Dipeptidyl peptidase-4 inhibitors and heart failure: a meta-analysis of randomized clinical trials

Alogliptin and Heart Failure Outcomes in Patients With Type 2 Diabetes

Background: In 2016, the FDA issued a warning for saxagliptin and alogliptin regarding an increased risk of heart failure (HF), potentially limiting the use of effective medications in type 2 diabetes. Current data and guideline recommendations regarding HF risk are conflicting, especially with alogliptin. In March 2019, the Memphis Veterans Affairs Medical Center made a formulary change from saxagliptin to alogliptin, creating an opportunity to evaluate a large number of patients receiving alogliptin. Objective: To evaluate the risk of HF with alogliptin use in type 2 diabetes patients. Methods: A retrospective chart review of patients prescribed alogliptin was performed. The primary outcome was the composite number of HF hospital admissions and ED visits. Secondary outcomes included exacerbation rates among established HF patients, incidence of new-onset HF, incidence of alogliptin discontinuation due to HF, comparison of HF exacerbations between saxagliptin and alogliptin in patients with prior saxagliptin use, and evaluation of concomitant cardiotoxic medications. Results: 455 patients were included. A composite of 28 hospital admissions and ED visits occurred for a HF exacerbation. Fourteen patients (26.4%) of 53 patients with established HF had an exacerbation, whereas 5 patients (1.2%) of 402 patients with no history of HF had an exacerbation. Eight patients (2%) developed new-onset HF. Alogliptin was discontinued in 4 patients (0.9%) due to HF. No statistically significant difference in HF exacerbations was found between patients on alogliptin who previously received saxagliptin (4.8% vs 4.2%, P = 0.726). Conclusions: Alogliptin may increase the risk of HF exacerbation in patients with established HF.

Effects of glucose-lowering agents on cardiovascular and renal outcomes in subjects with type 2 diabetes: An updated meta-analysis of randomized controlled trials with external adjudication of events

AIMS

To investigate the effects of glucose-lowering agents on all-cause mortality, and cardiovascular and renal outcomes in adults with type 2 diabetes.

METHODS

A MEDLINE and EMBASE search was performed to identify randomized controlled trials, published up to 28 February 2022, with a follow-up ≥52 weeks, in which glucose-lowering drugs were compared with either placebo or active comparators. We included only trials reporting formal external adjudication of events. All-cause mortality, 3-point MACE (major cardiovascular events), and hospitalization for heart failure (HHF) were considered as principal outcomes. Doubling of serum creatinine, worsening albuminuria, and renal death were considered as secondary endpoints.

RESULTS

We included randomized controlled trials performed on metformin (n = 17), pioglitazone (n = 20), alpha-glucosidase inhibitors (n = 9), insulin secretagogues (n = 42), dipeptidyl-peptidase-4 inhibitors (n = 67), glucagon-like peptide-1 receptor agonists (n = 45) or sodium-glucose co-transporter-2 inhibitors (SGLT-2i; n = 42) and insulin (n = 18). Glucagon-like peptide-1 receptor agonist and SGLT-2i were associated with a significant reduction in all-cause mortality [Mantel-Haenszel odds ratio (MH-OR), 95% confidence interval: 0.88 (0.83; 0.95) and 0.85 (0.79; 0.91), respectively] and MACE [MH-OR, 95% confidence interval: 0.89 (0.84; 0.94) and 0.90 (0.84; 0.96), respectively]. SGLT-2i was associated with a reduced risk of HHF [MH-OR 0.68 (0.62; 0.75)], worsening albuminuria [MH-OR 0.67 (0.55; 0.80)] and doubling of serum creatinine [MH-OR 0.58 (0.44; 0.79)]. Metformin and pioglitazone were associated with a significantly lower risk of MACE [MH-OR 0.60 (0.47; 0.80) and 0.85 (0.74; 0.97), respectively] and pioglitazone with a higher risk of HHF [MH-OR 1.30 (1.04; 1.62)]. Insulin secretagogues were associated with increased risk of all-cause mortality [MH-OR 1.12 (1.01; 1.24)] and MACE [MH-OR 1.19 (1.02; 1.39)].

CONCLUSIONS

The results of this updated meta-analysis need to be considered in the choice of drug treatment for type 2 diabetes mellitus, which cannot be merely based on the effect of glucose-lowering drugs on long-term glycaemic control.

Effects of DPP-4 inhibitors on brain natriuretic peptide, neuropeptide Y, glucagon like peptide-1, substance P levels and global longitudinal strain measurements in type 2 diabetes mellitus patients

Introduction: Previously, a significant relationship between saxagliptin treatment and increased rate of hospitalization for congestive heart failure was reported. We aimed to investigate effects of vildagliptin and saxagliptin on brain natriuretic peptide (BNP), neuropeptide Y (NPY), substance P (SP), glucagon like peptide-1 (GLP-1) levels and left ventricular global longitudinal strain (GLS), assessed by 3-dimensional speckle tracking echocardiography in uncontrolled type 2 Diabetes mellitus (T2DM). Material and method: Thirty seven uncontrolled T2DM (HbA1c>7,5%) patients who were recently prescribed to either vildagliptin 50 mg BID (n=21) or saxagliptin 5 mg QD (n=16) were included in this study. Levels of BNP, NPY, SP, GLP-1 levels were measured at admission, first and third months of treatment. GLS was measured at admission and third month. Results: In whole group, BNP and NPY values increased significantly at third month of treatment (p< 0.001, 0.004; respectively). In the vildagliptin group, BNP and NPY values increased significantly at third month of treatment (p=0.02 and p=0.04, respectively). In the saxagliptin group only BNP levels increased significantly (p=0.015). In both groups; SP, GLP-1 levels and GLS measurements did not change significantly during follow-up period. Conclusion: The current study demonstrated that treatment with saxagliptin and vildagliptin, was associated with increased levels of BNP and NPY levels. No evidence of subclinical myocardial damage or cardiac dysfunction could be detected by GLS measurements. Since our study population had no previous clinical cardiac disorders, increases in BNP and NPY levels with these two DPP4 inhibitors can be considered as a safety signal.

Inhibition of Dipeptidyl Peptidase-4 by Flavonoids: Structure–Activity Relationship, Kinetics and Interaction Mechanism

With the aim to establish a structure-inhibitory activity relationship of flavonoids against dipeptidyl peptidase-4 (DPP-4) and elucidate the interaction mechanisms between them, a pannel of 70 structurally diverse flavonoids was used to evaluate their inhibitory activities against DPP-4, among which myricetin, hyperoside, narcissoside, cyanidin 3-O-glucoside, and isoliquiritigenin showed higher inhibitory activities in a concentration-dependent manner. Structure-activity relationship analysis revealed that introducing hydroxyl groups to C3', C4', and C6 of the flavonoid structure was beneficial to improving the inhibitory efficacy against DPP-4, whereas the hydroxylation at position 3 of ring C in the flavonoid structure was unfavorable for the inhibition. Besides, the methylation of the hydroxyl groups at C3', C4', and C7 of the flavonoid structure tended to lower the inhibitory activity against DPP-4, and the 2,3-double bond and 4-carbonyl group on ring C of the flavonoid structure was essential for the inhibition. Glycosylation affected the inhibitory activity diversely, depending on the structure of flavonoid aglycone, type of glycoside, as well as the position of substitution. Inhibition kinetic analysis suggested that myricetin reversibly inhibited DPP-4 in a non-competitive mode, whereas hyperoside, narcissoside, cyanidin 3-O-glucoside, and isoliquiritigenin all reversibly inhibited DPP-4 in a mixed type. Moreover, the fluorescence quenching analysis indicated that all the five flavonoid compounds could effectively quench the intrinsic fluorescence of DPP-4 by spontaneously binding with it to form an unstable complex. Hydrogen bonds and van der Waals were the predominant forces to maintain the complex of myricetin with DPP-4, and electrostatic forces might play an important role in stabilizing the complexes of the remaining four flavonoids with DPP-4. The binding of the tested flavonoids to DPP-4 could also induce the conformation change of DPP-4 and thus led to inhibition on the enzyme. Molecular docking simulation further ascertained the binding interactions between DPP-4 and the selected five flavonoids, among which hyperoside, narcissoside, cyaniding 3-O-glucoside, and isoliquiritigenin inserted into the active site cavity of DPP-4 and interacted with the key amino acid residues of the active site, whereas the binding site of myricetin was located in a minor cavity close to the active pockets of DPP-4.

Contemporary Medical Therapies for Patients with Peripheral Artery Disease and Concomitant Type 2 Diabetes Mellitus: a Review of Current Evidence

PURPOSE OF REVIEW

The purpose of this review is to highlight the evidence behind landmark trials involving these two novel drug classes in conjunction with a review of long-standing therapies used to improve cardiovascular (CV) outcomes among patients with peripheral artery disease (PAD) patients and type 2 diabetes mellitus (T2DM).

RECENT FINDINGS

Recently, societal guideline recommendations have expanded the management of T2DM to incorporate therapies with CV risk factor modification. This is due to CV outcome trials (CVOT) uncovering advantageous cardioprotective effects of several novel therapies, including glucagon-like peptide-1 receptor agonists (GLP-1 RA) and sodium-glucose cotransporter-2 inhibitors (SGLT2i). Providers who manage high-risk patients with T2DM, such as those with concomitant PAD, are expected to incorporate these novel medical therapies into routine patient care. The body of evidence surrounding GLP-1 RA demonstrates a strong benefit in mitigating the innate heightened CV risk among patients with T2DM. Furthermore, SGLT2i not only have a favorable CV profile but also reduce the risk of HF hospitalizations and progression of renal disease. Patients with T2DM and PAD are known to be at a heightened risk for major adverse cardiac and lower extremity events, heart failure, and chronic kidney disease. As such, the use of novel therapies such as GLP-RA and SGLT2i should be strongly considered to minimize morbidity and mortality in this vulnerable population.

An overview of alogliptin + pioglitazone for the treatment of type 2 diabetes

INTRODUCTION

Type 2 diabetes (T2D) is a progressive condition, and sequential additions of therapy are usually required to maintain glycemic control. The options for glucose lowering therapies have increased considerably in recent years. Fixed-dose combinations such as alogliptin with pioglitazone provide a convenient choice which can improve medication adherence.

AREAS COVERED

The authors performed a literature search to identify publications describing the efficacy and safety of alogliptin and pioglitazone when used separately and in combinations.

EXPERT OPINION

Pioglitazone activates peroxisome proliferator-activated receptor-gamma which improves insulin sensitivity and helps to preserve β-cell function with a durable improvement in glycemic control. Pioglitazone can retard the progression of atherosclerosis and reduce cardiovascular events, but it is associated with adverse events including weight gain, fluid retention, and increased risk of fractures. Alogliptin improves glycemic control and appears neutral in terms of cardiovascular events. It does not appear to increase the adverse events associated with pioglitazone and use of the combination may permit the use of lower doses of pioglitazone with reduced adverse effects. There are no cardiovascular outcome studies with the combination but the cardiovascular benefits of pioglitazone and additional glucose lowering effects of alogliptin provide a useful combination with convenient once daily dosing.

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.

Cardiovascular events and all-cause mortality in patients with type 2 diabetes treated with dipeptidyl peptidase-4 inhibitors: An extensive meta-analysis of randomized controlled trials

AIMS

Meta-analyses of randomized trials on Dipeptidyl Peptidase-4 inhibitors (DPP4i) reported discordant results on major cardiovascular events (MACE), mortality, and heart failure. Aim of this meta-analysis of randomized trials is the assessment of the cardiovascular safety of DPP4i.

DATA SYNTHESIS

A Medline, Embase, Cochrane database search for sitagliptin, vildagliptin, omarigliptin, saxagliptin, alogliptin, trelagliptin, anagliptin, linagliptin, gemigliptin, evogliptin, and teneligliptin was performed up to up January 1st, 2020. All trials with a duration ≥24 weeks and comparing the effects of DPP4i with placebo or active drugs were collected. Mantel-Haenszel odds ratio (MH-OR) with 95% Confidence Interval (95% CI) was calculated for all outcomes defined above. A total of 182 eligible trials were identified. DPP-4i were not associated with an increased risk of MACE (MH-OR 0.99 [0.93, 1.04]), all-cause mortality (MH-OR 0.99 [0.93, 1.06]), and heart failure (MH-OR 1.05 [0.96, 1.15]) with no significant differences across individual molecules, except for saxagliptin, which was associated with an increased risk of heart failure.

CONCLUSIONS

As a class, DPP4i are not associated with any increase or reduction of MACE, all-cause mortality, and heart failure. Saxagliptin seems to be associated with an increased risk of hospitalization for heart failure.

Cardiovascular Safety and Benefits of Noninsulin Antihyperglycemic Drugs for the Treatment of Type 2 Diabetes Mellitus: Part 2

Ideal drugs to improve outcomes in type 2 diabetes mellitus (T2DM) are those with antiglycemic efficacy, as well as cardiovascular safety that has to be determined in appropriately designed cardiovascular outcome trials as mandated by regulatory agencies. The more recent antihyperglycemic medications have shown promise with regards to cardiovascular disease (CVD) risk reduction in T2DM patients at a high cardiovascular risk. Sodium glucose cotransporter-2 inhibitors and glucagon-like peptide-1 receptor agonists are associated with better cardiovascular outcomes and mortality in T2DM patients than are dipeptidylpeptidase-4 inhibitors, leading to the Food and Drug Administration's approval of empagliflozin to reduce mortality, and of liraglutide to reduce CVD risk in high-risk T2DM patients. For heart failure outcomes, sodium glucose cotransporter-2 inhibitors are beneficial, while glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors are neutral. Ongoing and planned randomized controlled trials of these newer drugs should clarify the possibility of class effects and of CVD risk reduction benefits in low-moderate cardiovascular risk patients. While we eagerly await the results on ongoing studies, these medications should be appropriately prescribed in T2DM patients with baseline CVD or those at a high CVD risk after carefully evaluating the elevated risk for adverse events like gastrointestinal disturbances, bladder cancer, genital infections, and amputations. Studies to understand the pleotropic and novel pathophysiological mechanisms demonstrated by the sodium glucose cotransporter-2 inhibitors will shed light on the effects of the modulation of microvascular, inflammatory, and thrombotic milieu for improving the CVD risk in T2DM patients. This is part 2 of the series on noninsulin antihyperglycemic drugs for the treatment of T2DM.

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.

Cardiovascular Outcomes Comparison of Dipeptidyl Peptidase-4 Inhibitors versus Sulfonylurea as Add-on Therapy for Type 2 Diabetes Mellitus: a Meta-Analysis

Objective

Recent studies have raised concern about the cardiovascular safety of dipeptidyl peptidase-4 (DPP4) inhibitors. We performed a systematic review through meta-analysis to compare cardiovascular outcomes of sulfonylurea (SU) versus DPP4 inhibitors when used in combination with metformin.

Methods

After searching for trials using combination therapy of metformin with DPP4 inhibitor or SU in PubMed, Cochrane Library, and Embase, one prospective observation study and 15 randomized controlled studies were selected.

Results

Regarding the primary analysis endpoint, there were no significant differences in the risk of all-cause mortality between SU and DPP4 inhibitors as an add-on therapy to metformin (random-effect relative risk [RR], 1.14; 95% confidence interval [CI], 0.98–1.33; p=0.811; I²=0%). Cardiovascular death was also similar between the two drug classes in the five studies which reported outcomes (random-effect RR, 1.03; 95% CI, 0.83–1.27; p=0.517; I²=0%). Furthermore, there were no significant differences in major adverse cardiac events (MACE), coronary heart disease, myocardial infarction, ischemic stroke and heart failure. However, there were less hypoglycemic events and weight gain in the DPP4 inhibitor group as compared with the SU group (random-effect RR, 3.79; 95% CI, 1.53–9.39; p<0.001; I²=98.2 and weighted mean difference, 1.68; 95% CI, 1.07–2.29; p<0.001; I²=94.7, respectively).

Conclusion

As add-on therapy to metformin, there were no significant differences in all-cause mortality and cardiovascular mortality between DPP4 inhibitors and SUs.

The Impact of Antidiabetic Therapies on Diastolic Dysfunction and Diabetic Cardiomyopathy

Diabetic cardiomyopathy is more prevalent in people with type 2 diabetes mellitus (T2DM) than previously recognized, while often being characterized by diastolic dysfunction in the absence of systolic dysfunction. This likely contributes to why heart failure with preserved ejection fraction is enriched in people with T2DM vs. heart failure with reduced ejection fraction. Due to revised mandates from major health regulatory agencies, all therapies being developed for the treatment of T2DM must now undergo rigorous assessment of their cardiovascular risk profiles prior to approval. As such, we now have data from tens of thousands of subjects with T2DM demonstrating the impact of major therapies including the sodium-glucose co-transporter 2 (SGLT2) inhibitors, glucagon-like peptide-1 receptor (GLP-1R) agonists, and dipeptidyl peptidase 4 (DPP-4) inhibitors on cardiovascular outcomes. Evidence to date suggests that both SGLT2 inhibitors and GLP-1R agonists improve cardiovascular outcomes, whereas DPP-4 inhibitors appear to be cardiovascular neutral, though evidence is lacking to determine the overall utility of these therapies on diastolic dysfunction or diabetic cardiomyopathy in subjects with T2DM. We herein will review the overall impact SLGT2 inhibitors, GLP-1R agonists, and DPP-4 inhibitors have on major parameters of diastolic function, while also highlighting the potential mechanisms of action responsible. A more complete understanding of how these therapies influence diastolic dysfunction will undoubtedly play a major role in how we manage cardiovascular disease in subjects with T2DM.

Higher-Dose Sitagliptin and the Risk of Congestive Heart Failure in Older Adults with CKD

BACKGROUND AND OBJECTIVES

Sitagliptin, a dipeptidyl peptidase-4 inhibitor, is commonly prescribed to patients with type 2 diabetes. As this drug is primarily eliminated by the kidney, a reduced dose is recommended for patients with CKD. Some evidence suggests that sitagliptin is associated with a higher risk of congestive heart failure, particularly at higher doses. We compare the 1-year risk of death or hospitalization with congestive heart failure in patients with CKD newly prescribed sitagliptin at >50 versus ≤50 mg/d.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This population-based cohort study included older adults (>66 years) with type 2 diabetes and an eGFR<45 ml/min per 1.73 m² (but not receiving dialysis) who were newly prescribed sitagliptin between 2010 and 2017 in Ontario, Canada. We used inverse probability of treatment weighting on the basis of propensity scores to balance baseline characteristics. The primary composite outcome was death or hospitalization with congestive heart failure. Secondary outcomes included hospitalization with pancreatitis or hypoglycemia, all-cause hospitalization, and glycemic control. Weighted hazard ratios were obtained using Cox proportional hazards regression, and 95% confidence intervals were obtained using bootstrap variance estimators.

RESULTS

Of 9215 patients, 6518 started sitagliptin at >50 mg/d, and 2697 started sitagliptin at ≤50 mg/d. The 1-year risk of death or hospitalization with congestive heart failure did not differ significantly between groups (79 versus 126 events per 1000 person-years; weighted hazard ratio, 0.88; 95% confidence interval, 0.67 to 1.14); hospitalization with pancreatitis (weighted hazard ratio, 0.98; 95% confidence interval, 0.32 to 3.03) and hypoglycemia (weighted hazard ratio, 1.10; 95% confidence interval, 0.64 to 1.90) also did not differ significantly between groups. Patients starting sitagliptin at >50 mg/d had lower mean glycated hemoglobin concentrations (weighted between-group difference, -0.12%; 95% confidence interval, -0.19 to -0.06) and a lower risk of all-cause hospitalization (weighted hazard ratio, 0.81; 95% confidence interval, 0.66 to 0.98).

CONCLUSIONS

The risk of death or congestive heart failure was not higher in older adults with CKD starting sitagliptin at >50 versus ≤50 mg/d.

PODCAST

This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2020_11_25_CJN08310520_final.mp3.

A facile method to synthesize vildagliptin

An efficient and high-yielding synthetic method for the preparation of vildagliptin via four steps is reported. The process starts from L-proline and involves a successful reaction with chloroacetyl chloride in tetrahydrofuran to afford ( S)-1-(2-chloroacetyl)pyrrolidine-2-carboxylic acid, followed by a reaction with acetonitrile in the presence of sulfuric acid to give ( S)-1-(2-chloroacetyl)pyrrolidine-2-carbonitrile. This is then reacted with 3-aminoadamantanol to give vildagliptin. 3-Aminoadamantanol is prepared from 1-aminoadamantane hydrochloride via oxidation with sulfuric acid/nitric acid and boric acid as the catalyst followed by ethanol extraction. The overall yield is 95%.

Efficacy and safety of DPP-IV inhibitors combined with basal insulin in the treatment of type 2 diabetes

BACKGROUND

To evaluate the efficacy and safety of dipeptidyl peptidase IV (DPP-IV) inhibitors when added to insulin therapy in patients with type 2 diabetes mellitus (T2DM).

METHODS

PubMed, EMBASE, the Web of Science, and the Cochrane Library were systematically searched for randomized controlled trials (RCTs) exploring the efficacy or safety of DPP-IV inhibitors in T2DM patients. The quality of the included RCTs was assessed with the Cochrane risk-of-bias tool. For outcomes, odds ratios or weighted mean differences (WMDs) with 95% CIs were calculated using both random- and fixed-effects models.

RESULTS

A total of 16 studies were included in the meta-analysis with 5418 participants. Glycosylated hemoglobin (HbA1c) was significantly decreased in the DPP-IV inhibitors with insulin (DPP-IVi/INS) group compared with the insulin-alone (with or without placebo) group (WMD = -0.62%; 95% CI: -0.74, -0.49; P < .05). Consistent with this finding, the fasting blood glucose (FBG)-lowering effect (WMD = -0.61 mmol/L; 95% CI: -0.77, -0.45; P < .05) and 2-hour postprandial glucose (2hPPG)-lowering efficacy (WMD = -2.39 mmol/L; 95% CI: -2.81, -1.97; P < .05) in the DPP-IVi/INS group were also significantly better than in the insulin-alone group. Regarding safety indicators, compared with the insulin-alone group, DPP-IVi/INS treatments had no association with the risk of adverse effects, including hypoglycemia, adverse events (AEs), and serious adverse events (SAEs).

CONCLUSIONS

Compared with insulin treatment alone, treatment with DPP-IVi/INS improved HbA1c, FBG, and 2hPPG without increasing the risk of hypoglycemia, AEs, or SAEs.

Potentially Inappropriate Prescriptions in Heart Failure with Reduced Ejection Fraction (PIP-HFrEF)

Heart failure (HF) is a chronic debilitating and potentially life-threatening condition. Heart Failure patients are usually at high risk of polypharmacy and consequently, potentially inappropriate prescribing leading to poor clinical outcomes. Based on the published literature, a comprehensive HF-specific prescribing review tool is compiled to avoid medications that may cause HF or harm HF patients and to optimize the prescribing practice of HF guideline-directed medical therapies. Recommendations are made in line with the last versions of ESC guidelines, ESC position papers, scientific evidence, and experts' opinions.

Effects of linagliptin on left ventricular DYsfunction in patients with type 2 DiAbetes and concentric left ventricular geometry: results of the DYDA 2 trial

AIMS

To evaluate the effect of linagliptin on left ventricular systolic function beyond glycaemic control in type 2 diabetes mellitus.

METHODS AND RESULTS

A multicentre, randomised, double-blind, placebo controlled, parallel-group study, was performed (the DYDA 2 trial). Individuals with type 2 diabetes mellitus and asymptomatic impaired left ventricular systolic function were randomly allocated in a 1:1 ratio to receive for 48 weeks either linagliptin 5 mg daily or placebo, in addition to their diabetes therapy. Eligibility criteria were age 40 years and older, haemoglobin A1c 8.0% or less (≤64 mmol/mol), no history of cardiac disease, concentric left ventricular geometry (relative wall thickness ≥0.42), impaired left ventricular systolic function defined as midwall fractional shortening 15% or less at baseline echocardiography. The primary end point was the modification of midwall fractional shortening over time. The main secondary objectives were changes in diastolic and/or in longitudinal left ventricular systolic function as measured by tissue Doppler echocardiography. One hundred and eighty-eight patients were enrolled, predominantly men with typical insulin-resistance comorbidities. At baseline, mean midwall fractional shortening was 13.3%±2.5. At final evaluation, 88 linagliptin patients and 86 placebo patients were compared: midwall fractional shortening increased from 13.29 to 13.82 (+4.1%) in the linagliptin group, from 13.58 to 13.84 in the placebo group (+1.8%, analysis of covariance P = 0.86), corresponding to a 2.3-fold higher increase in linagliptin than the placebo group, although non-statistically significant. Also, changes in diastolic and longitudinal left ventricular systolic function did not differ between the groups. Serious adverse events or linagliptin/placebo permanent discontinuation occurred in very few cases and in the same percentage between the groups.

CONCLUSIONS

In the DYDA 2 patients the addition of linagliptin to stable diabetes therapy was safe and provided a modest non-significant increase in left ventricular systolic function measured as midwall fractional shortening.

TRIAL REGISTRATION NUMBER

ClinicalTrial.gov (ID NCT02851745).

The Effect of Dipeptidyl Peptidase-4 Inhibitors on Macrovascular and Microvascular Complications of Diabetes Mellitus: A Systematic Review

Background

The World Health Organization estimates that diabetes is the seventh leading cause of death. Uncontrolled diabetes may cause severe consequences such as cardiovascular (CV) events (myocardial infarction, stroke, or CV mortality), lower-extremity amputations, and end-stage renal disease. Microvascular complications include retinopathy, autonomic and peripheral neuropathy, nephropathy, and diabetic ulcers. Major CV outcomes trials that were by the Food and Drug Administration for all new antihyperglycemia medications for patients at high risk for CV events were recently completed for all 4 US-marketed dipeptidyl peptidase-4 (DPP-4) inhibitors.

Objective

To present a comprehensive review of the clinical trials that evaluate macrovascular and microvascular complications reported with DPP-4 inhibitors in patients with type 2 diabetes mellitus.

Methods

In this review, we analyzed published articles in PubMed and Ovid databases between January 2008 and September 2019 that evaluated the effect of DPP-4 inhibitors on macrovascular and microvascular complications in patients with type 2 diabetes mellitus.

Results

A total of 18 studies, which included randomized controlled trials and meta-analyses were assessed. Current evidence demonstrates that the addition of DPP-4 inhibitors to standard antihyperglycemic and CV risk reduction treatment has not shown CV benefit relative to placebo in contrast to recently published studies for other medications within the glucagon-like peptide 1 agonist and sodium-glucose co-transporter 2 inhibitor classes. Notably, the potential risk for heart failure hospitalizations may exist for saxagliptin, and this effect is not extrapolated as a class effect. Based on our review, DPP-4 inhibitors may not influence microvascular complications in patients with diabetes. However, some studies have shown that saxagliptin and linagliptin may slow down the progression of albuminuria in patients with type 2 diabetes mellitus. The overall quality of the studies included in this review was high due to the inclusion of randomized controlled trials and meta-analyses.

Conclusions

DPP-4 inhibitors were found to have a neutral effect on macrovascular and microvascular complications, with the exception of saxagliptin, which may increase the risk for heart failure hospitalizations.

Add-on therapy in metformin-treated patients with type 2 diabetes at moderate cardiovascular risk: a nationwide study

BACKGROUND

In randomised clinical trials, glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and sodium-glucose cotransporter 2 (SGLT-2) inhibitors reduced cardiovascular events in patients with type 2 diabetes (T2D) at high cardiovascular risk, as compared to standard care. However, data comparing these agents in patients with T2D who are at moderate risk is sparse.

METHODS

From Danish national registries, we included patients with T2D previously on metformin monotherapy, who started an additional glucose-lowering agent [GLP-1 RA, SGLT-2 inhibitor, dipeptidyl peptidase-4 (DPP-4) inhibitor, sulfonylurea (SU), or insulin] in the period 2010-2016. Patients with a history of cardiovascular events [heart failure (HF), myocardial infarction (MI) or stroke] were excluded. Patients were followed for up to 2 years. Cause-specific adjusted Cox regression models were used to compare the risk of hospitalisation for HF, a composite endpoint of major adverse cardiovascular events (MACE) (MI, stroke or cardiovascular death), and all-cause mortality for each add-on therapy. Patients who initiated DPP-4 inhibitors were used as reference.

RESULTS

The study included 46,986 T2D patients with a median age of 61 years and of which 59% were male. The median duration of metformin monotherapy prior to study inclusion was 5.3 years. Add-on therapy was distributed as follows: 13,148 (28%) GLP-1 RAs, 2343 (5%) SGLT-2 inhibitors, 15,426 (33%) DPP-4 inhibitors, 8917 (19%) SUs, and 7152 (15%) insulin. During follow-up, 623 (1.3%, range 0.8-2.1%) patients were hospitalised for HF-hazard ratios (HR) were 1.11 (95% CI 0.89-1.39) for GLP-1 RA, 0.84 (0.52-1.36) for SGLT-2 inhibitors, 0.98 (0.77-1.26) for SU and 1.54 (1.25-1.91) for insulin. The composite MACE endpoint occurred in 1196 (2.5%, range 1.5-3.6%) patients, yielding HRs of 0.82 (0.69-0.97) for GLP-1 RAs, 0.79 (0.56-1.12) for SGLT-2 inhibitors, 1.22 (1.03-1.49) for SU and 1.23 (1.07-1.47) for insulin. 1865 (3.9%, range 1.9-9.0%) died from any cause during follow-up. HRs for all-cause mortality were 0.91 (0.78-1.05) for GLP-1 RAs, 0.79 (0.58-1.07) for SGLT-2 inhibitors, 1.13 (0.99-1.31) for SU and 2.33 (2.08-2.61) for insulin.

CONCLUSION

In a nationwide cohort of metformin-treated T2D patients and no history of cardiovascular events, the addition of either GLP-1 RA or SGLT-2 inhibitor to metformin treatment was associated with a similar risk of hospitalisation for HF and death, and a lower risk of MACE for GLP-1 RA when compared with add-on DPP-4 inhibitors. By contrast, initiation of treatment with SU and insulin were associated with a higher risk of MACE. Additionally, insulin was associated with an increased risk of all-cause mortality and hospitalisation for HF.

Effects of Dipeptidyl Peptidase-4 Inhibitor Linagliptin on Left Ventricular Dysfunction in Patients with Type 2 Diabetes and Concentric Left Ventricular Geometry (the DYDA 2™ Trial). Rationale, Design, and Baseline Characteristics of the Study Population

PURPOSE

A multicentre, randomized, double-blind, placebo-controlled, parallel-group study aimed to define the potential positive effect of dipeptidyl peptidase-4 inhibition on left ventricular systolic function (LVSF) beyond glycemic control in type 2 diabetes mellitus (T2DM) (DYDA 2™ trial).

METHODS

Individuals with fairly controlled T2DM and asymptomatic impaired LVSF were randomized in a 1:1 ratio to receive for 48 weeks either linagliptin 5 mg daily or placebo, in addition to their stable diabetes therapy. Eligibility criteria were age ≥ 40 years, history of T2DM with a duration of at least 6 months, HbA1c ≤ 8.0% (≤ 64 mmol/mol), no history or clinical signs/symptoms of cardiac disease, evidence at baseline echocardiography of concentric LV geometry (relative wall thickness ≥ 0.42), and impaired LVSF defined as midwall fractional shortening (MFS) ≤ 15%. The primary end-point was the modification from baseline to 48 weeks of MFS. As an exploratory analysis, significant changes in LV global longitudinal strain and global circumferential strain, measured by speckle tracking echocardiography, were also considered. Secondary objectives were changes in diastolic and/or in systolic longitudinal function as measured by tissue Doppler.

RESULTS

A total of 188 patients were enrolled. They were predominantly males, mildly obese, with typical insulin-resistance co-morbidities such as hypertension and dyslipidemia. Mean relative wall thickness was 0.51 ± 0.09 and mean MFS 13.3% ± 2.5.

CONCLUSIONS

DYDA 2 is the first randomized, double-blind, placebo-controlled trial to explore the effect of a dipeptidyl peptidase-4 inhibitor on LVSF in T2DM patients in primary prevention regardless of glycemic control. The main characteristics of the enrolled population are reported.

TRIAL REGISTRATION

ClinicalTrial.gov Identifier: NCT02851745.

GLP-1 analog liraglutide-induced cardiac dysfunction due to energetic starvation in heart failure with non-diabetic dilated cardiomyopathy

Background

Glucagon-like peptide-1 (GLP-1) reduces cardiovascular events in diabetic patients; however, its counter-protective effects have also been suggested in patients with heart failure and the clear explanation for its mechanisms have not yet been offered.

Methods

The effects of GLP-1 analog on cardiac function and energy metabolism, especially glycemic and lipid metabolisms were elucidated using non-diabetic J2N-k hamsters which showed spontaneous dilated cardiomyopathy. J2N-k hamsters were treated with PBS (HF group), low-dose (HF-L group) or high-dose liraglutide (HF-H group).

Results

In failing heart, GLP-1 analog exerted further deteriorated cardiac function (e.g. positive and negative dP/dt; p = 0.01 and p = 0.002, respectively) with overt fibrosis and cardiac enlargement (heart/body weight, 5.7 ± 0.2 in HF group versus 7.6 ± 0.2 in HF-H group; p = 0.02). The protein expression of cardiac muscles indicated the energy starvation status. Indirect calorimetry showed that failing hearts consumed higher energy and carbohydrate than normal hearts; moreover, this tendency was augmented by GLP-1 analog administration. Upon 10% glucose solution loading with GLP-1 analog administration (HF-H-G group) as complementary experiments, the cardiac function and fibrosis significantly ameliorated, whereas carbohydrate utilization augmented further and lipid utilization reduced more. The prognosis of HF-H-G group also significantly improved (p = 0.025).

Conclusions

Glucagon-like peptide-1 analog caused the relative but desperate shortage of glycemic energy source for the failing cardiac muscles and it may restrict ATP synthesis, resulting in cardiac function deterioration. Therefore, appropriate energy supply and amount of carbohydrate intake should be carefully considered when administrating incretin-related drugs to patients with heart failure.

SGLT2 Inhibitors: Cardiovascular Benefits Beyond HbA1c-Translating Evidence into Practice

Cardiovascular disease (CVD), including heart failure (HF), is a leading cause of morbidity and mortality in people with type 2 diabetes mellitus (T2DM). CVD and T2DM share common risk factors for development and progression, and there is significant overlap between the conditions in terms of worsening outcomes. In assessing the cardiovascular (CV) safety profiles of anti-diabetic drugs, sodium-glucose co-transporter-2 inhibitor (SGLT2i) therapies have emerged with robust evidence for reducing the risk of adverse CVD outcomes in people with T2DM who have either established CVD or are at risk of developing CVD. A previous consensus document from the Improving Diabetes Steering Committee has examined the potential role of SGLT2is in T2DM management and considered the risk-benefit profile of the class and the appropriate place for these medicines within the T2DM pathway. This paper builds on these findings and presents practical guidance for maximising the pleiotropic benefits of this class of medicines in people with T2DM in terms of reducing adverse CVD outcomes. The Improving Diabetes Steering Committee aims to offer evidence-based practical guidance for the use of SGLT2i therapies in people with T2DM stratified by CVD risk. This is of particular importance currently because some treatment guidelines have not been updated to reflect recent evidence from cardiovascular outcomes trials (CVOTs) and real-world studies that complement the CVOTs. The Improving Diabetes Steering Committee seeks to support healthcare professionals (HCPs) in appropriate treatment selection for people with T2DM who are at risk of developing or have established CVD and examines the role of SGLT2i therapy for these people.Funding: Napp Pharmaceuticals Limited.

Phosphodiesterase 5 Associates With β2 Adrenergic Receptor to Modulate Cardiac Function in Type 2 Diabetic Hearts

Background

In murine heart failure models and in humans with diabetic‐related heart hypertrophy, inhibition of phosphodiesterase 5 (PDE5) by sildenafil improves cardiac outcomes. However, the mechanism by which sildenafil improves cardiac function is unclear. We have observed a relationship between PDE5 and β2 adrenergic receptor (β2AR), which is characterized here as a novel mechanistic axis by which sildenafil improves symptoms of diabetic cardiomyopathy.

Methods and Results

Wild‐type and β2AR knockout mice fed a high fat diet (HFD) were treated with sildenafil, and echocardiogram analysis was performed. Cardiomyocytes were isolated for excitation‐contraction (E‐C) coupling, fluorescence resonant energy transfer, and proximity ligation assays; while heart tissues were implemented for biochemical and histological analyses. PDE5 selectively associates with β2AR, but not β1 adrenergic receptor, and inhibition of PDE5 with sildenafil restores the impaired response to adrenergic stimulation in HFD mice and isolated ventriculomyocytes. Sildenafil enhances β adrenergic receptor (βAR)‐stimulated cGMP and cAMP signals in HFD myocytes. Consequently, inhibition of PDE5 leads to protein kinase G–, and to a lesser extent, calcium/calmodulin‐dependent kinase II–dependent improvements in adrenergically stimulated E‐C coupling. Deletion of β2AR abolishes sildenafil's effect. Although the PDE5‐β2AR association is not altered in HFD, phosphodiesterase 3 displays an increased association with the β2AR‐PDE5 complex in HFD myocytes.

Conclusions

This study elucidates mechanisms by which the β2AR‐PDE5 axis can be targeted for treating diabetic cardiomyopathy. Inhibition of PDE5 enhances β2AR stimulation of cGMP and cAMP signals, as well as protein kinase G–dependent E‐C coupling in HFD myocytes.

Heart failure in the patient with diabetes: Epidemiology, aetiology, prognosis, therapy and the effect of glucose-lowering medications

In people with type 2 diabetes the frequency of heart failure (HF) is increased and mortality from HF is higher than with non-diabetic HF. The increased frequency of HF is attributable to the cardiotoxic tetrad of ischaemic heart disease, left ventricular hypertrophy, diabetic cardiomyopathy and an extracellular volume expansion resistant to atrial natriuretic peptides. Activation of the renin-angiotensin-aldosterone system and sympathetic nervous systems results in cardiac remodelling, which worsens cardiac function. Reversal of remodelling can be achieved, and cardiac function improved in people with HF with reduced ejection fraction (HFrEF) by treatment with angiotensin-converting enzyme inhibitors and β-blockers. However, with HF with preserved ejection fraction (HFpEF), only therapy for the underlying risk factors helps. Blockers of mineralocorticoid receptors may be beneficial in both HFrEF and HFpEF. Glucose-lowering drugs can have a negative effect (insulin, sulphonylureas, dipeptidyl peptidase-4 inhibitors and thiazolidinediones), a neutral effect (α-glucosidase inhibitors and glucagon-like peptide-1 receptor agonists) or a positive effect (sodium-glucose co-transporter-2 inhibitors and metformin).

Update on Cardiovascular Safety of Incretin-Based Therapy in Adults With Type 2 Diabetes Mellitus: A Meta-Analysis of Cardiovascular Outcome Trials

OBJECTIVES

The authors of 2 large randomized trials have recently published their findings related to the effects of a glucagon-like peptide 1 receptor agonist (GLP-1RA) (the HARMONY trial) and a dipeptidyl peptidase 4 (DPP-4) inhibitor (the CARMELINA trial) on cardiovascular (CV) outcomes in patients with type 2 diabetes mellitus. In light of these new data, we conducted a systematic review and meta-analysis of GLP-1RAs and DPP-4 inhibitors in CV outcome trials to assess their CV safety in patients with type 2 diabetes.

METHODS

We conducted a comprehensive literature search in the Embase and MEDLINE databases to identify trials involving GLP-1RAs and DPP-4 inhibitors with major CV-related outcomes reported, including major adverse CV events, CV death, myocardial infarction, stroke, death from any cause and hospitalization because of heart failure. A total of 9 CV outcome trials were included. Odds ratios and 95% confidence intervals were calculated based on the Mantel-Haenszel method.

RESULTS

Relative to placebo, GLP-1RAs were associated with a statistically significant reduction in the odds of major adverse CV events (13%), CV death (12%), death from any cause (11%) and stroke (13%). DPP-4 inhibitors were comparable to placebo for all outcomes. Moreover, DPP-4 inhibitors were associated with a nonsignificant 5% increase in the odds of hospitalization from heart failure compared to placebo.

CONCLUSIONS

This meta-analysis demonstrated that GLP-1RAs were associated with a significant reduction in major adverse CV events, CV death, stroke and death from any cause, while DPP-4 inhibitors were comparable to placebo for all CV outcomes, including hospitalizations for heart failure.

Comparative outcomes of heart failure among existent classes of anti-diabetic agents: a network meta-analysis of 171,253 participants from 91 randomized controlled trials

Background

The cardiovascular (CV) safety in terms of heart failure among different classes of treatment remains largely unknown. We sought to assess the comparative effect of these agents on heart failure outcomes.

Methods

This study was registered in the International Prospective Register of Systematic Reviews (CRD 42016042063). MEDLINE, EMBASE, and the Cochrane Library Central Register of Controlled Trials were searched. For the primary outcomes reported previously, studies between Jan 1, 1980 and June 30, 2016 were screened, and subsequently updated till Jan 24, 2019. We performed network meta-analysis to obtain estimates for the outcomes of heart failure, in particular by rankograms for ranking of heart failure risk as well as by pairwise comparisons among all classes of anti-diabetic medications.

Results

A total of 91 trials were included, among which were 171,253 participants and 4163 reported cases of heart failure events. As for rankograms, the surface under the cumulative ranking curves (SUCRA) of sodium-glucose co-transporters 2 and thiazolidinediones were 93.4% and 4.3%, respectively, signifying the lowest and highest risk of heart failure, respectively. As for pairwise comparisons in the network, sodium-glucose co-transporters 2 were significantly superior to insulin (OR: 0.75, 95% CI 0.62–0.91), dipeptidyl peptidase 4 inhibitors (OR: 0.68, 95% CI 0.59–0.78), glucagon-like peptide-1 receptor agonists (OR: 0.65, 95% CI 0.54–0.78), and thiazolidinediones (OR: 0.46, 95% CI 0.27–0.77) in terms of heart failure risk. Furthermore, in an exploratory analysis among subjects with underlying heart failure or at risk of heart failure, the superiority of sodium-glucose co-transporters 2 was still significant.

Conclusions

In terms of heart failure risk, sodium-glucose co-transporters 2 were the most favorable option among all classes of anti-diabetic medications.

Electronic supplementary material

The online version of this article (10.1186/s12933-019-0853-x) contains supplementary material, which is available to authorized users.

Dipeptidyl peptidase-4 inhibitor compared with sulfonylurea in combination with metformin: cardiovascular and renal outcomes in a propensity-matched cohort study

Background

To determine the impact of dipeptidyl peptidase-4 inhibitor (DPP4i) on the risk of major cardiocerebrovascular and renal outcomes compared with sulfonylurea (SU) combined with metformin in patients with type 2 diabetes from a population-based cohort.

Methods

From a nationwide cohort in Korea (2008–2013), 23,674 patients with type 2 diabetes treated with DPP4i plus metformin or SU plus metformin were selected and matched by propensity score. Composite cardiocerebrovascular events including incident ischemic heart disease (IHD), ischemic stroke (IS), hospitalization for heart failure (HHF), and cardiocerebrovascular death, as well as renal events including incident end-stage renal disease or initiation of renal-replacement therapy were assessed by Cox proportional-hazards models.

Results

During a median follow-up of 19.6 months (interquartile range 7.2–36.4), 762 composite cardiocerebrovascular events and 17 end-stage renal events occurred. There was no significant difference in the risk of IHD (hazard ratio [HR], 1.00; 95% CI 0.81–1.23), IS (HR, 0.95; 95% CI 0.74–1.23), or cardiocerebrovascular death (HR, 0.74; 95% CI 0.46–1.18) in the DPP4i group compared to that in the SU group. Likewise, DPP4i therapy was not associated with the risk of end-stage renal outcomes (HR, 1.23; 95% CI 0.41–3.62). However, the risk of HHF was significantly higher in the DPP4i group than in the SU group (HR, 1.47; 95% CI 1.07–2.04).

Conclusions

This real-world database analysis showed that DPP4i therapy did not increase the overall risk of major cardiovascular and renal outcomes compared to SU therapy. However, the DPP4i-associated risk of HHF remained significant.

Electronic supplementary material

The online version of this article (10.1186/s12933-019-0835-z) contains supplementary material, which is available to authorized users.

DPP-4 inhibitors and heart failure: a potential role for pharmacogenomics

There remains an ongoing controversy regarding the safety of dipeptidyl peptidase-4 (DPP-4) inhibitors and the risk of developing heart failure (HF). In addition, none of the animal studies suggested a mechanism for the DPP-4 inhibitors and HF risk. To date, advances in pharmacogenomics have enabled the identification of genetic variants in DPP-4 gene. Studies have shown that genetic polymorphisms in the gene encoding DPP-4 may be associated with potential pathways involved in HF risk. This review discusses the contradictory findings of DPP-4 inhibitors and HF and a potential role for pharmacogenomics. Pharmacogenomics of DPP-4 inhibitors is promising, and genetic information from randomized control trials is urgently needed to gain a full understanding of the safety of DPP-4 inhibitors and the risk of HF.

Common Co-Morbidities in Heart Failure – Diabetes, Functional Mitral Regurgitation and Sleep Apnoea

Heart failure (HF) is a condition that carries a considerable burden of disability many now related to co-existing co-morbidities. The drive to find newer effective therapies targeting novel mechanisms has led to a recent emphasis on treating common co-morbidities that are clustered around contemporary HF patients. Here is renewed contemporary co-morbidities that until recently have received little attention but which are now subject of considerable interest and potential therapeutic advance. These include, diabetes, functional mitral regurgitation and sleep disordered breathing. These three contemporary co-morbidities that have recently been subject to major trial evaluation will be reviewed in this paper.

[Use of dipeptidyl peptidase-4 inhibitors in diabetic patients in special situations]

Dipeptidyl peptidase-4 inhibitors form part of the group of incretin derivatives and conse-quently have a specific mechanism of action. The incretin effect avoids the adverse ef-fects of classic drugs (sulphonylureas) and provides specific benefits for their use in as-sociation with other drugs and in special situations. Because they have a low risk of pro-ducing hypoglycaemia or weight gain, these inhibitors are useful in combination with other oral antidiabetic drugs and even with insulin, although this latter combination may increase the risk of hypoglycaemia. Large studies of cardiovascular non-inferiority have reported that dipeptidyl peptidase-4 inhibitors are non-inferior to placebo, although one drug (saxagliptin) may increase the risk of hospital admission for heart failure. Because of these cardiovascular advantages, even in peripheral arterial disease, their usefulness in diabetic retinopathy, and their low risk of hypoglycaemia in renal insufficiency, dipeptidyl peptidase-4 inhibitors are the drugs of choice in elderly patients. Given the risk, although still not well defined, these drugs are not recommended in pa-tients with a history or risk of pancreatic disease, in children, in patients with type 1 diabetes, in adolescents, or in pregnant or breastfeeding women. Each of these special situ-ations is discussed in the present article.

Canagliflozin and Heart Failure in Type 2 Diabetes Mellitus: Results From the CANVAS Program

BACKGROUND

Canagliflozin is a sodium glucose cotransporter 2 inhibitor that reduces the risk of cardiovascular events. We report the effects on heart failure (HF) and cardiovascular death overall, in those with and without a baseline history of HF, and in other participant subgroups.

METHODS

The CANVAS Program (Canagliflozin Cardiovascular Assessment Study) enrolled 10 142 participants with type 2 diabetes mellitus and high cardiovascular risk. Participants were randomly assigned to canagliflozin or placebo and followed for a mean of 188 weeks. The primary end point for these analyses was adjudicated cardiovascular death or hospitalized HF.

RESULTS

Participants with a history of HF at baseline (14.4%) were more frequently women, white, and hypertensive and had a history of prior cardiovascular disease (all P<0.001). Greater proportions of these patients were using therapies such as blockers of the renin angiotensin aldosterone system, diuretics, and β-blockers at baseline (all P<0.001). Overall, cardiovascular death or hospitalized HF was reduced in those treated with canagliflozin compared with placebo (16.3 versus 20.8 per 1000 patient-years; hazard ratio [HR], 0.78; 95% confidence interval [CI], 0.67-0.91), as was fatal or hospitalized HF (HR, 0.70; 95% CI, 0.55-0.89) and hospitalized HF alone (HR, 0.67; 95% CI, 0.52-0.87). The benefit on cardiovascular death or hospitalized HF may be greater in patients with a prior history of HF (HR, 0.61; 95% CI, 0.46-0.80) compared with those without HF at baseline (HR, 0.87; 95% CI, 0.72-1.06; P interaction =0.021). The effects of canagliflozin compared with placebo on other cardiovascular outcomes and key safety outcomes were similar in participants with and without HF at baseline (all interaction P values >0.130), except for a possibly reduced absolute rate of events attributable to osmotic diuresis among those with a prior history of HF ( P=0.03).

CONCLUSIONS

In patients with type 2 diabetes mellitus and an elevated risk of cardiovascular disease, canagliflozin reduced the risk of cardiovascular death or hospitalized HF across a broad range of different patient subgroups. Benefits may be greater in those with a history of HF at baseline.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov . Unique identifiers: NCT01032629 and NCT01989754.

Impact of dipeptidyl-peptidase 4 inhibitors on cardiovascular diseases

Dipeptidyl peptidase 4 (DPP-4) inhibitor is a novel group of medicine employed in type 2 diabetes mellitus (T2DM),which improves meal stimulated insulin secretion by protecting glucagon-like peptide-1 (GLP-1) and glucose dependent insulinotropic polypeptide (GIP) from enzymatic degradation. Cardiovascular diseases are serious complications and leading causes of mortality among individuals with diabetes mellitus. Glycemic control per se seems to fail in preventing the progression of diabetic cardiovascular complications. DPP-4 has the capability to inactivate not only incretins, but also a series of cytokines, chemokines, and neuropeptides involved in inflammation, immunity, and vascular function. Pre-clinical studies suggested that DPP-4 inhibitors may have potential cardiovascular protective effects in addition to their antidiabetic actions. In recent years, a number of clinical trials have been conducted to evaluate the effect of different DPP-4 inhibitors on the cardiovascular system. We herein review the available clinical studies in cardiovascular effects played by each DPP-4 inhibitor and discuss the prospective application of DPP-4 inhibitors on cardiovascular diseases.

The pleiotropic cardiovascular effects of dipeptidyl peptidase-4 inhibitors

Patients with Type 2 diabetes have an excess risk for cardiovascular disease. One of the several approaches, included in the guidelines for the management of Type 2 diabetes, is based on dipeptidyl peptidase 4 (DPP-4; also termed CD26) inhibitors, also called gliptins. Gliptins inhibit the degradation of glucagon-like peptide-1 (GLP-1): this effect is associated with increased circulating insulin-to-glucagon ratio, and a consequent reduction of HbA1c. In addition to incretin hormones, there are several proteins that may be affected by DPP-4 and its inhibition: among these some are relevant for the cardiovascular system homeostasis such as SDF-1α and its receptor CXCR4, brain natriuretic peptides, neuropeptide Y and peptide YY. In this review, we will discuss the pathophysiological relevance of gliptin pleiotropism and its translational potential.

Molecular and clinical roles of incretin-based drugs in patients with heart failure

Glucagon-like peptide-1 (GLP-1) agonists and dipeptidyl peptidase-4 (DPP-4) inhibitors produce some beneficial and deleterious effects in diabetic patients not mediated by their glycemic lowering effects, and there is a need for better understanding of the molecular basis of these effects. They possess antioxidant and anti-inflammatory effects with some direct vasodilatory action (animal and human trial data) that may indirectly influence heart failure (HF). Unlike GLP-1R agonists, signaling for HF adverse effects was observed with two DPP-4 inhibitors, saxagliptin and alogliptin. Accordingly, these drugs should be used with caution in heart failure patients.

Type 2 diabetes and cardiovascular prevention: the dogmas disputed

In randomized controlled trials (RCTs), more intensive glucose control in patients with type 2 diabetes leads to a modest (9%) reduction in major cardiovascular events (MACE), associated with a 20% reduction of kidney events and 13% reduction of eye events. The FDA issued guidance in 2008 led to the conduct of numerous cardiovascular outcomes (CVOT) trials to assess cardiovascular safety of new antihyperglycemic therapies in patients with type 2 diabetes. The results of these trials show that insulin glargine, three different dipeptidyl peptidase-4 (DPP-4) inhibitors (saxagliptin, alogliptin, and sitagliptin) and lixisenatide (a glucagon like peptide-1 receptor agonist) produce no significant difference in CVOT when compared with usual care or placebo. Other trials with newer diabetes drugs, including empagliflozin and canagliflozin (two sodium-glucose co-transporter-2 inhibitors), liraglutide and semaglutide (two GLP-1 receptor agonists) succeeded in demonstrating CV benefit in people with type 2 diabetes. In the last two decades, the equation "diabetes equals myocardial infarction" have contributed to the development of preventive therapy for risk factors in diabetes. In both primary and secondary prevention, the diabetic patients with high rates of statin and aspirin treatment have improved CV outcome, as compared with non-users. The drugs used to reduce glucose levels in patients with type 2 diabetes seem important for the ultimate cardiovascular outcome: the combination of intensive glycemic control, when safely attainable, with newer diabetes drugs (empagliflozin, canagliflozin, liraglutide, and semaglutide) may decrease the incidence of MACE, nephropathy and retinopathy. Moreover, depending on the drug used, CV mortality and heart failure may also be reduced.

Role of the sodium-hydrogen exchanger in mediating the renal effects of drugs commonly used in the treatment of type 2 diabetes

Diabetes is characterized by increased activity of the sodium-hydrogen exchanger (NHE) in the glomerulus and renal tubules, which contributes importantly to the development of nephropathy. Despite the established role played by the exchanger in experimental studies, it has not been specifically targeted by those seeking to develop novel pharmacological treatments for diabetes. This review demonstrates that many existing drugs that are commonly prescribed to patients with diabetes act on the NHE1 and NHE3 isoforms in the kidney. This action may explain their effects on sodium excretion, albuminuria and the progressive decline of glomerular function in clinical trials; these responses cannot be readily explained by the influence of these drugs on blood glucose. Agents that may affect the kidney in diabetes by virtue of an action on NHE include: (1) insulin and insulin sensitizers; (2) incretin-based agents; (3) sodium-glucose cotransporter 2 inhibitors; (4) antagonists of the renin-angiotensin system (angiotensin converting-enzyme inhibitors, angiotensin receptor blockers and angiotensin receptor neprilysin inhibitors); and (5) inhibitors of aldosterone action and cholesterol synthesis (spironolactone, amiloride and statins). The renal effects of each of these drug classes in patients with type 2 diabetes may be related to a single shared biological mechanism.

Sitagliptin and heart failure hospitalization in patients with type 2 diabetes

This study evaluated the risk of heart failure hospitalization in a 1:1 matched pair sample of sitagliptin ever and never users derived from the Taiwan's National Health Insurance. A total of 85,859 ever users and 85,859 never users matched on 8 digits of propensity score were followed for the first event of heart failure hospitalization until December 31, 2011. The treatment effect (for ever versus never users, and for tertiles of cumulative duration of therapy) was estimated by Cox regression incorporated with the inverse probability of treatment weighting using propensity score. Additionally, adjusted hazard ratios for heart failure were estimated for the baseline characteristics in sitagliptin ever users. Results showed that the incidence of heart failure hospitalization was 1,020.16 and 832.54 per 100,000 person-years, respectively, for ever and never users, with an overall hazard ratio (95% confidence intervals) of 1.262 (1.167-1.364). While compared to never users, the respective hazard ratio for the first, second, and third tertile of cumulative duration < 3.7, 3.7-10.3 and >10.3 months was 2.721 (2.449-3.023), 1.472 (1.318-1.645) and 0.515 (0.447-0.594). Older age, longer diabetes duration, male sex, and use of insulin, sulfonylurea, calcium channel blockers, aspirin, ticlopidine, clopidogrel and dipyridamole were significantly associated with a higher risk in sitagliptin users, but dyslipidemia and use of metformin and statin were protective. In conclusion, sitagliptin increases the risk of heart failure hospitalization within one year of its use, but reduces the risk thereafter. Some factors predisposing to sitagliptin-related heart failure are worthy of attention in clinical practice.

DPP4 inhibitors and cardiovascular outcomes: safety on heart failure

Diabetes is an important risk factor for cardiovascular disease. However, clinical data suggests intensive glycemic control significantly increase rather than decrease cardiovascular mortality, which is largely due to the fact that a majority of oral anti-diabetic drugs have adverse cardiovascular effect. There are several large-scale clinical trials evaluating the cardiovascular safety of DPP4 inhibitors, a novel class of oral anti-diabetic medications, which have been recently completed. They were proven to be safe with regard to cardiovascular outcomes. However, concerns on the safety of heart failure have been raised as the SAVOR-TIMI 53 trial reported a 27% increase in the risk for heart failure hospitalization in diabetic patients treated with DPP4 inhibitor saxagliptin. In this review, we will discuss recent advances in the heart failure effects of DPP4 inhibition and GLP-1 agonism.

Worsening Heart Failure During the Use of DPP-4 Inhibitors: Pathophysiological Mechanisms, Clinical Risks, and Potential Influence of Concomitant Antidiabetic Medications

Although dipeptidyl peptidase (DPP)-4 inhibitors have been reported to have a neutral effect on thromboembolic vaso-occlusive events in large-scale trials, they act to potentiate several endogenous peptides that can exert deleterious cardiovascular effects. Experimentally, DPP-4 inhibitors may augment the ability of glucagon-like peptide-1 to stimulate cyclic adenosine monophosphate in cardiomyocytes, and potentiation of the effects of stromal cell-derived factor-1 by DPP-4 inhibitors may aggravate cardiac fibrosis. These potentially deleterious actions of DPP-4 inhibitors might not become clinically apparent if these drugs were to promote sodium excretion. However, the natriuretic effect of DPP-4 inhibitors is modest, because they act on the distal (rather than proximal) renal tubules. Accordingly, both clinical trials and observational studies have reported an increase in the risk of heart failure in patients with type 2 diabetes who were receiving DPP-4 inhibitors. This risk may be muted in trials with a high prevalence of metformin use or with low and declining background use of insulin and thiazolidinediones. Still, the most vulnerable patients (i.e., those with established heart failure) were not well represented in these studies. The only trial that specifically evaluated patients with pre-existing left ventricular dysfunction observed important drug-related adverse structural and clinical effects. In conclusion, an increased risk of worsening heart failure appears to be a class effect of DPP-4 inhibitors, even in patients without a history of heart failure. Additional clinical trials are urgently needed to elucidate the benefits and risks of DPP-4 inhibitors in patients with established left ventricular dysfunction.

Do DPP-4 Inhibitors Cause Heart Failure Events by Promoting Adrenergically Mediated Cardiotoxicity? Clues From Laboratory Models and Clinical Trials

RATIONALE

DPP-4 (dipeptidyl peptidase-4) inhibitors have increased the risk of heart failure events in both randomized clinical trials and observational studies, but the mechanisms that underlie their deleterious effect remain to be elucidated. Previous work has implicated a role of these drugs to promote cardiac fibrosis.

OBJECTIVE

This article postulates that DPP-4 inhibitors increase the risk of heart failure events by activating the sympathetic nervous system to stimulate cardiomyocyte cell death, and it crystallizes the findings from both experimental studies and clinical trials that support the hypothesis.

METHODS AND RESULTS

Inhibition of DPP-4 not only potentiates the actions of GLP-1 (glucagon-like peptide-1; which can increase myocardial cAMP) but also potentiates the actions of SDF-1 (stromal cell-derived factor 1), NPY (neuropeptide Y), and substance P to activate the sympathetic nervous system and stimulate β-adrenergic receptors to cause cardiomyocyte apoptosis, presumably through a CaMKII (Ca++/calmodulin-dependent protein kinase II) pathway. An action of SDF-1 to interfere with cAMP and protein kinase A signaling may account for the absence of a clinically overt positive chronotropic effect. This conceptual framework is supported by the apparent ability of β-blocking drugs to attenuate the increased risk of DPP-4 inhibitors in a large-scale clinical trial.

CONCLUSIONS

Sympathetic activation may explain the increased risk of heart failure produced by DPP-4 inhibitors. The proposed mechanism has major implications for clinical care because in the treatment of patients with type 2 diabetes mellitus, DPP-4 inhibitors are widely prescribed, but β-blockers are underutilized because of fears that they might mask hypoglycemia.

Echocardiographic feature of diabetic cardiomyopathy: where are we now?

We are now entering the very exciting era of treatment and management of diabetes mellitus (DM) with the emergence of new therapeutic agents, including sodium-glucose cotransporter 2 inhibitors (SGLT2i) and dipeptidyl peptidase-4 inhibitor (DPP-4i). From a cardiology and echocardiography perspective, the existence of diabetic cardiomyopathy has been proven through over four decades of discussion. DM is highly prevalent in patients with heart failure (HF). Independent associations are found after adjusting for hypertension (HTN) and coronary artery disease (CAD). In patients with both DM and HF, the prognosis is extremely dismal. In this review, the main focus is on both diabetic cardiomyopathy per se and its typical features (including myocardial additive insult related to DM), diagnosis, and management.

The cardiovascular effect of incretin-based therapies among type 2 diabetes: a systematic review and network meta-analysis

OBJECTIVE

To evaluate the comparative cardiovascular safety of incretin-based therapies in patients with type 2 diabetes mellitus (T2DM).

METHODS

Medline, Embase, the Cochrane Library and www.clinicaltrials.gov were searched for randomized controlled trials (RCTs) with duration≥12 weeks. Network meta-analysis was performed, followed by subgroup analysis and meta-regression. The Grading of Recommendations Assessment, Development and Evaluation system was used to assess the quality of evidence. The outcome of interest was a composite of cardiovascular death, myocardial infarction, stroke and heart failure. Odds ratio (OR) with 95% confidence interval (CI) was calculated as the measure of effect size.

RESULTS

281 RCTs (76.9% double-blinded) with 180,000 patients were included, comparing incretin-based therapies with other six classes of anti-diabetic drugs or placebo. A statistically significant reduction in the risk of cardiovascular events was found in favour of GLP-1RAs when compared with placebo (OR 0.89, 95%CI: 0.80-0.99) and sulfonylurea (OR 0.76, 95%CI: 0.59-0.99), whereas DPP-4 inhibitors showed a neutral effect compared with placebo (OR 0.92, 95%CI: 0.83-1.01).

CONCLUSIONS

Incretin-based therapies show similar cardiovascular risk in comparison with metformin, insulin, thiazolidinediones, alpha-glucosidase inhibitor and sodium-glucose co-transporter 2. GLP-1RA could decrease the risk compared with sulfonylurea or placebo, while DPP-4I appears to have neutral effect on cardiovascular risk.

Pharmacokinetic drug evaluation of empagliflozin plus linagliptin for the treatment of type 2 diabetes

INTRODUCTION

Type 2 diabetes mellitus has become a growing epidemic and therefore efficient treatment strategies that target its management are needed. The treatment of diabetic patients often requires the combination of antidiabetic drug classes. Sodium-glucose co-transporter 2 inhibitors (SGLT2i) block glucose reabsorption in the proximal renal tubules. Dipeptidyl peptidase-4 inhibitors (DPP-4i) improve glucose metabolism by blocking the enzyme that degrades incretins leading to increased insulin secretion. Areas covered: The aim of the review is to present the available data on pharmacokinetic properties/pharmacodynamics, metabolic and cardiovascular effects of empagliflozin plus linagliptin combination. Expert opinion: Both empagliflozin and linagliptin have established safety and efficacy in the treatment of diabetes. Available data demonstrate the absence of pharmacological interactions when the two drugs are given together. The complementary mechanisms of action would be expected to provide additive benefits on carbohydrate metabolism variables, but the results from clinical trials have shown that the empagliflozin/linagliptin combination provides only mild improvements of glycated hemoglobin compared with either monotherapy. However, the single-tablet formulation of empagliflozin/linagliptin is expected to provide better compliance and thus improved glycaemic control coupled with a favourable safety profile. Thus, the fixed-dose combination of empagliflozin/linagliptin has the capacity to both effectively and safely manage diabetic patients.

Effect of Dipeptidyl Peptidase-4 Inhibitors on Heart Failure: A Network Meta-Analysis

BACKGROUND

Previous meta-analyses evaluating the effectiveness of individual dipeptidyl peptidase-4 (DPP-4) inhibitors on the risk of heart failure (HF) were limited because of the small number of trials with direct comparisons between two treatments.

METHODS

A Bayesian network meta-analysis was performed to investigate the relationship between DPP-4 inhibitors and the risk of HF in patients with type-2 diabetes mellitus. The primary outcome was the occurrence of HF or hospital admission for HF.

RESULTS

Fifty randomized controlled trials were identified. Relative to placebo, no increased risk of HF events was seen for vildagliptin (risk ratio [RR] 0.71; 95% confidence interval [CI] 0.25-1.68), sitagliptin (RR 0.86; CI 0.43-1.57), or saxagliptin (RR 0.84; 95% CI 0.33-1.61), but alogliptin was associated with a higher risk of HF (RR 2.13; 95% CI 1.06-6.26). Vildagliptin and sitagliptin were associated with a significantly decreased risk of HF compared with alogliptin. Vildagliptin had the highest probability to be the safest option with regard to the risk of HF (49.18%), followed by saxagliptin (26.56%), sitagliptin (20.76%), linagliptin (0.25%), and alogliptin (0.12%). A statistically significant inconsistency was noted in some comparisons.

CONCLUSIONS

The risk of HF needs to be taken into account when prescribing DPP-4 inhibitors. Evidence suggests that vildagliptin may be the least harmful agent with regard to the risk of HF. However, a statistically significant inconsistency was identified in the Bayesian network meta-analysis. Therefore, further studies are warranted to evaluate the cardiovascular safety of DPP-4 inhibitors.