Heart rate acceleration with GLP-1 receptor agonists in type 2 diabetes patients: an acute and 12-week randomised, double-blind, placebo-controlled trial

Intestinal glucagon-like peptide-1: A new player associated with impaired counterregulatory responses to hypoglycaemia in type 1 diabetic mice

BACKGROUND

Impaired hypoglycaemic counterregulation has emerged as a critical concern for diabetic patients who may be hesitant to medically lower their blood glucose levels due to the fear of potential hypoglycaemic reactions. However, the patho-genesis of hypoglycaemic counterregulation is still unclear. Glucagon-like peptide-1 (GLP-1) and its analogues have been used as adjunctive therapies for type 1 diabetes mellitus (T1DM). The role of GLP-1 in counterregulatory dys-function during hypoglycaemia in patients with T1DM has not been reported.

AIM

To explore the impact of intestinal GLP-1 on impaired hypoglycaemic counterregulation in type 1 diabetic mice.

METHODS

T1DM was induced in C57BL/6J mice using streptozotocin, followed by intraperitoneal insulin injections to create T1DM models with either a single episode of hypoglycaemia or recurrent episodes of hypoglycaemia (DH5). Immunofluorescence, Western blot, and enzyme-linked immunosorbent assay were employed to evaluate the influence of intestinal GLP-1 on the sympathetic-adrenal reflex and glucagon (GCG) secretion. The GLP-1 receptor agonist GLP-1(7-36) or the antagonist exendin (9-39) were infused into the terminal ileum or injected intraperitoneally to further investigate the role of intestinal GLP-1 in hypoglycaemic counterregulation in the model mice.

RESULTS

The expression levels of intestinal GLP-1 and its receptor (GLP-1R) were significantly increased in DH5 mice. Consecutive instances of excess of intestinal GLP-1 weakens the sympathetic-adrenal reflex, leading to dysfunction of adrenal counterregulation during hypoglycaemia. DH5 mice showed increased pancreatic δ-cell mass, cAMP levels in δ cells, and plasma somatostatin concentrations, while cAMP levels in pancreatic α cells and plasma GCG levels decreased. Furthermore, GLP-1R expression in islet cells and plasma active GLP-1 levels were significantly increased in the DH5 group. Further experiments involving terminal ileal infusion and intraperitoneal injection in the model mice demonstrated that intestinal GLP-1 during recurrent hypoglycaemia hindered the secretion of the counterregulatory hormone GCG via the endocrine pathway.

CONCLUSION

Excessive intestinal GLP-1 is strongly associated with impaired counterregulatory responses to hypoglycaemia, leading to reduced appetite and compromised secretion of adrenaline, noradrenaline, and GCG during hypo-glycaemia.

Liraglutide Improves Myocardial Perfusion and Energetics and Exercise Tolerance in Patients With Type 2 Diabetes

BACKGROUND

Type 2 diabetes (T2D) is characterized by insulin resistance (IR) and dysregulated insulin secretion. Glucagon-like peptide-1 receptor agonist liraglutide promotes insulin secretion, whereas thiazolidinedione-pioglitazone decreases IR.

OBJECTIVES

This study aimed to compare the efficacies of increasing insulin secretion vs decreasing IR strategies for improving myocardial perfusion, energetics, and function in T2D via an open-label randomized crossover trial.

METHODS

Forty-one patients with T2D (age 63 years [95% CI: 59-68 years], 27 [66%] male, body mass index 27.8 kg/m2) [95% CI: 26.1-29.5 kg/m2)]) without cardiovascular disease were randomized to liraglutide or pioglitazone for a 16-week treatment followed by an 8-week washout and a further 16-week treatment with the second trial drug. Participants underwent rest and dobutamine stress 31phosphorus magnetic resonance spectroscopy and cardiovascular magnetic resonance for measuring the myocardial energetics index phosphocreatine to adenosine triphosphate ratio, myocardial perfusion (rest, dobutamine stress myocardial blood flow, and myocardial perfusion reserve), left ventricular (LV) volumes, systolic and diastolic function (mitral in-flow E/A ratio), before and after treatment. The 6-minute walk-test was used for functional assessments.

RESULTS

Pioglitazone treatment resulted in significant increases in LV mass (96 g [95% CI: 68-105 g] to 105 g [95% CI: 74-115 g]; P = 0.003) and mitral-inflow E/A ratio (1.04 [95% CI: 0.62-1.21] to 1.34 [95% CI: 0.70-1.54]; P = 0.008), and a significant reduction in LV concentricity index (0.79 mg/mL [95% CI: 0.61-0.85 mg/mL] to 0.73 mg/mL [95% CI: 0.56-0.79 mg/mL]; P = 0.04). Liraglutide treatment increased stress myocardial blood flow (1.62 mL/g/min [95% CI: 1.19-1.75 mL/g/min] to 2.08 mL/g/min [95% CI: 1.57-2.24 mL/g/min]; P = 0.01) and myocardial perfusion reserve (2.40 [95% CI: 1.55-2.68] to 2.90 [95% CI: 1.83-3.18]; P = 0.01). Liraglutide treatment also significantly increased the rest (1.47 [95% CI: 1.17-1.58] to 1.94 [95% CI: 1.52-2.08]; P =0.00002) and stress phosphocreatine to adenosine triphosphate ratio (1.32 [95% CI: 1.05-1.42] to 1.58 [95% CI: 1.19-1.71]; P = 0.004) and 6-minute walk distance (488 m [95% CI: 458-518 m] to 521 m [95% CI: 481-561 m]; P = 0.009).

CONCLUSIONS

Liraglutide treatment resulted in improved myocardial perfusion, energetics, and 6-minute walk distance in patients with T2D, whereas pioglitazone showed no effect on these parameters (Lean-DM [Targeting Beta-cell Failure in Lean Patients With Type 2 Diabetes]; NCT04657939).

Liraglutide does not increase heart rate of diabetic patients during acute myocardial infarction

BACKGROUND

Glucagon-like peptide 1 receptor agonists have been shown to reduce all-cause and cardiovascular mortality in patients with Type 2 diabetes mellitus (T2DM). The probable increase in heart rate hinders its early usage in acute myocardial infarction patients. In our study, we aimed to find out whether the use of liraglutide in patients with acute myocardial infarction as early as at the time of hospitalization would increase the heart rate.

METHODS

This was an observational retrospective study. From December 2020 to August 2021, 200 patients with acute myocardial infarction were included in our study and divided into three groups: T2DM + liraglutide group (n = 46), T2DM + non-liraglutide group (n = 42), and non-T2DM group (n = 112). The primary outcomes were the differences in heart rate. Secondary outcomes were differences in systolic and diastolic blood pressure.

RESULTS

There were no significant differences in heart rate among the three groups at admission, the day before the first shot of liraglutide, and before discharge. There was also no significant difference in heart rate between diabetic patients with acute myocardial infarction and those on liraglutide during the hospital stay. And there were no differences of beta-blocker dosages among the three groups. Liraglutide did not affect the blood pressure during acute myocardial infarction.

CONCLUSIONS

Liraglutide did not increase the heart rate in diabetic patients during acute myocardial infarction and did not lead to an increase in the dose of beta-blockers in the patients. It also had no effect on blood pressure and showed better efficacy in lowering glucose levels without additional hypoglycemic events.

The effect of SGLT2 inhibitors and GLP1 receptor agonists on arterial stiffness: A meta-analysis of randomized controlled trials

BACKGROUND

Pulse wave velocity (PWV) and augmentation index (AIx) are indices used to assess arterial stiffness. We evaluated the effect of sodium glucose co-transporter-2 inhibitors (SGLT2i) and glucagon-like peptide-1 receptor agonists (GLP1-RA) on arterial stiffness indices.

METHODS

We searched PubMed (up to January 2024) for RCTs assessing the effect of SGLT2i or GLP1-RA on arterial stiffness with reporting outcomes PWV and AIx. Effect sizes of the included studies were expressed as weighted mean difference (WMD) and 95 % confidence interval. Subgroup analyses were performed based on comparator (placebo vs. active comparator), design (RCT vs. crossover), population (diabetic vs. all) and blindness (yes vs. no).

RESULTS

A total of 19 studies (SGLT2i, 12 studies; GLP1-RA, 5 studies; SGLT2i/GLP1-RA combination, 2 studies) assessing 1212 participants were included. We did not find any statistically significant association between GLP1-RA or SGLT2i and PWV or AIx. None of the subgroup analyses showed any statistically significant result.

CONCLUSION

No evidence of a favorable change in arterial stiffness indices (PWV, AIx) was found following the administration of SGLT2i or GLP1-RA.

Chronotropic Responses to GLP-1 Receptor Agonists and Sitagliptin in Atria From Diabetic Rats

ABSTRACT

Type 2 diabetes mellitus increases the risk of cardiovascular diseases. Therefore, elucidation of the cardiovascular effects of antidiabetics is crucial. Incretin-based therapies are increasingly used for type 2 diabetes mellitus treatment as monotherapy and in combination. We aimed to study the effects of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and sitagliptin on beating rates in isolated atria from diabetic rats. The chronotropic responses to GLP-1 RAs and sitagliptin as monotherapy and in combinations with metformin, pioglitazone, and glimepiride in isolated atria from control and diabetic rats were determined. GLP-1 (7-36), GLP-1 (9-36), and exendin-4 (1-39) produced increases in beating rates in both control and diabetic rat atria. However, sitagliptin increased the beating frequency only in the diabetic group. Exendin (9-39), nitro- l -arginine methyl ester hydrochloride, and indomethacin blocked responses to GLP-1 RAs but not the response to sitagliptin. Glibenclamide, 4-aminopyridine, apamin, charybdotoxin, superoxide dismutase, and catalase incubations did not change responses to GLP-1 RAs and sitagliptin. GLP-1 RAs increase beating rates in isolated rat atrium through GLP-1 receptor, nitric oxide, and cyclooxygenase pathways but not potassium channels and reactive oxygen radicals.

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Cyclic Adenosine Monophosphate in Cardiac and Sympathoadrenal GLP-1 Receptor Signaling: Focus on Anti-Inflammatory Effects

Glucagon-like peptide-1 (GLP-1) is a multifunctional incretin hormone with various physiological effects beyond its well-characterized effect of stimulating glucose-dependent insulin secretion in the pancreas. An emerging role for GLP-1 and its receptor, GLP-1R, in brain neuroprotection and in the suppression of inflammation, has been documented in recent years. GLP-1R is a G protein-coupled receptor (GPCR) that couples to Gs proteins that stimulate the production of the second messenger cyclic 3',5'-adenosine monophosphate (cAMP). cAMP, acting through its two main effectors, protein kinase A (PKA) and exchange protein directly activated by cAMP (Epac), exerts several anti-inflammatory (and some pro-inflammatory) effects in cells, depending on the cell type. The present review discusses the cAMP-dependent molecular signaling pathways elicited by the GLP-1R in cardiomyocytes, cardiac fibroblasts, central neurons, and even in adrenal chromaffin cells, with a particular focus on those that lead to anti-inflammatory effects by the GLP-1R. Fully elucidating the role cAMP plays in GLP-1R's anti-inflammatory properties can lead to new and more precise targets for drug development and/or provide the foundation for novel therapeutic combinations of the GLP-1R agonist medications currently on the market with other classes of drugs for additive anti-inflammatory effect.

Does Semaglutide Use Decrease Complications and Costs Following Total Knee Arthroplasty?

BACKGROUND

Diabetes mellitus (DM) and obesity are associated with total knee arthroplasty (TKA) complications. Semaglutide, a medication for DM and weight loss, can potentially affect TKA outcomes. This study investigated whether semaglutide use during TKA demonstrates fewer: (1) medical complications; (2) implant-related complications; (3) readmissions; and (4) costs.

METHODS

A retrospective query was performed using a National database to 2021. Patients undergoing TKA for osteoarthritis with DM and semaglutide use were successfully propensity score-matched to controls semaglutide = 7,051; control = 34,524. Outcomes included 90-day postoperative medical complications, 2-year implant-related complications, 90-day readmissions, in-hospital lengths of stay, and costs. Multivariate logistical regressions calculated odds ratios (ORs), 95% confidence intervals, and P values (P < .003 as significance threshold after Bonferroni correction).

RESULTS

Semaglutide cohorts had higher incidence and odds of myocardial infarction (1.0 versus 0.7%; OR 1.49; P = .003), acute kidney injury (4.9 versus 3.9%; OR 1.28; P < .001), pneumonia (2.8 versus 1.7%; OR 1.67; P < .001), and hypoglycemic events (1.9 versus 1.2%; OR 1.55; P < .001), but lower odds of sepsis (0 versus 0.4%; OR 0.23; P < .001). Semaglutide cohorts also had lower odds of prosthetic joint infections (2.1 versus 3.0%; OR 0.70; P < .001) and readmission (7.0 versus 9.4%; OR 0.71; P < .001), and trended toward lower odds of revisions (4.0 versus 4.5%; OR 0.86; P = .02) and 90-day costs ($15,291.66 versus $16,798.46; P = .012).

CONCLUSION

Semaglutide use during TKA decreased risk for sepsis, prosthetic joint infections, and readmissions, but also increased risk for myocardial infarction, acute kidney injury, pneumonia, and hypoglycemic events.

Sodium-Glucose Cotransporter 2 Inhibitor Treatment and Risk of Atrial Fibrillation: Scandinavian Cohort Study

OBJECTIVE

To assess the association between use of sodium-glucose cotransporter 2 (SGLT2) inhibitors and the risk of new-onset atrial fibrillation (AF) in routine clinical practice.

RESEARCH DESIGN AND METHODS

We used nationwide registers in Denmark, Norway, and Sweden from 2013 to 2018 in order to include patients without a history of AF who were newly prescribed an SGLT2 inhibitor or an active comparator (glucagon-like peptide 1 [GLP-1] receptor agonist). We performed a cohort study to assess new-onset AF in intention-to-treat analyses using Cox regression, adjusted for baseline covariates with propensity score weighting.

RESULTS

We identified 79,343 new users of SGLT2 inhibitors (59.2% dapagliflozin, 40.0% empagliflozin, 0.8% canagliflozin, <0.1% ertugliflozin) and 57,613 new users of GLP-1 receptor agonists. Mean age of the study cohort was 61 years and 60% were men. The adjusted incidence rate of new-onset AF was 8.6 per 1,000 person-years for new users of SGLT2 inhibitors compared with 10.0 per 1,000 person-years for new users of GLP-1 receptor agonists. The adjusted hazard ratio (aHR) was 0.89 (95% CI 0.81-0.96), and the rate difference was 1.4 fewer events per 1,000 person-years (95% CI 0.6-2.1). Using an as-treated exposure definition, the aHR for new-onset AF was 0.87 (95% CI 0.76-0.99). No statistically significant heterogeneity of the aHRs was observed between subgroups of patients with and without a history of heart failure or major cardiovascular disease.

CONCLUSIONS

In this cohort study using nationwide data from three countries, use of SGLT2 inhibitors, compared with GLP-1 receptor agonists, was associated with a modestly reduced risk of new-onset AF.

Cardiovascular effects of incretins - focus on GLP-1 receptor agonists

GLP-1 receptor agonists (GLP-1 RAs) have been used to treat patients with type 2 diabetes since 2005 and have become popular because of the efficacy and durability in relation to glycaemic control in combination with weight loss in most patients. Today in 2022, seven GLP-1 RAs, including oral semaglutide are available for treatment of type 2 diabetes. Since the efficacy in relation to reduction of HbA1c and body weight as well as tolerability and dosing frequency vary between agents, the GLP-1 RAs cannot be considered equal. The short acting lixisenatide showed no cardiovascular benefits, while once daily liraglutide and the weekly agonists, subcutaneous semaglutide, dulaglutide, and efpeglenatide, all lowered the incidence of cardiovascular events. Liraglutide, oral semaglutide and exenatide once weekly also reduced mortality. GLP-1 RAs reduce the progression of diabetic kidney disease. In the 2019 consensus report from EASD/ADA, GLP-1 RAs with demonstrated cardio-renal benefits (liraglutide, semaglutide and dulaglutide) are recommended after metformin to patients with established cardiovascular diseases or multiple cardiovascular risk factors. European Society of Cardiology (ESC) suggests starting with a SGLT-2 inhibitor or a GLP-1 RA in drug naïve patients with type 2 diabetes and atherosclerotic CVD or high CV Risk. However, the results from cardiovascular outcome trials (CVOT) are very heterogeneous suggesting that some GLP-1RA are more suitable to prevent CVD than others. The CVOTs provide a basis upon which individual treatment decisions for patients with T2D and CVD can be made.

Meta-analysis of cardiovascular outcome trials assessing the impact of glucagon-like peptide-1 receptor agonists on major cardiac arrhythmias

OBJECTIVE

Glucagon-like peptide-1 receptor agonists (GLP-1RAs), a group of novel antidiabetic agents, demonstrated beneficial cardiovascular effects in recent large, placebo-controlled randomised clinical trials (RCTs); their clear antiarrhythmic benefit has not been yet underlined. The purpose of the present meta-analysis is to clarify the impact of GLP-1RAs on different types of cardiac arrhythmias.

METHODS

We searched PubMed from its inception up to 8 October 2020 for all available cardiovascular and renal outcome, placebo-controlled RCTs utilising GLP-1RAs versus placebo. The present meta-analysis is reported according to the Preferred Reporting Items for Systematic reviews and Meta-analyses (PRISMA) statement.

RESULTS

We included data from 7 RCTs with GLP-1RAs in a total of 55,943 participants. Treatment with GLP-1RAs did not provide significant benefit in the risk for atrial fibrillation (RR = 0.81, 95%CI; 0.78-1.15, I² = 51%), atrial flutter (RR = 0.79, 95%CI; 0.53-1.16, I² = 0%), ventricular fibrillation (RR = 0.99, 95%CI; 0.48-2.04, I² = 0%), ventricular tachycardia (RR = 1.41, 95%CI; 0.87-2.28, I² = 10%), atrial tachycardia (RR = 0.63, 95%CI; 0.10-3.90, I² = 24%), sinus node dysfunction (RR = 0.70, 95%CI; 0.40-1.23, I² = 0%), ventricular extrasystoles (RR = 1.37, 95%CI; 0.56-3.30, I² = 0%), second-degree atrioventricular block (RR = 0.96, 95%CI; 0.52-1.74, I² = 0%) or complete atrioventricular block (RR = 0.78, 95%CI; 0.39-1.54, I² = 38%).

CONCLUSIONS

In patients with type 2 diabetes mellitus, treatment with GLP-1RAs does not significantly affect the risk for major cardiac arrhythmias.

Mechanisms underlying the blood pressure lowering effects of dapagliflozin, exenatide, and their combination in people with type 2 diabetes: a secondary analysis of a randomized trial

BACKGROUND

Sodium-glucose cotransporter-2 inhibitors (SGLT2i) and glucagon-like peptide-1 receptor agonists (GLP-1RA) lower blood pressure (BP). When SGLT2i and GLP-1RA are combined, synergistic effects on BP have been observed. The mechanisms underlying these BP reductions are incompletely understood. The aim of this study was to assess the mechanisms underlying the BP reduction with the SGLT2i dapagliflozin, GLP-1RA exenatide, and dapagliflozin-exenatide compared with placebo in people with obesity and type 2 diabetes.

METHODS

Sixty-six people with type 2 diabetes were randomized to 16 weeks of dapagliflozin 10 mg/day, exenatide 10 µg twice daily, dapagliflozin-exenatide, or placebo treatment. The effect of treatments on estimates of: (1) plasma volume (calculated by Strauss formula, bioimpedance spectroscopy, hematocrit, (2) autonomic nervous system activity (heart rate variability), (3) arterial stiffness (pulse wave applanometry), (4) systemic hemodynamic parameters including peripheral vascular resistance, cardiac output and stroke volume (all derived from non-invasively systemic hemodynamic monitoring), and (5) natriuresis (24-hour urine collection) were assessed after 10 days and 16 weeks of treatment.

RESULTS

After 10 days, dapagliflozin reduced systolic BP (SBP) by - 4.7 mmHg, and reduced plasma volume. After 16 weeks, dapagliflozin reduced SBP by - 4.4 mmHg, and reduced sympathetic nervous system (SNS) activity. Exenatide had no effect on SBP, but reduced parasympathetic nervous system activity after 10 days and 16 weeks. After 10 days, dapagliflozin-exenatide reduced SBP by - 4.2 mmHg, and reduced plasma volume. After 16 weeks, dapagliflozin-exenatide reduced SBP by - 6.8 mmHg, and the reduction in plasma volume was still observed, but SNS activity was unaffected.

CONCLUSIONS

The dapagliflozin-induced plasma volume contraction may contribute to the initial SBP reduction, while a reduction in SNS activity may contribute to the persistent SBP reduction. Dapagliflozin-exenatide resulted in the largest decrease in SBP. The effect on plasma volume was comparable to dapagliflozin monotherapy, and SNS activity was not reduced, therefore other mechanisms are likely to contribute to the blood pressure lowering effect of this combination, which need further investigation. Trial registration Clinicaltrials.gov, NCT03361098.

Glucagon-Like Peptide-1 Receptor Agonists in Type 2 Diabetes Mellitus and Cardiovascular Disease: The Past, Present, and Future

Type 2 diabetes mellitus (T2DM) is associated with high cardiovascular morbidity and mortality, and cardiovascular diseases are the leading causes of death and disability in people with T2DM. Unfortunately, therapies strictly aimed at glycemic control have poorly contributed to a significant reduction in the risk of cardiovascular events. On the other hand, randomized controlled trials have shown that five glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and one exendin-based GLP-1 RA reduced atherosclerotic cardiovascular events in patients with diabetes at high cardiovascular risk. Furthermore, a meta-analysis including these six agents showed a reduction in major adverse cardiovascular events as well as all-cause mortality compared with placebo, regardless of structural homology. Evidence has also shown that some drugs in this class have beneficial effects on renal outcomes, such as preventing the onset of macroalbuminuria. In addition to lowering blood pressure, these drugs also favorably impacted on body weight in large randomized controlled trials as in real-world studies, a result considered a priority in T2DM management; these and other factors may justify the benefits of GLP-1 RAs upon the cardiovascular system, regardless of glycemic control. Finally, studies showed safety with a low risk of hypoglycemia and no increase in pancreatitis events. Given these benefits, GLP-1 RAs were preferentially endorsed in the guidelines of the European and American societies for patients with these conditions. This narrative review provides a current and comprehensive overview of GLP-1 RAs as cardiovascular and renal protective agents, far beyond their use as glucose-lowering drugs, supporting their effectiveness in treating patients with T2DM at high cardiovascular risk.

Safety of Semaglutide

The glucagon-like peptide-1 receptor agonist (GLP-1RA) semaglutide is the most recently approved agent of this drug class, and the only GLP-1RA currently available as both subcutaneous and oral formulation. While GLP-1RAs effectively improve glycemic control and cause weight loss, potential safety concerns have arisen over the years. For semaglutide, such concerns have been addressed in the extensive phase 3 registration trials including cardiovascular outcome trials for both subcutaneous (SUSTAIN: Semaglutide Unabated Sustainability in Treatment of Type 2 Diabetes) and oral (PIONEER: Peptide InnOvatioN for the Early diabEtes tReatment) semaglutide and are being studied in further trials and registries, including real world data studies. In the current review we discuss the occurrence of adverse events associated with semaglutide focusing on hypoglycemia, gastrointestinal side effects, pancreatic safety (pancreatitis and pancreatic cancer), thyroid cancer, gallbladder events, cardiovascular aspects, acute kidney injury, diabetic retinopathy (DRP) complications and injection-site and allergic reactions and where available, we highlight potential underlying mechanisms. Furthermore, we discuss whether effects are specific for semaglutide or a class effect. We conclude that semaglutide induces mostly mild-to-moderate and transient gastrointestinal disturbances and increases the risk of biliary disease (cholelithiasis). No unexpected safety issues have arisen to date, and the established safety profile for semaglutide is similar to that of other GLP-1RAs where definitive conclusions for pancreatic and thyroid cancer cannot be drawn at this point due to low incidence of these conditions. Due to its potent glucose-lowering effect, patients at risk for deterioration of existing DRP should be carefully monitored if treated with semaglutide, particularly if also treated with insulin. Given the beneficial metabolic and cardiovascular actions of semaglutide, and the low risk for severe adverse events, semaglutide has an overall favorable risk/benefit profile for patient with type 2 diabetes.

Effects of dapagliflozin and gliclazide on the cardiorenal axis in people with type 2 diabetes

OBJECTIVES

There is a bidirectional relationship between cardiovascular and renal disease. The drug-class of SGLT2 inhibitors improves outcomes at both ends of this so called cardiorenal axis. We assessed the effects of SGLT2 inhibition and sulfonylurea treatment on systemic hemodynamic function and investigated whether SGLT2 inhibitor-induced changes in systemic hemodynamics correlate with changes in renal hemodynamics.

METHODS

Forty-four people with type 2 diabetes were randomized to 12 weeks of dapagliflozin 10 mg/day or gliclazide 30 mg/day treatment. Systemic hemodynamic function, autonomic nervous system activity, and vascular stiffness were measured noninvasively, whereas renal hemodynamics, glomerular filtration rate (GFR) and effective renal plasma flow, were assessed with gold-standard urinary clearances of inulin or iohexol and para-aminohippuric acid, respectively. Correlation analyses were performed to assess relationships between dapagliflozin-induced changes in cardiovascular and renal variables.

RESULTS

Dapagliflozin reduced stroke volume by 4%, cardiac output by 5%, vascular stiffness by 11%, and mean arterial pressure by 5% from baseline, without increasing heart rate or sympathetic activity, while simultaneously lowering glomerular filtration rate by 8%. Despite similar improvements in glycemic control by dapagliflozin and gliclazide (-0.5 ± 0.5 versus-0.7 ± 0.5%; P = 0.12), gliclazide did not affect any of these measurements. There was no clear association between the dapagliflozin-induced changes in cardiovascular and renal physiology.

CONCLUSION

Dapagliflozin seemingly influences systemic and renal hemodynamics independently and beyond glucose lowering in people with type 2 diabetes.This clinical trial was registered at https://clinicalTrials.gov (ID: NCT02682563).

Treating Arterial Ageing in Patients with Diabetes: From Mechanisms to Effective Drugs

Diabetes mellitus is a major healthcare problem. It is not only characterized by hyperglycemia and chronic complications, but in longer lasting diabetes and a longer living population, it is also associated with accelerated arterial ageing, which importantly contributes to cardiovascular complications. The accelerated arterial ageing in patients with diabetes should be considered separately from arterial ageing in patients without diabetes. Basic and clinical research have allowed better insight into the mechanisms of arterial ageing. In a simplified mechanistic way, it could be considered that the three tightly connected cornerstone characteristics of arterial ageing in patients with diabetes are: phenotypic presentation as endothelial dysfunction and arterial stiffness, and the underlying basic ageing-facilitating mechanism represented as the impaired expression of genetic longevity pathways. Currently, specific drugs for preventing/treating arterial ageing are not available. Therefore, we aimed to review the capacity of available drugs, particularly antidiabetic drugs, to interfere with the arterial ageing process. In the near future, these characteristics could help to guide therapy in patients with diabetes. Overall, it appears that arterial ageing could become a new target in diabetes. The expanding knowledge regarding the capability of antidiabetic drugs and other available drugs to inhibit/delay arterial aging is therefore essential.

Glucagon-Like Peptide-1 (GLP-1) in the Integration of Neural and Endocrine Responses to Stress

Glucagon like-peptide 1 (GLP-1) within the brain is produced by a population of preproglucagon neurons located in the caudal nucleus of the solitary tract. These neurons project to the hypothalamus and another forebrain, hindbrain, and mesolimbic brain areas control the autonomic function, feeding, and the motivation to feed or regulate the stress response and the hypothalamic-pituitary-adrenal axis. GLP-1 receptor (GLP-1R) controls both food intake and feeding behavior (hunger-driven feeding, the hedonic value of food, and food motivation). The activation of GLP-1 receptors involves second messenger pathways and ionic events in the autonomic nervous system, which are very relevant to explain the essential central actions of GLP-1 as neuromodulator coordinating food intake in response to a physiological and stress-related stimulus to maintain homeostasis. Alterations in GLP-1 signaling associated with obesity or chronic stress induce the dysregulation of eating behavior. This review summarized the experimental shreds of evidence from studies using GLP-1R agonists to describe the neural and endocrine integration of stress responses and feeding behavior.

Cardiovascular effects of glucagon-like peptide 1 receptor agonists: from mechanistic studies in humans to clinical outcomes

Type 2 diabetes mellitus (T2DM) is currently one of the most prevalent diseases, with as many as 415 million patients worldwide. T2DM is characterized by elevated blood glucose levels and is often accompanied by several comorbidities, such as cardiovascular disease. Treatment of T2DM is focused on reducing glucose levels by either lifestyle changes or medical treatment. One treatment option for T2DM is based on the gut-derived hormone glucagon-like peptide 1 (GLP-1). GLP-1 reduces blood glucose levels by stimulating insulin secretion, however, it is rapidly degraded, and thereby losing its glycaemic effect. GLP-1 receptor agonists (GLP-1RAs) are immune to degradation, prolonging the glycaemic effect. Lately, GLP-1RAs have spiked the interest of researchers and clinicians due to their beneficial effects on cardiovascular disease. Preclinical and clinical data have demonstrated that GLP-1 receptors are abundantly present in the heart and that stimulation of these receptors by GLP-1 has several effects. In this review, we will discuss the effects of GLP-1RA on heart rate, blood pressure, microvascular function, lipids, and inflammation, as measured in human mechanistic studies, and suggest how these effects may translate into the improved cardiovascular outcomes as demonstrated in several trials.

A review of GLP-1 receptor agonists in type 2 diabetes: A focus on the mechanism of action of once-weekly agents

WHAT IS KNOWN AND OBJECTIVE

Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are one of the preferred approved treatment options for people with type 2 diabetes (T2D) and inadequate glycaemic control. The objective of this review is to provide a general clinical overview of the similarities and differences in the mechanisms of action (MoA) of the once-weekly GLP-1 RA class of medications, highlighting the role of pharmacists in providing optimal medication management, education and care for people with diabetes.

METHODS

This is a narrative review of the published literature regarding the MoA of the currently available once-weekly GLP-1 RAs in T2D.

RESULTS AND DISCUSSION

GLP-1 RAs have an established efficacy and safety profile. Their benefits derive from their blood glucose-lowering effects, which include pancreatic beta-cell-mediated glucose-dependent insulin secretion and suppressed glucagon release, and their ability to slow gastric emptying and promote satiety. GLP-1 RAs may also exert beneficial effects on multiple organ systems in which GLP-1 receptors are present, including the cardiovascular and renal systems. Differences between individual GLP-1 RAs with regard to their molecular size, structure and duration of action (short or longer acting) have led to differing pharmacodynamics and clinical effects such as degree of glycaemic control, weight loss abilities, cardiovascular effects and tolerability profiles.

WHAT IS NEW AND CONCLUSION

From the literature, this appears to be the first review of the evidence base supporting the MoA of once-weekly GLP-1 RAs in T2D aimed at pharmacists, with a particular emphasis on the expanding role of pharmacists in team-based diabetes management. As a class, GLP-1 RAs are an effective treatment option for people with T2D, shown to achieve multi-factorial clinical benefits. The results suggest that when selecting or advising about treatments, pharmacists should consider how the different once-weekly GLP-1 RAs and their MoA affect clinical outcomes in order to ensure optimal treatment for individuals.

Liraglutide reduces systolic blood pressure in patients with type 2 diabetes mellitus: A meta-analysis of randomized trials

The antidiabetic effect of liraglutide in patients with type 2 diabetes mellitus has been explored in several trials. We performed this meta-analysis determining the effects of liraglutide on blood pressure in these patients. Three electronic databases (Pubmed, Web of Science, and Cochrane Central) were searched for all published articles evaluating the effects of liraglutide on blood pressure in subjects with type 2 diabetes mellitus. Total 968 patients were included in 10 randomized, double-blind, placebo-controlled trials with a follow-up of 16 ± 9 weeks. Liraglutide 1.8 mg/day reduced systolic blood pressure (weighted mean differences -5.39 (95% confidence interval, -7.26, -3.51) mm Hg, p < .001) and body weight (weighted mean differences -2.07 (95% confidence interval, -2.62, -1.51) kg, p < .001) in patients with type 2 diabetes mellitus. There was no significant difference for changes of diastolic blood pressure between liraglutide 1.8 mg/day and placebo in these patients (weighted mean differences -0.53 (95% confidence interval, -1.96, 0.89) mm Hg, p > .05). The increases of heart rate were greater than placebo in patients treated with liraglutide 1.8 mg/day (weighted mean differences 6.03 (95% confidence interval, 4.78, 7.29) kg, p < .001). There was no significant correlation between reduction of systolic blood pressure and weight loss in patients treated with liraglutide 1.8 mg/day (p = .24). In conclusion, liraglutide reduces systolic blood pressure and body weight in patients with type 2 diabetes mellitus. These data suggest the beneficial effects of liraglutide on cardiovascular protection and may improve prognosis in these patients.

Semaglutide injection for the treatment of adults with type 2 diabetes

INTRODUCTION

Current estimates suggest that approximately 10% of the global adult population have type 2 diabetes. In recent years there has been a significant increase in the therapeutic options available for its treatment. This article examines the use of injectable semaglutide in the treatment of type 2 diabetes.

AREAS COVERED

We will describe the global problem posed by type 2 diabetes followed by consideration of the glucagon-like peptide 1 receptor agonist class of glucose lowering therapies. The focus is then shifted to semaglutide and a description of the large phase 3 pre-approval trial programme known as SUSTAIN. There is consideration of glucose control, the primary end-point of the phase 3 programme, as well as secondary end-points such as weight and blood pressure. There follows a précis of the cardiovascular outcomes trial for subcutaneous semaglutide (SUSTAIN 6) and the post-approval publications. As well as the SUSTAIN trial programme we used PubMed to identify relevant publications.

EXPERT OPINION

This section discusses the position of semaglutide and the risks and benefits versus other once weekly GLP-1RAs and finally the development of an oral version of semaglutide, which has recently been approved in the United States.

Glucagon-like peptide-1 receptors in the kidney: impact on renal autoregulation

Glucagon-like peptide-1 (GLP-1) and strategies based on this blood sugar-reducing and appetite-suppressing hormone are used to treat obesity and type 2 diabetes. However, the GLP-1 receptor (GLP-1R) is also present in the kidney, where it influences renal function. The effect of GLP-1 on the kidney varies between humans and rodents. The effect of GLP-1 on kidney function also seems to vary depending on its concentration and the physiological or pathological state of the kidney. In studies with rodents or humans, acute infusion of pharmacological doses of GLP-1 stimulates natriuresis and diuresis. However, the effect on the renal vasculature is less clear. In rodents, GLP-1 infusion increases renal plasma flow and glomerular filtration rate, suggesting renal vasodilation. In humans, only a subset of the study participants exhibits increased renal plasma flow and glomerular filtration rate. Differential status of kidney function and changes in renal vascular resistance of the preglomerular arterioles may account for the different responses of the human study participants. Because renal function in patients with type 2 diabetes is already at risk or compromised, understanding the effects of GLP-1R activation on kidney function in these patients is particularly important. This review examines the distribution of GLP-1R in the kidney and the effects elicited by GLP-1 or GLP-1R agonists. By integrating results from acute and chronic studies in healthy individuals and patients with type 2 diabetes along with those from rodent studies, we provide insight into how GLP-1R activation affects renal function and autoregulation.

How Do SGLT2 (Sodium-Glucose Cotransporter 2) Inhibitors and GLP-1 (Glucagon-Like Peptide-1) Receptor Agonists Reduce Cardiovascular Outcomes?: Completed and Ongoing Mechanistic Trials

OBJECTIVE

There is substantial interest in how GLP-1RA (glucagon-like peptide-1 receptor agonists) and SGLT2 (sodium-glucose cotransporter 2) inhibitors reduce cardiovascular and renal events; yet, robust mechanistic data in humans remain sparse. We conducted a narrative review of published and ongoing mechanistic clinical trials investigating the actions of SGLT2 inhibitors and GLP-1RAs to help the community appreciate the extent of ongoing work and the variety and design of such trials. Approach and Results: To date, trials investigating the mechanisms of action of SGLT2 inhibitors have focused on pathways linked to glucose metabolism and toxicity, hemodynamic/volume, vascular and renal actions, and cardiac effects, including those on myocardial energetics. The participants studied have included those with established cardiovascular disease (including coronary artery disease and heart failure), liver disease, renal impairment, obesity, and hypertension; some of these trials have enrolled patients both with and without type 2 diabetes mellitus. GLP-1RA mechanistic trials have focused on glucose-lowering, insulin-sparing, weight reduction, and blood pressure-lowering effects, as well as possible direct vascular, cardiac, and renal effects of these agents. Very few mechanisms of action of SGLT2 inhibitors or GLP-1RAs have so far been convincingly demonstrated. One small trial (n=97) of SGLT2 inhibitors has investigated the cardiac effects of these drugs, where a small reduction in left ventricular mass was found. Data on vascular effects are limited to one trial in type 1 diabetes mellitus, which suggests some beneficial actions. SGLT2 inhibitors have been shown to reduce liver fat. We highlight the near absence of mechanistic data to explain the beneficial effects of SGLT2 inhibitors in patients without diabetes mellitus. GLP-1RAs have not been found to have major cardiovascular mechanisms of action in the limited, completed trials. Conflicting data around the impact on infarct size have been reported. No effect on left ventricular ejection fraction has been demonstrated.

CONCLUSIONS

We have tabulated the extensive ongoing mechanistic trials that will report over the coming years. We report 2 exemplar ongoing mechanistic trials in detail to give examples of the designs and techniques employed. The results of these many ongoing trials should help us understand how SGLT2 inhibitors and GLP-1RAs improve cardiovascular and renal outcomes and may also identify unexpected mechanisms suggesting novel therapeutic applications.

Liraglutide as Adjunct to Insulin Treatment in Patients with Type 1 Diabetes: A Systematic Review and Meta-analysis

BACKGROUND

A few Randomized Controlled Trials (RCTs) have evaluated the use of liraglutide in Type 1 Diabetes (T1D). Through the present systematic review and meta-analysis, we aim at critically appraising and summarizing those RCTs, providing precise effect estimates.

METHODS

We searched major databases and grey literature from their inception to October 2018, for RCTs with a duration ≥ 12 weeks, comparing liraglutide with placebo or any other comparator as adjunct to insulin in patients with T1D, investigating major efficacy and safety endpoints. This review is reported in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement.

RESULTS

We included 5 trials with 2,445 randomized participants. Liraglutide provided modest reductions in HbA1c, with liraglutide 1.8 mg producing the greatest decrease (MD = -0.24%, 95% CI -0.32 to -0.16, I2=0%). Significant weight reduction, up to 4.87 kg with liraglutide 1.8 mg was also observed (95% CI -5.31 to -4.43, I2=0%). Decrease in total daily insulin dose, primarily driven by a decrease in bolus insulin requirements, was demonstrated. Liraglutide decreased non-significantly the odds for severe hypoglycemia (OR=0.80, 95% CI 0.57-1.14, I2=0%), while it increased significantly the odds for gastrointestinal adverse events (for nausea, OR=4.70, 95% CI 3.68-6.00, I2=37%, and for vomiting, OR=2.50, 95% CI 1.54-4.72, I2=27%). A significant increase in heart rate was also demonstrated. No association with diabetic ketoacidosis or malignancies was identified.

CONCLUSION

In patients with T1D, liraglutide might prove be an adjunct to insulin, improving glycemic control, inducing body weight loss and decreasing exogenous insulin requirements and severe hypoglycemia.

Cardiovascular, renal and liver protection with novel antidiabetic agents beyond blood glucose lowering in type 2 diabetes: consensus article from the European Society of Hypertension Working Group on Obesity, Diabetes and the High-risk Patient

: The prevalence of type 2 diabetes (T2D) has increased over the past few decades. T2D has a strong genetic propensity that becomes overt when a patient is exposed to a typical Western lifestyle, gain weight and becomes obese, whereas weight loss protects from the development of T2D. Except of lifestyle modifications, the choice of the appropriate treatment is essential in the management of patients with T2D and appears critical for the obese population with T2D. The new pharmacological approach for the treatment of T2D, sodium-glucose cotransporter 2 inhibitors and glucagon-like peptide 1 receptor agonists, seems to be effective not only in the management of T2D but also for weight loss, reduction of blood pressure and improvement of nonalcoholic fatty liver disease. Sodium-glucose cotransporter 2 inhibitors and glucagon-like peptide 1 analogues reduced cardiovascular risk, prevented cardiovascular disease and mortality, thereby playing an important role in the treatment of obese patients with hypertension and T2D.

Greater glucagon-like peptide-1 responses to oral glucose are associated with lower central and peripheral blood pressures

Background and aim

Cardiovascular diseases (CVDs) are globally the leading cause of death and hypertension is a significant risk factor. Treatment with glucagon-like peptide-1 (GLP-1) receptor agonists has been associated with decreases in blood pressure and CVD risk. Our aim was to investigate the association between endogenous GLP-1 responses to oral glucose and peripheral and central haemodynamic measures in a population at risk of diabetes and CVD.

Methods

This cross-sectional study included 837 Danish individuals from the ADDITION-PRO cohort (52% men, median (interquartile range) age 65.5 (59.8 to 70.7) years, BMI 26.1 (23.4 to 28.5) kg/m², without antihypertensive treatment and known diabetes). All participants received an oral glucose tolerance test with measurements of GLP-1 at 0, 30 and 120 min. Aortic stiffness was assessed by pulse wave velocity (PWV). The associations between GLP-1 response and central and brachial blood pressure (BP) and PWV were assessed in linear regression models adjusting for age and sex.

Results

A greater GLP-1 response was associated with lower central systolic and diastolic BP of − 1.17 mmHg (95% confidence interval (CI) − 2.07 to − 0.27 mmHg, P = 0.011) and − 0.74 mmHg (95% CI − 1.29 to − 0.18 mmHg, P = 0.009), respectively, as well as lower brachial systolic and diastolic BP of − 1.27 mmHg (95% CI − 2.20 to − 0.33 mmHg, P = 0.008) and − 1.00 (95% CI − 1.56 to − 0.44 mmHg, P = 0.001), respectively. PWV was not associated with GLP-1 release (P = 0.3). Individuals with the greatest quartile of GLP-1 response had clinically relevant lower BP measures compared to individuals with the lowest quartile of GLP-1 response (central systolic BP: − 4.94 (95% CI − 8.56 to − 1.31) mmHg, central diastolic BP: − 3.05 (95% CI − 5.29 to − 0.80) mmHg, brachial systolic BP: − 5.18 (95% CI − 8.94 to − 1.42) mmHg, and brachial diastolic BP: − 2.96 (95% CI − 5.26 to − 0.67) mmHg).

Conclusion

Greater glucose-stimulated GLP-1 responses were associated with clinically relevant lower central and peripheral blood pressures, consistent with beneficial effects on the cardiovascular system and reduced risk of CVD and mortality.

Trial registration ClinicalTrials.gov Identifier: NCT00237549. Retrospectively registered 10 October 2005

Heart rate variability in type 2 diabetic subjects randomized to liraglutide or glimepiride treatment, both in combination with metformin: A randomized, open, parallel-group study

AIMS

Reduced heart rate variability (HRV) and increased heart rate (HR) are associated with cardiovascular (CV) mortality. In the Liraglutide Effect and Action in Diabetes outcome trial, it was demonstrated a lower rate of CV events in type 2 diabetes (T2D) patients treated with liraglutide compared to placebo. We aimed to investigate the effects of liraglutide compared with glimepiride treatment in T2D patients on the CV risk parameters HR and HRV.

METHODS

This was a post hoc study whereas sixty-two T2D individuals (45 males) were randomized to once daily 1.8 mg liraglutide or once daily 4 mg glimepiride, both in combination with 1 g metformin. HR and measurement of sympathetic activity, that is standard deviation (SD) of beat-to-beat (NN) intervals (SDNN), was assessed by 24-hour Holter monitoring system. Parasympathetic activity was analysed by root mean square of successive differences (RMSSD) in NN intervals and high-frequency (HF), low-frequency (LF) and very low-frequency power.

RESULTS

Baseline clinical characteristics for liraglutide (n = 33) and glimepiride (n = 29) groups were well matched. There was a persistent increase in diurnal HR followed by a significantly increased HR at daytime 5.4 beats per minute, P = 0.011 in the liraglutide-treated group. There was no treatment change between groups in SDNN and RMSSD, or in HF and LF frequency power analysis.

CONCLUSIONS

Liraglutide treatment increased diurnal variation in hourly mean HR followed by an increase in mean daytime HR, independently of changes in sympathetic or parasympathetic activity.

Iloprost infusion prevents the insulin-induced reduction in skeletal muscle microvascular blood volume but does not enhance peripheral glucose uptake in type 2 diabetic patients

AIMS

In type 2 diabetes impaired insulin-induced muscle perfusion is thought to contribute to reduced whole-body glucose uptake. In this study, we examined the effects of iloprost, a stable prostacyclin analogue, on insulin-induced muscle capillary recruitment and whole-body glucose uptake.

MATERIALS AND METHODS

In a randomized cross-over design, 12 type 2 diabetes patients (age, 55 [46-69] years; BMI, 33.1 [31.0-39] kg/m² ) underwent two hyperinsulinaemic-euglycaemic clamps, one with and one without simultaneous low-dose iloprost infusion. Contrast-enhanced ultrasonography of the vastus lateralis muscle was performed before and during the clamp. Muscle capillary recruitment was calculated as percentage change in microvascular blood volume (MBV) before and during the clamp.

RESULTS

Insulin infusion reduced skeletal muscle MBV by ~50% compared to the fasting state (fasting, 1.77·10^-4 [1.54·10^-5 -2.44·10^-3 ] arbitrary units (AU); hyperinsulinaemia, 6.69·10^-5 [2.68·10^-6 -5.72·10^-4 ] AU; P = 0.050). Infusion of iloprost prevented this insulin-induced skeletal muscle capillary derecruitment, from (-49.5 [-89.5 to 55.3] %) to (8.0 [-68.8 to 306.6] %), for conditions without and with iloprost, respectively. The rate of glucose disappearance (R_d ) did not change significantly during iloprost infusion (17.3 [10.0-40.8] μmol/kg/min) compared with insulin infusion alone (17.6 [9.9-68.7] μmol/kg/min).

CONCLUSIONS

Our data suggest that acute improvement in insulin-stimulated muscle perfusion is not an attractive therapeutic approach to bypass cellular resistance to glucose uptake in type 2 diabetes. Whether long-term improvements in insulin-induced muscle perfusion may prove beneficial for glucose disposal remains to be determined.

Lixisenatide Versus Insulin Glulisine on Fasting and Postbreakfast Systemic Hemodynamics in Type 2 Diabetes Mellitus Patients

The prolonged treatment effects of a short-acting GLP-1RA (glucagon-like peptide-1 receptor agonist), such as lixisenatide, on fasting and postprandial systemic hemodynamics in type 2 diabetes mellitus patients are unknown. In this secondary analysis, we included 34 overweight insulin glargine-treated type 2 diabetes mellitus patients (mean±SD age, 62±7 years; HbA_1c, 8.0±0.9%; systolic blood pressure [BP], 133.9±16.1 mm Hg; diastolic BP, 75.4±8.39 mm Hg) that were randomized to once-daily lixisenatide 20 μg or once-daily titrated insulin glulisine for 8 weeks. Systemic hemodynamics (oscillometric device and finger photoplethysmography), arterial stiffness (applanation tonometry), and cardiac sympathovagal balance (heart rate variability) were measured in the fasting state and repetitively (up to minute 175) after a standardized mixed breakfast. Acetaminophen was given orally to estimate gastric emptying rate. Lixisenatide did not affect fasting systemic hemodynamics compared with insulin glulisine from baseline to week 8. Postbreakfast overall, lixisenatide compared with insulin glulisine tended to increase systolic BP by 5.2±2.9 mm Hg (P=0.087) and increased diastolic BP by 5.4±1.4 mm Hg (P<0.001), with respective maximal differences of +10.2±3.7 mm Hg (P=0.007) and +7.2±1.5 mm Hg (P<0.001). Lixisenatide increased systemic vascular resistance (P<0.001) and arterial stiffness (P=0.007). No between-group differences in overall postbreakfast heart rate, cardiac output, or cardiac sympathovagal balance, and circulating catecholamines, angiotensin II, or aldosterone were observed. Both treatments lowered HbA_1c similarly, whereas lixisenatide achieved greater reductions in postbreakfast plasma glucose excursions. Lixisenatide slowed gastric emptying rate, which statistically explained changes in postbreakfast BP. Lixisenatide compared with once-daily titrated insulin glulisine for 8 weeks does not affect fasting but increases postbreakfast BP in insulin glargine-treated type 2 diabetes mellitus patients. This effect could, at least in part, be explained by reduced passage rate of nutrients and water and activation of the gastrovascular reflex.

Do sodium-glucose co-transporter-2 inhibitors prevent heart failure with a preserved ejection fraction by counterbalancing the effects of leptin? A novel hypothesis

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce the risk of serious heart failure events in patients with type 2 diabetes, but little is known about mechanisms that might mediate this benefit. The most common heart failure phenotype in type 2 diabetes is obesity-related heart failure with a preserved ejection fraction (HFpEF). It has been hypothesized that the synthesis of leptin in this disorder leads to sodium retention and plasma volume expansion as well as to cardiac and renal inflammation and fibrosis. Interestingly, leptin-mediated neurohormonal activation appears to enhance the expression of SGLT2 in the renal tubules, and SGLT2 inhibitors exert natriuretic actions at multiple renal tubular sites in a manner that can oppose the sodium retention produced by leptin. In addition, SGLT2 inhibitors reduce the accumulation and inflammation of perivisceral adipose tissue, thus minimizing the secretion of leptin and its paracrine actions on the heart and kidneys to promote fibrosis. Such fibrosis probably contributes to the impairment of cardiac distensibility and glomerular function that characterizes obesity-related HFpEF. Ongoing clinical trials with SGLT2 inhibitors in heart failure are positioned to confirm or refute the hypothesis that these drugs may favourably influence the course of obesity-related HFpEF by their ability to attenuate the secretion and actions of leptin.

Augmentation of glucagon-like peptide-1 receptor signalling by neprilysin inhibition: potential implications for patients with heart failure

Augmentation of glucagon-like peptide-1 (GLP-1) receptor signalling is an established approach to the treatment of type 2 diabetes. However, endogenous GLP-1 and long-acting GLP-1 receptor analogues are degraded not only by dipeptidyl peptidase-4, but also by neprilysin. This observation raises the possibilities that endogenous GLP-1 contributes to the clinical effects of neprilysin inhibition and that patients concurrently treated with sacubitril/valsartan and incretin-based drugs may experience important drug-drug interactions. Specifically, potentiation of GLP-1 receptor signalling may underlie the antihyperglycaemic actions of sacubitril/valsartan. Neprilysin inhibitors may also be able to augment the effects of long-acting GLP-1 analogues to increase heart rate and myocardial cyclic AMP, and thus, potentiate these deleterious actions; if so, concomitant treatment with GLP-1 receptor agonists may limit the efficacy of neprilysin inhibitors in patients with both heart failure and diabetes. For patients not concurrently treated with GLP-1 analogues, the action of neprilysin to enhance the effects of GLP-1 may be particularly relevant in the brain, where augmentation of GLP-1 and other endogenous peptides may act to inhibit amyloid-induced neuroinflammation and cytotoxicity and improve memory formation and executive functioning. Experimentally, neprilysin inhibitors may also potentiate the effects of endogenous GLP-1 and GLP-1 receptor agonists on blood vessels and the kidney. The role of neprilysin in the metabolism of endogenous GLP-1 and long-acting GLP-1 analogues points to a range of potential pathophysiological effects that may be clinically relevant to patients with heart failure, with or without diabetes.

Postprandial renal haemodynamic effect of lixisenatide vs once-daily insulin-glulisine in patients with type 2 diabetes on insulin-glargine: An 8-week, randomised, open-label trial

AIM

To determine whether lixisenatide, a prandial short-acting glucagon-like peptide receptor agonist (GLP-1RA), ameliorates postprandial glomerular hyperfiltration in patients with type 2 diabetes mellitus (T2DM) compared with insulin-glulisine (iGlu).

METHODS

Postprandial renal haemodynamic effects of 8-week treatment with lixisenatide 20 µg vs once-daily titrated iGlu were measured in 35 overweight patients with T2DM inadequately controlled on insulin-glargine, with or without metformin [mean ± SD age 62 ± 7 years, HbA1c 8.0% ± 0.9%, estimated glomerular filtration rate (GFR) 85 ± 12 mL/min/1.73 m² , median (IQR) urinary albumin/creatinine ratio 1.5 (0.9-3.0) mg/mmol]. After a standardised breakfast, GFR (primary endpoint) and effective renal plasma flow (ERPF) were determined by inulin and para-aminohippuric acid renal clearance, respectively, based on timed urine sampling. Intrarenal haemodynamic functions were estimated using Gomez equations.

RESULTS

Compared with iGlu, lixisenatide did not affect GFR [+0.1 mL/min/1.73 m² (95% CI -9 to 9)], ERPF [-17 mL/min/1.73 m² (-61 to 26)], other (intra-)renal haemodynamics or renal damage markers, but increased fractional sodium excretion [+0.25% (0.09-0.41)] and urinary pH [+0.7 (0.3-1.2)]. Plasma renin, angiotensin-II and aldosterone were unchanged. Lixisenatide and iGlu reduced HbA1c similarly, by 0.8% ± 0.1% and 0.6% ± 0.1%, respectively, while postprandial glucose was lower with lixisenatide (P = .002). Compared with iGlu, lixisenatide reduced bodyweight [-1.4 kg (-2.5 to -0.2)] and increased postprandial mean arterial pressure [+9 mm Hg (4-14)].

CONCLUSION

Eight-week lixisenatide treatment does not affect postprandial (intra-)renal haemodynamics compared with iGlu when added to insulin-glargine in patients with T2DM without overt nephropathy. Prolonged lixisenatide treatment has a sustained natriuretic effect, which is in contrast to previous reports on long-acting GLP-1RA, reduces body weight and increases postprandial blood pressure compared with iGlu.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT02276196.

Long-Acting GLP-1 Receptor Agonist Exenatide Influence on the Autonomic Cardiac Sympatho-Vagal Balance

Long-acting glucagon-like peptide 1 receptor agonists are increasingly used to treat type 2 diabetes. An increase of heart rate (HR) has been observed with their use. To elucidate the role of the cardiac sympatho-vagal balance as a possible mediator of the reported increase in HR, we performed power spectral analysis of HR variability (HRV) in patients receiving exenatide extended-release (ER). Twenty-eight ambulatory patients with type 2 diabetes underwent evaluation at initiation of exenatide-ER and thereafter at 3 and at 6 months. To obtain spectral analyses of HRV, a computerized acquisition of 10 minutes of RR electrocardiogram intervals (mean values of ~700 RR intervals) were recorded both in lying and in standing positions. All patients showed a substantial increase of HR both in lying and in standing positions. Systolic blood pressure, body weight, and glycated hemoglobin A1c significantly decreased both at 3 and 6 months compared with basal levels. The low-frequency/high-frequency ratio varied from 3.05 ± 0.4 to 1.64 ± 0.2 (P < 0.001) after 3 months and to 1.57 ± 0.3 (P < 0.001) after 6 months in a lying position and from 4.56 ± 0.8 to 2.24 ± 0.3 (P < 0.001) after 3 months and to 2.38 ± 0.4 (P < 0.001) after 6 months in a standing position compared with basal values, respectively. HR variations, induced by exenatide-ER treatment, do not appear to be related to sympathetic autonomic tone. Of note, we observed a relative increase of vagal influence on the heart.