Dipeptidyl peptidase-4 inhibitors and risk of heart failure in type 2 diabetes: systematic review and meta-analysis of randomised and observational studies

Perioperative Considerations of Novel Antidiabetic Agents in Heart Failure Patients Undergoing Cardiac Surgery

Diabetes mellitus (DM) is a major risk factor for cardiovascular disease, including heart failure (HF). A high proportion of DM patients eventually require cardiac surgery. While the traditional approach to DM therapy focuses on tight glucose control with insulin and oral hypoglycemic agents, novel antidiabetic drugs have emerged over the past two decades that offer not only improved glycemic control but also cardiovascular and renal protection, such as benefits in HF management. The aim of this review is to examine and evaluate the perioperative risk and benefits of novel antidiabetic agents in HF treatment for both DM and non-DM patients undergoing cardiac surgery. We specifically studied glucagon-like peptide-1 receptor agonists (GLP-1RAs), dipeptidyl peptidase-4 (DPP-4) inhibitors, and sodium-glucose cotransporter 2 inhibitors (SGLT2is). Although studies on novel antidiabetic therapy in cardiac surgeries were limited, the results showed all three agents to be safe for use in the perioperative period, with SLGT2i demonstrating the most benefits in HF management for those with or without DM and kidney impairment undergoing cardiac surgery. Future research on larger study populations and using a more rigorous study design is necessary in bridging current knowledge to improve patient outcomes.

Uncovering the role of prokineticin pathway on Epicardial Adipose Tissue (EAT) development and EAT-associated cardiomyopathy

Epicardial adipose tissue (EAT), a unique fat depot surrounding the heart, plays a multifaceted role in glucose and lipid metabolism, thermogenesis, and the secretion of bioactive molecules that influence cardiac structure and function. Its proximity to the myocardium allows it to contribute directly to CVDs, including coronary artery disease, arrhythmias, and heart failure. In particular, excessive EAT has emerged as a significant factor in heart failure with preserved ejection fraction (HFpEF), the most common form of heart failure, especially in individuals with obesity and diabetes. Traditional metrics like body mass index (BMI) fail to capture the complexities of visceral fat, as patients with similar BMIs can exhibit varying CVD risks. EAT accumulation induces mechanical stress and fosters a pro-inflammatory and fibrotic environment, driving cardiac remodeling and dysfunction. Pharmacological modulation of EAT has shown promise in delivering cardiometabolic benefits. Recent advancements in diabetes therapies, such as SGLT2 inhibitors and GLP-1 receptor agonists, and antilipidemic drugs have demonstrated their potential in reducing pro-inflammatory cytokine production and improving glucose regulation, which directly influences EAT. These discoveries suggest that EAT could be a significant therapeutic target, though further investigation is necessary to elucidate its role in HFpEF and other CVDs. Recent advances have identified the prokineticin/PKR1 signaling pathway as pivotal in EAT development and remodeling. This pathway regulates epicardial progenitor cells (EPDCs), promoting angiogenesis while reducing EAT accumulation and metabolic stress on the heart, particularly under high-calorie conditions. Prokineticin, acting through its receptor PKR1, limits visceral adipose tissue growth, enhances insulin sensitivity, and offers cardioprotection by reducing oxidative stress and activating cellular survival pathways. In this review, we provide a comprehensive analysis of EAT's role in CVDs, explore novel therapeutic strategies targeting EAT, and highlight the potential of prokineticin signaling as a promising treatment for HFpEF, obesity, and diabetes.

Effects of administering berberine alone or in combination on type 2 diabetes mellitus: a systematic review and meta-analysis

Background

Despite the availability of multiple therapies for Type 2 diabetes mellitus (T2DM), challenges remain due to side effects and efficacy limitations. Berberine (BBR) has shown broad anti-diabetic effects, prompting a systematic assessment of its efficacy and safety through a meta-analysis.

Methods

A comprehensive search was conducted across eight database and search engines from inception until 06/09/2024. Only randomized controlled trials (RCTs) meeting inclusion criteria were analyzed. The Cochrane risk of bias assessment tool and Jadad scale were used to evaluate study quality. Meta-analysis was performed using RevMan v5.3 and Stata/SE v15.1.

Results

Fifty studies involving 4,150 participants were included. BBR alone significantly reduced fasting plasma glucose (FPG) (MD = -0.59 mmol/L, p = 0.048), 2-h postprandial blood glucose (2hPBG) (MD = -1.57 mmol/L, p < 0.01), low-density lipoprotein cholesterol (LDL-C) (MD = -0.30 mmol/L, p < 0.01), total cholesterol (TC) (MD = -0.30 mmol/L, p = 0.034), and triglycerides (TG) (MD = -0.35 mmol/L, p < 0.01). When combined with hypoglycemic drugs, BBR significantly improved FPG (MD = -0.99 mmol/L, p < 0.01), 2hPBG (MD = -1.07 mmol/L, p < 0.01), glycated hemoglobin (HbA1c) (MD = -0.69%, p < 0.01), and other metabolic markers, including fasting insulin (Fins), homeostasis model assessment index for assessing insulin resistance (HOMA-IR), lipid profiles and inflammatory markers. The most common BBR dosage was 0.9-1.5 g/d, with treatment cycles typically lasting 1-3 months.

Conclusion

Current evidence suggests that BBR alone or in combination has significant potential for treating type 2 diabetes mellitus (T2DM). Future research should encompass a broader scope, including not just the beneficial effects of BBR in head-to-head studies, but more crucially, delving into its mechanisms of action with hypoglycemic drugs to optimize T2DM treatment strategies.

Comparing various Bayesian random-effects models for pooling randomized controlled trials with rare events

The meta-analysis of rare events presents unique methodological challenges owing to the small number of events. Bayesian methods are often used to combine rare events data to inform decision-making, as they can incorporate prior information and handle studies with zero events without the need for continuity corrections. However, the comparative performances of different Bayesian models in pooling rare events data are not well understood. We conducted a simulation to compare the statistical properties of four parameterizations based on the binomial-normal hierarchical model, using two different priors for the treatment effect: weakly informative prior (WIP) and non-informative prior (NIP), pooling randomized controlled trials with rare events using the odds ratio metric. We also considered the beta-binomial model proposed by Kuss and the random intercept and slope generalized linear mixed models. The simulation scenarios varied based on the treatment effect, sample size ratio between the treatment and control arms, and level of heterogeneity. Performance was evaluated using median bias, root mean square error, median width of 95% credible or confidence intervals, coverage, Type I error, and empirical power. Two reviews are used to illustrate these methods. The results demonstrate that the WIP outperforms the NIP within the same model structure. Among the compared models, the model that included the treatment effect parameter in the risk model for the control arm did not perform well. Our findings confirm that rare events meta-analysis faces the challenge of being underpowered, highlighting the importance of reporting the power of results in empirical studies.

Advances in pharmacotherapy for heart failure and reduced ejection fraction: what's new in 2024?

INTRODUCTION

Updated guidelines for heart failure with reduced ejection fraction (HFrEF) and acute decompensation have improved outcomes, but ongoing efforts are focused on uncovering new evidence and developing novel therapies. This review examines the limitations of current treatments and the potential impact of emerging therapies.

AREAS COVERED

A literature search focused on studies investigating drugs for HFrEF. We review recent clinical trials and emerging therapies to assess evidence strength, explore guideline updates, and identify strategies to optimize patient outcomes.

EXPERT OPINION

The HFrEF treatment landscape is rapidly evolving, with advances in therapies like sodium/glucose cotransporter inhibitors and sacubitril-valsartan. Though managing acute decompensated heart failure remains challenging, recent trials suggest improvements in diuretic strategies and anti-inflammatory treatments. Ongoing research is essential for validating these therapies and incorporating them into standard practice.

A Bayesian bias-adjusted random-effects model for synthesizing evidence from randomized controlled trials and nonrandomized studies of interventions

OBJECTIVE

An important consideration when combining RCTs and NRSIs is how to address their potential biases in the pooled estimates. This study aimed to propose a Bayesian bias-adjusted random effects model for the synthesis of evidence from RCTs and NRSIs.

METHODS

We present a Bayesian bias-adjusted random effects model based on power prior method, which combines the likelihood contribution of the NRSIs, raised to the power parameter of alpha, with the likelihood of the RCT data, modeled with an additive bias. The method was illustrated using a meta-analysis on the association between low-dose methotrexate exposure and melanoma. We also combined RCTs and NRSIs using the naïve data synthesis.

RESULTS

The results including only RCTs has a posterior median and 95% credible interval (CrI) of 1.18 (0.31-4.04), the posterior probability of any harm (> 1.0) and a meaningful association (> 1.15) were 0.61 and 0.52, respectively. The posterior median and 95% CrI based on the naïve data synthesis resulted in 1.17 (0.96-1.47), and the posterior probability of any harm and a meaningful association were 0.96 and 0.60, respectively. For the Bayesian bias-adjusted analysis, the median OR was 1.16 (95% CrI: 0.83-1.71), and the posterior probabilities of any and a meaningful clinical association were 0.88 and 0.53, respectively.

CONCLUSIONS

The results indicated that integrating NRSIs into meta-analysis could increase the certainty of the body of evidence. However, directly combining RCTs and NRSIs in the same meta-analysis without distinction may lead to misleading conclusions.

Targeting autophagy in diabetic cardiomyopathy: From molecular mechanisms to pharmacotherapy

Diabetic cardiomyopathy (DCM) is a cardiac microvascular complication caused by metabolic disorders. It is characterized by myocardial remodeling and dysfunction. The pathogenesis of DCM is associated with abnormal cellular metabolism and organelle accumulation. Autophagy is thought to play a key role in the diabetic heart, and a growing body of research suggests that modulating autophagy may be a potential therapeutic strategy for DCM. Here, we have summarized the major signaling pathways involved in the regulation of autophagy in DCM, including Adenosine 5'-monophosphate-activated protein kinase (AMPK), mechanistic target of rapamycin (mTOR), Forkhead box subfamily O proteins (FOXOs), Sirtuins (SIRTs), and PTEN-inducible kinase 1 (PINK1)/Parkin. Given the significant role of autophagy in DCM, we further identified natural products and chemical drugs as regulators of autophagy in the treatment of DCM. This review may help to better understand the autophagy mechanism of drugs for DCM and promote their clinical application.

The role of nanosystems in the delivery of glucose-lowering drugs for the preemption and treatment of diabetes-associated atherosclerosis

Diabetes is one of the most prevalent diseases worldwide. In recent decades, type-2 diabetes has become increasingly common, particularly in younger individuals. Diabetes leads to many vascular complications, including atherosclerosis. Atherosclerosis is a cardiovascular disease characterized by lipid-rich plaques within the vasculature. Plaques develop over time, restricting blood flow, and can, therefore, be the underlying cause of major adverse cardiovascular events, including myocardial infarction and stroke. Diabetes and atherosclerosis are intrinsically linked. Diabetes is a metabolic syndrome that accelerates atherosclerosis and increases the risk of developing other comorbidities, such as diabetes-associated atherosclerosis (DAA). Gold standard antidiabetic medications focus on attenuating hyperglycemia. Though recent evidence suggests that glucose-lowering drugs may have broader applications, beyond diabetes management. This review mainly evaluates the role of glucagon-like peptide-1 receptor agonists (GLP-1 RAs), such as liraglutide and semaglutide in DAA. These drugs mimic gut hormones (incretins), which inhibit glucagon secretion while stimulating insulin secretion, thus improving insulin sensitivity. This facilitates delayed gastric emptying and increased patient satiety; hence, they are also indicated for the treatment of obesity. GLP-1 RAs have significant cardioprotective effects, including decreasing low-density lipoprotein (LDL) cholesterol and triglycerides levels. Liraglutide and semaglutide have specifically been shown to decrease cardiovascular risk. Liraglutide has displayed a myriad of antiatherosclerotic properties, with the potential to induce plaque regression. This review aims to address how glucose-lowering medications can be applied to treat diseases other than diabetes. We specifically focus on how nanomedicines can be used for the site-specific delivery of antidiabetic medicines for the treatment of diabetes-associated atherosclerosis.

Cardiovascular safety of evogliptin dual and triple therapy in patients with type 2 diabetes: a nationwide cohort study

OBJECTIVE

To investigate the risk of cardiovascular events associated with commonly used dual and triple therapies of evogliptin, a recently introduced dipeptidyl peptidase-4 inhibitor (DPP4i), for managing type 2 diabetes in routine clinical practice.

DESIGN

A retrospective cohort study.

SETTING

Korean Health Insurance Review and Assessment database.

PARTICIPANTS

Patients who initiated metformin-based dual therapy and metformin+sulfonylurea-based triple therapy in South Korea from 2014 to 2018.

INTERVENTIONS

Initiation of combination therapy with evogliptin.

PRIMARY AND SECONDARY OUTCOME MEASURES

Hazards of cardiovascular events, a composite endpoint of myocardial infarction, heart failure and cerebrovascular events, and its individual components. Cox proportional hazards model with propensity score-based inverse probability of treatment weighting were used to estimate HRs and 95% CIs.

RESULTS

From the dual and triple therapy cohorts, 5830 metformin+evogliptin users and 2198 metformin+sulfonylurea+evogliptin users were identified, respectively. Metformin+evogliptin users, as compared with metformin+non-DPP4i, had a 29% reduced risk of cardiovascular events (HR 0.71, 95% CI 0.62 to 0.82); HRs for individual outcomes were cerebrovascular events (0.71, 95% CI 0.53 to 0.95), heart failure (0.70, 95% CI 0.59 to 0.82), myocardial infarction (0.89, 95% CI 0.60 to 1.31). Metformin+sulfonylurea+evogliptin users, compared with metformin+sulfonylurea+non-DPP4i, had a 24% reduced risk of cardiovascular events (0.76, 95% CI 0.59 to 0.97); HRs for individual outcomes were myocardial infarction (0.57, 95% CI 0.27 to 1.19), heart failure (0.74, 95% CI 0.55 to 1.01), cerebrovascular events (0.96, 95% CI 0.61 to 1.51).

CONCLUSIONS

These findings suggest that dual or triple therapies of evogliptin for the management of type 2 diabetes in routine clinical practice present no cardiovascular harms, but could alternatively offer cardiovascular benefits in this patient population.

Comparison of statistical methods for integrating real-world evidence in a rare events meta-analysis of randomized controlled trials

Rare events meta-analyses of randomized controlled trials (RCTs) are often underpowered because the outcomes are infrequent. Real-world evidence (RWE) from non-randomized studies may provide valuable complementary evidence about the effects of rare events, and there is growing interest in including such evidence in the decision-making process. Several methods for combining RCTs and RWE studies have been proposed, but the comparative performance of these methods is not well understood. We describe a simulation study that aims to evaluate an array of alternative Bayesian methods for including RWE in rare events meta-analysis of RCTs: the naïve data synthesis, the design-adjusted synthesis, the use of RWE as prior information, the three-level hierarchical models, and the bias-corrected meta-analysis model. The percentage bias, root-mean-square-error, mean 95% credible interval width, coverage probability, and power are used to measure performance. The various methods are illustrated using a systematic review to evaluate the risk of diabetic ketoacidosis among patients using sodium/glucose co-transporter 2 inhibitors as compared with active-comparators. Our simulations show that the bias-corrected meta-analysis model is comparable to or better than the other methods in terms of all evaluated performance measures and simulation scenarios. Our results also demonstrate that data solely from RCTs may not be sufficiently reliable for assessing the effects of rare events. In summary, the inclusion of RWE could increase the certainty and comprehensiveness of the body of evidence of rare events from RCTs, and the bias-corrected meta-analysis model may be preferable.

Cardiovascular and Renal Outcomes With Sodium-Glucose Cotransporter-2 Inhibitors and Dipeptidyl Peptidase-4 Inhibitors Combination Therapy: A Meta-Analysis of Randomized Cardiovascular Outcome Trials

OBJECTIVE

The cardiovascular (CV) and renal benefits of sodium-glucose cotransporter-2 inhibitors (SGLT2i) in people with type 2 diabetes are well known. However, similar beneficial effects of SGLT2i in combination with dipeptidyl peptidase-4 inhibitors (DPP4i) are unknown. It is of interest to explore a trial-level meta-analysis to fill this knowledge gap.

METHODS

A literature search was conducted in the PubMed and Embase databases until January 31, 2023. All CV outcome trials (CVOTs) reporting the CV and renal outcomes of SGLT2i with or without background DPP4i therapy against the placebo were retrieved. A meta-analysis was subsequently conducted by applying the inverse variance-weighted averages of pooled logarithmic hazard ratio using primarily random-effects analysis.

RESULTS

This meta-analysis showed that the beneficial 3-point major adverse cardiovascular events composite (3 CVOTs; N = 32 418), the composite of CV death or heart failure hospitalization (hHF) (4 CVOTs; N = 37 687), hHF (3 CVOTs; N = 27 545), CV death (4 CVOTs; N = 34 565), and renal outcomes (2 CVOTs; N = 25 406) with SGLT2i were similar with or without background DPP4i therapy against the placebo (Pheterogeneity = .71, .07, .87, .72, and .25; respectively). However, against the placebo, the summary estimates for the 3-point major adverse cardiovascular events composite, hHF, and renal outcomes were stronger with SGLT2i alone, whereas the summary estimates for CV death or hHF composite were larger with SGLT2i with background DPP4i therapy.

CONCLUSION

Beneficial CV and renal effects of SGLT2i are similar against the placebo regardless of background DPP4i therapy.

Factors contributing to the adverse drug reactions associated with the dipeptidyl peptidase-4 (DPP-4) inhibitors: A scoping review

BACKGROUND AND AIM

Adverse drug reactions are one of the contributors to increased hospital admission and length of hospital stay. Among the various antidiabetic agents prescribed, dipeptidyl peptidase-4 (DPP-4) inhibitors have gained wide recognition and shown more persistence than other novel hypoglycemic agents. We performed a scoping review to identify the risk factors contributing to the adverse drug reactions with DPP-4 inhibitors.

METHODOLOGY

We followed Preferred Reporting Items for Scoping Review (PRISMA-ScR) Guidelines for reporting the findings. Data sources such as PubMed/MEDLINE, Scopus, Embase, and Cochrane were assessed. We included studies that reported the risk factors contributing to the DPP-4 inhibitor-associated adverse drug reactions. The Joanna Briggs Institute (JBI) critical appraisal checklist was used to assess the methodological quality of the studies.

RESULTS

Of the 6406 studies retrieved, 11 studies met our inclusion criteria. Of these 11 studies, seven were post-marketing surveillance studies, one nested case-control study, one comparator cohort study, one food and drug administration (FDA) adverse event reporting system (FAERS)-based observational study, and one questionnaire-based cross-sectional survey study. A total of eight factors were identified that contributed to the DPP-4 inhibitor-associated adverse drug reactions.

CONCLUSION

The included studies suggested age >65 years, females, grade 4 and 5 renal impairment, concomitant drugs, disease and drug therapy duration, liver disease, non-smokers, and non-hypertension as risk factors. Further studies should be conducted to provide insight into these risk factors so that the appropriate use of DPP-4 inhibitors in the diabetic population can be encouraged to improve the health-related quality of life.

PROSPERO REGISTRATION

CRD42022308764.

Targeting epicardial adipose tissue: A potential therapeutic strategy for heart failure with preserved ejection fraction with type 2 diabetes mellitus

Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous syndrome with various comorbidities, multiple cardiac and extracardiac pathophysiologic abnormalities, and diverse phenotypic presentations. Since HFpEF is a heterogeneous disease with different phenotypes, individualized treatment is required. HFpEF with type 2 diabetes mellitus (T2DM) represents a specific phenotype of HFpEF, with about 45%-50% of HFpEF patients suffering from T2DM. Systemic inflammation associated with dysregulated glucose metabolism is a critical pathological mechanism of HFpEF with T2DM, which is intimately related to the expansion and dysfunction (inflammation and hypermetabolic activity) of epicardial adipose tissue (EAT). EAT is well established as a very active endocrine organ that can regulate the pathophysiological processes of HFpEF with T2DM through the paracrine and endocrine mechanisms. Therefore, suppressing abnormal EAT expansion may be a promising therapeutic strategy for HFpEF with T2DM. Although there is no treatment specifically for EAT, lifestyle management, bariatric surgery, and some pharmaceutical interventions (anti-cytokine drugs, statins, proprotein convertase subtilisin/kexin type 9 inhibitors, metformin, glucagon-like peptide-1 receptor agonists, and especially sodium-glucose cotransporter-2 inhibitors) have been shown to attenuate the inflammatory response or expansion of EAT. Importantly, these treatments may be beneficial in improving the clinical symptoms or prognosis of patients with HFpEF. Accordingly, well-designed randomized controlled trials are needed to validate the efficacy of current therapies. In addition, more novel and effective therapies targeting EAT are needed in the future.

Methods for the Inclusion of Real-World Evidence in a Rare Events Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Many rare events meta-analyses of randomized controlled trials (RCTs) have lower statistical power, and real-world evidence (RWE) is becoming widely recognized as a valuable source of evidence. The purpose of this study is to investigate methods for including RWE in a rare events meta-analysis of RCTs and the impact on the level of uncertainty around the estimates.

METHODS

Four methods for the inclusion of RWE in evidence synthesis were investigated by applying them to two previously published rare events meta-analyses: the naïve data synthesis (NDS), the design-adjusted synthesis (DAS), the use of RWE as prior information (RPI), and the three-level hierarchical models (THMs). We gauged the effect of the inclusion of RWE by varying the degree of confidence placed in RWE.

RESULTS

This study showed that the inclusion of RWE in a rare events meta-analysis of RCTs could increase the precision of the estimates, but this depended on the method of inclusion and the level of confidence placed in RWE. NDS cannot consider the bias of RWE, and its results may be misleading. DAS resulted in stable estimates for the two examples, regardless of whether we placed high- or low-level confidence in RWE. The results of the RPI approach were sensitive to the confidence level placed in RWE. The THM was effective in allowing for accommodating differences between study types, while it had a conservative result compared with other methods.

CONCLUSION

The inclusion of RWE in a rare events meta-analysis of RCTs could increase the level of certainty of the estimates and enhance the decision-making process. DAS might be appropriate for inclusion of RWE in a rare event meta-analysis of RCTs, but further evaluation in different scenarios of empirical or simulation studies is still warranted.

Beneficial Effects of Dipeptidyl Peptidase-4 Inhibitors on Heart Failure With Preserved Ejection Fraction and Diabetes

BACKGROUND

Dipeptidyl peptidase-4 (DPP-4) inhibitors have been shown to exert pleiotropic effects on heart failure (HF) in animal experiments.

OBJECTIVES

This study sought to investigate the impact of DPP-4 inhibitors on HF patients with diabetes mellitus (DM).

METHODS

We analyzed hospitalized patients with HF and DM enrolled in the JROADHF (Japanese Registry Of Acute Decompensated Heart Failure) registry, a nationwide registry of acute decompensated HF. Primary exposure was the use of a DPP-4 inhibitor. The primary outcome was a composite of cardiovascular death or HF hospitalization during the median follow-up of 3.6 years according to left ventricular ejection fraction.

RESULTS

Out of 2,999 eligible patients, 1,130 had heart failure with preserved ejection fraction (HFpEF), 572 had heart failure with midrange ejection fraction (HFmrEF), and 1,297 had heart failure with reduced ejection fraction (HFrEF). In each cohort, 444, 232, and 574 patients received a DPP-4 inhibitor, respectively. A multivariable Cox regression model showed that DPP-4 inhibitor use was associated with a lower composite of cardiovascular death or HF hospitalization in HFpEF (HR: 0.69; 95% CI: 0.55-0.87; P = 0.002) but not in HFmrEF and HFrEF. Restricted cubic spline analysis demonstrated that DPP-4 inhibitors were beneficial in patients with higher left ventricular ejection fraction. In HFpEF cohort, propensity score matching yielded 263 pairs. DPP-4 inhibitor use was associated with a lower incidence rate of the composite of cardiovascular death or HF hospitalization (19.2 vs 25.9 events per 100 patient-years; rate ratio: 0.74; 95% CI: 0.57-0.97; P = 0.027) in matched patients.

CONCLUSIONS

DPP-4 inhibitor use was associated with better long-term outcomes in HFpEF patients with DM.

Novel Approaches to the Management of Diabetes Mellitus in Patients with Coronary Artery Disease

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in individuals with diabetes mellitus (DM). Although benefit has been attributed to the strict control of hyperglycemia with traditional antidiabetic treatments, novel antidiabetic medications have demonstrated cardiovascular (CV) safety and benefits by reducing major adverse cardiac events, improving heart failure (HF), and decreasing CVD-related mortality. Emerging data underline the interrelation between diabetes, as a metabolic disorder, and inflammation, endothelial dysfunction, and oxidative stress in the pathogenesis of microvascular and macrovascular complications. Conventional glucose-lowering medications demonstrate controversial CV effects. Dipeptidyl peptidase- 4 inhibitors have not only failed to prove to be beneficial in patients with coronary artery disease, but also their safety is questionable for the treatment of patients with CVD. However, metformin, as the first-line option for type 2 DM (T2DM), shows CVD protective properties for DM-induced atherosclerotic and macrovascular complications. Thiazolidinedione and sulfonylureas have questionable effects, as evidence from large studies shows a reduction in the risk of CV events and deaths, but with an increased rate of hospitalization for HF. Moreover, several studies have revealed that insulin monotherapy for T2DM treatment increases the risk of major CV events and deaths from HF, when compared to metformin, although it may reduce the risk of myocardial infarction. Finally, this review aimed to summarize the mechanisms of action of novel antidiabetic drugs acting as glucagon-like peptide-1 receptor agonists and sodium-glucose co-transporter-2 inhibitors that show favorable effects on blood pressure, lipid levels, and inflammation, leading to reduced CVD risk in T2DM patients.

An empirical evaluation of the impact scenario of pooling bodies of evidence from randomized controlled trials and cohort studies in medical research

BACKGROUND

Randomized controlled trials (RCTs) and cohort studies are the most common study design types used to assess treatment effects of medical interventions. We aimed to hypothetically pool bodies of evidence (BoE) from RCTs with matched BoE from cohort studies included in the same systematic review.

METHODS

BoE derived from systematic reviews of RCTs and cohort studies published in the 13 medical journals with the highest impact factor were considered. We re-analyzed effect estimates of the included systematic reviews by pooling BoE from RCTs with BoE from cohort studies using random and common effects models. We evaluated statistical heterogeneity, 95% prediction intervals, weight of BoE from RCTs to the pooled estimate, and whether integration of BoE from cohort studies modified the conclusion from BoE of RCTs.

RESULTS

Overall, 118 BoE-pairs based on 653 RCTs and 804 cohort studies were pooled. By pooling BoE from RCTs and cohort studies with a random effects model, for 61 (51.7%) out of 118 BoE-pairs, the 95% confidence interval (CI) excludes no effect. By pooling BoE from RCTs and cohort studies, the median I² was 48%, and the median contributed percentage weight of RCTs to the pooled estimates was 40%. The direction of effect between BoE from RCTs and pooled effect estimates was mainly concordant (79.7%). The integration of BoE from cohort studies modified the conclusion (by examining the 95% CI) from BoE of RCTs in 32 (27%) of the 118 BoE-pairs, but the direction of effect was mainly concordant (88%).

CONCLUSIONS

Our findings provide insights for the potential impact of pooling both BoE in systematic reviews. In medical research, it is often important to rely on both evidence of RCTs and cohort studies to get a whole picture of an investigated intervention-disease association. A decision for or against pooling different study designs should also always take into account, for example, PI/ECO similarity, risk of bias, coherence of effect estimates, and also the trustworthiness of the evidence. Overall, there is a need for more research on the influence of those issues on potential pooling.

DPP-4 inhibitors and GLP-1RAs: cardiovascular safety and benefits

Glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors are commonly used treatments for patients with type 2 diabetes mellitus (T2DM). Both anti-diabetic treatments function by playing key modulatory roles in the incretin system. Though these drugs have been deemed effective in treating T2DM, the Food and Drug Administration (FDA) and some members of the scientific community have questioned the safety of these therapeutics relative to important cardiovascular endpoints. As a result, since 2008, the FDA has required all new drugs for glycemic control in T2DM patients to demonstrate cardiovascular safety. The present review article strives to assess the safety and benefits of incretin-based therapy, a new class of antidiabetic drug, on the health of patient cardiovascular systems. In the process, this review will also provide a physiological overview of the incretin system and how key components function in T2DM.

New antidiabetic therapy and HFpEF: light at the end of tunnel?

New antidiabetic therapy that includes sodium-glucose co-transporter 2 (SGLT2) inhibitors, glucagon-like peptide-1 receptor (GLP-1R) agonists, and dipeptidyl peptidase 4 (DPP-4) inhibitors showed significant benefit on cardiovascular outcomes in patients with and without type 2 diabetes mellitus, and this was particularly confirmed for SGLT2 inhibitors in subjects with heart failure (HF) with reduced ejection fraction (HFrEF). Their role on patients with HF with preserved ejection fraction (HFpEF) is still not elucidated, but encouraging results coming from the clinical studies indicate their beneficial role. The role of GLP-1R agonists and particularly DPP-4 inhibitors is less clear and debatable. Findings from the meta-analyses are sending positive message about the use of GLP-1R agonists in HFrEF therapy and revealed the improvement of left ventricular (LV) diastolic function in HFpEF. Nevertheless, the relevant medical societies still consider their effect as neutral or insufficiently investigated in HF patients. The impact of DPP-4 inhibitors in HF is the most controversial due to conflicting data that range from negative impact and increased risk of hospitalization due to HF, throughout neutral effect, to beneficial influence on LV diastolic dysfunction. However, this is a very heterogeneous group of medications and some professional societies made clear discrepancy between saxagliptin that might increase risk of HF hospitalization and those DPP-4 inhibitors that have no effect on hospitalization. The aim of this review is to summarize current clinical evidence about the effect of new antidiabetic medications on LV diastolic function and their potential benefits in HFpEF patients.

Evaluating agreement between bodies of evidence from randomized controlled trials and cohort studies in medical research: a meta-epidemiological study

BACKGROUND

Randomized controlled trials (RCTs) and cohort studies are the most common study design types used to assess the treatment effects of medical interventions. To evaluate the agreement of effect estimates between bodies of evidence (BoE) from randomized controlled trials (RCTs) and cohort studies and to identify factors associated with disagreement.

METHODS

Systematic reviews were published in the 13 medical journals with the highest impact factor identified through a MEDLINE search. BoE-pairs from RCTs and cohort studies with the same medical research question were included. We rated the similarity of PI/ECO (Population, Intervention/Exposure, Comparison, Outcome) between BoE from RCTs and cohort studies. The agreement of effect estimates across BoE was analyzed by pooling ratio of ratios (RoR) for binary outcomes and difference of mean differences for continuous outcomes. We performed subgroup analyses to explore factors associated with disagreements.

RESULTS

One hundred twenty-nine BoE pairs from 64 systematic reviews were included. PI/ECO-similarity degree was moderate: two BoE pairs were rated as "more or less identical"; 90 were rated as "similar but not identical" and 37 as only "broadly similar". For binary outcomes, the pooled RoR was 1.04 (95% CI 0.97-1.11) with considerable statistical heterogeneity. For continuous outcomes, differences were small. In subgroup analyses, degree of PI/ECO-similarity, type of intervention, and type of outcome, the pooled RoR indicated that on average, differences between both BoE were small. Subgroup analysis by degree of PI/ECO-similarity revealed high statistical heterogeneity and wide prediction intervals across PI/ECO-dissimilar BoE pairs.

CONCLUSIONS

On average, the pooled effect estimates between RCTs and cohort studies did not differ. Statistical heterogeneity and wide prediction intervals were mainly driven by PI/ECO-dissimilarities (i.e., clinical heterogeneity) and cohort studies. The potential influence of risk of bias and certainty of the evidence on differences of effect estimates between RCTs and cohort studies needs to be explored in upcoming meta-epidemiological studies.

Diabetes mellitus and heart failure: an update on pathophysiology and therapy

Diabetes mellitus (DM) is frequent among heart failure (HF) patients with a further projected increase in prevalence in next years. DM promotes the development of both HF with reduced (HFrEF) and preserved ejection fraction (HFpEF) through different mechanisms. As the general prevalence of both DM and HF is growing worldwide, it is important to define the pathophysiologic mechanisms driving the development of HF in DM patients. These include changes in the cardiac metabolism, mitochondrial dysfunction, impairment in insulin signaling, maladaptive inflammation, coronary microvascular dysfunction, endoplasmic reticulum stress, autophagy suppression, and structural changes, among the main ones. In recent years, novel glucose-lowering treatments, especially sodium-glucose cotransporter 2 inhibitors (SGLT-2is), have shown a strikingly positive impact on the natural history of HF. This has led to a progressive change in choosing SGLT-2is in DM patients at high risk for CV disease, supported by recent guidelines. The knowledge about novel pathophysiological mechanisms linking DM and HF may open the way to the development of new targeted therapies in the future. In this review, we will summarize general aspects dealing with incidence, prevalence, and pathophysiology of DM in HF patients. As well, we discuss the therapeutic targets to reduce the disease burden and the current evidence of glucose-lowering drugs in patients with DM and HF.

Safety of dipeptidyl peptidase-4 inhibitors in older adults with type 2 diabetes: a systematic review and meta-analysis of randomized controlled trials

Registration:

PROSPERO: CRD42020210645

Introduction:

We aimed to assess the safety of dipeptidyl peptidase-4 (DPP-4) inhibitors in older patients with type 2 diabetes with inadequate glycaemic control.

Methods:

We included randomized controlled trials (RCTs) in older (⩾65 years) patients with type 2 diabetes. The intervention group was randomized to treatment with any DPP-4 inhibitors. A systematic search in MEDLINE and Embase was performed in December 2020. For assessing the risk of bias, RoB 2 tool was applied. The quality of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. We pooled outcomes using random effects meta-analyses.

Results:

We identified 16 RCTs that included 19,317 patients with a mean age of greater than 70 years. The mean HbA1c level ranged between 7.1 and 10.0 g/dl. Adding DPP-4 inhibitors to standard care alone may increase mortality slightly [risk ratio (RR) 1.04; 95% confidence interval (CI) 0.89–1.21]. Adding DPP-4 inhibitors to standard care increases the risk for hypoglycaemia (RR 1.08; 95% CI 1.01–1.16), but difference in overall adverse events is negligible. DPP-4 inhibitors added to standard care may reduce mortality compared with sulfonylureas (RR 0.88; 95% CI 0.75–1.04). DPP-4 inhibitors probably reduce the risk for hypoglycaemia compared with sulfonylureas (magnitude of effect not quantifiable because of heterogeneity) but difference in overall adverse events is negligible. There is insufficient evidence on hospitalizations, falls, fractures, renal impairment and pancreatitis.

Conclusion:

There is no evidence that DPP-4 inhibitors in addition to standard care decrease mortality but DPP-4 inhibitors increase hypoglycaemia risk. Second-line therapy in older patients should be considered cautiously even in drugs with a good safety profile such as DPP-4 inhibitors. In case second-line treatment is necessary, DPP-4 inhibitors appear to be preferable to sulfonylureas.

Plain language summary

Safety of dipeptidyl peptidase-4 inhibitors in older adults with type 2 diabetes Introduction: We performed the review to assess the safety of dipeptidyl peptidase-4 (DPP-4) inhibitors in older type 2 diabetes patients with blood sugar outside the normal level. Methods: To answer the question, we searched various electronic databases. We included studies in older (⩾65 years) patients with type 2 diabetes that assessed the safety of DPP-4 inhibitors. The data from the different studies were quantitatively summarized using statistical methods. We assessed the quality of the data to judge the certainty of the findings. Results: We identified 16 studies that included 19,317 patients with a mean age greater than 70 years. The average blood sugar level of patients in the included studies was slightly or moderately increased. Adding DPP-4 inhibitors to standard care alone may increase mortality slightly. Adding DPP-4 inhibitors to standard care increases the risk for hypoglycaemia, but difference in overall adverse events is negligible. DPP-4 inhibitors added to standard care may reduce mortality compared with sulfonylureas. DPP-4s probably reduce the risk of hypoglycaemia compared with sulfonylureas (magnitude of effect not quantifiable because of heterogeneity) but difference in overall adverse events is negligible. There is insufficient evidence on hospitalizations, falls, fractures, renal impairment and pancreatitis. Conclusion: There is no evidence that DPP-4 inhibitors in addition to standard care decrease mortality but DPP-4 inhibitors increase the risk that blood sugar falls below normal. Adding DPP-4 inhibitorss to standard care in older patients should be considered cautiously even in drugs with a good safety profile such as DPP-4 inhibitors. In case additional treatment is necessary, DPP-4 inhibitors appear to be preferable to sulfonylureas.

Comprehensive Management of Cardiovascular Risk Factors for Adults With Type 2 Diabetes: A Scientific Statement From the American Heart Association

Cardiovascular disease remains the leading cause of death in patients with diabetes. Cardiovascular disease in diabetes is multifactorial, and control of the cardiovascular risk factors leads to substantial reductions in cardiovascular events. The 2015 American Heart Association and American Diabetes Association scientific statement, "Update on Prevention of Cardiovascular Disease in Adults With Type 2 Diabetes Mellitus in Light of Recent Evidence," highlighted the importance of modifying various risk factors responsible for cardiovascular disease in diabetes. At the time, there was limited evidence to suggest that glucose-lowering medications reduce the risk of cardiovascular events. At present, several large randomized controlled trials with newer antihyperglycemic agents have been completed, demonstrating cardiovascular safety and reduction in cardiovascular outcomes, including cardiovascular death, myocardial infarction, stroke, and heart failure. This AHA scientific statement update focuses on (1) the evidence and clinical utility of newer antihyperglycemic agents in improving glycemic control and reducing cardiovascular events in diabetes; (2) the impact of blood pressure control on cardiovascular events in diabetes; and (3) the role of newer lipid-lowering therapies in comprehensive cardiovascular risk management in adults with diabetes. This scientific statement addresses the continued importance of lifestyle interventions, pharmacological therapy, and surgical interventions to curb the epidemic of obesity and metabolic syndrome, important precursors of prediabetes, diabetes, and comorbid cardiovascular disease. Last, this scientific statement explores the critical importance of the social determinants of health and health equity in the continuum of care in diabetes and cardiovascular disease.

Management of Hyperglycemia in Older Adults with Type 2 Diabetes

The increasing incidence of type 2 diabetes in the general population as well as enhanced life expectancy has resulted in a rapid rise in the prevalence of diabetes in the older population. Diabetes causes significant morbidity and impairs quality of life. Managing diabetes in older adults is a daunting task due to unique health and psychosocial challenges. Medical management is complicated by polypharmacy, cognitive impairment, urinary incontinence, injurious falls, and persistent pain. Health care providers now have several traditional and contemporary pharmacologic agents to manage diabetes. Avoidance of hypoglycemia is critical; however, evidence-based guidelines are lacking due to the paucity of clinical trials in older adults. For many in this population, maintaining independence is more important than adherence to published guidelines to prevent diabetes complications. The goal of diabetes care in older adults is to enhance the quality of life without subjecting these patients to intrusive and complicated interventions. Recent technological advancements such as continuous glucose monitoring systems can have crucial supplementary benefits in the geriatric population.

Comparative effectiveness and safety of pharmaceuticals assessed in observational studies compared with randomized controlled trials

BACKGROUND

There have been ongoing efforts to understand when and how data from observational studies can be applied to clinical and regulatory decision making. The objective of this review was to assess the comparability of relative treatment effects of pharmaceuticals from observational studies and randomized controlled trials (RCTs).

METHODS

We searched PubMed and Embase for systematic literature reviews published between January 1, 1990, and January 31, 2020, that reported relative treatment effects of pharmaceuticals from both observational studies and RCTs. We extracted pooled relative effect estimates from observational studies and RCTs for each outcome, intervention-comparator, or indication assessed in the reviews. We calculated the ratio of the relative effect estimate from observational studies over that from RCTs, along with the corresponding 95% confidence interval (CI) for each pair of pooled RCT and observational study estimates, and we evaluated the consistency in relative treatment effects.

RESULTS

Thirty systematic reviews across 7 therapeutic areas were identified from the literature. We analyzed 74 pairs of pooled relative effect estimates from RCTs and observational studies from 29 reviews. There was no statistically significant difference (based on the 95% CI) in relative effect estimates between RCTs and observational studies in 79.7% of pairs. There was an extreme difference (ratio < 0.7 or > 1.43) in 43.2% of pairs, and, in 17.6% of pairs, there was a significant difference and the estimates pointed in opposite directions.

CONCLUSIONS

Overall, our review shows that while there is no significant difference in the relative risk ratios between the majority of RCTs and observational studies compared, there is significant variation in about 20% of comparisons. The source of this variation should be the subject of further inquiry to elucidate how much of the variation is due to differences in patient populations versus biased estimates arising from issues with study design or analytical/statistical methods.

Impact of diabetes on cardiopulmonary function: the added value of a combined cardiopulmonary and echocardiography stress test

Type 2 diabetes mellitus (T2DM) represents a major health issue worldwide, as patients with T2DM show an excess risk of death for cardiovascular causes, twice as high as the general population. Among the many complications of T2DM, heart failure (HF) deserves special consideration as one of the leading causes of morbidity and reduced life expectancy. T2DM has been associated with different phenotypes of HF, including HF with reduced and preserved ejection fraction. Cardiopulmonary exercise testing (CPET) can evaluate the metabolic and ventilatory alterations related to myocardial dysfunction and/or peripheral impairment, representing a unique tool for the clinician to study the whole HF spectrum. While CPET allows for a thorough evaluation of functional capacity, it cannot directly differentiate central and peripheral determinants of effort intolerance. Combining CPET with imaging techniques could provide even higher accuracy and further insights into the progression of the disease since signs of left ventricular systolic and diastolic dysfunction can be detected during exercise, even in asymptomatic diabetic individuals. This review aims to dissect the alterations in cardiopulmonary function characterising patients with T2DM and HF to improve patient risk stratification.

Heart failure in type 2 diabetes: current perspectives on screening, diagnosis and management

Type 2 diabetes is one of the most relevant risk factors for heart failure, the prevalence of which is increasing worldwide. The aim of the review is to highlight the current perspectives of the pathophysiology of heart failure as it pertains to type 2 diabetes. This review summarizes the proposed mechanistic bases, explaining the myocardial damage induced by diabetes-related stressors and other risk factors, i.e., cardiomyopathy in type 2 diabetes. We highlight the complex pathology of individuals with type 2 diabetes, including the relationship with chronic kidney disease, metabolic alterations, and heart failure. We also discuss the current criteria used for heart failure diagnosis and the gold standard screening tools for individuals with type 2 diabetes. Currently approved pharmacological therapies with primary use in type 2 diabetes and heart failure, and the treatment-guiding role of NT-proBNP are also presented. Finally, the influence of the presence of type 2 diabetes as well as heart failure on COVID-19 severity is briefly discussed.

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.

Heart failure outcomes and glucagon-like peptide-1 receptor agonists: A systematic review of observational studies

AIM/OBJECTIVE

Recently, the glucagon-like peptide-1 receptor agonists (GLP-1RA) class showed a significant reduction in heart failure (HF) hospitalization in several meta-analyses of cardiovascular outcome trials (CVOTs). The objective of this systematic review is to summarize the real-world evidence regarding HF outcomes of GLP-1RAs.

METHODS

We searched the PubMed and EMBASE databases for observational studies that investigated HF outcomes of GLP-1RAs.

RESULTS

Our search yielded 10 observational studies. Of those, 7 were cohort studies, and 3 were nested case-control studies. The risk of HF was the outcome in four cohort studies. One study that compared exenatide and exenatide combined with insulin to insulin showed a reduction in HF risk in the exenatide and exenatide plus insulin groups (HR 0.34, 95% CI 0.22-0.52, p-value <0.001 and HR 0.40, 95% CI 0.32-0.50, p-value <0.001, respectively). The other three cohort studies did not show a statistically significant result. In the three cohort studies that investigated HF hospitalization as an outcome, two showed a lower rate of HF hospitalization [48 (16.7%) vs. 76 (28%), p-value <0.05 and HR 0.51, 95% CI 0.34-0.77, p = 0.002] in the GLP-1RA groups. Conversely, the remaining study showed a reduction of 14% in HF hospitalization in the dipeptidyl peptidase-4 inhibitors (DPP-4i) group compared to the GLP-1RA group (HR 0.86, 95% CI 0.83-0.90). In contrast to the cohort studies, the three nested case-control studies showed similar results of no association of GLP-1RA use and HF hospitalization with OR 0.67 (95% CI 0.32-1.42), HR 0.95 (95% CI 0.83-1.10), and OR 0.84 (95% CI 0.48-1.47), respectively.

CONCLUSION

The real-world evidence regarding the reduction in HF risk and hospitalization in GLP-1RA users is conflicting. Further well-designed, large multicenter, observational studies are needed to show clearer evidence.

Glucose-lowering Drugs and Hospitalization for Heart Failure: A Systematic Review and Additive-effects Network Meta-analysis With More Than 500 000 Patient-years

BACKGROUND

Sodium glucose co-transporter 2 inhibitors (SGLT2is) prevent hospitalization resulting from heart failure (HHF). However, patients with type 2 diabetes mellitus use multiple antihyperglycemic drugs to achieve glycosylated hemoglobin (HbA1c) targets. In these drug combinations, the risk of HHF is unpredictable and so is the parallel effect of glucose-lowering.

PURPOSE

To examine the impact of antihyperglycemic drugs and their association on HHF.

DATA SOURCES

Forty randomized controlled trials (RCTs) reporting HHF.

STUDY SELECTION

Published RCTs were the data source.

DATA EXTRACTION

Incidence rates of HHF.

DATA SYNTHESIS

Random additive-effects network meta-analysis showed that metformin (P = 0.55), sulfonylureas (P = 0.51), glucagon-like peptide-1 receptor-agonist (P = 0.16), and dipeptidyl peptidase 4 inhibitors (DPP4is; P = 0.54) were neutral on the risk of HHF. SGLT2is and SGLT2is + DPP4is reduced the risk of HHF with a hazard ratio (HR) of 0.68 (95% CI, 0.60-0.76; P < 0.0001) and 0.70 (95% CI, 0.60-0.81; P < 0.0001), respectively. Increased risk of HHF was associated with thiazolidinediones (TZDs) as monotherapy or in combination with DPP4is (HR: 1.45; 95% CI, 1.18-1.78; P = 0.0004) and 1.49 (95% CI, 1.18-1.88; P = 0.0008), respectively. Regardless of the therapy, a 1% reduction in HbA1c reduced the risk of HHF by 31.3% (95% CI, 9-48; P = 0.009).

LIMITATIONS

There are no data to verify drug combinations available for clinical use and to discriminate the effect of drugs within each of the therapeutic classes.

CONCLUSIONS

The risk of HHF is reduced by SGLT2is as monotherapy or in combination with DPP4is and increased by TZDs as monotherapy or in combination. Glucose-lowering provides an additive effect of reducing HHF.

Outcomes of patients with type 2 diabetes treated with SGLT-2 inhibitors versus DPP-4 inhibitors. An Italian real-world study in the context of other observational studies

AIMS

We compared cardiovascular outcomes of patients with type 2 diabetes (T2D) receiving sodium glucose cotransporter-2 inhibitors (SGLT2i) or dipeptidyl peptidase-4 inhibitors (DPP4i) under routine care.

METHODS

From an administrative claims database of >5.2M citizen, we identified patients with T2D who initiated SGLT2i or DPP4i from 2014 to 2018. Patients were matched by propensity scores. The primary outcome was the 3-point major adverse cardiovascular events (3P-MACE).

RESULTS

After matching, we included 3216 patients/group, with mean age of 63 years, diabetes duration of 8.7 years, and 20% had cardiovascular disease. During a median follow-up of 18 months, the rate of 3P-MACE was lower among patients who initiated SGLT2i versus DPP4i (HR 0.74; 95 %C.I. 0.58-0.94). Initiators of SGLT2i also showed significantly lower rates of myocardial infarction (HR 0.75; 95 %C.I. 0.56-1.00), hospitalization for heart failure (HR 0.44; 95 %C.I. 0.25-0.95) or cardiovascular causes (HR 0.72; 95 %C.I. 0.60-0.87), and all-cause death (HR 0.49; 95 %C.I. 0.25-0.95). Renal failure was less common with SGLT2i than with DPP4i. Results were consistent to those obtained in a meta-analysis of 10 observational studies on ~1.5M patients.

CONCLUSIONS

Patients with T2D who initiated SGLT2i under routine care had better cardio-renal outcomes and lower all-cause mortality than similar patients who initiated DPP4i.

New Aspects of Diabetes Research and Therapeutic Development

Both type 1 and type 2 diabetes mellitus are advancing at exponential rates, placing significant burdens on health care networks worldwide. Although traditional pharmacologic therapies such as insulin and oral antidiabetic stalwarts like metformin and the sulfonylureas continue to be used, newer drugs are now on the market targeting novel blood glucose-lowering pathways. Furthermore, exciting new developments in the understanding of beta cell and islet biology are driving the potential for treatments targeting incretin action, islet transplantation with new methods for immunologic protection, and the generation of functional beta cells from stem cells. Here we discuss the mechanistic details underlying past, present, and future diabetes therapies and evaluate their potential to treat and possibly reverse type 1 and 2 diabetes in humans. SIGNIFICANCE STATEMENT: Diabetes mellitus has reached epidemic proportions in the developed and developing world alike. As the last several years have seen many new developments in the field, a new and up to date review of these advances and their careful evaluation will help both clinical and research diabetologists to better understand where the field is currently heading.

Association between Add-On Dipeptidyl Peptidase-4 Inhibitor Therapy and Diabetic Retinopathy Progression

This study aimed to investigate the association of add-on dipeptidyl peptidase-4 inhibitor (DPP4i) therapy and the progression of diabetic retinopathy (DR). In this retrospective population-based cohort study, we examined Taiwanese patients with type 2 diabetes, preexisting DR, and aged ≥40 years from 2009 to 2013. Prescription of DPP4i was defined as a medication possession ratio of ≥80% during the first 6 months. The outcomes included vitreous hemorrhage (VH), tractional retinal detachment, macular edema, and interventions including retinal laser therapy, intravitreal injection (IVI), and vitrectomy. Of 1,767,640 patients, 62,824 were eligible for analysis. After matching, the DPP4i and non-DPP4i groups each contained 20,444 patients. The risks of VH (p = 0.013) and macular edema (p = 0.035) were higher in the DPP4i group. The DPP4i group also had higher risks of receiving surgical interventions (retinal laser therapy (p < 0.001), IVI (p = 0.049), vitrectomy (p < 0.001), and any surgical intervention (p < 0.001)). More patients in the DPP4i group received retinal laser therapy (p < 0.001) and IVI (p = 0.001) than in the non-DPP4i group. No between-group differences in cardiovascular outcomes were noted. In the real-world database study, add-on DPP4i therapy may be associated with the progression of DR in patients with type 2 diabetes. No additional cardiovascular risks were found. The early progression of DR in rapid glycemic control was inconclusive in our study. The possible effect of add-on DPP4i therapy in the progression of DR in patients with type 2 diabetes requires further research.

Cardiovascular safety of evogliptin in patients with type 2 diabetes: A nationwide cohort study

AIM

To assess whether the use of evogliptin, a novel dipeptidyl peptidase-4 inhibitor (DPP-4i), was associated with an increased risk of cardiovascular events compared with glimepiride in patients with type 2 diabetes (T2D).

METHODS

We conducted a population-based cohort study using South Korea's nationwide healthcare database from 1 January 2014 to 31 December 2018. We identified a base cohort of patients with T2D who newly initiated metformin monotherapy, from which we identified a study cohort of patients who either added or switched to glimepiride or DPP-4is (including evogliptin). Patients were followed up from initiation of DPP-4is or glimepiride until the earliest of either outcome occurrence or 31 December 2018. Our primary outcome was hospitalization or an emergency visit for cardiovascular events, a composite endpoint comprised of cerebrovascular events, heart failure, myocardial infarction, transient ischaemic attack, angina pectoris and revascularization procedures; secondary outcomes were the individual components of the primary outcome. A multivariable Cox proportional hazards model was used to estimate adjusted hazard ratios (aHRs) with 95% confidence intervals (CIs) for the risk of study outcomes associated with evogliptin compared with glimepiride.

RESULTS

Our base and study cohorts had 317,307 and 128,788 patients, respectively, of which 100,038 were DPP-4i users (2946 were evogliptin users) and 28,750 were glimepiride users within the study cohort. The median follow-up was 195 days for evogliptin and 113 days for glimepiride users. Compared with glimepiride, evogliptin was associated with a reduced risk of the primary outcome (aHR 0.67, 95% CI 0.48-0.95) and cerebrovascular events (aHR 0.41, 95% CI 0.22-0.78) but showed non-significant associations for myocardial infarction (aHR 0.63, 95% CI 0.27-1.46), heart failure (aHR 0.35, 95% CI 0.09-1.47), transient ischaemic attack (aHR 0.23, 95% CI 0.03-1.72) and angina pectoris (aHR 1.35, 95% CI 0.82-2.21).

CONCLUSIONS

Findings from this population-based cohort study provide novel real-world evidence that the use of evogliptin, compared with glimepiride, did not increase the risk of cardiovascular events, including cerebrovascular events, myocardial infarction, heart failure, transient ischaemic attack and angina pectoris.

Diabetes Management in Patients with Heart Failure

Diabetes and heart failure (HF) are common diseases, each affecting large segments of the world population. Moreover, prevalence rates for both are expected to rise dramatically over coming decades. The high prevalence rates of both diseases and wellrecognized association of diabetes as a risk factor for HF make it inevitable that both diseases co-exist in a large number of patients, complicating their management and increasing the risk of a poor outcome. Management of diabetes has been shown to impact clinical events in patients with HF and there is emerging evidence that agents used to treat diabetes can reduce HF events, even in non-diabetic patients. In this review we summarize the clinical course and treatment of patients with type 2 diabetes mellitus (T2DM) and HF and review the efficacy and safety of pharmacological agents in patients with T2DM at risk for HF and those with established disease.

A comprehensive review on the antidiabetic activity of flavonoids targeting PTP1B and DPP-4: a structure-activity relationship analysis

Type 2 diabetes (T2D) is an expanding global health problem, resulting from defects in insulin secretion and/or insulin resistance. In the past few years, both protein tyrosine phosphatase 1B (PTP1B) and dipeptidyl peptidase-4 (DPP-4), as well as their role in T2D, have attracted the attention of the scientific community. PTP1B plays an important role in insulin resistance and is currently one of the most promising targets for the treatment of T2D, since no available PTP1B inhibitors were still approved. DPP-4 inhibitors are among the most recent agents used in the treatment of T2D (although its use has been associated with possible cardiovascular adverse events). The antidiabetic properties of flavonoids are well-recognized, and include inhibitory effects on the above enzymes, although hitherto not therapeutically explored. In the present study, a comprehensive review of the literature of both synthetic and natural isolated flavonoids as inhibitors of PTP1B and DPP-4 activities is made, including their type of inhibition and experimental conditions, and structure-activity relationship, covering a total of 351 compounds. We intend to provide the most favorable chemical features of flavonoids for the inhibition of PTP1B and DPP-4, gathering information for the future development of compounds with improved potential as T2D therapeutic agents.

Long-term safety and efficacy of alogliptin, a DPP-4 inhibitor, in patients with type 2 diabetes: a 3-year prospective, controlled, observational study (J-BRAND Registry)

INTRODUCTION

Given an increasing use of dipeptidyl peptidase-4 (DPP-4) inhibitors to treat patients with type 2 diabetes mellitus in the real-world setting, we conducted a prospective observational study (Japan-based Clinical Research Network for Diabetes Registry: J-BRAND Registry) to elucidate the safety and efficacy profile of long-term usage of alogliptin.

RESEARCH DESIGN AND METHODS

We registered 5969 patients from April 2012 through September 2014, who started receiving alogliptin (group A) or other classes of oral hypoglycemic agents (OHAs; group B), and were followed for 3 years at 239 sites nationwide. Safety was the primary outcome. Symptomatic hypoglycemia, pancreatitis, skin disorders of non-extrinsic origin, severe infections, and cancer were collected as major adverse events (AEs). Efficacy assessment was the secondary outcome and included changes in hemoglobin A1c (HbA1c), fasting blood glucose, fasting insulin and urinary albumin.

RESULTS

Of the registered, 5150 (group A: 3395 and group B: 1755) and 5096 (3358 and 1738) were included for safety and efficacy analysis, respectively. Group A patients mostly (>90%) continued to use alogliptin. In group B, biguanides were the primary agents, while DPP-4 inhibitors were added in up to ~36% of patients. The overall incidence of AEs was similar between the two groups (42.7% vs 42.2%). Kaplan-Meier analysis revealed the incidence of cancer was significantly higher in group A than in group B (7.4% vs 4.8%, p=0.040), while no significant incidence difference was observed in the individual cancer. Multivariate Cox regression analysis revealed that the imbalanced patient distribution (more elderly patients in group A than in group B), but not alogliptin usage per se, contributed to cancer development. The incidence of other major AE categories was with no between-group difference. Between-group difference was not detected, either, in the incidence of microvascular and macrovascular complications. HbA1c and fasting glucose decreased significantly at the 0.5-year visit and nearly plateaued thereafter in both groups.

CONCLUSIONS

Alogliptin as a representative of DPP-4 inhibitors was safe and durably efficacious when used alone or with other OHAs for patients with type 2 diabetes in the real world setting.

Roles and Mechanisms of Dipeptidyl Peptidase 4 Inhibitors in Vascular Aging

Vascular aging is characterized by alterations in the constitutive properties and biological functions of the blood vessel wall. Endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) are indispensability elements in the inner layer and the medial layer of the blood vessel wall, respectively. Dipeptidyl peptidase-4 (DPP4) inhibitors, as a hypoglycemic agent, play a protective role in reversing vascular aging regardless of their effects in meliorating glycemic control in humans and animal models of type 2 diabetes mellitus (T2DM) through complex cellular mechanisms, including improving EC dysfunction, promoting EC proliferation and migration, alleviating EC senescence, obstructing EC apoptosis, suppressing the proliferation and migration of VSMCs, increasing circulating endothelial progenitor cell (EPC) levels, and preventing the infiltration of mononuclear macrophages. All of these showed that DPP4 inhibitors may exert a positive effect against vascular aging, thereby preventing vascular aging-related diseases. In the current review, we will summarize the cellular mechanism of DPP4 inhibitors regulating vascular aging; moreover, we also intend to compile the roles and the promising therapeutic application of DPP4 inhibitors in vascular aging-related diseases.

Phosphodiesterase Type 5 Inhibitors and Risk of Skin Cancers in Men: A Meta-Analysis and Trial Sequential Analysis Involving 7,479,852 Subjects

Purpose

We conducted a systematic review and meta-analysis to quantify the association between phosphodiesterase type 5 inhibitors (PDE5Is) use and skin cancers and we also examined whether down-expression of the PDE5A gene was related to worse prognosis for malignant melanoma (MM) patients.

Materials and Methods

The PubMed, Cochrane Library, Web of Science, EMBASE, and ClinicalTrails.gov databases were searched. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to evaluate the association between PDE5Is use and risk of skin cancers. Cumulative meta-analysis and trial sequential analysis (TSA) were also conducted. Survival outcomes were analyzed online.

Results

After pooling all 8 eligible studies comprising 7,479,852 subjects, we found that PDE5Is use was significantly associated with slightly increased risk of developing MM (OR: 1.13, 95% CI: 1.05 to 1.21, I²=67.1%), basal cell carcinoma (OR: 1.16, 95% CI: 1.13 to 1.19, I²=49.6%), and squamous cell carcinoma (OR: 1.07, 95% CI: 1.01 to 1.13, I²=0.0%). Totally, PDE5Is increased the risk of developing skin cancers (OR: 1.13, 95% CI: 1.09 to 1.17, I²=70.8%). TSA results showed that the sample size was enough to reach a positive conclusion.

Conclusions

The use of PDE5Is may be slightly associated with increased risk of developing skin cancers. There should be a balance between drug benefits and potential safety issues. However, the pooled results should be considered tentative until confounding factors such as sun exposure and lifestyle are well-controlled in further studies.

Comparing the incidence of major cardiovascular events and severe microvascular complications in patients with type 2 diabetes mellitus: A systematic review and meta-analysis

BACKGROUND

Type 2 diabetes mellitus (T2DM) causes both macrovascular and microvascular complications. However, currently, selection of glycemic measures and their thresholds to diagnose T2DM, and efficacy outcomes in evaluation of anti-diabetic drugs is predominantly informed by the relation of T2DM to microvascular complications. We can be severely mistaken on T2DM by neglecting macrovascular complications which are generally more severe, if they also occur more commonly than microvascular complications.

AIM

To compare the incidence of major cardiovascular events (MACEs) and severe microvascular complications (SMICs) in T2DM patients.

METHODS

MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials were searched from inception to September 2017. Cohort studies or trials of T2DM patients aged 18 years or older that reported incidence of both MACEs and SMICs were included. MACEs were defined as nonfatal myocardial infarction and stroke, and cardiovascular death, while SMICs included serious retinopathy, nephropathy and diabetic disorder. The relative risk (RR) was estimated as the incidence of MACEs divided by that of SMICs in same patients and combined with meta-analysis in a random-effect model.

RESULTS

Twelve studies with a total of 16 cohorts and 387376 patients were included, and the combined RR was 2.02 (95%CI: 1.46–2.79). The higher incidence of MACEs remained in various subgroup and sensitivity analyses.

CONCLUSION

Patients with T2DM are much more likely to develop MACEs than SMICs. By taking more serious consequences and relatively higher incidence into consideration, macrovascular complications deserve more emphasis in developing the diagnostic criteria of T2DM and in evaluating the efficacy of anti-diabetic drugs.

Proteomic exploration of common pathophysiological pathways in diabetes and cardiovascular disease

Aims

The epidemiological association between diabetes and cardiovascular disease is well established, but the pathophysiological link is complex and multifactorial. We investigated seven proteins, previously linked to incident diabetes mellitus, and their association with cardiovascular disease and mortality.

Methods and results

Plasma samples from 1713 individuals from the Swedish population‐based Malmö Preventive Project (mean age 67.4 ± 6.0 years; 29.1% women) were analysed with a proximity extension assay panel. Seven proteins [scavenger receptor cysteine rich type 1 protein M130 (CD163), fatty acid‐binding protein 4 (FABP4), plasminogen activator inhibitor 1 (PAI), insulin‐like growth factor‐binding protein 2 (IGFB2), cathepsin D (CTSD), galectin‐4 (GAL4), and paraoxonase‐3 (PON3)] previously shown to be associated with incident diabetes were analysed for associations with all‐cause mortality (ACM), cardiovascular mortality (CVM), incident coronary events (CEs), and incident heart failure (HF). After exclusion of prevalent cases of respective outcome, proteins that met Bonferroni‐corrected significance were analysed in multivariable Cox regression models. Significant associations were identified between five proteins [GAL4 (hazard ratio; 95% confidence interval: 1.17–1.41), CTSD (1.15–1.37), CD163 (1.09–1.30), IGFBP2 (1.05–1.30), and FABP4 (1.04–1.29)] and ACM and four proteins [GAL4 (1.38–1.56), CTSD (1.14–1.43), CD163 (1.09–1.36), and IGFBP2 (1.03–1.35)] with CVM. Three proteins [GAL4 (1.14–1.57), CTSD (1.12–1.50), and FABP4 (1.05–1.55)] were significantly associated with incident CE and two [GAL4 (1.03–1.54) and CTSD (1.01–1.46)] were associated with incident HF after adjusting for traditional risk factors including N‐terminal pro‐brain natriuretic peptide.

Conclusions

In a general Swedish population, four proteins previously shown to be associated with diabetes were associated with ACM and CVM. Three proteins were associated with incident CE. Finally, GAL4 and CTSD displayed novel associations with incident HF and were the only proteins associated with all outcomes.

The DPP-IV inhibitor saxagliptin promotes the migration and invasion of papillary thyroid carcinoma cells via the NRF2/HO1 pathway

Dipeptidyl peptidase-IV (DPP-IV) inhibitors are used to control blood glucose levels in patients with type 2 diabetes. However, the influence of DPP-IV inhibitors on malignant tumors remains unknown. The present study aimed to investigate the effect of the DPP-IV inhibitor saxagliptin on thyroid carcinoma cells. Transwell assays and a nude mouse lung metastasis model were used to evaluate the invasion and metastasis of thyroid carcinoma cells. Western blotting was used to determine the protein levels of migration and invasion-related molecules. We tested the expression and distribution of nuclear factor, erythroid 2 like 2 (NRF2) in thyroid carcinoma cells with and without saxagliptin. Furthermore, we silenced NRF2 and observed saxagliptin's effect on migration and invasion. Quantitative real-time reverse transcription PCR (qRT-PCR) and western blotting were then used to measure the expression of NFR2's downstream molecules (heme oxygenase 1 (HO1), matrix metalloproteinase 2 (MMP2), and vascular endothelial growth factor (VEGF)). A luciferase reporter assay was used to validate whether NRF2 could regulate the transcriptional activity of the HO1 promoter. Saxagliptin enhanced the migratory and invasive ability of thyroid carcinoma cells. MMP2 and VEGF levels were also elevated by saxagliptin treatment. We found that saxagliptin treatment increases the nuclear and cytoplasmic accumulation NRF2. Silencing NRF2 abolished the effect of saxagliptin on migration and invasion. Accordingly, NRF2 silencing downregulated HO1, MMP2, and VEGF levels. The luciferase assay showed that NRF2 activated transcription from the HO1 promoter. Saxagliptin could promote this transcriptional activity by upregulating NRF2. Saxagliptin enhanced the migratory and invasive ability of human thyroid carcinoma cells, as well as the expression of MMP2 and VEGF, by activating the NRF2/HO1 pathway.