's effect on nonfatal MI.

Effects of SGLT2 inhibitors on stroke and its subtypes in patients with type 2 diabetes: a systematic review and meta-analysis

Sodium-glucose cotransporter 2 (SGLT2) inhibitors have shown impressive effects in reducing major vascular events in several randomized controlled trials (RCTs). The purpose of this study was to perform a meta-analysis to evaluate the effect of SGLT2 inhibitors on the risk of stroke and its subtypes. All data from prospective RCTs up to 20 October 2020 involving SGLT2 inhibitors that reported stroke events as the primary endpoint or safety in subjects with type 2 diabetes were subjected to meta-analysis. Five eligible RCTs (EMPA-REG, CANVAS, DECLARE-TIMI 58, CREDENCE and VERTIS CV) involving 46,969 participants were included. Pooled analysis of the RCTs showed no significant effect of SGLT2 inhibitors on total stroke [risk ratio (RR) = 0.95; 95% confidence interval (CI) 0.79-1.13, P = 0.585]. Subgroup analysis indicated that SGLT2 inhibitors had no significant effect against fatal stroke, non-fatal stroke, ischemic stroke or transient ischemic attack. When only hemorrhagic stroke was included, SGLT2 inhibitors were associated with a significant 50% reduction compared with placebo (RR = 0.49, 95% CI 0.30-0.82, P = 0.007). This meta-analysis shows that SGLT2 inhibitors have a neutral effect on the risk of stroke and its subtypes but a potential protective effect against hemorrhagic stroke.

SGLT2 inhibitors and GLP-1 receptor agonists: established and emerging indications

SGLT2 inhibitors and GLP-1 receptor agonists are used in patients with type 2 diabetes as glucose lowering therapies, with additional benefits of weight loss and blood pressure reduction. Data from cardiovascular outcome trials have highlighted that these drugs confer protection against major cardiovascular disease in those with established atherosclerotic cardiovascular disease, reduce the risk of admission to hospital for heart failure, and reduce cardiovascular and all-cause mortality. Ongoing research using hard renal endpoints such as end stage kidney disease rather than surrogate markers might clarify the renoprotective benefits of both agents. When used for glucose lowering, SGLT2 inhibitors are most effective if the estimated glomerular filtration rate is more than 60 ml per min per 1·73m² at initiation and should be avoided where there is a risk of diabetic ketoacidosis. GLP-1 receptor agonists are contraindicated in those with a history of medullary thyroid cancer and used with caution in patients with a history of pancreatitis of a known cause. These drugs are now second-line, or even arguably first-line, glucose lowering therapies in patients with cardiorenal disease, irrespective of glycaemic control. If an SGLT2 inhibitor or GLP-1 receptor agonist is considered suitable in patients with type 2 diabetes, treatment should be prioritised according to existing evidence: GLP-1 receptor agonists should be considered in patients at a high risk of, or with established, cardiovascular disease and SGLT2 inhibitors considered for patients with heart failure (with reduced ejection fraction) or chronic kidney disease (with or without established cardiovascular disease). There is now compelling data on the benefits of these drugs for a range of other clinical indications even without type 2 diabetes, including for GLP-1 receptor agonists in patients with obesity and overweight with weight-related comorbidities.

Glucagon-like peptide-1 receptor agonists as neuroprotective agents for ischemic stroke: a systematic scoping review

Stroke mortality and morbidity is expected to rise. Despite considerable recent advances within acute ischemic stroke treatment, scope remains for development of widely applicable neuroprotective agents. Glucagon-like peptide-1 receptor agonists (GLP-1RAs), originally licensed for the management of Type 2 Diabetes Mellitus, have demonstrated pre-clinical neuroprotective efficacy in a range of neurodegenerative conditions. This systematic scoping review reports the pre-clinical basis of GLP-1RAs as neuroprotective agents in acute ischemic stroke and their translation into clinical trials. We included 35 pre-clinical studies, 11 retrospective database studies, 7 cardiovascular outcome trials and 4 prospective clinical studies. Pre-clinical neuroprotection was demonstrated in normoglycemic models when administration was delayed by up to 24 h following stroke induction. Outcomes included reduced infarct volume, apoptosis, oxidative stress and inflammation alongside increased neurogenesis, angiogenesis and cerebral blood flow. Improved neurological function and a trend towards increased survival were also reported. Cardiovascular outcomes trials reported a significant reduction in stroke incidence with semaglutide and dulaglutide. Retrospective database studies show a trend towards neuroprotection. Prospective interventional clinical trials are on-going, but initial indicators of safety and tolerability are favourable. Ultimately, we propose that repurposing GLP-1RAs is potentially advantageous but appropriately designed trials are needed to determine clinical efficacy and cost-effectiveness.

Expert Consensus on Telemedicine Management of Diabetes (2020 Edition)

Diabetes is a chronic disease that is very suitable for telemedicine management. Owing to the coronavirus disease 2019 (COVID-19) pandemic, telemedicine management of diabetes is particularly important. This consensus proposes 38 recommendations for key issues in telemedicine management of diabetes and provides preliminary specifications for diabetes management. It is recommended to use the most current information and communication technologies for telemanagement of patients' diet, exercise, behavior, and drug therapy. A strategy for drug therapy that is more suitable for telemedicine management of diabetes than previous ones is established. During online follow-up visits, major changes of antihyperglycemic agents must be avoided, and treatment modification should be done in a stepwise manner. Greater attention should be paid to the occurrence and prevention of hypoglycemia, in addition to educating patients about the side effects of the drugs used and encouraging them to actively report adverse drug reactions. Conditions are clarified under which online follow-up visits must be terminated and in-person visits or emergency visits must be initiated. Telemedicine can improve the management level and control rate of diabetes. The present consensus for the standardized diagnosis and treatment of diabetes can reduce the potential risks of telemedicine management, yield great benefits to patients, and reduce chronic complications and comorbidities.

Brain uptake pharmacokinetics of incretin receptor agonists showing promise as Alzheimer's and Parkinson's disease therapeutics

Among the more promising treatments proposed for Alzheimer's disease (AD) and Parkinson's disease (PD) are those reducing brain insulin resistance. The antidiabetics in the class of incretin receptor agonists (IRAs) reduce symptoms and brain pathology in animal models of AD and PD, as well as glucose utilization in AD cases and clinical symptoms in PD cases after their systemic administration. At least 9 different IRAs are showing promise as AD and PD therapeutics, but we still lack quantitative data on their relative ability to cross the blood-brain barrier (BBB) reaching the brain parenchyma. We consequently compared brain uptake pharmacokinetics of intravenous 125I-labeled IRAs in adult CD-1 mice over the course of 60 min. We tested single IRAs (exendin-4, liraglutide, lixisenatide, and semaglutide), which bind receptors for one incretin (glucagon-like peptide-1 [GLP-1]), and dual IRAs, which bind receptors for two incretins (GLP-1 and glucose-dependent insulinotropic polypeptide [GIP]), including unbranched, acylated, PEGylated, or C-terminally modified forms (Finan/Ma Peptides 17, 18, and 20 and Hölscher peptides DA3-CH and DA-JC4). The non-acylated and non-PEGylated IRAs (exendin-4, lixisenatide, Peptide 17, DA3-CH and DA-JC4) had significant rates of blood-to-brain influx (Ki), but the acylated IRAs (liraglutide, semaglutide, and Peptide 18) did not measurably cross the BBB. The brain influx of the non-acylated, non-PEGylated IRAs were not saturable up to 1 μg of these drugs and was most likely mediated by adsorptive transcytosis across brain endothelial cells, as observed for exendin-4. Of the non-acylated, non-PEGylated IRAs tested, exendin-4 and DA-JC4 were best able to cross the BBB based on their rate of brain influx, percentage reaching the brain that accumulated in brain parenchyma, and percentage of the systemic dose taken up per gram of brain tissue. Exendin-4 and DA-JC4 thus merit special attention as IRAs well-suited to enter the central nervous system (CNS), thus reaching areas pathologic in AD and PD.

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.

Diabetes Mellitus and Noncardiac Atherosclerotic Vascular Disease-Pathogenesis and Pharmacological Treatment Options

Diabetes mellitus (DM) is also a cause of cardiovascular (CV) disease (CVD). Addressing the atherosclerotic CVD (ASCVD) burden in DM should reduce premature death and improve quality of life. Diabetes mellitus-associated ASCVD can lead to complications in all vascular beds (carotids as well as coronary, lower extremity, and renal arteries). This narrative review considers the diagnosis and pharmacological treatment of noncardiac atherosclerotic vascular disease (mainly in patients with DM). Based on current knowledge and the fact that modern DM treatment guidelines are based on CV outcome trials, it should be noted that patients with noncardiac CVD may not have the same benefits from certain drugs compared with patients who predominantly have cardiac complications. This leads to the conclusion that in the future, consideration should be given to conducting well-designed trials that will answer which pharmacological treatment modalities will be of greatest benefit to patients with noncardiac ASCVD.

Potential of Glucagon-Like Peptide 1 as a Regulator of Impaired Cholesterol Metabolism in the Brain

Cerebral vascular diseases are the most common high-mortality diseases worldwide. Their onset and development are associated with glycemic imbalance, genetic background, alteration of atherosclerotic factors, severe inflammation, and abnormal cholesterol metabolism. Recently, the gut-brain axis has been highlighted as the key to the solution for cerebral vessel dysfunction in view of cholesterol metabolism and systemic lipid circulation. In particular, glucagon-like peptide 1 (GLP-1) is a cardinal hormone that regulates blood vessel function and cholesterol homeostasis and acts as a critical messenger between the brain and gut. GLP-1 plays a systemic regulatory role in cholesterol homeostasis and blood vessel function in various organs through blood vessels. Even though GLP-1 has potential in the treatment and prevention of cerebral vascular diseases, the importance of and relation between GLP-1 and cerebral vascular diseases are not fully understood. Herein, we review recent findings on the functions of GLP-1 in cerebral blood vessels in association with cholesterol metabolism.

The treament of hyperglycemia in acute ischemic stroke with incretin-based drugs

Stroke is a major cause of mortality and morbidity worldwide. Considerable experimental and clinical evidence suggests that both diabetes mellitus (DM) and post-stroke hyperglycemia are associated with increased mortality rate and worsened clinical conditions in acute ischemic stroke (AIS) patients. Insulin treatment does not seem to provide convincing benefits for these patients, therefore prompting a change of strategy. The selective agonists of Glucagon-Like Peptide-1 Receptors (GLP-1Ras) and the Inhibitors of Dipeptidyl Peptidase-IV (DPP-IVIs, gliptins) are two newer classes of glucose-lowering drugs used for the treatment of DM. This review examines in detail the rationale for their development and the physicochemical, pharmacokinetic and pharmacodynamic properties and clinical activities. Emphasis will be placed on their neuroprotective effects at cellular and molecular levels in experimental models of acute cerebral ischemia. In perspective, an adequate basis does exist for a novel therapeutic approach to hyperglycemia in AIS patients through the additive treatment with GLP-1Ras plus DPP-IVIs.

Stroke in the patient with diabetes (Part 2) - Prevention and the effects of glucose lowering therapies

There is a higher incidence of stroke in both the type 2 diabetic and the non-diabetic insulin resistant patient which is accompanied by higher morbidity and mortality. Stroke primary prevention can be achieved by controlling atrial fibrillation and hypertension, and the utilization of statins and anticoagulant therapies. Utilizing pioglitazone and GLP-1 receptor agonists reduce the risk of stroke while the utilization of metformin, α-glucosidase inhibitors, DPP-4 and SGLT-2 inhibitors have no effect. Insulin use may be a marker of increased risk of stroke, but not necessarily causative. Utilizing intravenous insulin to normalize plasma glucose levels in the acute phase of a stroke does not improve the outcome. Antiplatelet agents are not proven to be of benefit in primary prevention whereas the use of direct-acting oral anticoagulants to avoid stroke and the early use of tpA in the acute phase have been shown to be beneficial.

Invited review. Series: Implications of the recent CVOTs in type 2 diabetes: Which patients for GLP-1RA or SGLT-2 inhibitor?

Large cardiovascular outcome trials (CVOTs) have lent support to a cardiovascular protection with the use of SGLT2-inhibitors (SGLT2is) and GLP1-Receptor Agonists (GLP1-RAs) in subjects with type 2 diabetes. These two classes of novel glucose lowering agents have been shown to have a similar effect on the risk reduction of Major Adverse Cardiovascular Events (MACE: nonfatal myocardial infarction, nonfatal stroke, cardiovascular mortality). Nonetheless, they may not be simply interchangeable. Rather, careful evaluation of all the results of CVOTs leads identification of different effects that may allow profiling of the ideal individuals with T2DM who may benefit most from the use of one or the other class of agents. These differences include effect on heart failure, stroke and diabetic kidney disease that have prompt recent guidelines and recommendation for the treatment of type 2 diabetes to suggest the preferential use of SGLT2is in those with evidence of heart failure and impaired kidney function, while both SGLT2i and GLP1-RAs with proven effect could be use in those with prevalent atherosclerotic cardiovascular disease. This review discusses all these elements of differentiation along with others that in the future may help establishing the best cardiorenal benefit for individuals with T2DM.

The effect of dulaglutide on stroke: an exploratory analysis of the REWIND trial

BACKGROUND

Cardiovascular outcome trials have suggested that glucagon-like peptide 1 (GLP-1) receptor agonists might reduce strokes. We analysed the effect of dulaglutide on stroke within the researching cardiovascular events with a weekly incretin in diabetes (REWIND) trial.

METHODS

REWIND was a multicentre, randomised, double-blind, placebo-controlled trial done at 371 sites in 24 countries. Men and women (aged ≥50 years) with established or newly detected type 2 diabetes whose HbA_1c was 9·5% or less (with no lower limit) on stable doses of up to two oral glucose-lowering drugs with or without basal insulin therapy were eligible if their body-mass index was at least 23 kg/m². Participants were randomly assigned (1:1) to weekly subcutaneous injections of either masked dulaglutide 1·5 mg or the same volume of masked placebo (containing the same excipients but without dulaglutide). Randomisation was done by a computer-generated random code with an interactive web response system with stratification by site. Participants, investigators, the trial leadership, and all other personnel were masked to treatment allocation until the trial was completed and the database was locked. During the treatment period, participants in both groups were instructed to inject study drug on the same day at around the same time, each week. Strokes were categorised as fatal or non-fatal, and as either ischaemic, haemorrhagic, or undetermined. Stroke severity was assessed using the modified Rankin scale. Participants were seen at 2 weeks, 3 months, 6 months, and then every 3 months for drug dispensing and every 6 months for detailed assessments, until 1200 confirmed primary outcomes accrued. The primary endpoint was the first occurrence of any component of the composite outcome, which comprised non-fatal myocardial infarction, non-fatal stroke, or death from cardiovascular or unknown causes. All analyses were done according to an intention-to-treat strategy that included all randomly assigned participants, irrespective of adherence. The trial is registered with ClinicalTrials.gov, number NCT01394952.

FINDINGS

Between Aug 18, 2011, and Aug 14, 2013, we screened 12 133 patients, of whom 9901 with type 2 diabetes and additional cardiovascular risk factors were randomly assigned to either dulaglutide (n=4949) or an equal volume of placebo (n=4952). During a median follow-up of 5·4 years, cerebrovascular and other cardiovascular outcomes were ascertained and adjudicated. 158 (3·2%) of 4949 participants assigned to dulaglutide and 205 (4·1%) of 4952 participants assigned to placebo had a stroke during follow-up (hazard ratio [HR] 0·76, 95% CI 0·62-0·94; p=0·010). Dulaglutide reduced ischaemic stroke (0·75, 0·59-0·94, p=0·012) but had no effect on haemorrhagic stroke (1·05, 0·55-1·99; p=0·89). Dulaglutide also reduced the composite of non-fatal stroke or all-cause death (0·88, 0·79-0·98; p=0·017) and disabling stroke (0·74, 0·56-0·99; p=0·042). The degree of disability after stroke did not differ by treatment group.

INTERPRETATION

Long-term dulaglutide use might reduce clinically relevant ischaemic stroke in people with type 2 diabetes but does not affect stroke severity.

FUNDING

Eli Lilly and Company.

GLP-1 secretion in acute ischemic stroke: association with functional outcome and comparison with healthy individuals

BACKGROUND

Glucagon-like peptide-1 (GLP-1) treatment has been shown to reduce stroke incidence in diabetes and also to be neuroprotective in experimental stroke models. The prognostic value of endogenous levels of GLP-1 in the recovery phase after stroke remains to be elucidated. The aim of the study was to investigate the potential association between GLP-1 levels and functional outcome after stroke and to determine whether GLP-1 is altered in the acute phase of stroke compared to 3 months post stroke and to healthy controls.

METHODS

Fasting GLP-1 was measured on hospital day 2-4 in patients without previously known diabetes (n = 59) that received recombinant tissue plasminogen activator (rtPA) for ischemic stroke. Fasting GLP-1 was measured again after 3 months and neurologic outcome was measured as modified Rankin Scale (mRS). mRS ≥ 2 was considered as unfavorable outcome. A control group of healthy individuals (n = 27) was recruited and their fasting GLP-1 was measured.

RESULTS

Fasting GLP-1 was higher in the patients that suffered a stroke compared to healthy controls (25.1 vs. 18.0 pmol/L; p = 0.004). The GLP-1 levels did not change significantly at the 3-month follow up OGTT (25.8 vs. 25.6; p = 0.80). There was no significant association between GLP-1 levels and unfavorable mRS (OR 1.03, 95% CI 0.95-1.12, p = 0.50).

CONCLUSIONS

Endogenous GLP-1 levels in patients that recently suffered an ischemic stroke are higher than in healthy controls and remained unchanged at the 3 months follow-up, possibly indicating an elevation of the levels of GLP-1 already pre-stroke. However, no association between endogenous GLP-1 and functional outcome of stroke 3 months post stroke was found.

Dulaglutide and cardiovascular outcomes in type 2 diabetes (REWIND): a double-blind, randomised placebo-controlled trial

BACKGROUND

Three different glucagon-like peptide-1 (GLP-1) receptor agonists reduce cardiovascular outcomes in people with type 2 diabetes at high cardiovascular risk with high glycated haemoglobin A_1c (HbA_1c) concentrations. We assessed the effect of the GLP-1 receptor agonist dulaglutide on major adverse cardiovascular events when added to the existing antihyperglycaemic regimens of individuals with type 2 diabetes with and without previous cardiovascular disease and a wide range of glycaemic control.

METHODS

This multicentre, randomised, double-blind, placebo-controlled trial was done at 371 sites in 24 countries. Men and women aged at least 50 years with type 2 diabetes who had either a previous cardiovascular event or cardiovascular risk factors were randomly assigned (1:1) to either weekly subcutaneous injection of dulaglutide (1·5 mg) or placebo. Randomisation was done by a computer-generated random code with stratification by site. All investigators and participants were masked to treatment assignment. Participants were followed up at least every 6 months for incident cardiovascular and other serious clinical outcomes. The primary outcome was the first occurrence of the composite endpoint of non-fatal myocardial infarction, non-fatal stroke, or death from cardiovascular causes (including unknown causes), which was assessed in the intention-to-treat population. This study is registered with ClinicalTrials.gov, number NCT01394952.

FINDINGS

Between Aug 18, 2011, and Aug 14, 2013, 9901 participants (mean age 66·2 years [SD 6·5], median HbA_1c 7·2% [IQR 6·6-8·1], 4589 [46·3%] women) were enrolled and randomly assigned to receive dulaglutide (n=4949) or placebo (n=4952). During a median follow-up of 5·4 years (IQR 5·1-5·9), the primary composite outcome occurred in 594 (12·0%) participants at an incidence rate of 2·4 per 100 person-years in the dulaglutide group and in 663 (13·4%) participants at an incidence rate of 2·7 per 100 person-years in the placebo group (hazard ratio [HR] 0·88, 95% CI 0·79-0·99; p=0·026). All-cause mortality did not differ between groups (536 [10·8%] in the dulaglutide group vs 592 [12·0%] in the placebo group; HR 0·90, 95% CI 0·80-1·01; p=0·067). 2347 (47·4%) participants assigned to dulaglutide reported a gastrointestinal adverse event during follow-up compared with 1687 (34·1%) participants assigned to placebo (p<0·0001).

INTERPRETATION

Dulaglutide could be considered for the management of glycaemic control in middle-aged and older people with type 2 diabetes with either previous cardiovascular disease or cardiovascular risk factors.

FUNDING

Eli Lilly and Company.

Once-weekly Dulaglutide and Major Cardiovascular Events—Results of the REWIND Trial

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