Effects of Liraglutide on Cardiovascular Outcomes in Patients With Type 2 Diabetes Mellitus With or Without History of Myocardial Infarction or Stroke

Approach to Obesity Treatment in Primary Care: A Review

Importance

More than 40% of US adults have obesity, which increases the risks for multiple chronic diseases and premature mortality. Historically, nonsurgical interventions often have not led to sufficient weight loss and maintenance to improve health, but highly effective antiobesity medications (AOMs) have recently become available, and additional effective therapeutics are under development. Given that most medical care for adults with obesity is delivered in primary care settings, guidance for integrating weight-management approaches is needed.

Observations

Lifestyle interventions can lead to a mean weight loss of 2% to 9% of initial weight at 1 year and increase the likelihood of weight loss of 5% or more, but weight regain over time is common even with continued treatment. Adjunctive treatments, including AOMs and surgical approaches, can lead to larger, more sustained weight loss and improvements in numerous obesity-associated medical conditions. Highly effective AOMs, including nutrient-stimulated hormone-based therapies, induce mean weight loss of 15% or more. Barriers to intervention, including access to care, have a disproportionate influence on populations most affected by obesity and its consequences.

Conclusions and Relevance

Primary care clinicians play a vital role in the assessment, management, and support of patients with obesity. With careful clinical assessment and shared decision-making, a flexible treatment plan can be developed that reflects evidence of treatment efficacy, patient preference, and feasibility of implementation. Adjunctive therapies to lifestyle interventions, including more effective pharmacotherapeutics for obesity, offer hope to patients and the potential for considerable improvements in health and quality of life.

Risk of major adverse cardiovascular events and stroke associated with treatment with GLP-1 or the dual GIP/GLP-1 receptor agonist tirzepatide for type 2 diabetes: A systematic review and meta-analysis

INTRODUCTION

Mounting evidence suggests that glucagon-like-peptide-1 receptor-agonists (GLP-1 RAs) attenuate cardiovascular-risk in type-2 diabetes (T2DM). Tirzepatide is the first-in-class, dual glucose-dependent-insulinotropic-polypeptide GIP/GLP-1 RA approved for T2DM.

PATIENTS AND METHODS

A systematic review and meta-analysis of randomized-controlled clinical trials (RCTs) was performed to estimate: (i) the incidence of major adverse cardiovascular events (MACE); and (ii) incidence of stroke, fatal, and nonfatal stroke in T2DM-patients treated with GLP-1 or GIP/GLP-1 RAs (vs placebo).

RESULTS

Thirteen RCTs (9 and 4 on GLP-1 RAs and tirzepatide, respectively) comprising 65,878 T2DM patients were included. Compared to placebo, GLP-1RAs or GIP/GLP-1 RAs reduced MACE (OR: 0.87; 95% CI: 0.81-0.94; p < 0.01; I2 = 37%), all-cause mortality (OR: 0.88; 95% CI: 0.82-0.96; p < 0.01; I2 = 21%) and cardiovascular-mortality (OR: 0.88; 95% CI: 0.80-0.96; p < 0.01; I2 = 14%), without differences between GLP-1 versus GIP/GLP-1 RAs. Additionally, GLP-1 RAs reduced the odds of stroke (OR: 0.84; 95% CI: 0.76-0.93; p < 0.01; I2 = 0%) and nonfatal stroke (OR: 0.85; 95% CI: 0.76-0.94; p < 0.01; I2 = 0%), whereas no association between fatal stroke and GLP-1RAs was uncovered (OR: 0.80; 95% CI: 0.61-1.05; p = 0.105; I2 = 0%). In secondary analyses, GLP-1 RAs prevented ischemic stroke (OR: 0.74; 95% CI: 0.61-0.91; p < 0.01; I2 = 0%) and MACE-recurrence, but not hemorrhagic stroke (OR: 0.92; 95% CI: 0.51-1.66; p = 0.792; I2 = 0%). There was no association between GLP-1RAs or GIP/GLP-1 RAs and fatal or nonfatal myocardial infarction.

DISCUSSION AND CONCLUSION

GLP-1 and GIP/GLP-1 RAs reduce cardiovascular-risk and mortality in T2DM. While there is solid evidence that GLP-1 RAs significantly attenuate the risk of ischemic stroke in T2DM, dedicated RCTs are needed to evaluate the efficacy of novel GIP/GLP-1 RAs for primary and secondary stroke prevention.

Trends and Outcomes Associated With Bariatric Surgery and Pharmacotherapies With Weight Loss Effects Among Patients With Heart Failure and Obesity

BACKGROUND

Utilization patterns of bariatric surgery among older patients with heart failure (HF), and the associations with cardiovascular outcomes, are not well known.

METHODS

Medicare beneficiaries with HF and at least class II obesity from 2013 to 2020 were identified with Medicare Provider Analysis and Review 100% inpatient files and Medicare 5% outpatient files. Patients who underwent bariatric surgery were matched to controls in a 1:2 ratio (matched on exact age, sex, race, body mass index, HF encounter year, and HF hospitalization rate pre-surgery/matched period). In an exploratory analysis, patients prescribed pharmacotherapies with weight loss effects (semaglutide, liraglutide, naltrexone-bupropion, or orlistat) were identified and matched to controls with a similar strategy in addition to HF medical therapy data. Cox models evaluated associations between weight loss therapies (as a time-varying covariate) and mortality risk and HF hospitalization rate (calculated as the rate of HF hospitalizations following index HF encounter per 100 person-months) during follow-up.

RESULTS

Of 298 101 patients with HF and body mass index ≥35 kg/m2, 2594 (0.9%) underwent bariatric surgery (45% men; mean age, 56.2 years; mean body mass index, 51.5 kg/m2). In propensity-matched analyses over a median follow-up of 4.7 years, bariatric surgery was associated with lower risk of all-cause mortality (HR, 0.55 [95% CI, 0.49-0.63]; P<0.001), greater reduction in HF hospitalization rate (rate ratio, 0.72 [95% CI, 0.67-0.77]; P<0.001), and lower atrial fibrillation risk (HR, 0.78 [95% CI, 0.65-0.93]; P=0.006). Use of pharmacotherapies with weight loss effects was low (4.8%), with 96.3% prescribed GLP-1 (glucagon-like peptide-1) agonists (semaglutide, 23.6%; liraglutide, 72.7%). In propensity-matched analysis over a median follow-up of 2.8 years, patients receiving pharmacotherapies with weight loss effects (versus matched controls) had a lower risk of all-cause mortality (HR, 0.82 [95% CI, 0.71-0.95]; P=0.007) and HF hospitalization rate (rate ratio, 0.87 [95% CI, 0.77-0.99]; P=0.04).

CONCLUSIONS

Bariatric surgery and pharmacotherapies with weight loss effects are associated with a lower risk of adverse outcomes among older patients with HF and obesity; however, overall utilization remains low.

A Methodological Framework for Meta-analysis and Clinical Interpretation of Subgroup Data: The Case of Major Adverse Cardiovascular Events With GLP-1 Receptor Agonists and SGLT2 Inhibitors in Type 2 Diabetes

We present a methodological framework for conducting and interpreting subgroup meta-analyses. Methodological steps comprised evaluation of clinical heterogeneity regarding the definition of subpopulations, credibility assessment of subgroup meta-analysis, and translation of relative into absolute treatment effects. We used subgroup data from type 2 diabetes cardiovascular outcomes trials (CVOTs) with glucagon-like peptide 1 (GLP-1) receptor agonists and sodium-glucose cotransporter 2 (SGLT2) inhibitors for patients with established cardiovascular disease and those at high cardiovascular risk without manifest cardiovascular disease. First, we evaluated the variability in definitions of the subpopulations across CVOTs using major adverse cardiovascular events (MACE) incidence in the placebo arm as a proxy for baseline cardiovascular risk. As baseline risk did not differ considerably across CVOTs, we conducted subgroup meta-analyses of hazard ratios (HRs) for MACE and assessed the credibility of a potential effect modification. Results suggested using the same overall relative effect for each of the two subpopulations (HR 0.85, 95% CI 0.80-0.90, for GLP-1 receptor agonists and HR 0.91, 95% CI 0.85-0.97, for SGLT2 inhibitors). Finally, we calculated 5-year absolute treatment effects (number of fewer patients with event per 1,000 patients). Treatment with GLP-1 receptor agonists resulted in 30 fewer patients with event in the subpopulation with established cardiovascular disease and 14 fewer patients with event in patients without manifest cardiovascular disease. For SGLT2 inhibitors, the respective absolute effects were 18 and 8 fewer patients with event per 1,000 patients. This framework can be applied to subgroup meta-analyses regardless of outcomes or modification variables.

Discovery of non-peptide GLP-1r natural agonists for enhancing coronary safety in type 2 diabetes patients

This study explores the computational discovery of non-peptide agonists targeting the Glucagon-Like Peptide-1 Receptor (GLP-1R) to enhance the safety of major coronary outcomes in individuals affected by Type 2 Diabetes. The objective is to identify novel compounds that can activate the GLP-1R pathway without the limitations associated with peptide agonists. Type 2 diabetes mellitus (T2DM) is associated with an increased risk of cardiovascular disease (CVD) and mortality, which is attributed to the accumulation of fat in organs, including the heart. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are frequently used to manage T2DM and could potentially offer cardiovascular benefits. Therefore, this study examines non-peptide agonists of GLP-1R to improve coronary safety in type 2 diabetes patients. After rigorous assessments, two standout candidates were identified, with natural compound 12 emerging as the most promising. This study represents a notable advancement in enhancing the management of coronary outcomes among individuals with type 2 diabetes. The computational methodology employed successfully pinpointed potential GLP-1R natural agonists, providing optimism for the development of safer and more effective therapeutic interventions. Although computational methodologies have provided crucial insights, realizing the full potential of these compounds requires extensive experimental investigations, crucial in advancing therapeutic strategies for this critical patient population.Communicated by Ramaswamy H. Sarma.

Down the rabbit hole: reviewing the evidence for primary prevention of cardiovascular disease in people with obesity

Obesity is a prevalent chronic disorder and a well-known risk factor for cardiovascular disease. However, the evidence of treating obesity for primary prevention of major cardiovascular events is still scarce and controversial. In this review, we provided a comprehensive description of the current evidence in treating obesity regarding cardiovascular protection. Bariatric surgery appears to be the most robust method to reduce events in people without established cardiovascular disease. High compliance to lifestyle interventions can further reduce cardiovascular risk. Concerning pharmacological therapies, a post hoc analysis from SUSTAIN-6 and a meta-analysis from STEP trials suggest that semaglutide, a GLP-1 receptor agonist, could reduce cardiovascular events in people without established cardiovascular disease. The first study addressed specifically a high-risk population with diabetes and, the second, low- or intermediary-risk individuals without diabetes. Tirzepatide, a novel dual GIP/GLP-1 agonist, although not yet tested in specific cardiovascular outcomes trials, could be an alternative since it induces loss in weight similar to the achieved by bariatric surgery. Therefore, extrapolated data in distinct baseline cardiovascular risk populations suggest that these two drugs could be used in primary prevention with the aim of preventing cardiovascular events, but the grade of this evidence is still low. Specifically designed studies are needed to address this specific topic.

mTORC1 and SGLT2 Inhibitors-A Therapeutic Perspective for Diabetic Cardiomyopathy

Diabetic cardiomyopathy is a critical diabetes-mediated co-morbidity characterized by cardiac dysfunction and heart failure, without predisposing hypertensive or atherosclerotic conditions. Metabolic insulin resistance, promoting hyperglycemia and hyperlipidemia, is the primary cause of diabetes-related disorders, but ambiguous tissue-specific insulin sensitivity has shed light on the importance of identifying a unified target paradigm for both the glycemic and non-glycemic context of type 2 diabetes (T2D). Several studies have indicated hyperactivation of the mammalian target of rapamycin (mTOR), specifically complex 1 (mTORC1), as a critical mediator of T2D pathophysiology by promoting insulin resistance, hyperlipidemia, inflammation, vasoconstriction, and stress. Moreover, mTORC1 inhibitors like rapamycin and their analogs have shown significant benefits in diabetes and related cardiac dysfunction. Recently, FDA-approved anti-hyperglycemic sodium-glucose co-transporter 2 inhibitors (SGLT2is) have gained therapeutic popularity for T2D and diabetic cardiomyopathy, even acknowledging the absence of SGLT2 channels in the heart. Recent studies have proposed SGLT2-independent drug mechanisms to ascertain their cardioprotective benefits by regulating sodium homeostasis and mimicking energy deprivation. In this review, we systematically discuss the role of mTORC1 as a unified, eminent target to treat T2D-mediated cardiac dysfunction and scrutinize whether SGLT2is can target mTORC1 signaling to benefit patients with diabetic cardiomyopathy. Further studies are warranted to establish the underlying cardioprotective mechanisms of SGLT2is under diabetic conditions, with selective inhibition of cardiac mTORC1 but the concomitant activation of mTORC2 (mTOR complex 2) signaling.

Treatment effect heterogeneity following type 2 diabetes treatment with GLP1-receptor agonists and SGLT2-inhibitors: a systematic review

BACKGROUND

A precision medicine approach in type 2 diabetes requires the identification of clinical and biological features that are reproducibly associated with differences in clinical outcomes with specific anti-hyperglycaemic therapies. Robust evidence of such treatment effect heterogeneity could support more individualized clinical decisions on optimal type 2 diabetes therapy.

METHODS

We performed a pre-registered systematic review of meta-analysis studies, randomized control trials, and observational studies evaluating clinical and biological features associated with heterogenous treatment effects for SGLT2-inhibitor and GLP1-receptor agonist therapies, considering glycaemic, cardiovascular, and renal outcomes. After screening 5,686 studies, we included 101 studies of SGLT2-inhibitors and 75 studies of GLP1-receptor agonists in the final systematic review.

RESULTS

Here we show that the majority of included papers have methodological limitations precluding robust assessment of treatment effect heterogeneity. For SGLT2-inhibitors, multiple observational studies suggest lower renal function as a predictor of lesser glycaemic response, while markers of reduced insulin secretion predict lesser glycaemic response with GLP1-receptor agonists. For both therapies, multiple post-hoc analyses of randomized control trials (including trial meta-analysis) identify minimal clinically relevant treatment effect heterogeneity for cardiovascular and renal outcomes.

CONCLUSIONS

Current evidence on treatment effect heterogeneity for SGLT2-inhibitor and GLP1-receptor agonist therapies is limited, likely reflecting the methodological limitations of published studies. Robust and appropriately powered studies are required to understand type 2 diabetes treatment effect heterogeneity and evaluate the potential for precision medicine to inform future clinical care.

Safety and Efficacy of Liraglutide on Cardiovascular Outcomes in Patients With Diabetes Mellitus: A Meta-Analysis of Randomized Controlled Trials

Diabetes mellitus (DM) is a chronic metabolic disorder, with type 2 diabetes (T2DM) significantly impacting the cardiovascular (CV) system. Our comprehensive study on the cardiovascular effects of liraglutide, conducted concurrently with the formulation of diabetes treatment guidelines, aims to provide healthcare providers and patients with reassurance regarding the safety and effectiveness of liraglutide. From the beginning until August 20, 2023, we conducted searches in databases including PubMed, Web of Science, Embase, Cochrane Library, Scopus, and Google Scholar. These searches aimed to identify studies comparing liraglutide to control in terms of symptom resolution among patients with T2DM. For all relevant outcomes, we calculated risk ratios along with their corresponding 95% confidence intervals. Thirteen randomized controlled trials (RCTs) were included in this analysis. The results demonstrated a significant reduction in the risk of major adverse cardiovascular events (MACE), myocardial infarction, CV mortality, and all-cause mortality. No significant difference was found between the liraglutide and control groups for the outcome of stroke. However, sensitivity analysis revealed a significant reduction in the risk of stroke among patients taking liraglutide. Our comprehensive meta-analysis strongly supports the use of liraglutide for managing cardiovascular disease (CVD) due to its established safety and effectiveness. Further RCTs and meta-analyses are needed to more thoroughly evaluate liraglutide's therapeutic potential, with the aim of enhancing the quality of life for those with CVD.

Effects of GLP-1 receptor agonists on neurological complications of diabetes

Emerging evidence suggests that treatment with glucagon-like peptide-1 receptor agonists (GLP-1 RAs) could be an interesting treatment strategy to reduce neurological complications such as stroke, cognitive impairment, and peripheral neuropathy. We performed a systematic review to examine the evidence concerning the effects of GLP-1 RAs on neurological complications of diabetes. The databases used were Pubmed, Scopus and Cochrane. We selected clinical trials which analysed the effect of GLP-1 RAs on stroke, cognitive impairment, and peripheral neuropathy. We found a total of 19 studies: 8 studies include stroke or major cardiovascular events, 7 involve cognitive impairment and 4 include peripheral neuropathy. Semaglutide subcutaneous and dulaglutide reduced stroke cases. Liraglutide, albiglutide, oral semaglutide and efpeglenatide, were not shown to reduce the number of strokes but did reduce major cardiovascular events. Exenatide, dulaglutide and liraglutide improved general cognition but no significant effect on diabetic peripheral neuropathy has been reported with GLP-1 RAs. GLP-1 RAs are promising drugs that seem to be useful in the reduction of some neurological complications of diabetes. However, more studies are needed.

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

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

Liraglutide alleviates myocardial ischemia‒reperfusion injury in diabetic mice

Diabetic patients are prone to acute myocardial infarction. Although reperfusion therapy can preserve the viability of the myocardium, it also causes fatal ischemia‒reperfusion injury. Diabetes can exacerbate myocardial ischemia‒reperfusion injury, but the mechanism is unclear. We aimed to characterize the effects of liraglutide on the prevention of ischemia‒reperfusion injury and inadequate autophagy. Liraglutide reduced the myocardial infarction area and improved cardiac function in diabetic mice. We further demonstrated that liraglutide mediated these protective effects by activating AMPK/mTOR-mediated autophagy. Liraglutide markedly increased p-AMPK levels and the LC3 II/LC3 I ratio and reduced p-mTOR levels and p62 expression. Pharmacological inhibition of mTOR increased cell viability and autophagy levels in high glucose and H/R-treated H9C2 cells. Overall, our study reveals that liraglutide acts upstream of the AMPK/mTOR pathway to effectively counteract high glucose- and H/R-induced cell dysfunction by activating AMPK/mTOR-dependent autophagy, providing a basis for the clinical prevention and treatment of ischemia‒reperfusion in diabetes.

Precision medicine in type 2 diabetes: A systematic review of treatment effect heterogeneity for GLP1-receptor agonists and SGLT2-inhibitors

Background

A precision medicine approach in type 2 diabetes requires identification of clinical and biological features that are reproducibly associated with differences in clinical outcomes with specific anti-hyperglycaemic therapies. Robust evidence of such treatment effect heterogeneity could support more individualized clinical decisions on optimal type 2 diabetes therapy.

Methods

We performed a pre-registered systematic review of meta-analysis studies, randomized control trials, and observational studies evaluating clinical and biological features associated with heterogenous treatment effects for SGLT2-inhibitor and GLP1-receptor agonist therapies, considering glycaemic, cardiovascular, and renal outcomes.

Results

After screening 5,686 studies, we included 101 studies of SGLT2-inhibitors and 75 studies of GLP1-receptor agonists in the final systematic review. The majority of papers had methodological limitations precluding robust assessment of treatment effect heterogeneity. For glycaemic outcomes, most cohorts were observational, with multiple analyses identifying lower renal function as a predictor of lesser glycaemic response with SGLT2-inhibitors and markers of reduced insulin secretion as predictors of lesser response with GLP1-receptor agonists. For cardiovascular and renal outcomes, the majority of included studies were post-hoc analyses of randomized control trials (including meta-analysis studies) which identified limited clinically relevant treatment effect heterogeneity.

Conclusions

Current evidence on treatment effect heterogeneity for SGLT2-inhibitor and GLP1-receptor agonist therapies is limited, likely reflecting the methodological limitations of published studies. Robust and appropriately powered studies are required to understand type 2 diabetes treatment effect heterogeneity and evaluate the potential for precision medicine to inform future clinical care.

Plain language summary

This review identifies research that helps understand which clinical and biological factors that are associated with different outcomes for specific type 2 diabetes treatments. This information could help clinical providers and patients make better informed personalized decisions about type 2 diabetes treatments. We focused on two common type 2 diabetes treatments: SGLT2-inhibitors and GLP1-receptor agonists, and three outcomes: blood glucose control, heart disease, and kidney disease. We identified some potential factors that are likely to lessen blood glucose control including lower kidney function for SGLT2-inhibitors and lower insulin secretion for GLP1-receptor agonists. We did not identify clear factors that alter heart and renal disease outcomes for either treatment. Most of the studies had limitations, meaning more research is needed to fully understand the factors that influence treatment outcomes in type 2 diabetes.

New Insights into the Use of Liraglutide-Impact on Cardiovascular Risk and Microvascular Outcomes

Despite the availability of many glucose-lowering drugs, patients with type 2 diabetes mellitus (T2DM) often do not achieve the desired effect, and cardiovascular complications remain the leading cause of death in this group of patients. Recently, more and more attention has been paid to the properties of drugs, with particular emphasis on the possibility of reducing cardiovascular risk. One of them is liraglutide, which belongs to long-acting analogs of glucagon-like peptides-1 (GLP-1); it imitates incretins and causes an increase in insulin secretion. The current study focused on analyzing the efficacy and safety of liraglutide, as well as its impact on microvascular and cardiovascular outcomes in the treatment of patients with T2DM. Hyperglycemia-induced endothelial dysfunction, which is known to play a key role in maintaining cardiovascular homeostasis, is common in diabetes. Liraglutide reduces endothelial dysfunction by reversing damage to endothelial cells. By reducing the generation of reactive oxygen species (ROS), thereby affecting Bax, Bcl-2 protein levels, and restoring signaling pathways, Liraglutide reduces oxidative stress, inflammation, and prevents endothelial cell apoptosis. Liraglutide has beneficial effects on the cardiovascular system; patients with high cardiovascular risk particularly benefit from treatment, as it reduces their major adverse cardiovascular event (MACE) rate, which takes into account cardiovascular death, stroke, and non-fatal myocardial infarction. Liraglutide reduces the occurrence and progression of nephropathy, which is one of the most common microvascular complications of diabetes.

Pharmacotherapy of obesity: an update on the available medications and drugs under investigation

Obesity is an epidemic and a public health threat. Medical weight management remains one of the options for the treatment of excess weight and recent advances have revolutionized how we treat, and more importantly how we will be treating obesity in the near future. Metreleptin and Setmelanotide are currently indicated for rare obesity syndromes, and 5 other medications (orlistat, phentermine/topiramate, naltrexone/bupropion, liraglutide, semaglutide) are approved for non-syndromic obesity. Tirzepatide is about to be approved, and other drugs, with exciting novel mechanisms of action primarily based on incretins, are currently being investigated in different phases of clinical trials. The majority of these compounds act centrally, to reduce appetite and increase satiety, and secondarily, in the gastrointestinal tract to slow gastric emptying. All anti-obesity medications improve weight and metabolic parameters, with variable potency and effects depending on the specific drug. The currently available data do not support a reduction in hard cardiovascular outcomes, but it is almost certain that such data are forthcoming in the very near future. The choice of the anti-obesity medication needs to take into consideration the patient's clinical and biochemical profile, co-morbidities, and drug contra-indications, as well as expected degree of weight loss and improvements in cardio-renal and metabolic risk. It also remains to be seen whether precision medicine may offer personalized solutions to individuals with obesity, and whether it may represent the future of medical weight management along with the development of novel, very potent, anti-obesity medications currently in the pipeline.

Funding

None.

The Safety Profile of Sodium-Glucose Cotransporter-2 Inhibitors and Glucagon-like Peptide 1 Receptor Agonists in the Standard of Care Treatment of Type 2 Diabetes Mellitus

AIM

We evaluated the safety of sodium-glucose cotransporter-2 inhibitors (SGLT2i) and glucagon-like peptide 1 receptor agonists (GLP-1 RAs) for their use with other glucose-lowering drugs and drugs for the treatment of type 2 diabetes mellitus (T2DM), in a standard-of-care regimen with maximum tolerated doses, and, respectively, when compared with metformin.

METHODS

We conducted a retrospective, observational study on 405 patients that were seen in the outpatient clinic of the N Paulescu National Institute for Diabetes Mellitus, Bucharest, Romania, in 2019. Their demographics, metabolic parameters, and medication safety were evaluated at three follow-up visits, from baseline, six months, and twelve months.

RESULTS

Both SGLT-2is and GLP-1 RAs are safe regarding creatinine, eGFR, urea, GOT, and GPT upon the comparison of the data from the six- and twelve-month visits with the initial visit, and also the twelve-month visit with the six-month visit. Moreover, when comparing SGLT-2is and GLP-1 RAs with metformin, there are safety data only for urea.

CONCLUSIONS

In this retrospective analysis, both SGLT-2is and GLP-1 RAs, when used in conjunction with other glucose-lowering, blood-pressure-lowering, and lipid-lowering medications, appeared to be safe for the management of T2DM.

Obesity, diabetes mellitus, and cardiometabolic risk: An Obesity Medicine Association (OMA) Clinical Practice Statement (CPS) 2023

Background

This Obesity Medicine Association (OMA) Clinical Practice Statement (CPS) is intended to provide clinicians an overview of type 2 diabetes mellitus (T2DM), an obesity-related cardiometabolic risk factor.

Methods

The scientific support for this CPS is based upon published citations and clinical perspectives of OMA authors.

Results

Topics include T2DM and obesity as cardiometabolic risk factors, definitions of obesity and adiposopathy, and mechanisms for how obesity causes insulin resistance and beta cell dysfunction. Adipose tissue is an active immune and endocrine organ, whose adiposopathic obesity-mediated dysfunction contributes to metabolic abnormalities often encountered in clinical practice, including hyperglycemia (e.g., pre-diabetes mellitus and T2DM). The determination as to whether adiposopathy ultimately leads to clinical metabolic disease depends on crosstalk interactions and biometabolic responses of non-adipose tissue organs such as liver, muscle, pancreas, kidney, and brain.

Conclusions

This review is intended to assist clinicians in the care of patients with the disease of obesity and T2DM. This CPS provides a simplified overview of how obesity may cause insulin resistance, pre-diabetes, and T2DM. It also provides an algorithmic approach towards treatment of a patient with obesity and T2DM, with "treat obesity first" as a priority. Finally, treatment of obesity and T2DM might best focus upon therapies that not only improve the weight of patients, but also improve the health outcomes of patients (e.g., cardiovascular disease and cancer).

Exendin-4 alleviates myocardial ischemia reperfusion injury by enhancing autophagy through promoting nuclear translocation of TFEB

Ischemia-reperfusion (I/R) injury (IRI) is a common clinical consequence of myocardial infarction. Exendin-4 is a glucagon-like peptide-1 (GLP-1) analog that has been demonstrated to alleviate myocardial IRI. Autophagy, a lysosomal pathway balancing cell survival and cell death, is engaged in myocardial IRI. However, whether exendin-4 exerts a protective effect on myocardial IRI by modulating autophagy remains elusive. Herein, we investigated the effect of exendin-4 on autophagic flux and explored the underlying molecular mechanisms. Our data revealed that the autophagic flux was blocked in the human ventricular cardiomyocyte cell lines (AC16) subjected to oxygen glucose deprivation/reoxygenation (OGD/R) in vitro. Exendin-4 pre-treatment markedly restored the blocked autophagic flux induced by OGD/R through promoting nuclear translocation of TFEB and transcription of genes involving autophagy initiation, the effect of which was reversed by TFEB knockdown. The restoration of autophagic flux contributed to multiple beneficial effects of exendin-4 in cardiomyocytes, including reduction of oxidative stress, preservation of mitochondrial network as well as inhibition of cytochrome c leakage from mitochondrial permeability transition pore (MPTP) and the resulting apoptosis. Moreover, the administration of exendin-4 reduced infarct size and preserved cardiac function through its anti-apoptosis and antioxidative effects in vivo. These results shed some light on understanding the novel mechanism of exendin-4 as a protective agent against myocardial IRI.

Major adverse cardiovascular events among patients with type-2 diabetes, a nationwide cohort study comparing primary metabolic and bariatric surgery to GLP-1 receptor agonist treatment

BACKGROUND

Glucagon-like Peptide-1 receptor agonists (GLP-1 RA) and metabolic and bariatric surgery (MBS) both improve cardiovascular outcomes in patients with severe obesity and type-2 diabetes (T2D). The aim of the present study was to assess the impact of MBS on major cardiovascular adverse events (MACE) in patients with severe obesity and T2D compared to patients with T2D treated with GLP-1 RA.

SUBJECTS AND METHODS

In this propensity score matched cohort study on nationwide data, patients with T2D and severe obesity who underwent MBS in Sweden from 2007 until 2019 were identified from the Scandinavian Obesity Surgery Registry and matched to a non-surgical group with T2D treated with GLP-1 RA (81.7% liraglutide, 9.0% dulaglutide, 6.0% exenatide, 1.6% lixisenatide and 0.8% semaglutide) from the general population using generalized linear model. Major outcome was MACE (hospitalization for acute coronary syndrome or cerebrovascular event or all-cause death), evaluated with multivariable Cox regression.

RESULTS

In total 2161 patients (obesity class I (10.2%), class II (40.3%), class III (49.5%)) were matched to 2161 non-surgical patients (mean age 51.1 ± 9.29 vs 51.5 ± 8.92 years, 64.8% vs. 64.4% women, with mean number of diabetes drugs of 2.5 ± 0.89 vs 2.6 ± 0.87, a mean duration of diabetes of 6.0 ± 4.15 vs 6.0 ± 4.51 years with 44.2% vs. 42.8% being treated with insulin at baseline). During the study period, 113 patients (8-year cumulative incidence 9.3%) compared to 130 non-surgical patients (8-year cumulative incidence 11.3%) suffered from MACE or all-cause mortality (HR 0.76, 95%CI 0.59-0.98), and 69 patients (8-year cumulative incidence 5.1%) compared to 92 non-surgical patients (8-year cumulative incidence 7.6%) suffered from a non-fatal MACE (HR 0.68, 95%CI 0.49-0.93).

CONCLUSION

In this matched cohort study, MBS was associated with lower risk for MACE compared to treatment with early GLP-1 RA in patients with T2D.

Diabetes and Stroke: What Are the Connections?

Stroke is a major cause of death and long-term disability worldwide. Diabetes is associated with an increased risk of cardiovascular complications, including stroke. People with diabetes have a 1.5-2 times higher risk of stroke compared with people without diabetes, with risk increasing with diabetes duration. These risks may also differ according to sex, with a greater risk observed among women versus men. Several mechanisms associated with diabetes lead to stroke, including large artery atherosclerosis, cerebral small vessel disease, and cardiac embolism. Hyperglycemia confers increased risk for worse outcomes in people presenting with acute ischemic stroke, compared with people with normal glycemia. Moreover, people with diabetes may have poorer post-stroke outcomes and higher risk of stroke recurrence than those without diabetes. Appropriate management of diabetes and other vascular risk factors may improve stroke outcomes and reduce the risk for recurrent stroke. Secondary stroke prevention guidelines recommend screening for diabetes following a stroke. The diabetes medications pioglitazone and glucagon-like peptide-1 receptor agonists have demonstrated protection against stroke in randomized controlled trials; this protective effect is believed to be independent of glycemic control. Neurologists are often involved in the management of modifiable risk factors for stroke (including hypertension, hyperlipidemia, and atrial fibrillation), but less often in the direct management of diabetes. This review provides an overview of the relationships between diabetes and stroke, including epidemiology, pathophysiology, post-stroke outcomes, and treatments for people with stroke and diabetes. This should aid neurologists in diabetes-related decision-making when treating people with acute or recurrent stroke.

Glucagon-like peptide 1-receptor agonists and A1c: Good for the heart but less so for the eyes?

BACKGROUND AND AIMS

Glucagon-like peptide1-receptor agonists (GLP1-RA) decrease major adverse cardiovascular events (MACE) in people with type 2 diabetes mellitus and cardiovascular disease (CVD). Caution is recommended for semaglutide and dulaglutide with risk of exacerbating diabetic retinopathy (DR). Analyses were performed to determine if worsening of DR was dependent on drug class or fall in A1c.

RESEARCH DESIGN AND METHODS

Meta-analyses and meta-regressions (MR) were performed on the 7 major cardiovascular outcome trial (CVOTs) (n = 56004 patients) of GLP1-RA. A second analysis of 11 studies (n = 11894 subjects) with semaglutide documenting DR followed.

RESULTS

Six of the CVOTs evaluated DR. For the GLP1-RA class, there was no increase in the relative rate (rr) for retinopathy (rr = 1.09,95%CI; 0.925,1.289, p = 0.30), with only an increase with parenteral semaglutide (rr = 1.73; 1.10:2.71, p = 0.02). MR showed that decreases in A1c correlated with decreases in MACE (log rr = 0.364∗(Δ A1c), p = 0.014), but increases in DR (log rr= (-0.67∗(ΔA1c), p = 0.076). The change in DR was predominantly found for subcutaneous semaglutide given for >1 year (rr = 1.559,1.068,2.276, p = 0.022) and with decreases in A1c > 1.0% (rr = 1.59; 1.092,2.316, p = 0.016). For the class of GLP1-RA, the rate difference (rd) for worsening retinopathy was = 0.001 (and number needed to harm [NNH] = 1000) compared with rd for MACE = -0.013 (number needed to treat [NNT] = 77). The computation for semaglutide was NNH = 77 and NNT = 43.

CONCLUSIONS

This meta-analysis may assist in decisions balancing the relative risk (of existing retinopathy) versus benefits (to existing CVD). There should be close collaboration with ophthalmology to grade the baseline degree of retinopathy when initiating and following patients.

GLP-1 Receptor Agonists for the Reduction of Atherosclerotic Cardiovascular Risk in Patients With Type 2 Diabetes

Patients with type 2 diabetes are at high risk for development of cardiovascular disease, including myocardial infarction, stroke, heart failure, and cardiovascular death. Multiple large cardiovascular outcome trials with novel glucose-lowering agents, namely SGLT2i (SGLT2 inhibitors) and GLP-1 RA (GLP-1 receptor agonists), have demonstrated robust and significant reductions of major adverse cardiovascular events and additional cardiovascular outcomes, such as hospitalizations for heart failure. This evidence has changed the landscape for treatment of patients with type 2 diabetes. Both diabetes and cardiology guidelines and professional societies have responded to this paradigm shift by including strong recommendations to use SGLT2i and/or GLP-1 RA, with evidence-based benefits to reduce cardiovascular risk in high-risk individuals with type 2 diabetes, independent of the need for additional glucose control. GLP-1 RA were initially developed as glucose-lowering drugs because activation of the GLP-1 receptor by these agents leads to a reduction in blood glucose and an improvement in postprandial glucose metabolism. By stimulating GLP-1R in hypothalamic neurons, GLP-1 RA additionally induce satiety and lead to weight loss. Data from cardiovascular outcome trials demonstrated a robust and consistent reduction in atherothrombotic events, particularly in patients with established atherosclerotic cardiovascular disease. Despite the consistent evidence of atherosclerotic cardiovascular disease benefit from these trials, the number of patients receiving these drugs remains low. This overview summarizes the experimental and clinical evidence of cardiovascular risk reduction offered by GLP-1 RA, and provides practical information on how these drugs should be implemented in the treatment of type 2 diabetes in the cardiology community.

Liraglutide Improves the Angiogenic Capability of EPC and Promotes Ischemic Angiogenesis in Mice under Diabetic Conditions through an Nrf2-Dependent Mechanism

The impairment in endothelial progenitor cell (EPC) functions results in dysregulation of vascular homeostasis and dysfunction of the endothelium under diabetic conditions. Improving EPC function has been considered as a promising strategy for ameliorating diabetic vascular complications. Liraglutide has been widely used as a therapeutic agent for diabetes. However, the effects and mechanisms of liraglutide on EPC dysfunction remain unclear. The capability of liraglutide in promoting blood perfusion and angiogenesis under diabetic conditions was evaluated in the hind limb ischemia model of diabetic mice. The effect of liraglutide on the angiogenic function of EPC was evaluated by cell scratch recovery assay, tube formation assay, and nitric oxide production. RNA sequencing was performed to assess the underlying mechanisms. Liraglutide enhanced blood perfusion and angiogenesis in the ischemic hindlimb of db/db mice and streptozotocin-induced type 1 diabetic mice. Additionally, liraglutide improved tube formation, cell migration, and nitric oxide production of high glucose (HG)-treated EPC. Assessment of liraglutide target pathways revealed a network of genes involved in antioxidant activity. Further mechanism study showed that liraglutide decreased the production of reactive oxygen species and increased the activity of nuclear factor erythroid 2-related factor 2 (Nrf2). Nrf2 deficiency attenuated the beneficial effects of liraglutide on improving EPC function and promoting ischemic angiogenesis under diabetic conditions. Moreover, liraglutide activates Nrf2 through an AKT/GSK3β/Fyn pathway, and inhibiting this pathway abolished liraglutide-induced Nrf2 activation and EPC function improvement. Overall, these results suggest that Liraglutide represents therapeutic potential in promoting EPC function and ameliorating ischemic angiogenesis under diabetic conditions, and these beneficial effects relied on Nrf2 activation.

Glucagon-like peptide-1 analog liraglutide leads to multiple metabolic alterations in diet-induced obese mice

Liraglutide, a glucagon-like peptide-1 analog, has beneficial metabolic effects in patients with type 2 diabetes and obesity. Although the high efficacy of liraglutide as an anti-diabetic and anti-obesity drug is well known, liraglutide-induced metabolic alterations in diverse tissues remain largely unexplored. Here, we report the changes in metabolic profiles induced by a 2-week subcutaneous injection of liraglutide in diet-induced obese mice fed a high-fat diet for 8 weeks. Our comprehensive metabolomic analyses of the hypothalamus, plasma, liver, and skeletal muscle showed that liraglutide intervention led to various metabolic alterations in comparison with diet-induced obese or nonobese mice. We found that liraglutide remarkably coordinated not only fatty acid metabolism in the hypothalamus and skeletal muscle but also amino acid and carbohydrate metabolism in plasma and liver. Comparative analyses of metabolite dynamics revealed that liraglutide rewired intertissue metabolic correlations. Our study points to a previously unappreciated metabolic alteration by liraglutide in several tissues, which may underlie its therapeutic effects within and across the tissues.

Absolute treatment effects for the primary outcome and all-cause mortality in the cardiovascular outcome trials of new antidiabetic drugs: a meta-analysis of digitalized individual patient data

AIMS

Treatment effects from the large cardiovascular outcome trials (CVOTs) of new antidiabetic drugs are almost exclusively communicated as hazard ratios, although reporting guidelines recommend to report treatment effects also on an absolute scale, e.g. as numbers needed to treat (NNT). We aimed to analyse NNTs in CVOTs comparing dipeptidyl peptidase-4 (DPP-4) inhibitors, glucagon-like peptide-1 (GLP-1) receptor agonists, or sodium-glucose cotransporter-2 (SGLT2) inhibitors to placebo.

METHODS

We digitalized individual time-to-event information for the primary outcome and all-cause mortality from 19 CVOTs that compared DPP-4 inhibitors, GLP-1 receptor agonists, or SGLT2 inhibitors to placebo. We estimated Weibull models for each trial and outcome and derived monthly NNTs. NNTs were summarized across all trials and within drug classes by random effects meta-analysis methods.

RESULTS

Treatment effects in the CVOTs appear smaller if they are reported as NNTs: Overall, 100 (95%-CI: 60, 303) patients have to be treated for 29 months (the median follow-up time across all trials) to avoid a single event of the primary outcome, and 128 (95%-CI: 85, 265) patients have to be treated for 39 months to avoid a single death. NNT time courses are very similar for GLP-1 receptor agonists and SGLT2 inhibitors, whereas treatment effects with DPP-4 inhibitors are smaller.

CONCLUSIONS

We found that the respective treatment effects look less impressive when communicated on an absolute scale, as numbers needed to treat. For a valid overall picture of the benefit of new antidiabetic drugs, trial authors should also report treatment effects on an absolute scale.

A Glucagon-like Peptide 1 Analog Protects Mitochondria and Attenuates Hypoxia-Reoxygenation Injury in Cultured Cardiomyocytes

ABSTRACT

Glucagon-like peptide 1 (GLP-1) analogs improve glycemic control in diabetes and protect the heart against ischemia-reperfusion injury. However, the mechanisms underlying this protection remain unclear. Mitochondria are essential for myocyte homeostasis. Therefore, we herein examined the effects of a GLP-1 analog on mitochondria after the hypoxia-reoxygenation of rat neonatal cultured cardiomyocytes. Cardiomyocytes were subjected to hypoxia for 5 hours followed by reoxygenation for 30 minutes in the presence or absence of exendin-4 (50 nmol/L), a GLP-1 analog. Hypoxia-reoxygenation increased lactate dehydrogenase and caspase-3 activities, indicators of lethal myocyte injury and apoptosis, respectively, and exendin-4 attenuated these increases. The content of ATP in myocytes decreased after hypoxia-reoxygenation but was preserved by exendin-4. The membrane potential and shape of mitochondria were assessed using a fluorescent probe. Exendin-4 attenuated the hypoxia-reoxygenation-induced disruption of the mitochondrial membrane potential and shortening. Mitochondrial quality control-related factors, such as optic atrophy protein 1, mitofusin 2, dynamin-related protein 1, and parkin, were examined by Western blotting. Exendin-4 significantly increased the expression of the fusion proteins, optic atrophy protein 1 and mitofusin 2, and decreased that of the mitophagy-related protein, parkin, without altering dynamin-related protein 1 expression levels. Exendin-4 also preserved Akt phosphorylation levels after hypoxia-reoxygenation, whereas wortmannin, an inhibitor of the phosphoinositide 3-kinase-Akt pathway, blunted exendin-4-induced myocyte protection and its effects on mitochondrial quality control factors. In conclusion, exendin-4 protected mitochondria by preserving the phosphorylation of Akt and fusion proteins, leading to the attenuation of hypoxia-reoxygenation-induced injury in cultured myocytes.

Diabetes Mellitus and Heart Failure With Preserved Ejection Fraction: Role of Obesity

Heart failure with preserved ejection fraction is a growing epidemic and accounts for half of all patients with heart failure. Increasing prevalence, morbidity, and clinical inertia have spurred a rethinking of the pathophysiology of heart failure with preserved ejection fraction. Unlike heart failure with reduced ejection fraction, heart failure with preserved ejection fraction has distinct clinical phenotypes. The obese-diabetic phenotype is the most often encountered phenotype in clinical practice and shares the greatest burden of morbidity and mortality. Left ventricular remodeling plays a major role in its pathophysiology. Understanding the interplay of obesity, diabetes mellitus, and inflammation in the pathophysiology of left ventricular remodeling may help in the discovery of new therapeutic targets to improve clinical outcomes in heart failure with preserved ejection fraction. Anti-diabetic agents like glucagon-like-peptide 1 analogs and sodium-glucose co-transporter 2 are promising therapeutic modalities for the obese-diabetic phenotype of heart failure with preserved ejection fraction and aggressive weight loss via lifestyle or bariatric surgery is still key to reverse adverse left ventricular remodeling. This review focuses on the obese-diabetic phenotype of heart failure with preserved ejection fraction highlighting the interaction between obesity, diabetes, and coronary microvascular dysfunction in the development and progression of left ventricular remodeling. Recent therapeutic advances are reviewed.

Association of Diabetes Duration and Glycemic Control With Stroke Rate in Patients With Atrial Fibrillation and Diabetes: A Population-Based Cohort Study

Background

There are limited data on the association of diabetes duration and glycemic control with stroke risk in atrial fibrillation (AF). Our objective was to study the association of diabetes duration and glycated hemoglobin (HbA1c) with the rate of stroke in people with diabetes and newly diagnosed AF.

Methods and Results

This was a population‐based cohort study using linked administrative data sets. We studied 37 209 individuals aged ≥66 years diagnosed with AF in Ontario between April 2009 and March 2019, who had diabetes diagnosed 1 to 16 years beforehand. The primary outcome was hospitalization for stroke at 1 year. Cause‐specific hazard regression was used to model the association of diabetes duration and glycated hemoglobin (HbA1c) with the rate of stroke. Restricted cubic spline analyses showed increasing hazard ratios (HR) for stroke with longer diabetes duration that plateaued after 10 years and increasing HRs for stroke with HbA1c levels >7%. Relative to patients with <5 years diabetes duration, stroke rates were significantly higher for patients with ≥10 years duration (HR, 1.45; 95% CI, 1.16–1.82; P=0.001), while diabetes duration 5 to <10 years was not significantly different. Relative to glycated hemoglobin 6% to <7%, values ≥8% were associated with higher stroke rates (HR, 1.44; 95% CI, 1.12–1.84; P=0.004), while other HbA1c categories were not significantly different.

Conclusions

Longer diabetes duration and higher glycated hemoglobin were associated with significantly higher stroke rates in patients with AF and diabetes. Models for stroke risk prediction and preventive care in AF may be improved by considering patients’ diabetes characteristics.

Cardiovascular Effects of Incretin-Based Therapies: Integrating Mechanisms With Cardiovascular Outcome Trials

As the worldwide prevalence of diabetes and obesity continues to rise, so does the risk of debilitating cardiovascular complications. Given the significant association between diabetes and cardiovascular risk, the actions of glucose-lowering therapies within the cardiovascular system must be clearly defined. Incretin hormones, including GLP-1 (glucagon-like peptide 1) and GIP (glucose-dependent insulinotropic polypeptide), are gut hormones secreted in response to nutrient intake that maintain glycemic control by regulating insulin and glucagon release. GLP-1 receptor agonists (GLP-1Ras) and dipeptidyl peptidase 4 inhibitors (DPP-4is) represent two drug classes used for the treatment of type 2 diabetes mellitus (T2DM) that improve glucose regulation through stimulating the actions of gut-derived incretin hormones or inhibiting their degradation, respectively. Despite both classes acting to potentiate the incretin response, the potential cardioprotective benefits afforded by GLP-1Ras have not been recapitulated in cardiovascular outcome trials (CVOTs) evaluating DPP-4is. This review provides insights through discussion of clinical and preclinical studies to illuminate the physiological mechanisms that may underlie and reconcile observations from GLP-1Ra and DPP-4i CVOTs. Furthermore, critical knowledge gaps and areas for further investigation will be emphasized to guide future studies and, ultimately, facilitate improved clinical management of cardiovascular disease in T2DM.

Dipeptidyl peptidase-4 inhibitors, glucagon-like peptide 1 receptor agonists and sodium-glucose co-transporter-2 inhibitors for people with cardiovascular disease: a network meta-analysis

BACKGROUND

Cardiovascular disease (CVD) is a leading cause of death globally. Recently, dipeptidyl peptidase-4 inhibitors (DPP4i), glucagon-like peptide-1 receptor agonists (GLP-1RA) and sodium-glucose co-transporter-2 inhibitors (SGLT2i) were approved for treating people with type 2 diabetes mellitus. Although metformin remains the first-line pharmacotherapy for people with type 2 diabetes mellitus, a body of evidence has recently emerged indicating that DPP4i, GLP-1RA and SGLT2i may exert positive effects on patients with known CVD.

OBJECTIVES

To systematically review the available evidence on the benefits and harms of DPP4i, GLP-1RA, and SGLT2i in people with established CVD, using network meta-analysis.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, and the Conference Proceedings Citation Index on 16 July 2020. We also searched clinical trials registers on 22 August 2020. We did not restrict by language or publication status.

SELECTION CRITERIA

We searched for randomised controlled trials (RCTs) investigating DPP4i, GLP-1RA, or SGLT2i that included participants with established CVD. Outcome measures of interest were CVD mortality, fatal and non-fatal myocardial infarction, fatal and non-fatal stroke, all-cause mortality, hospitalisation for heart failure (HF), and safety outcomes.

DATA COLLECTION AND ANALYSIS

Three review authors independently screened the results of searches to identify eligible studies and extracted study data. We used the GRADE approach to assess the certainty of the evidence. We conducted standard pairwise meta-analyses and network meta-analyses by pooling studies that we assessed to be of substantial homogeneity; subgroup and sensitivity analyses were also pursued to explore how study characteristics and potential effect modifiers could affect the robustness of our review findings. We analysed study data using the odds ratios (ORs) and log odds ratios (LORs) with their respective 95% confidence intervals (CIs) and credible intervals (Crls), where appropriate. We also performed narrative synthesis for included studies that were of substantial heterogeneity and that did not report quantitative data in a usable format, in order to discuss their individual findings and relevance to our review scope.

MAIN RESULTS

We included 31 studies (287 records), of which we pooled data from 20 studies (129,465 participants) for our meta-analysis. The majority of the included studies were at low risk of bias, using Cochrane's tool for assessing risk of bias. Among the 20 pooled studies, six investigated DPP4i, seven studied GLP-1RA, and the remaining seven trials evaluated SGLT2i. All outcome data described below were reported at the longest follow-up duration. 1. DPP4i versus placebo Our review suggests that DPP4i do not reduce any risk of efficacy outcomes: CVD mortality (OR 1.00, 95% CI 0.91 to 1.09; high-certainty evidence), myocardial infarction (OR 0.97, 95% CI 0.88 to 1.08; high-certainty evidence), stroke (OR 1.00, 95% CI 0.87 to 1.14; high-certainty evidence), and all-cause mortality (OR 1.03, 95% CI 0.96 to 1.11; high-certainty evidence). DPP4i probably do not reduce hospitalisation for HF (OR 0.99, 95% CI 0.80 to 1.23; moderate-certainty evidence). DPP4i may not increase the likelihood of worsening renal function (OR 1.08, 95% CI 0.88 to 1.33; low-certainty evidence) and probably do not increase the risk of bone fracture (OR 1.00, 95% CI 0.83 to 1.19; moderate-certainty evidence) or hypoglycaemia (OR 1.11, 95% CI 0.95 to 1.29; moderate-certainty evidence). They are likely to increase the risk of pancreatitis (OR 1.63, 95% CI 1.12 to 2.37; moderate-certainty evidence). 2. GLP-1RA versus placebo Our findings indicate that GLP-1RA reduce the risk of CV mortality (OR 0.87, 95% CI 0.79 to 0.95; high-certainty evidence), all-cause mortality (OR 0.88, 95% CI 0.82 to 0.95; high-certainty evidence), and stroke (OR 0.87, 95% CI 0.77 to 0.98; high-certainty evidence). GLP-1RA probably do not reduce the risk of myocardial infarction (OR 0.89, 95% CI 0.78 to 1.01; moderate-certainty evidence), and hospitalisation for HF (OR 0.95, 95% CI 0.85 to 1.06; high-certainty evidence). GLP-1RA may reduce the risk of worsening renal function (OR 0.61, 95% CI 0.44 to 0.84; low-certainty evidence), but may have no impact on pancreatitis (OR 0.96, 95% CI 0.68 to 1.35; low-certainty evidence). We are uncertain about the effect of GLP-1RA on hypoglycaemia and bone fractures. 3. SGLT2i versus placebo This review shows that SGLT2i probably reduce the risk of CV mortality (OR 0.82, 95% CI 0.70 to 0.95; moderate-certainty evidence), all-cause mortality (OR 0.84, 95% CI 0.74 to 0.96; moderate-certainty evidence), and reduce the risk of HF hospitalisation (OR 0.65, 95% CI 0.59 to 0.71; high-certainty evidence); they do not reduce the risk of myocardial infarction (OR 0.97, 95% CI 0.84 to 1.12; high-certainty evidence) and probably do not reduce the risk of stroke (OR 1.12, 95% CI 0.92 to 1.36; moderate-certainty evidence). In terms of treatment safety, SGLT2i probably reduce the incidence of worsening renal function (OR 0.59, 95% CI 0.43 to 0.82; moderate-certainty evidence), and probably have no effect on hypoglycaemia (OR 0.90, 95% CI 0.75 to 1.07; moderate-certainty evidence) or bone fracture (OR 1.02, 95% CI 0.88 to 1.18; high-certainty evidence), and may have no impact on pancreatitis (OR 0.85, 95% CI 0.39 to 1.86; low-certainty evidence). 4. Network meta-analysis Because we failed to identify direct comparisons between each class of the agents, findings from our network meta-analysis provided limited novel insights. Almost all findings from our network meta-analysis agree with those from the standard meta-analysis. GLP-1RA may not reduce the risk of stroke compared with placebo (OR 0.87, 95% CrI 0.75 to 1.0; moderate-certainty evidence), which showed similar odds estimates and wider 95% Crl compared with standard pairwise meta-analysis. Indirect estimates also supported comparison across all three classes. SGLT2i was ranked the best for CVD and all-cause mortality.

AUTHORS' CONCLUSIONS

Findings from both standard and network meta-analyses of moderate- to high-certainty evidence suggest that GLP-1RA and SGLT2i are likely to reduce the risk of CVD mortality and all-cause mortality in people with established CVD; high-certainty evidence demonstrates that treatment with SGLT2i reduce the risk of hospitalisation for HF, while moderate-certainty evidence likely supports the use of GLP-1RA to reduce fatal and non-fatal stroke. Future studies conducted in the non-diabetic CVD population will reveal the mechanisms behind how these agents improve clinical outcomes irrespective of their glucose-lowering effects.

Revealing the Angiopathy of Lacrimal Gland Lesion in Type 2 Diabetes

For a better understanding of diabetic angiopathy (DA), the potential biomarkers in lacrimal DA and its potential mechanism, we evaluated the morphological and hemodynamic alterations of lacrimal glands (LGs) in patients with type 2 diabetes and healthy counterparts by color Doppler flow imaging (CDFI). We further established a type 2 diabetic mice model and performed hematoxylin-eosin (HE) staining, immunofluorescence staining of CD31, RNA-sequencing analysis, and connectivity map (CMap) analysis. We found atrophy and ischemia in patients with type 2 diabetes and mice models. Furthermore, we identified 846 differentially expressed genes (DEGs) between type 2 diabetes mellitus (T2DM) and vehicle mice by RNA-seq. The gene ontology (GO) analysis indicated significant enrichment of immune system process, regulation of blood circulation, apoptotic, regulation of secretion, regulation of blood vessel diameter, and so on. The molecular complex detection (MCODE) showed 17 genes were involved in the most significant module, and 6/17 genes were involved in vascular disorders. CytoHubba revealed the top 10 hub genes of DEGs, and four hub genes (App, F5, Fgg, and Gas6) related to vascular regulation were identified repeatedly by MCODE and cytoHubba. GeneMANIA analysis demonstrated functions of the four hub genes above and their associated molecules were primarily related to the regulation of circulation and coagulation. CMap analysis found several small molecular compounds to reverse the altered DEGs, including disulfiram, bumetanide, genistein, and so on. Our outputs could empower the novel potential targets to treat lacrimal angiopathy, diabetes dry eye, and other diabetes-related diseases.

Effect of once-weekly exenatide on hospitalization for acute coronary syndrome or coronary revascularization in patients with type 2 diabetes mellitus

Cardiovascular (CV) outcome studies of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have shifted the paradigm of type 2 diabetes management given their benefits regarding a reduction in major adverse CV events. However, the relationship between GLP-1 RAs and coronary revascularization remains poorly understood. In this EXSCEL post-hoc analysis, we used univariate Cox proportional models and Kaplan Meier survival analysis to evaluate the effect of once-weekly exenatide (EQW) on a composite outcome of hospitalization for acute coronary syndrome (ACS) or coronary revascularization. Similar models were utilized to evaluate the relationship between significant participant characteristics within the entire study population and the composite outcome. Of the 14,736 participants in EXSCEL with complete follow-up data, 1642 (11.1%) experienced an ACS or coronary revascularization event during a median follow-up of 3.3 years (interquartile range, 2.3-4.4). EQW had no effect on hospitalization for ACS or coronary revascularization (HR 1.00, 95% CI 0.91-1.10). Among EXSCEL participants, enrollment in Latin America (HR 0.51, 95% CI 0.43-0.60) and a history of peripheral artery disease (HR 0.79, 95% CI 0.70-0.90) were associated with a reduced risk for coronary revascularization, whereas enrollment in North America (HR 1.92, 95% CI 1.74-2.12), a history of CV disease (HR 3.24, 95% CI 2.78-3.78), and a previous myocardial infarction (HR 1.54, 95% CI 1.39-1.71) were associated with increased risk for study end points. EQW had no association with hospitalization for ACS or coronary revascularization. Participant enrollment location and CV disease burden may play a role in the variable CV efficacy of GLP-1 RAs that has been observed in trials thus far.

Major adverse cardiovascular and limb events in patients with diabetes treated with GLP-1 receptor agonists vs DPP-4 inhibitors

AIMS/HYPOTHESIS

The safety and efficacy of glucagon-like peptide-1 receptor agonists (GLP1RAs) and dipeptidyl peptidase-4 inhibitors (DPP4is) in major cardiovascular adverse events were previously examined in cardiovascular outcome trials. However, the effects of these drugs on adverse limb outcomes were poorly examined. This study aimed to determine the real-world outcomes of patients with diabetes mellitus receiving GLP1RAs as compared with those receiving DPP4is in terms of major adverse cardiovascular and limb events.

METHODS

A retrospective cohort study was conducted with data collected by the Taiwan National Health Insurance database between 1 May 2011 and 31 December 2017. Patients who were treated for type 2 diabetes with a GLP1RA or DDP4i during this period (n = 1,080,993), were identified. The primary outcome was a composite of major adverse limb events, defined as peripheral artery disease (PAD), critical limb ischaemia, percutaneous transluminal angioplasty or peripheral bypass for PAD, and amputation. The secondary cardiovascular outcome was the composite of cardiovascular death, non-fatal myocardial infarction and non-fatal ischaemic stroke. Propensity-score matching (PSM) at a 1:3 ratio between GLP1RA and DPP4i groups was done to minimise possible selection bias.

RESULTS

A total of 948,342 individuals treated between 1 May 2011 and 31 December 2017, were identified, with 4460 in the GLP1RA group and 13,380 in the DPP4i group after PSM. The incidence of primary composite outcome events was significantly lower in those treated with GLP1RAs compared with those treated with DPP4is (2.59 vs 4.22 events per 1000 person-years; subdistribution HR [SHR] 0.63 [95% CI 0.41, 0.96]), primarily due to lower rates of amputation (1.29 events per 1000 person-years for GLP1RAs vs 2.4 events per 1000 person-years for DPP4is; SHR 0.55 [95% CI 0.30, 0.99]). Treatment with GLP1RAs was also associated with significantly lower risks of secondary composite outcome events (11.02 vs 17.95 events per 1000 person-years; HR 0.62 [95% CI 0.51, 0.76]). Moreover, the observed beneficial effects of GLP1RAs on reducing composite adverse limb outcomes were particularly noticeable in the non-cardiovascular patients and statin users (p for interaction <0.05).

CONCLUSIONS/INTERPRETATION

In individuals with diabetes, the use of GLP1RAs was associated with significantly lower risks of major adverse limb events when compared with the use of DPP4is. The reduction in risk was driven largely by reduced rate of amputations. Moreover, treatment with GLP1RAs was also associated with lower risks of cardiovascular death, non-fatal stroke, non-fatal myocardial infarction and death from any cause. However, some unexplored confounding factors may exist in this observation study and future large-scale randomised controlled trials are needed.

Clinical Phenotypes in Patients With Type 2 Diabetes Mellitus: Characteristics, Cardiovascular Outcomes and Treatment Strategies

PURPOSE OF REVIEW

With recent advances in the pharmacological management of type 2 diabetes mellitus (T2DM), there is a growing need to understand which patients optimally benefit from these novel therapies. Various clinical clustering methodologies have emerged that utilise data-agnostic strategies to categorise patients that have similar clinical characteristics and outcomes; broadly, this characterisation is termed phenotyping. In patients with T2DM, we aimed to describe patient characteristics from phenotype studies, their cardiovascular risk profiles and the impact of antihyperglycemic treatment.

RECENT FINDINGS

Numerous phenotypic studies have been undertaken that have utilised a combination of clinical, biochemical, imaging and genetic variables. Each of these has produced phenotypes that display a spectrum of cardiovascular risk. Studies that aimed to describe pathophysiological phenotypes generally identified five phenotypes: autoimmune phenotype, insulin-related phenotypes (including permutations of insulin deficiency and resistance), obesity phenotype, ageing phenotype, and a sex-related phenotype. Studies examining risk profiles have demonstrated that across such phenotypes there is a spectrum of risk for diabetic complications. Few studies have examined treatment effects across these phenotypes, and thus provide little insights towards making phenotype-guided treatment decisions Clustering analyses in patients with T2DM have identified distinct phenotypes with unique risk profiles. Further studies are needed that harness the use of clinical, biochemical, imaging and genetic data to explore therapeutic heterogeneity and response to antihyperglycemic treatment across the spectrum of patient phenotypes.

Obesity Management in Cardiometabolic Disease: State of the Art

PURPOSE OF REVIEW

To summarize research from the last 5 years on the effects of weight loss treatments, including lifestyle changes, anti-obesity medications, and bariatric procedures on cardiovascular disease (CVD) risk factors and CVD outcomes in adults.

RECENT FINDINGS

This narrative review includes and summarizes the contemporary evidence of the effects of these different weight loss approaches individually. A literature search was performed using the key words obesity, weight loss, CVD, cardiometabolic, and risk factors and included key clinical trials from the past 5 years. Obesity management through weight loss is associated with improvements in CVD risk factors, such as improved blood pressure, lipid profiles, and glycemic control, with greater weight loss leading to greater improvements in CVD risk factors. Bariatric surgery is associated with greater weight loss than the other procedures and treatments for obesity, and for this, and possibly for other reasons, it is associated with greater reductions in CVD outcomes and mortality. Obesity is an independent risk factor and modulator of other CVD risk factors, and thus, treatment of obesity should be an integral part of management strategies to reduce CVD risk. Future trials and real-world studies of longer duration are needed to inform providers and patients on how to individualize the approach to modifying risks of cardiometabolic disorders through obesity management.

Favorable Effects of GLP-1 Receptor Agonist against Pancreatic β-Cell Glucose Toxicity and the Development of Arteriosclerosis: "The Earlier, the Better" in Therapy with Incretin-Based Medicine

Fundamental pancreatic β-cell function is to produce and secrete insulin in response to blood glucose levels. However, when β-cells are chronically exposed to hyperglycemia in type 2 diabetes mellitus (T2DM), insulin biosynthesis and secretion are decreased together with reduced expression of insulin transcription factors. Glucagon-like peptide-1 (GLP-1) plays a crucial role in pancreatic β-cells; GLP-1 binds to the GLP-1 receptor (GLP-1R) in the β-cell membrane and thereby enhances insulin secretion, suppresses apoptotic cell death and increase proliferation of β-cells. However, GLP-1R expression in β-cells is reduced under diabetic conditions and thus the GLP-1R activator (GLP-1RA) shows more favorable effects on β-cells at an early stage of T2DM compared to an advanced stage. On the other hand, it has been drawing much attention to the idea that GLP-1 signaling is important in arterial cells; GLP-1 increases nitric oxide, which leads to facilitation of vascular relaxation and suppression of arteriosclerosis. However, GLP-1R expression in arterial cells is also reduced under diabetic conditions and thus GLP-1RA shows more protective effects on arteriosclerosis at an early stage of T2DM. Furthermore, it has been reported recently that administration of GLP-1RA leads to the reduction of cardiovascular events in various large-scale clinical trials. Therefore, we think that it would be better to start GLP-1RA at an early stage of T2DM for the prevention of arteriosclerosis and protection of β-cells against glucose toxicity in routine medical care.

Efficacy and Safety of the New Appetite Suppressant, Liraglutide: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Obesity is a chronic disease associated with metabolic diseases such as diabetes and cardiovascular disease. Since the U.S. Food and Drug Administration approved liraglutide as an anti-obesity drug for nondiabetic patients in 2014, it has been widely used for weight control in overweight and obese people. This study aimed to systematically analyze the effects of liraglutide on body weight and other cardiometabolic parameters.

METHODS

We investigated articles from PubMed, EMBASE, and the Cochrane Library to search randomized clinical trials that examined body weight changes with liraglutide treatment.

RESULTS

We included 31 studies with 8,060 participants for this meta-analysis. The mean difference (MD) between the liraglutide group and the placebo group was -4.19 kg (95% confidence interval [CI], -4.84 to -3.55), with a -4.16% change from the baseline (95% CI, -4.90 to -3.43). Liraglutide treatment correlated with a significantly reduced body mass index (MD: -1.55; 95% CI, -1.76 to -1.34) and waist circumference (MD: -3.11 cm; 95% CI, -3.59 to -2.62) and significantly decreased blood pressure (systolic blood pressure, MD: -2.85 mm Hg; 95% CI, -3.36 to -2.35; diastolic blood pressure, MD: -0.66 mm Hg; 95% CI, -1.02 to -0.30), glycated hemoglobin (MD: -0.40%; 95% CI, -0.49 to -0.31), and low-density lipoprotein cholesterol (MD: -2.91 mg/dL; 95% CI, -5.28 to -0.53; MD: -0.87% change from baseline; 95% CI, -1.17 to -0.56).

CONCLUSION

Liraglutide is effective for weight control and can be a promising drug for cardiovascular protection in overweight and obese people.

Sex Differences of the Diabetic Heart

Type 2 diabetes is a chronic disease associated with micro- and macro-vascular complications, including myocardial ischemia, and also with a specific and intrinsic cardiac dysfunction called diabetic cardiomyopathy (DCM). Both clinical and animal studies demonstrate significant sex differences in prevalence, pathophysiology, and outcomes of cardiovascular diseases (CVDs), including those associated with diabetes. The increased risk of CVDs with diabetes is higher in women compared to men with 50% higher risk of coronary artery diseases and increased mortality when exposed to acute myocardial infarction. Clinical studies also reveal a sexual dimorphism in the incidence and outcomes of DCM. Based on these clinical findings, growing experimental research was initiated to understand the impact of sex on CVDs associated with diabetes and to identify the molecular mechanisms involved. Endothelial dysfunction, atherosclerosis, coagulation, and fibrosis are mechanisms found to be sex-differentially modulated in the diabetic cardiovascular system. Recently, impairment of energy metabolism also emerged as a determinant of multiple CVDs associated with diabetes. Therefore, future studies should thoroughly analyze the sex-specific metabolic determinants to propose new therapeutic targets. With current medicine tending toward more personalized care of patients, we finally propose to discuss the importance of sex as determinant in the treatment of diabetes-associated cardiac diseases to promote a more systemic inclusion of both males and females in clinical and preclinical studies.

Glucagon-like peptide 1 analogue prevents cholesterol gallstone formation by modulating intestinal farnesoid X receptor activity

BACKGROUND & AIMS

Cholesterol gallstone disease (CGD) is a common gastrointestinal disease. Liraglutide, an analogue of glucagon-like peptide 1, has been approved to treat type 2 diabetes. Clinical studies have suggested a potential role of liraglutide in CGD.

METHODS

Mice were subcutaneously injected with liraglutide, then fed a lithogenic diet. Bile duct cannulation was performed to collect bile output in mice. Intestinal-specific ablation or pharmacological inhibition of farnesoid X receptor (FXR) was used to study its functions in CGD.

RESULTS

Liraglutide could protect mice against CGD. Liraglutide treatment increased the biliary concentration of cholesterol, phospholipids and bile acids and thereby decreased the cholesterol saturation index. The resistance to CGD conferred by liraglutide is likely a result of increased bile acid synthesis and efficient bile acid transport. The expression of a key bile acid synthetic enzyme, Cyp7a1, was significantly increased in liraglutide-treated mice. The increased expression of Cyp7a1 resulted from a relieved suppression signal of Fgf15 from the ileum. Mechanistically, liraglutide treatment altered bile acid composition and suppressed FXR activity in the ileum. Genetic ablation or pharmacological inhibition of FXR in the intestine protected mice against CGD. More importantly, intestinal FXR was required for liraglutide-mediated regulation of hepatic expression of Cyp7a1.

CONCLUSION

Liraglutide improved CGD by increasing bile acid secretion and decreasing cholesterol saturation index. Liraglutide attenuates the negative feedback inhibition of bile acids through inhibiting intestinal FXR activity. Our results suggest that liraglutide may represent a novel way for treating or preventing cholesterol gallstones in individuals with high risk of CGD.

Pharmacotherapy for Weight Loss in Cirrhosis and Liver Transplantation: Translating the Data and Underused Potential

BACKGROUND AND AIMS

Thirty percent of patients with cirrhosis are obese and the prevalence of obesity increases after transplant to >40% post-transplant. There are currently four weight loss medications approved by the FDA for treatment of obesity (orlistat, phentermine-topiramate, naltrexone-bupropion, and liraglutide). The aim of this review was to investigate the data on the use of these weight loss medications and alternative medicines in patients with cirrhosis and in liver transplant recipients (LTRs).

APPROACH AND RESULTS

While there is paucity of data for these medications in patients with cirrhosis and LTRs, Liraglutide appears to be generally safe in view of its pharmacokinetic properties. Phentermine-topiramate seems to have the highest weight loss potential but special consideration should be given to neuropsychiatric disorders, cardiovascular comorbidities, and drug interactions. There are emerging data on use of alternative medicines for weight loss but more data are needed.

CONCLUSIONS

The use of weight loss medications is feasible in this patient population but the decision of which medication to prescribe should be individualized based on the degree of renal and hepatic impairment, other co-morbidities, and concomitant medications.

Multifaceted Mechanisms of Action of Metformin Which Have Been Unraveled One after Another in the Long History

While there are various kinds of drugs for type 2 diabetes mellitus at present, in this review article, we focus on metformin which is an insulin sensitizer and is often used as a first-choice drug worldwide. Metformin mainly activates adenosine monophosphate-activated protein kinase (AMPK) in the liver which leads to suppression of fatty acid synthesis and gluconeogenesis. Metformin activates AMPK in skeletal muscle as well, which increases translocation of glucose transporter 4 to the cell membrane and thereby increases glucose uptake. Further, metformin suppresses glucagon signaling in the liver by suppressing adenylate cyclase which leads to suppression of gluconeogenesis. In addition, metformin reduces autophagy failure observed in pancreatic β-cells under diabetic conditions. Furthermore, it is known that metformin alters the gut microbiome and facilitates the transport of glucose from the circulation into excrement. It is also known that metformin reduces food intake and lowers body weight by increasing circulating levels of the peptide hormone growth/differentiation factor 15 (GDF15). Furthermore, much attention has been drawn to the fact that the frequency of various cancers is lower in subjects taking metformin. Metformin suppresses the mechanistic target of rapamycin (mTOR) by activating AMPK in pre-neoplastic cells, which leads to suppression of cell growth and an increase in apoptosis in pre-neoplastic cells. It has been shown recently that metformin consumption potentially influences the mortality in patients with type 2 diabetes mellitus and coronavirus infectious disease (COVID-19). Taken together, metformin is an old drug, but multifaceted mechanisms of action of metformin have been unraveled one after another in its long history.

Cardiovascular outcomes and healthcare costs of liraglutide versus basal insulin for type 2 diabetes patients at high cardiovascular risk

We aimed to compare the (1) clinical outcomes including composite cardiovascular outcomes, cardiovascular death, and all-cause death, and (2) healthcare costs of using liraglutide and basal insulin as an initial treatment for patients with type 2 diabetes mellitus (T2DM) and high cardiovascular diseases (CVD) risk. This is a retrospective cohort study using Taiwan’s Health and Welfare Database. A total of 1057 patients treated with liraglutide were identified and matched with 4600 patients treated with basal insulin. The liraglutide group had a lower risk of a composite CVD outcome (hazard ratio (HR) 0.65; 95% confidence interval (CI) 0.50–0.85; p < 0.01), all-cause mortality (HR 0.40; 95% CI 0.28–0.59; p < 0.0001), and nonfatal stroke (HR 0.54; 95% CI 0.34–0.87; p = 0.01). Compared to the basal insulin group, the liraglutide group had lower median per-patient-per-month (PPPM) inpatient, emergency room (ER), and total medical costs, but higher median PPPM outpatient, total pharmacy, and total costs (all p < 0.0001). In conclusion, compared to basal insulin, liraglutide was found to be associated with reduced risk of a composite CVD outcome, nonfatal stroke, and all-cause mortality among high CVD risk patients with T2DM. In addition, liraglutide users had lower inpatient, ER, and total medical costs, but they had higher outpatient and total pharmacy costs.

Stress-Induced Hyperglycaemia in Non-Diabetic Patients with Acute Coronary Syndrome: From Molecular Mechanisms to New Therapeutic Perspectives

Stress-induced hyperglycaemia (SIH) at hospital admission for acute coronary syndrome is associated with poor outcome, especially in patients without known diabetes. Nevertheless, insulin treatment in these subjects was not correlated with the reduction of mortality. This is likely due to the fact that SIH in the context of an acute coronary syndrome, compared to that in known diabetes, represents an epiphenomenon of other pathological conditions, such as adrenergic and renin-angiotensin system over-activity, hyperglucagonaemia, increase of circulating free fatty acids and pancreatic beta-cell dysfunction, which are not completely reversed by insulin therapy and so worsen the prognosis. Thus, SIH may be considered not only as a biomarker of organ damage, but also as an indicator of a more complex therapeutic strategy in these subjects. The aim of this review is to analyse the molecular mechanisms by which SIH may favour a worse prognosis in non-diabetic patients with acute coronary syndrome and identify new therapeutic strategies, in addition to insulin therapy, for a more appropriate treatment and improved outcomes.

Therapies for the Treatment of Cardiovascular Disease Associated with Type 2 Diabetes and Dyslipidemia

Cardiovascular disease (CVD) is the leading cause of death worldwide and is the clinical manifestation of the atherosclerosis. Elevated LDL-cholesterol levels are the first line of therapy but the increasing prevalence in type 2 diabetes mellitus (T2DM) has positioned the cardiometabolic risk as the most relevant parameter for treatment. Therefore, the control of this risk, characterized by dyslipidemia, hypertension, obesity, and insulin resistance, has become a major goal in many experimental and clinical studies in the context of CVD. In the present review, we summarized experimental studies and clinical trials of recent anti-diabetic and lipid-lowering therapies targeted to reduce CVD. Specifically, incretin-based therapies, sodium-glucose co-transporter 2 inhibitors, and proprotein convertase subtilisin kexin 9 inactivating therapies are described. Moreover, the novel molecular mechanisms explaining the CVD protection of the drugs reviewed here indicate major effects on vascular cells, inflammatory cells, and cardiomyocytes, beyond their expected anti-diabetic and lipid-lowering control. The revealed key mechanism is a prevention of acute cardiovascular events by restraining atherosclerosis at early stages, with decreased leukocyte adhesion, recruitment, and foam cell formation, and increased plaque stability and diminished necrotic core in advanced plaques. These emergent cardiometabolic therapies have a promising future to reduce CVD burden.

Adiponectin, Leptin and Cardiovascular Disorders

The landmark discoveries of leptin and adiponectin firmly established adipose tissue as a sophisticated and highly active endocrine organ, opening a new era of investigating adipose-mediated tissue crosstalk. Both obesity-associated hyperleptinemia and hypoadiponectinemia are important biomarkers to predict cardiovascular outcomes, suggesting a crucial role for adiponectin and leptin in obesity-associated cardiovascular disorders. Normal physiological levels of adiponectin and leptin are indeed essential to maintain proper cardiovascular function. Insufficient adiponectin and leptin signaling results in cardiovascular dysfunction. However, a paradox of high levels of both leptin and adiponectin is emerging in the pathogenesis of cardiovascular disorders. Here, we (1) summarize the recent progress in the field of adiponectin and leptin and its association with cardiovascular disorders, (2) further discuss the underlying mechanisms for this new paradox of leptin and adiponectin action, and (3) explore the possible application of partial leptin reduction, in addition to increasing the adiponectin/leptin ratio as a means to prevent or reverse cardiovascular disorders.

Liraglutide Reduces Carotid Intima-Media Thickness by Reducing Small Dense Low-Density Lipoproteins in a Real-World Setting of Patients with Type 2 Diabetes: A Novel Anti-Atherogenic Effect

INTRODUCTION

Liraglutide has several non-glycemic effects, including those on plasma lipids and lipoproteins, contributing to its cardiovascular benefit; however, the exact underlying mechanisms remain unclear. We investigated a novel anti-atherogenic effect of liraglutide in a real-world prospective study on patients with type 2 diabetes (T2DM).

METHODS

Sixty-two patients with T2DM (31 men, 31 women; mean age ± standard deviation 61 ± 9 years) naïve to incretin-based therapies were treated with liraglutide (1.2 mg/day) as add-on therapy to metformin (1500-3000 mg/day) for 4 months. Laboratory analyses included the assessment of lipoprotein subclass profile by gel electrophoresis (Lipoprint; Quantimetrix Corp., Redondo Beach, CA, USA). Carotid intima-media thickness (cIMT) was assessed by Doppler ultrasonography. Statistical analyses included the paired t test, Spearman correlation and multiple regression analysis.

RESULTS

The addition of liraglutide to metformin monotherapy resulted in significant reductions in fasting glycemia, hemoglobin A1c, body mass index, waist circumference, total cholesterol, triglycerides and low-density lipoprotein (LDL)-cholesterol, as well as in cIMT. There was an increase in the large LDL-1 subfraction, with a concomitant reduction in atherogenic small dense LDL-3 and LDL-4 subfractions. Correlation analysis revealed a significant association between changes in cIMT and changes in small dense LDL-3 subfraction (r = 0.501; p < 0.0001). Multivariate analysis, including all of the measured anthropometric and laboratory parameters, revealed that only changes in the small dense LDL-3 subfraction were independent predictors of changes in cIMT (p < 0.0001).

CONCLUSION

Our findings are the first to show that the vascular benefit of liraglutide in patients with T2DM is associated with reductions in atherogenic small dense LDL. This effect is independent of glycemic control and body weight reduction and may represent one of the key mechanisms by which liraglutide is able to reduce cardiovascular events.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01715428.

Notable Underlying Mechanism for Pancreatic β-Cell Dysfunction and Atherosclerosis: Pleiotropic Roles of Incretin and Insulin Signaling

Under healthy conditions, pancreatic β-cells produce and secrete the insulin hormone in response to blood glucose levels. Under diabetic conditions, however, β-cells are compelled to continuously secrete larger amounts of insulin to reduce blood glucose levels, and thereby, the β-cell function is debilitated in the long run. In the diabetic state, expression levels of insulin gene transcription factors and incretin receptors are downregulated, which we think is closely associated with β-cell failure. These data also suggest that it would be better to use incretin-based drugs at an early stage of diabetes when incretin receptor expression is preserved. Indeed, it was shown that incretin-based drugs exerted more protective effects on β-cells at an early stage. Furthermore, it was shown recently that endothelial cell dysfunction was also associated with pancreatic β-cell dysfunction. After ablation of insulin signaling in endothelial cells, the β-cell function and mass were substantially reduced, which was also accompanied by reduced expression of insulin gene transcription factors and incretin receptors in β-cells. On the other hand, it has been drawing much attention that incretin plays a protective role against the development of atherosclerosis. Many basic and clinical data have underscored the importance of incretin in arteries. Furthermore, it was shown recently that incretin receptor expression was downregulated in arteries under diabetic conditions, which likely diminishes the protective effects of incretin against atherosclerosis. Furthermore, a series of large-scale clinical trials (SPAED-A, SPIKE, LEADER, SUSTAIN-6, REWIND, PIONEER trials) have shown that various incretin-related drugs have beneficial effects against atherosclerosis and subsequent cardiovascular events. These data strengthen the hypothesis that incretin plays an important role in the arteries of humans, as well as rodents.

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.