Assessing the cardio-cerebrovascular safety of vildagliptin: meta-analysis of adjudicated events from a large Phase III type 2 diabetes population

Sustained-Release Vildagliptin 100 mg in Type 2 Diabetes Mellitus: A Review

Dipeptidyl peptidase-4 inhibitors (DPP4Is) were introduced into the management of type 2 diabetes mellitus (T2DM) as they are insulinotropic and have no inherent risk of hypoglycemia and no effect on body weight. Currently, 11 drugs in this class are available for the management of diabetes. Although they have a similar mechanism of action, they differ from one other in their binding mechanisms, which influences their therapeutic and pharmacological profiles. Vildagliptin's overall safety and tolerability profile was comparable to placebo throughout clinical studies, and real-world data in a large group of T2DM patients corroborated this finding. Therefore, DPP4Is like vildagliptin is a secure alternative for treating patients with T2DM. Vildagliptin treatment given as a once-daily (QD) 100 mg sustained release (SR) formulation fits the criteria of adherence and compliance. This SR formulation, given once daily has the potential to provide glycemic control like the vildagliptin 50 mg twice-daily (BD) formulation. This comprehensive review discusses the journey of vildagliptin as 50 mg BD therapy as well as 100 mg SR QD therapy.

Vildagliptin Attenuates Myocardial Dysfunction and Restores Autophagy via miR-21/SPRY1/ERK in Diabetic Mice Heart

Aim: Vildagliptin (vild) improves diastolic dysfunction and is associated with a lower relative risk of major adverse cardiovascular events in younger patients. The present study aimed to evaluate whether vild prevents the development of diabetic cardiomyopathy in type 2 diabetic mice and identify its underlying mechanisms. Methods: Type 2 diabetic mouse model was generated using wild-type (WT) (C57BL/6J) and miR-21 knockout mice by treatment with HFD/STZ. Cardiomyocyte-specific miR-21 overexpression was achieved using adeno-associated virus 9. Echocardiography was used to evaluate cardiac function in mice. Morphology, autophagy, and proteins levels in related pathway were analyzed. qRT-PCR was used to detect miR-21. Rat cardiac myoblast cell line (H9c2) cells were transfected with miR-21 mimics and inhibitor to explore the related mechanisms of miR-21 in diabetic cardiomyopathy. Results: Vild restored autophagy and alleviated fibrosis, thereby enhancing cardiac function in DM mice. In addition, miR-21 levels were increased under high glucose conditions. miR-21 knockout DM mice with miR-21 knockout had reduced cardiac hypertrophy and cardiac dysfunction compared to WT DM mice. Overexpression of miR-21 aggravated fibrosis, reduced autophagy, and attenuated the protective effect of vild on cardiac function. In high-glucose-treated H9c2 cells, the downstream effectors of sprouty homolog 1 (SPRY1) including extracellular signal-regulated kinases (ERK) and mammalian target of rapamycin showed significant changes following transfection with miR-21 mimics or inhibitor. Conclusion: The results of our study indicate that vild prevents DCM by restoring autophagy through the miR-21/SPRY1/ERK/mTOR pathway. Therefore, miR-21 is a target in the development of DCM, and vild demonstrates significant potential for clinical application in prevention of DCM.

The Safety of Pharmacological and Surgical Treatment of Diabetes in Patients with Diabetic Retinopathy-A Review

BACKGROUND

Diabetes mellitus (DM) is a non-infectious pandemic of the modern world; it is estimated that in 2045 it will affect 10% of the world's population. As the prevalence of diabetes increases, the problem of its complications, including diabetic retinopathy (DR), grows. DR is a highly specific neurovascular complication of diabetes that occurs in more than one third of DM patients and accounts for 80% of complete vision loss cases in the diabetic population. We are currently witnessing many groundbreaking studies on new pharmacological and surgical methods of treating diabetes.

AIM

The aim of the study is to assess the safety of pharmacological and surgical treatment of DM in patients with DR.

MATERIAL AND METHODS

An analysis of the data on diabetes treatment methods currently available in the world literature and their impact on the occurrence and progression of DR.

RESULTS

A rapid decrease in glycaemia leads to an increased occurrence and progression of DR. Its greatest risk accompanies insulin therapy and sulfonylurea therapy. The lowest risk of DR occurs with the use of SGLT2 inhibitors; the use of DPP-4 inhibitors and GLP-1 analogues is also safe. Patients undergoing pancreatic islet transplants or bariatric surgeries require intensive monitoring of the state of the eye, both in the perioperative and postoperative period.

CONCLUSIONS

It is of utmost importance to individualize therapy in diabetic patients, in order to gradually achieve treatment goals with the use of safe methods and minimize the risk of development and progression of DR.

Comparative clinical study evaluating the effect of adding Vildagliptin versus Glimepiride to ongoing Metformin therapy on diabetic patients with symptomatic coronary artery disease

BACKGROUND AND OBJECTIVE

Cardiovascular diseases (CVDs) remain the most identified cause of death in patients with diabetes mellitus (DM). This study aimed to evaluate the effect of adding Vildagliptin versus Glimepiride to ongoing Metformin on the biomarkers of inflammation, thrombosis, and atherosclerosis in T2DM patients with symptomatic coronary artery disease (CAD).

METHODS

This study included 80 patients with uncontrolled T2DM and symptomatic CAD who were randomized to add either Vildagliptin 50 mg/day "group I" or Glimepiride 4 mg/day "group II" to ongoing Metformin therapy (1000 mg/day). Blood samples were collected at baseline and 3 months after intervention for biochemical analysis of HbA1c %, IL-1β, adiponectin, hsCRP and lipid profile. Additionally atherogenic index (AI) and coronary risk index (CRI) were determined.

RESULTS

Three months after intervention and as compared to group II (Glimepiride/Metformin), group 1 (Vildagliptin/Metformin) showed significantly lower BMI (28.73 ± 3.48 versus 30.55 ± 3.15; p = 0.02), HbA1c (6.05 ± 0.72 versus 7.06 ± 0.89; p < 0.0001), hsCRP (0.96 ± 0.20 versus 1.72 ± 0.38; p < 0.0001), IL-1β (34.95 ± 10.01 versus 45.13 ± 10.26; p < 0.0001), TC (136 ± 23.45 versus 169 ± 35.72; p < 0.0001), TG (116 ± 29.10 versus 146 ± 56.58; p = 0.005), and CRI (2.47 ± 0.90 versus 3.65 ± 1.19; p < 0.0001) which was associated with significantly higher adiponectin and HDL-C (4.42 ± 1.29 versus 2.52 ± 1.86; p < 0.0001 and 61 ± 23.04 versus 48 ± 12.92; p = 0.003 respectively).

CONCLUSION

In patients with T2DM and symptomatic CAD, the addition of Vildagliptin to ongoing metformin showed better glycemic control, lower inflammatory markers (IL-1β and hsCRP), higher protective markers (adiponectin and HDL-C) and improved lipid profile compared to Glimepiride/metformin therapy.

Dipeptidyl peptidase-4 inhibitors as new tools for cardioprotection

Previous studies have demonstrated that individuals with type 2 diabetes mellitus (T2DM) have a two- to fourfold propensity to develop cardiovascular disease (CVD) than nondiabetic population, making CVD a major cause of death and disability among people with T2DM. The present treatment options for management of diabetes propose the earlier and more frequent use of new antidiabetic drugs that could control hyperglycaemia and reduce the risk of cardiovascular events. Findings from basic and clinical studies pointed out DPP-4 inhibitors as potentially novel pharmacological tools for cardioprotection. There is a growing body of evidence suggesting that these drugs have ability to protect the heart against acute ischaemia-reperfusion injury as well as reduce the size of infarction. Consequently, the prevention of degradation of the incretin hormones by the use of DPP-4 inhibitors represents a new strategy in the treatment of patients with T2DM and reduction of CV events in these patients. Here, we discuss the cardioprotective effects of DPP-4 inhibitors as well as proposed pathways that these hypoglycaemic agents target in the cardiovascular system.

Cardiovascular outcomes of vildagliptin in patients with type 2 diabetes mellitus after acute coronary syndrome or acute ischemic stroke

AIMS/INTRODUCTION

The cardiovascular (CV) outcomes of vildagliptin - a dipeptidyl peptidase-4 inhibitor - in patients with type 2 diabetes mellitus after acute coronary syndrome or acute ischemic stroke are unclear.

MATERIALS AND METHODS

We analyzed data from the Taiwan National Health Insurance Research Database on 3,750 type 2 diabetes mellitus patients with acute coronary syndrome or acute ischemic stroke within 3 months between 1 August 2011 and 31 December 2013. Clinical outcomes were evaluated by comparing 1,250 participants receiving vildagliptin with 2,500 propensity score-matched participants. The primary composite outcome included CV death, non-fatal myocardial infarction and non-fatal stroke.

RESULTS

The primary composite outcome occurred in 122 patients (9.8%) in the vildagliptin group and 263 patients (10.5%) in the control group (hazard ratio [HR] 0.90, 95% confidence interval [CI] 0.72-1.11) with a mean follow-up period of 9.9 months. No significant between-group differences were observed for CV death (HR 0.93, 95% CI 0.56-1.52), non-fatal myocardial infarction (HR 0.79, 95% CI 0.46-1.36) and non-fatal stroke (HR 0.96, 95% CI 0.74-1.24). The vildagliptin group was at similar risks of hospitalization for heart failure (HF) or coronary intervention to the control group (P = 0.312 and 0.430, respectively). For patients with HF at baseline, the risk of hospitalization for HF was similar between the vildagliptin and control groups (HR 1.04, 95% CI 0.57-1.88).

CONCLUSIONS

Among patients with type 2 diabetes mellitus after a recent acute coronary syndrome or acute ischemic stroke, treatment with vildagliptin was not associated with increased risks of CV death, non-fatal myocardial infarction, non-fatal stroke and hospitalization for HF.

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.

The future of new drugs for diabetes management

The future of the newer classes of glucose-lowering drugs, namely dipeptidyl peptidase-4 (DPP-4) inhibitors, glucagon-like peptide-1 receptor agonists (GLP-1RAs) and sodium/glucose co-transporter-2 (SGLT-2) inhibitors, is being redefined by the large prospective cardiovascular outcome trials (CVOTs). These trials have more than confirmed cardiovascular (CV) safety: indeed, various cardio-renal parameters have improved during some of the trials with GLP-1RAs and SGLT-2 inhibitors in type 2 diabetes. Benefits have included reductions in major adverse cardiovascular events such as fatal and non-fatal myocardial infarction and stroke, decreased hospitalization for heart failure, a slower decline in glomerular filtration rate and reduced onset and progression of albuminuria. In consequence, the CVOTs have raised expectations that newer glucose-lowering agents should offer advantages that extend beyond glycaemic control and weight management to address complications and comorbidities of type 2 diabetes, particularly cardio-renal diseases. Although large prospective outcome trials incur a high cost which may prompt reconsideration of their design, these trials are generating evidence to enable more exacting and more effective management of type 2 diabetes and its accompanying cardio-renal diseases.

Dypeptidylpeptidase-4 inhibitors and the cardiovascular system: How to manage the fil rouge

Dypeptidylpeptidase-4 (DPP-4) inhibitors are a therapeutic option for improving glucose control in patients with type 2 diabetes. They can be prescribed at different stages of the natural history of the disease because of their low risk for hypoglycemia and associated weight gain. For all new drugs for diabetes, the US Food and Drug Administration requires the demonstration of the cardiovascular (CV) safety profile through pooled analyses of phase 3 studies or specifically designed trials. A significant superiority over placebo has been observed with a sodium-dependent glucose transporter-2 inhibitor, empagliflozin, and two glucagon-like peptide-1 receptor agonists, liraglutide and semaglutide, thus suggesting cardioprotective effects for some antidiabetic drugs. The neutral results of CV safety trials on DPP-4 inhibitors have been disappointing, appearing to contradict the data from pooled analyses and meta-analyses of early trials. The main aim of this review is to find a possible interpretation for the differences between the results of these early trials and the CV safety studies with DPP-4 inhibitors. We conclude that the hypothesis of additional beneficial effects by DPP-4 inhibitors (beyond the improvement of glucose control), on the CV system in low-risk patients in primary prevention, needs to be verified with specifically designed studies.

A Review on Cardiovascular Outcome Studies of Dipeptidyl Peptidase-4 Inhibitors

The U.S. Food and Drug Administration issued a guidance for pharmaceutical industry defining preapproval and postapproval requirements for the demonstration of cardiovascular (CV) safety for all new medications developed for glycemic management in type 2 diabetes. However, results published from the studies of dipeptidyl peptidase-4 (DPP-4) inhibitors are conflicting with regard to different CV endpoints. Upcoming CV outcome studies perhaps will be able to provide additional insights related to diabetes management and help to provide the answers to some of these concerns. This article provides a brief overview regarding how various CV safety evidence of DPP-4 inhibitor evolved over time that highlights possible implication in clinical practice and translates them into effective diabetes management.

Cardiovascular Safety of Empagliflozin Versus Dipeptidyl Peptidase-4 (DPP-4) Inhibitors in Type 2 Diabetes: Systematic Literature Review and Indirect Comparisons

INTRODUCTION

Clinical trials conducted in patients with type 2 diabetes (T2DM) treated with glucose-lowering drugs and examining cardiovascular-related outcomes have yielded mixed results. In this work, we aimed to assess the relative treatment effects of empagliflozin versus sitagliptin and saxagliptin (dipeptidyl peptidase-4 (DPP-4) inhibitors) on cardiovascular-related outcomes in patients with T2DM.

METHODS

We conducted a systematic literature review to identify clinical trials assessing cardiovascular-related outcomes for sitagliptin-, saxagliptin-, and empagliflozin-treated patients with T2DM. A network meta-analysis of indirect treatment comparisons was conducted in a Bayesian framework. Hazard ratios (HR) and 95% credible intervals (CrI) were computed for six cardiovascular-related outcomes to estimate the relative efficacies of these agents.

RESULTS

Empagliflozin showed a statistically significant superiority over saxagliptin (HR 0.60; 95% CrI 0.46-0.80) and sitagliptin (HR 0.60; 95% CrI 0.46-0.79) to reduce the risk for cardiovascular-related mortality. For all-cause mortality, empagliflozin showed a statistically significant risk reduction compared to saxagliptin (HR 0.61; 95% CrI 0.49-0.76) and sitagliptin (HR 0.67; 95% CrI 0.54-0.83). A similar pattern was observed in the risk reduction for hospitalization due to heart failure, where empagliflozin was found to be statistically significantly superior to saxagliptin (HR 0.51; 95% CrI 0.37-0.70) and sitagliptin (HR 0.65; 95% CrI 0.47-0.90). Empagliflozin was not statistically significantly different to sitagliptin and saxagliptin with regard to the risk of a composite endpoint composed of death, stroke or myocardial infarction.

CONCLUSION

In this indirect comparison to the DPP-4 inhibitors saxagliptin and sitagliptin, empagliflozin significantly lowered the risk of cardiovascular-related mortality, all-cause mortality and hospitalizations due to heart failure.

FUNDING

Boehringer Ingelheim GmbH.

Combination of Vildagliptin and Ischemic Postconditioning in Diabetic Hearts as a Working Strategy to Reduce Myocardial Reperfusion Injury by Restoring Mitochondrial Function and Autophagic Activity

Purpose: Diabetic hearts are resistant to cardioprotection by ischemic-postconditioning (IPostC). Protection of diabetic hearts and finding related interfering mechanisms would have clinical benefits. This study investigated the combination effects of vildagliptin (Vilda) and IPostC on cardioprotection and the levels of autophagy and mitochondrial function following myocardial ischemia/reperfusion (I/R) injury in type-II diabetic rats.

Methods: Diabetes was established by high fat diet/low dose of streptozotocin and lasted for 12 weeks. The diabetic rats received Vilda (6 mg/kg/day, orally) for one month before I/R. Myocardial regional ischemia was induced through the ligation of left coronary artery, and IPostC was applied immediately at the onset of reperfusion. The infarct size was assessed by a computerised planimetry and left ventricles samples were harvested for cardiac mitochondrial function studies (ROS production, membrane potential and staining) and western blotting was used for determination of autophagy markers.

Results: None of Vilda or IPostC but combination of them could significantly reduce the infarct size of diabetic hearts, comparing to control (P<0.001). IPostC could not significantly affect p62 expression level in diabetic hearts, but pre-treatment with Vilda alone (p<0.05) and in combination with IPostC (p<0.01) more significantly decreased p62 expression in comparison with corresponding control group. The expression of LC3B-II and LC3BII/LC3BI as well as mitochondrial ROS production were decreased significantly in treatment groups (p<0.001). Mitochondrial membrane depolarization was significantly higher and mitochondrial density was lower in untreated diabetic I/R hearts than treated groups (p<0.001). IPostC in combination with vildagliptin prevented the mitochondrial membrane depolarization and increased the mitochondrial content more potent than IPostC alone in diabetic hearts.

Conclusion: Combination of vildagliptin and IPostC in diabetic hearts was a well-working strategy to reduce myocardial I/R damages by restoring mitochondrial membrane potential and ROS production and modulating the autophagic activity in I/R hearts.

Glycemic control of type 2 diabetes mellitus across stages of renal impairment: information for primary care providers

Chronic kidney disease (CKD) is a frequent complication of type 2 diabetes mellitus (T2DM) and elevates individuals' risk for cardiovascular disease, the leading cause of morbidity and mortality in T2DM. Achieving and maintaining tight glycemic control is key to preventing development or progression of CKD; however, improving glycemic control may be limited by effects of renal impairment on the efficacy and safety of T2DM treatments, necessitating dosing adjustments and careful evaluation of contraindications. Understanding the treatment considerations specific to each class of T2DM medication is important in individualizing therapy and improving glycemic, renal, and cardiovascular outcomes. Traditional glucose-lowering treatments include insulin, metformin, sulfonylureas, meglitinides, and thiazolidinediones. Each of these agents exhibits altered pharmacokinetics in patients with renal impairment except for the thiazolidinediones, which are metabolized by the liver and do not accumulate appreciably in patients with renal impairment. Newer glucose-lowering treatments include GLP-1 receptor agonists, DPP-4 inhibitors, and SGLT2 inhibitors. Of these, only the DPP-4 inhibitor linagliptin can be used across all stages of renal impairment without dosing restrictions or concerns regarding dose escalation, and all SGLT2 inhibitors are contraindicated when eGFR <45 mL/min/1.73m². Several of the newer treatments have also been investigated for effects on renal and cardiovascular outcomes, demonstrating potential benefits of the GLP-1 agonists liraglutide and semaglutide, as well as the SGLT2 inhibitors canagliflozin and empagliflozin, in reducing risk for some adverse renal and cardiovascular events. In addition, some DPP-4 inhibitors have been shown to reduce albuminuria, an indicator of glomerular dysfunction. Consideration of this information is useful in informing optimal management strategies for patients with T2DM and concomitant CKD. More clinical data from future and ongoing clinical trials, including data regarding potential renal and cardiovascular benefits, will be important in clarifying the safety and efficacy profiles of each of these agents in patients with CKD.

Comparative Cardiovascular Risks of Dipeptidyl Peptidase-4 Inhibitors: Analyses of Real-world Data in Korea

Background and Objectives

To compare cardiovascular disease (CVD) risk associated with 5 different dipeptidyl peptidase-4 inhibitors (DPP-4is) in people with type 2 diabetes.

Methods

We identified 534,327 people who were newly prescribed sitagliptin (n=167,157), vildagliptin (n=67,412), saxagliptin (n=29,479), linagliptin (n=220,672), or gemigliptin (n=49,607) between January 2013 and June 2015 using the claims database of the Korean National Health Insurance System. A Cox proportional hazards model was used to estimate hazard ratios (HRs) for major CVD events (myocardial infarction, stroke, or death) among users of different DPP-4is. The model was adjusted for sex, age, duration of DPP-4i use, use of other glucose-lowering drugs, use of antiplatelet agents, hypertension, dyslipidemia, atrial fibrillation, chronic kidney disease, microvascular complications of diabetes, Charlson comorbidity index, and the calendar index year as potential confounders.

Results

Compared to sitagliptin users, the fully adjusted HRs for CVD events were 0.97 (95% confidence interval [CI], 0.94–1.01; p=0.163) for vildagliptin, 0.76 (95% CI, 0.71–0.81; p<0.001) for saxagliptin, 0.95 (95% CI, 0.92–0.98; p<0.001) for linagliptin, and 0.84 (95% CI, 0.80–0.88; p<0.001) for gemigliptin.

Conclusions

Compared to sitagliptin therapy, saxagliptin, linagliptin, and gemigliptin therapies were all associated with a lower risk of cardiovascular events.

Factors that may Account for Cardiovascular Risk Reduction with a Dipeptidyl Peptidase-4 Inhibitor, Vildagliptin, in Young Patients with Type 2 Diabetes Mellitus

INTRODUCTION

In a meta-analysis, we observed a significant 37% relative risk reduction in prospectively adjudicated major adverse cardiac events [MACEs, comprising of non-fatal myocardial infarction, non-fatal stroke, cardiovascular (CV) death] with vildagliptin vs. comparators in younger (< 65 years) patients with type 2 diabetes mellitus (T2DM), while the risk was similar in older patients (≥ 65 years). We carried out an exploratory analysis to identify the patient characteristics and on-treatment effects that may have contributed to the different outcomes in the two age groups.

METHODS

On-treatment differences (vildagliptin vs. comparators) for the change from baseline in CV risk factors were analyzed using an analysis of covariance model with the baseline value for each variable of interest, treatment and study as covariates. Additional adjustments for background antihypertensive and statin use were performed when analyzing changes in blood pressure and lipids, respectively. Baseline characteristics and patient demographics were analyzed using descriptive statistics.

RESULTS

Patients aged < 65 years had shorter diabetes duration (4.4 vs. 8.2 years) and slightly higher glycated hemoglobin (HbA1c) at baseline (8.3% vs. 8.0%) than patients aged ≥ 65 years. More patients in the  ≥ 65 year age group had hypertension (73.1% vs. 51.3%), dyslipidemia (53.3% vs. 43.9%) and a history of CV events (32.2% vs. 12.9%). There were small, but statistically significant differences in the change in HbA1c and total cholesterol in favor of vildagliptin relative to comparators, which were similar in both age groups. Significant differences were observed in the reduction in systolic blood pressure (SBP) (- 0.52 mmHg; 95% CI - 0.97, - 0.07; p = 0.023), low-density lipoprotein (LDL cholesterol) (- 0.12 mmol/l; 95% CI - 0.19, - 0.04; p = 0.002) and weight (- 0.48 kg; 95% CI - 0.95, - 0.01; p < 0.047) in patients < 65 years, but not in patients ≥ 65 years. The incidence of hypoglycemic events was lower in patients treated with vildagliptin [2.1 and 3.5 per 100 subject years exposure (SYEs) in < 65 and ≥ 65 years, respectively] than with comparators (5.8 and 7.5 per 100 SYEs, respectively).

CONCLUSION

Based on our findings, it can be hypothesized that the positive effects of vildagliptin on SBP, LDL cholesterol, hypoglycemia and weight observed in younger, but not in older patients could be associated with the lower risk of MACE in younger patients with T2DM.

FUNDING

Novartis.

Effectiveness and safety of dipeptidyl peptidase 4 inhibitors in the management of type 2 diabetes in older adults: a systematic review and development of recommendations to reduce inappropriate prescribing

Background

Preventable drug-related hospital admissions can be associated with drugs used in diabetes and the benefits of strict diabetes control may not outweigh the risks, especially in older populations. The aim of this study was to look for evidence on risks and benefits of DPP-4 inhibitors in older adults and to use this evidence to develop recommendations for the electronic decision support tool of the PRIMA-eDS project.

Methods

Systematic review using a staged approach which searches for systematic reviews and meta-analyses first, then individual studies only if prior searches were inconclusive. The target population were older people (≥65 years old) with type 2 diabetes. We included studies reporting on the efficacy and/or safety of DPP-4 inhibitors for the management of type 2 diabetes. Studies were included irrespective of DPP-4 inhibitors prescribed as monotherapy or in combination with any other drug for the treatment of type 2 diabetes. The target intervention was DPP-4 inhibitors compared to placebo, no treatment, other drugs to treat type 2 diabetes or a non-pharmacological intervention.

Results

Thirty studies (reported in 33 publications) were included: 1 meta-analysis, 17 intervention studies and 12 observational studies. Sixteen studies were focused on older adults and 14 studies reported subgroup analyses in participants ≥65, ≥70, or ≥75 years. Comorbidities were reported by 26 studies and frailty or functional status by one study. There were conflicting findings regarding the effectiveness of DPP-4 inhibitors in older adults. In general, DPP-4 inhibitors showed similar or better safety than placebo and other antidiabetic drugs. However, these safety data are mainly based on short-term outcomes like hypoglycaemia in studies with HbA1c control levels recommended for younger people. One recommendation was developed advising clinicians to reconsider the use of DPP-4 inhibitors for the management of type 2 diabetes in older adults with HbA1c <8.5% because of scarce data on clinically relevant benefits of their use. Twenty-two of the included studies were funded by pharmaceutical companies and authored or co-authored by employees of the sponsor.

Conclusions

Other than the surrogate endpoint of improved glycaemic control, data on clinically relevant benefits of DPP-4 inhibitors in the treatment of type 2 diabetes mellitus in older adults is scarce. DPP-4 inhibitors might have a lower risk of hypoglycaemia compared to other antidiabetic drugs but data show conflicting findings for long-term benefits. Further studies are needed that evaluate the risks and benefits of DPP-4 inhibitors for the management of type 2 diabetes mellitus in older adults, using clinically relevant outcomes and including representative samples of older adults with information on their frailty status and comorbidities. Studies are also needed that are independent of pharmaceutical company involvement.

Electronic supplementary material

The online version of this article (doi:10.1186/s12877-017-0571-8) contains supplementary material, which is available to authorized users.

Interpreting Cardiovascular Endpoints in Trials of Antihyperglycemic Drugs

In view of the significant cardiovascular (CV) morbidity and mortality in patients with type 2 diabetes mellitus, and concerns raised about the CV safety of some glucose-lowering drugs, the US Food and Drug Administration (FDA) issued guidance for the industry in 2008 to demonstrate CV safety for the approval of all new antihyperglycemic drugs. Seven randomized controlled trials involving around 60,000 participants have been completed so far and have demonstrated the CV safety of dipeptidyl peptidase 4 inhibitors (saxagliptin, alogliptin and sitagliptin), glucagon-like peptide-1 receptor agonists (lixisenatide, liraglutide and semaglutide) and a sodium-glucose co-transporter 2 inhibitor (empagliflozin) in patients with type 2 diabetes. Three of these trials have in fact reported superiority of the study drug over placebo in terms of CV outcomes. However, all these trials were primarily designed as non-inferiority trials to exclude an unacceptable risk of CV events with these drugs in the shortest possible time period. The potential long-term benefit or risks were not assessed effectively as the median follow-up in these studies was limited to 1.5-3 years. Also, these trials included patients with relatively long duration of diabetes, advanced atherosclerosis and higher CV risk. Thus, these trials were not intended to assess CV benefit and are best interpreted as evidence for CV safety of these antihyperglycemic medications.

Cardiovascular Safety of Dipeptidyl-Peptidase IV Inhibitors: A Meta-Analysis of Placebo-Controlled Randomized Trials

BACKGROUND

Large randomized trials have shown conflicting evidence regarding the cardiovascular safety of dipeptidyl-peptidase 4 (DPP-4) inhibitors. Systematic reviews have been limited by incomplete data and inclusion of observational studies. This study aimed to systematically evaluate the cardiovascular safety of DPP-4 inhibitors in patients with type 2 diabetes.

METHODS

Electronic databases were searched for randomized trials that compared DPP-4 inhibitors versus placebo and reported cardiovascular outcomes. The main outcome assessed in this analysis was heart failure. Other outcomes included all-cause mortality, cardiovascular mortality, myocardial infarction, and ischemic stroke. Summary odds ratios (ORs) were primarily constructed using Peto's model.

RESULTS

A total of 90 trials with 66,730 patients were included. Compared with placebo, DPP-4 inhibitors were associated with a non-significant increased risk of heart failure [OR 1.11, 95% confidence interval (CI) 0.99-1.25, P = 0.07] at a mean of 108 weeks. The risk of all-cause mortality (OR 1.03, 95% CI 0.94-1.12, P = 0.53), cardiovascular mortality (OR 1.02, 95% CI 0.92-1.14, P = 0.72), myocardial infarction (OR 0.98, 95% CI 0.88-1.09, P = 0.69), and ischemic stroke (OR 0.99, 95% CI 0.85-1.15, P = 0.92) was similar between both groups.

CONCLUSION

In patients with type 2 diabetes, the safety profile of DPP-4 inhibitors is similar to placebo. As a class, there is only weak evidence for an increased risk of heart failure.

Monitoring safety and use of old and new treatment options for type 2 diabetic patients: a two-year (2013-2016) analysis

OBJECTIVE

To compare patients' and physicians' perceptions regarding effectiveness and tolerability of non-insulin hypoglycemic drugs in a cohort of type 2 diabetic patients; to verify whether a possible tridimensional link between effectiveness, tolerability, and adherence affects long-term therapeutic outcomes.

METHODS

A two-year observational study was performed in 1389 Type 2 diabetic patients by involving general practitioner clinics and Diabetes Centers. A decimal scale and the Morisky questionnaire were used, respectively, to assess effectiveness and tolerability perceptions, and medication adherence.

RESULTS

Physicians perceived therapy as more efficacious compared to their patients: perceived effectiveness was steady for physicians during the study whereas patients' perception not significantly decreased (mean score from >8 to 7.84 ± 1.69). Physicians assigned higher tolerability scores compared to patients but only at the beginning of the study; interestingly, physicians' tolerability perception was poorer than patients' perception at last follow-up (mean score = 7.57 ± 1.40 vs. 7.88 ± 1.84). Favorable (score >7) patients' perceptions about treatment effectiveness and tolerability were associated with higher adherence. Patients showed medium adherence across the study.

CONCLUSIONS

A mutual relationship between clinical effectiveness, adverse drug reactions, and adherence has been established, significantly impacting the clinical management of diabetic patients. A careful monitoring of this link by clinicians appears therefore necessary.

Mechanisms of Cardiovascular Injury in Type 2 Diabetes and Potential Effects of Dipeptidyl Peptidase-4 Inhibition

BACKGROUND

Cardiovascular (CV) disease is the major cause of mortality and morbidity in patients with type 2 diabetes mellitus (T2DM). The pathogenesis of CV disease in T2DM is complex and multifactorial and involves direct and indirect injury to the vasculature and heart. The impact of intensive glucose-lowering therapy with antihyperglycemic agents on CV outcomes is not clear, and questions remain as to which glucose-lowering agents may be beneficial to CV health in patients with T2DM.

PURPOSE

This review discusses findings regarding the known mechanisms of CV injury in T2DM and current knowledge regarding the potential cardioprotective effects of dipeptidyl peptidase-4 (DPP-4) inhibitors.

CONCLUSIONS

Dipeptidyl peptidase-4 inhibitors are relatively new antihyperglycemic agents. Their main mechanism of action is to inhibit the degradation of the incretin hormones glucagon-like peptide-1 and glucose-dependent insulinotropic peptide by DPP-4. By increasing levels of glucagon-like peptide-1, glucose-dependent insulin secretion is enhanced, glucagon secretion is suppressed, and the rate of gastric emptying is decreased. Dipeptidyl peptidase-4 also degrades other substances that are important in the regulation of CV function and inflammation. Animal studies, small observational studies in humans, and analyses of clinical trial data suggest that DPP-4 inhibitors may have beneficial CV effects. Recent prospectively designed CV outcomes trials with saxagliptin and alogliptin in patients with T2DM and high CV risk presented evidence that these DPP-4 inhibitors neither increased nor decreased adverse CV outcomes in this select patient population.

CLINICAL IMPLICATIONS

Dipeptidyl peptidase-4 inhibitors are promising therapies for the treatment of T2DM. Able to improve glycemic control without the risk of weight gain or hypoglycemia, they provide a safe alternative to sulfonylureas and are an effective adjunct to metformin. To date, this class of drugs seems to be at least neutral in terms of CV effects. Time will tell if these findings translate into a benefit for our patients.

Cardiovascular Safety of Incretin-Based Therapies in Type 2 Diabetes: Systematic Review of Integrated Analyses and Randomized Controlled Trials

Introduction

Regulatory requirements mandate that new drugs for treatment of patients with type 2 diabetes mellitus (T2DM), such as dipeptidyl peptidase-4 (DPP-4) inhibitors and glucagon-like peptide-1 (GLP-1) receptor agonists, are evaluated to show that they do not increase cardiovascular (CV) risk.

Methods

A systematic review was undertaken to evaluate the association between DPP-4 inhibitor and GLP-1 receptor agonist use and major adverse cardiac events (MACE). The National Institutes of Health Medline database was searched for pooled analyses, meta-analyses, and randomized controlled trials (RCTs) of DPP-4 inhibitors and GLP-1 receptor agonists that included CV endpoints.

Results

Thirty-six articles met the inclusion criteria encompassing 11 pooled analyses, 17 meta-analyses, and eight RCTs (including secondary analyses). Over the short term (up to 4 years), patients with T2DM exposed to a DPP-4 inhibitor or GLP-1 receptor agonist were not at increased risk for MACE (or its component endpoints) compared with those who received comparator agents. Two meta-analyses showed a significant reduction in the incidence of MACE associated with DPP-4 inhibitor therapy as a drug class, but this beneficial effect was not observed in other meta-analyses that included large RCT CV outcome studies. In four RCTs that evaluated alogliptin, saxagliptin, sitagliptin, or lixisenatide, there was no overall increased risk for MACE relative to placebo in T2DM patients at high risk for CV events or with established CV disease, although there was an increased rate of hospitalization for heart failure associated with saxagliptin. A fifth RCT showed that liraglutide reduced MACE risk by 13% versus placebo.

Conclusion

Overall, incretin therapy does not appear to increase risk for MACE in the short term.

Pattern of Onset and Risk Factors for Peripheral Oedema During Vildagliptin Use: Analysis from the Vildagliptin Prescription-Event Monitoring Study in England

INTRODUCTION

Clinical trials have identified peripheral oedema (PO) as an adverse event of vildagliptin (an oral anti-diabetic drug [OAD]). A post-marketing study (PMS) was conducted to advance the understanding of vildagliptin use and particular safety concerns identified within the risk-management plan. PMS objectives included comparing the hazards between vildagliptin monotherapy and combination therapy for selected a priori identified risks, including PO.

AIM

This study was a per-protocol supplementary analysis to investigate the pattern of onset and effect of vildagliptin combination therapy on PO risk.

METHODS

The PMS used an observational cohort design. OAD exposure, selected risk factors and outcome data were collected from general practitioners in England regarding vildagliptin users for the 6-month period after starting treatment. Data analysis comprised univariate case/non-case analysis, time-to-onset analysis and Cox proportional hazard models to estimate hazard ratios (HR) of PO adjusting for selected patients' baseline characteristics.

RESULTS

The study cohort included 4828 patients (median age 63 years; interquartile range [IQR] 54-71), 2692 of whom were male (55.8 %). The crude cumulative hazard of PO was 19.09 cases (95 % confidence interval [CI] 13.54-26.10) per 1000 person-years; 50 % of cases occurred during the first 34 days of treatment. A significantly faster time to PO onset was observed in patients prescribed concomitant sulfonylureas versus other treatment combinations (log rank test [LRT] p = 0.0365); in patients with a prior history of PO (LRT p < 0.001), arrhythmia (LRT p = 0.0003) or hypertension (LRT p = 0.0125); and in patients aged ≥60 years (LRT p = 0.0047). Similarly, the case/non-case univariate analysis indicated that patients with PO were older; had a higher prevalence of a history of either arrhythmia, hypertension or PO; and frequently used a sulfonylurea in combination. In the hazard function analysis, only sex and prior PO history had a profound effect on risk of PO after starting vildagliptin. Furthermore, effect modification was observed between sex and prior PO history; in male patients of average age (62 years), the HR was 12.84 (95 % CI 4.96-33.23); in females, it was 1.44 (95 % CI 0.32-6.40).

CONCLUSIONS

In this planned supplementary analysis, the findings suggest that PO occurred most frequently within 1 month after starting treatment with vildagliptin, and previous PO history and male sex in elderly patients were important predictors of this risk. The observation that concomitant use of a sulfonylurea may also increase PO risk early after starting treatment should be taken into consideration if prescribing OADs in combination with vildagliptin.

Reporting of Sex Effects by Systematic Reviews on Interventions for Depression, Diabetes, and Chronic Pain

Systematic reviews (SRs) have the potential to contribute uniquely to the evaluation of sex and gender differences (termed "sex effects"). This article describes the reporting of sex effects by SRs on interventions for depression, type 2 diabetes mellitus, and chronic pain conditions (chronic low back pain, knee osteoarthritis, and fibromyalgia). It includes SRs published since 1 October 2009 that evaluate medications, behavioral interventions, exercise, quality improvement, and some condition-specific treatments. The reporting of sex effects by primary randomized, controlled trials is also examined. Of 313 eligible SRs (86 for depression, 159 for type 2 diabetes mellitus, and 68 for chronic pain), few (n = 29) reported sex effects. Most SRs reporting sex effects used metaregression, whereas 9 SRs used subgroup analysis or individual-patient data meta-analysis. The proportion of SRs reporting the sex distribution of primary studies varied from a low of 31% (n = 8) for low back pain to a high of 68% (n = 23) for fibromyalgia. Primary randomized, controlled trials also infrequently reported sex effects, and most lacked an adequate sample size to examine them. Therefore, all SRs should report the proportion of women enrolled in primary studies and evaluate sex effects using appropriate methods whenever power is adequate.

Analyses of Results From Cardiovascular Safety Trials With DPP-4 Inhibitors: Cardiovascular Outcomes, Predefined Safety Outcomes, and Pooled Analysis and Meta-analysis

The U.S. Food and Drug Administration requires that the cardiovascular (CV) safety of all new drugs for diabetes be demonstrated through pooled analyses of phase III studies or specifically designed trials. This requirement prompted several placebo-controlled, noninferiority CV safety trials in high-risk patients; to date, all completed trials showed that dipeptidyl peptidase (DPP)-4 inhibitors do not increase or reduce the risk of major CV events. These results apparently contrast with those of pooled analyses and meta-analyses of previous, smaller trials with metabolic end points, which had suggested a reduction of risk. However, the design of CV trials, which were required to demonstrate safety, is not adequate (for duration, management of concurrent therapies, etc.) for the assessment of potential therapeutic benefits. In addition, CV safety trials enroll patients at high risk of CV events, who are different from those included in earlier trials with metabolic end points. Differences in characteristics of patients enrolled probably account for most of the discrepancy in CV outcomes between CV safety studies and earlier trials. The availability of several large-scale trials with longer duration provides the unique opportunity for assessment of the safety of DPP-4 inhibitors not only with respect to major CV events but also with reference to other safety issues. For example, CV safety trials can be a source of information for pancreatitis, cancer, or hypoglycemia.

Cardiovascular effects of anti-diabetes drugs

INTRODUCTION

Cardiovascular disease remains the major contributor to morbidity and mortality in diabetes. From the need to reduce cardiovascular risk in diabetes and to ensure that such risk is not exacerbated by drug treatments, governmental regulators and drug manufacturers have focused on clinical trials evaluating cardiovascular outcomes.

AREAS COVERED

Findings from mechanistic and clinical trials of biguanides, sulfonylureas, thiazolidinediones, dipeptidyl peptidase-4 (DPP-4) inhibitors, glucagon-like peptide-1 (GLP-1) receptor agonists, and sodium-glucose co-transporter 2 (SGLT-2) inhibitors will be reviewed. These drug classes will be compared within the context of available cardiovascular outcomes data. Clinical implications of new study regulations will be examined.

EXPERT OPINION

Recent cardiovascular studies provide a more comprehensive evaluation of specific anti-diabetes therapy in individuals with high cardiovascular risk. Long-term effects of anti-hyperglycemic agents in patients with lower cardiovascular risk are still speculative. Historical data supports continued use of metformin as a first-line agent. DPP-4 inhibitors and GLP-1 receptor agonists appear to have neutral effects on cardiovascular outcomes. The significantly decreased cardiovascular risk associated with empagliflozin SGLT-2 inhibitor therapy is impressive and may change how practitioners prescribe add-on therapy to metformin.

Systematic review and meta-analysis of vildagliptin for treatment of type 2 diabetes

This systematic review and meta-analysis provides an update on the efficacy and safety of vildagliptin for treatment of type 2 diabetes mellitus (T2DM). We searched MEDLINE, COCHRANE, EMBASE and the drug manufacturer's website for randomised controlled trials of vildagliptin in patients with T2DM. Sixty-nine studies (28,006 patients) were included in the meta-analysis. Compared with placebo vildagliptin reduced HbA1c (weighted mean difference WMD -0.69 %; 95 % CI -0.83 to -0.56 %; I (2) = 82 %), and it was as effective as other antidiabetic agents (WMD -0.01 %; 95 % CI -0.16 to 0.14 %; I (2) = 93 %), without increasing the risk for hypoglycemia (OR 0.83; 95 % CI 0.59 to 1.16; I (2) = 0 % vs. placebo, and OR 0.19; 95 % CI 0.15 to 0.24; I (2) = 78 % versus active comparators). However, it was associated with an increase in the incidence of arthralgia compared with other comparators (OR 1.23; 95 % CI 1.02 to 1.48; I (2) = 0 %). On the contrary, vildagliptin did not increase the incidence of pancreatitis (OR 0.97; 95 % CI 0.37 to 2.53; I (2) = 0 %), serious adverse events (OR 0.98; 95 % CI 0.88 to 1.09; I (2) = 0 %) or death (OR 1.10, 95 % CI 0.75 to 1.61; I (2) = 0 %). Finally, odds ratio (OR) for heart failure, and overall cardiovascular and cerebrovascular events was 0.77 (95 % CI 0.46 to 1.30; I (2) = 0 %) and 0.91 (95 % CI 0.73 to 1.14; I (2) = 0 %), respectively. Vildagliptin is an effective and safe therapeutic option for patients with T2DM, both as monotherapy and as add-on treatment.

Cardiovascular Effect of Incretin-Based Therapy in Patients with Type 2 Diabetes Mellitus: Systematic Review and Meta-Analysis

BACKGROUND

To assess the cardiovascular (CV) risk associated with the use of incretin-based therapy in adult patients with type 2 diabetes mellitus (T2DM) primary prevention group with low CV risks.

METHODS

The clinical studies on incretin-based therapy published in medical journals until August 2014 were comprehensively searched using MEDLINE, EMBASE and CENTRAL with no language restriction. The studies were systemically reviewed and evaluated for CV risks using a meta-analysis approach and where they meet the following criteria: clinical trial, incidence of predefined CV disease, T2DM with no comorbidities, age > 18 years old, duration of at least 12 weeks, incretin-based therapy compared with other antihyperglycaemic agents or placebo. Statistical analyses were performed using a Mantel-Haenszel (M-H) test. The odds ratios (OR) and their 95% confidence interval (CI) were estimated and displayed for comparison.

RESULTS

A total of 75 studies comprising 45,648 patients with T2DM were selected. The pooled estimate demonstrated no significance in decreased CV risk with incretin-based therapy versus control (M-H OR, 0.90; 95% CI, 0.81-1.00).

CONCLUSIONS

This meta-analysis suggests that incretin-based therapy show no significant protective effect on CV events in T2DM primary prevention group with low CV risks. Prospective randomized controlled trials are required to confirm the results of this analysis.

Assessment of cardiovascular risk of new drugs for the treatment of diabetes mellitus: risk assessment vs. risk aversion

The Food and Drug Administration issued guidance for evaluating the cardiovascular risk of new diabetes mellitus drugs in 2008. Accumulating evidence from several completed trials conducted within this framework raises questions as to whether requiring safety outcome studies for all new diabetes mellitus therapies remains justified. Given the burden of cardiovascular disease in patients with diabetes, the focus should shift towards cardiovascular outcome studies designed to evaluate efficacy (i.e. to determine the efficacy of a drug over placebo or standard care) rather than demonstrating that risk is not increased by a pre-specified safety margin. All stakeholders are responsible for ensuring that new drug approvals occur under conditions of appropriate safety and effectiveness. It is also a shared responsibility to avoid unnecessary hurdles that may compromise access to useful drugs and threaten the sustainability of health systems. It is critical to renew this debate so that stakeholders can collectively determine the optimal approach for developing new drugs to treat type 2 diabetes mellitus.

DPP-4 inhibitors and cardiovascular disease in type 2 diabetes mellitus. Expectations, observations and perspectives

AIMS

Cardiovascular disease (CVD) is the greatest burden of type 2 diabetes mellitus (T2DM) in terms of morbility, mortality and costs for individuals and societies. Therefore, its prevention is a major goal in diabetes care. Optimal treatment of hyperglycemia is certainly instrumental to CVD prevention. Optimal treatment means both establishing the most appropriate glycemic target for the given individual and selecting the medication(s) with the most favourable benefit/safety ratio. CVD safety, if not a clear CVD benefit, is certainly required for all antidiabetic agents. Dipeptidyl-peptidase-4 (DPP-4) inhibitors are among the classes of antidiabetic agents most recently made available for diabetes care. A major question to be addressed is the effect of these compounds on CVD. Expectations were high for their mechanism of action, which targets also post-prandial glucose and minimize hypoglycemia risk, thereby providing a sort of global glucose control, and for some potentially beneficial extra-glycemic effects. This article reviews the existing literature on this issue.

DATA SYNTHESIS

Data published so far document that DPP-4 inhibitors have a wide spectrum of glycemic and extra-glycemic effects potentially reducing the risk of CVD as well as favourable effects on intermediate or surrogate CVD endpoints. These data heralded a better CVD outcome. Accordingly, pooling CVD safety data from phase 3 and 4 studies conducted with DPP-4 inhibitors suggested that their use might translate into a better CVD outcome. Data from three CVD outcome RCTs with alogliptin, saxagliptin and sitagliptin documented no harm but did not show any benefit on major CVD events. A modest but significant increased risk of hospitalization for heart failure was observed with saxagliptin and with alogliptin (only in subjects with no history of heart failure before randomization) but not with sitagliptin. A study currently in progress with linagliptin will provide further insights in the issue of CVD safety and benefit.

CONCLUSIONS

It should be considered that most alternative oral antidiabetic agents generally do not possess a better CVD risk profile than DPP-4 inhibitors and that some of them, indeed, should be used with caution because of potentially adverse effects on heart and vasculature. Overall, the selection of antidiabetic agent(s) with the most favourable CVD profile is mandatory but still challenging in diabetes care.

Cardiovascular safety for once-weekly dulaglutide in type 2 diabetes: a pre-specified meta-analysis of prospectively adjudicated cardiovascular events

BACKGROUND

Patients with type 2 diabetes (T2D) have a substantial increased risk for cardiovascular (CV) disease and associated mortality than those without diabetes. Dulaglutide is a once-weekly glucagon-like peptide-1 receptor agonist that is approved for treatment of T2D.

METHODS

This meta-analysis evaluates the CV risk in patients with T2D treated with dulaglutide in 9 randomized safety and efficacy trials. Mean (median) treatment duration was 333 (358) days. Reported CV events were independently adjudicated by a treatment-blinded clinical endpoint committee. The primary measure was a 4-component major adverse CV event (4-component MACE) composite endpoint of death due to CV causes, nonfatal myocardial infarction (MI), nonfatal stroke, or hospitalization for unstable angina. Additional pre-specified endpoints included adjudicated coronary revascularizations, hospitalization for heart failure, and all-cause mortality. A Cox proportional hazards regression model (stratified by study) was used to estimate the hazard ratio (HR) and confidence interval (CI). Tests of treatment effects for the primary endpoint were conducted at a 2-sided alpha level of 0.0198 and a corresponding 98.02 % CI was calculated. Statistical heterogeneity between the strata (studies) was tested by including in the Cox model an interaction term between treatment and strata.

RESULTS

The analysis included 6010 randomized patients [dulaglutide: 3885; comparator therapy (active or placebo): 2125]; cumulative exposure to dulaglutide or comparator therapy was 3941 and 2223 patient-years, respectively. The demographic and baseline CV disease characteristics were similar across groups. Twenty-six (0.67 %) patients in the dulaglutide group versus 25 (1.18 %) in the comparator group experienced a primary 4-component MACE (HR 0.57; adjusted 98.02 % CI 0.30, 1.10). Results for the 3-component MACE (composite endpoint of death due to CV causes, nonfatal MI or stroke), 6-component MACE (composite endpoint of death due to CV causes, nonfatal MI or stroke, hospitalization for unstable angina or heart failure, or coronary revascularizations) and all-cause mortality were consistent with the primary analysis (HR < 1.0 for all).

CONCLUSIONS

These results suggest that dulaglutide does not increase the risk of major CV events in T2D patients. The ongoing CV outcomes study, Researching CV Events with a Weekly Incretin in Diabetes (REWIND), will further assess CV safety of dulaglutide.

Vildagliptin efficacy in combination with metformin among Jordanian patients with type 2 diabetes mellitus inadequately controlled with metformin

Objective: To assess the efficacy and safety of vildagliptin added to metformin in patients with type 2 diabetes mellitus (T2DM) inadequately controlled with metformin monotherapy.

Methods: This was a 12-week prospective observational study where vildagliptin 50 mg twice daily was added to patients with T2DM inadequately controlled (glycosylated hemoglobin type A1c (Hba1c) 7–10%) by a daily dose of metformin ≥1700 mg between June 2012 and May 2013. Efficacy was assessed by change in Hba1c and fasting plasma glucose (FPG) levels, and safety was assessed by reported adverse events (AEs).

Results: A total of 58 patients were enrolled in this study. Their age ranged between 39.0 and 71.0 years, with a mean of 52.6 years, and a standard deviation (SD) of 7.8. The average duration of diabetes mellitus (DM) was 4.0 years (SD 3.0) and half of the patients have had DM for more than three years. The mean baseline levels of Hba1c and FPG were 8% and 10.8 mmol/L, respectively. Patients treated with vildagliptin achieved clinically significant reductions in Hba1c of 1.1% (p value <.005) and reduction in FPG of 1.8 mmol/L (p value <.005) from baseline. Overall, 62.1% had achieved the target of Hba1c of <7% after vildagliptin use. Greater reductions in Hba1c were linked to higher baseline levels as well as to the daily frequency of metformin use. Mild AEs were reported by 16 patients. There was no incidence of hypoglycemia and there were no significant changes in body weight after treatment.

Conclusions: Vildagliptin as add-on therapy to metformin improved glycemic control and was highly tolerable in T2DM patients who were inadequately controlled by metformin monotherapy.

Effect of Dipeptidyl Peptidase-4 Inhibitor on All-Cause Mortality and Coronary Revascularization in Diabetic Patients

BACKGROUND

Anti-atherosclerotic effect of dipeptidyl peptidase-4 (DPP-4) inhibitors has been suggested from previous studies, and yet, its association with cardiovascular outcome has not been demonstrated. We aimed to evaluate the effect of DPP-4 inhibitors in reducing mortality and coronary revascularization, in association with baseline coronary computed tomography (CT).

METHODS

The current study was performed as a multi-center, retrospective observational cohort study. All subjects with diabetes mellitus who had diagnostic CT during 2007-2011 were included, and 1866 DPP-4 inhibitor users and 5179 non-users were compared for outcome. The primary outcome was all-cause mortality and secondary outcome included any coronary revascularization therapy after 90 days of CT in addition to all-cause mortality.

RESULTS

DPP-4 inhibitors users had significantly less adverse events [0.8% vs. 4.4% in users vs. non-users, adjusted hazard ratios (HR) 0.220, 95% confidence interval (CI) 0.102-0.474, p = 0.0001 for primary outcome, 4.1% vs. 7.6% in users vs. non-users, HR 0.517, 95% CI 0.363-0.735, p = 0.0002 for secondary outcome, adjusted variables were age, sex, presence of hypertension, high sensitivity C-reactive protein, glycated hemoglobin, statin use, coronary artery calcium score and degree of stenosis]. Interestingly, DPP-4 inhibitor seemed to be beneficial only in subjects without significant stenosis (adjusted HR 0.148, p = 0.0013 and adjusted HR 0.525, p = 0.0081 for primary and secondary outcome).

CONCLUSION

DPP-4 inhibitor is associated with reduced all-cause mortality and coronary revascularization in diabetic patients. Such beneficial effect was significant only in those without significant coronary stenosis, which implies that DPP-4 inhibitor may have beneficial effect in earlier stage of atherosclerosis.

Insights from cardiovascular outcome trials with novel antidiabetes agents: what have we learned? An industry perspective

Owing to the close association of cardiovascular (CV) disease with type 2 diabetes and the uncertainty surrounding the CV safety of antidiabetes agents, in 2008 the Food and Drug Administration issued guidance for the demonstration of CV safety for new antidiabetes drugs. Recently the results from CV outcomes trials of three dipeptidyl peptidase-4 (DPP-4) inhibitors and a glucagon-like peptide-1 receptor agonist have been reported. The Saxagliptin Assessment of Vascular Outcomes Recorded in Patients with Diabetes Mellitus (SAVOR) trial, the Examination of Cardiovascular Outcomes with Alogliptin versus Standard of Care in Patients with Type 2 Diabetes Mellitus and Acute Coronary Syndrome (EXAMINE) trial, and the Trial Evaluating Cardiovascular Outcomes with Sitagliptin (TECOS) assessed the safety of saxagliptin, alogliptin, and sitagliptin, respectively, in patients with type 2 diabetes with CV disease or at high risk for CV disease. The Evaluation of Lixisenatide in Acute Coronary Syndrome (ELIXA) assessed the safety of lixisenatide in patients with type 2 diabetes and a recent acute coronary syndrome event. The results show that these agents neither increased nor deceased major adverse CV events (CV death, nonfatal myocardial infarction, and nonfatal stroke) compared with placebo. However, the resources needed to conduct these studies may detract from the ability to understand the potential long-term benefit and risk in the majority of patients that are candidates for use of these medications.

Cardiovascular and heart failure safety profile of vildagliptin: a meta-analysis of 17 000 patients

AIMS

To report the cardiovascular (CV) safety profile and heart failure (HF) risk of vildagliptin from a large pool of studies, including trials in high-risk patients with type 2 diabetes mellitus (T2DM), such as those with congestive HF and/or moderate/severe renal impairment.

METHODS

We conducted a retrospective meta-analysis of prospectively adjudicated CV events. Patient-level data were pooled from 40 double-blind, randomized controlled phase III and IV vildagliptin studies. The primary endpoint was occurrence of major adverse CV events (MACEs; myocardial infarction, stroke and CV death). Assessments of the individual MACE components and HF events (requiring hospitalization or new onset) were secondary endpoints. The risk ratio (RR) of vildagliptin (50 mg once- and twice-daily combined) versus comparators (placebo and all non-vildagliptin treatments) was calculated using the Mantel-Haenszel (M-H) method.

RESULTS

Of the 17 446 patients, 9599 received vildagliptin (9251.4 subject-years of exposure) and 7847 received comparators (7317.0 subject-years of exposure). The mean age of the patients was 57 years, body mass index 30.5 kg/m(2) (nearly 50% obese), glycated haemoglobin concentration 8.1% and T2DM duration 5.5 years. A MACE occurred in 83 (0.86%) vildagliptin-treated patients and 85 (1.20%) comparator-treated patients, with an M-H RR of 0.82 [95% confidence interval (CI) 0.61-1.11]. Similar RRs were observed for the individual events. Confirmed HF events were reported in 41 (0.43%) vildagliptin-treated patients and 32 (0.45%) comparator-treated patients, with an M-H RR 1.08 (95% CI 0.68-1.70).

CONCLUSIONS

This large meta-analysis indicates that vildagliptin is not associated with an increased risk of adjudicated MACEs relative to comparators. Moreover, this analysis did not find a significant increased risk of HF in vildagliptin-treated patients.

Efficacy and Cardiovascular Safety of Linagliptin as an Add-On to Insulin in Type 2 Diabetes: A Pooled Comprehensive Post Hoc Analysis

OBJECTIVE

With the expanding armamentarium of noninsulin therapies for type 2 diabetes mellitus, the use of insulin with various oral agents is becoming more common. In this study, we assessed the efficacy and cardiovascular (CV) safety of the dipeptidyl peptidase-4 inhibitor linagliptin as add-on to insulin in patients with type 2 diabetes.

METHODS

In this post hoc analysis, data for patients receiving basal or basal-bolus insulin were pooled from 4 randomized, double-blind, phase 3 clinical trials of linagliptin 5 mg once daily or placebo given as add-on to background glucose-lowering treatment. Changes in glycated hemoglobin (A1C) and CV risk factors were assessed from baseline to end of trial. The primary CV endpoint was a composite of CV death, nonfatal myocardial infarction, nonfatal stroke and hospitalization due to unstable angina.

RESULTS

The number of patients receiving basal or basal-bolus insulin as background therapy was 1613 (linagliptin: n=811; placebo: n=802). The placebo-adjusted mean (SE) change from baseline in A1C was -0.41 (0.05)% (95% CI -0.50, -0.32; p<0.0001). Treatment with linagliptin provided a relative weight benefit and reduced insulin requirements without affecting blood pressure, heart rate or lipids. The incidence of hypoglycemia with linagliptin was similar to that for placebo (38.7% vs. 39.4%, respectively). The hazard ratio (HR) for the primary endpoint showed that treatment with linagliptin was not associated with an increased CV risk (HR 1.07 [95% CI 0.62, 1.85]).

CONCLUSIONS

Linagliptin, when added to ongoing insulin treatment in patients with type 2 diabetes, improves glycemic control and has a neutral impact on major adverse CV events.

Dipeptidyl Peptidase 4 Inhibitors and the Risk of Cardiovascular Disease in Patients with Type 2 Diabetes: A Tale of Three Studies

Dipeptidyl peptidase 4 (DPP4) inhibitors have been touted as promising antihyperglycemic agents due to their beneficial effects on glycemia without inducing hypoglycemia or body weight gain and their good tolerability. Beyond their glucose-lowering effects, numerous clinical trials and experimental studies have suggested that DPP4 inhibitors may exert cardioprotective effects through their pleiotropic actions via glucagon-like peptide 1-dependent mechanisms or involving other substrates. Since 2008, regulatory agencies have required an assessment of cardiovascular disease (CVD) safety for the approval of all new anti-hyperglycemic agents, including incretin-based therapies. Three large prospective DPP4 inhibitor trials with cardiovascular (CV) outcomes have recently been published. According to the Saxagliptin Assessment of Vascular Outcomes Recorded in Patients with Diabetes Mellitus (SAVOR-TIMI 53) and EXamination of cArdiovascular outcoMes with alogliptIN versus standard of carE in patients with type 2 diabetes mellitus and acute coronary syndrome (EXAMINE) trials, DPP4 inhibitors, including saxagliptin and alogliptin, did not appear to increase the risk of CV events in patients with type 2 diabetes and established CVD or high risk factors. Unexpectedly, saxagliptin significantly increased the risk of hospitalization for heart failure by 27%, a finding that has not been explained and that requires further exploration. More recently, the Trial Evaluating Cardiovascular Outcomes with Sitagliptin (TECOS) trial demonstrated the CV safety of sitagliptin, including assessments of the primary composite CV endpoint and hospitalization for heart failure in patients with type 2 diabetes and established CVD. The CV outcomes of an ongoing linagliptin trial are expected to provide new evidence about the CV effects of a DPP4-inhibitor in patients with type 2 diabetes.

Incretins and selective renal sodium-glucose co-transporter 2 inhibitors in hypertension and coronary heart disease

Hyperglycemia is associated with an increased risk of cardiovascular disease, and the consequences of intensive therapy may depend on the mechanism of the anti-diabetic agent(s) used to achieve a tight control. In animal models, stable analogues of glucagon-like peptide-1 (GLP-1) were able to reduce body weight and blood pressure and also had favorable effects on ischemia following coronary reperfusion. In a similar way, dipeptidyl peptidase IV (DPP-IV) showed to have favorable effects in animal models of ischemia/reperfusion. This could be due to the fact that DPP-IV inhibitors were able to prevent the breakdown of GLP-1 and glucose-dependent insulinotropic polypeptide, but they also decreased the degradation of several vasoactive peptides. Preclinical data for GLP-1, its derivatives and inhibitors of the DPP-IV enzyme degradation suggests that these agents may be able to, besides controlling glycaemia, induce cardio-protective and vasodilator effects. Notwithstanding the many favorable cardiovascular effects of GLP-1/incretins reported in different studies, many questions remain unanswered due the limited number of studies in human beings that aim to examine the effects of GLP-1 on cardiovascular endpoints. For this reason, long-term trials searching for positive cardiovascular effects are now in process, such as the CAROLINA and CARMELINA trials, which are supported by small pilot studies performed in humans (and many more animal studies) with incretin-based therapies. On the other hand, selective renal sodium-glucose co-transporter 2 inhibitors were also evaluated in the prevention of cardiovascular outcomes in type 2 diabetes. However, it is quite early to draw conclusions, since data on cardiovascular outcomes and cardiovascular death are limited and long-term studies are still ongoing. In this review, we will analyze the mechanisms underlying the cardiovascular effects of incretins and, at the same time, we will present a critical position about the real value of these compounds in the cardiovascular system and its protection.

Direct effects of DPP-4 inhibition on the vasculature. Reconciling basic evidence with lack of clinical evidence

Diabetes is burdened by macrovascular and microvascular complications that collectively reduce life expectancy. As the ultimate goal of diabetes treatment is to prevent excess morbidity and mortality associated with its complications, the interest on cardiovascular effects of glucose lowering medications is high. Dipeptidyl peptidase-4 inhibitors (DPP-4i) lower blood glucose by protecting the incretin hormone glucagon-like peptide-1 (GLP-1) from enzymatic degradation, thereby restoring meal-stimulated insulin release. DPP-4 has several non-incretin substrates, including cytokines, chemokines, and neurohormones, which can exert favourable, but also unpredictable, vascular effects, once they are stabilized by DPP-4i. Choi et al. now provide additional evidence that DPP-4i counteracts vascular smooth muscle cell proliferation and migration, resulting in an attenuation of neointimal hyperplasia. Though several other in vitro, preclinical, and preliminary clinical studies on surrogate end-points suggest that DPP-4i can exert similar direct vasculoprotective actions, results of placebo-controlled phase IV trials have so far shown no reduction cardiovascular endpoints by DPP-4i. In this commentary, we put DPP-4 pleiotropy and complexity into context, trying to reconcile why results from basic science have not yet translated into clinical evidence of cardiovascular protection.

Impact of glucose-lowering drugs on cardiovascular disease in type 2 diabetes

Type 2 diabetes mellitus (T2DM) is characterized by multiple pathophysiologic abnormalities. With time, multiple glucose-lowering medications are commonly required to reduce and maintain plasma glucose concentrations within the normal range. Type 2 diabetes mellitus individuals also are at a very high risk for microvascular complications and the incidence of heart attack and stroke is increased two- to three-fold compared with non-diabetic individuals. Therefore, when selecting medications to normalize glucose levels in T2DM patients, it is important that the agent not aggravate, and ideally even improve, cardiovascular risk factors (CVRFs) and reduce cardiovascular morbidity and mortality. In this review, we examine the effect of oral (metformin, sulfonylureas, meglitinides, thiazolidinediones, DPP4 inhibitors, SGLT2 inhibitors, and α-glucosidase inhibitors) and injectable (glucagon-like peptide-1 receptor agonists and insulin) glucose-lowering drugs on established CVRFs and long-term studies of cardiovascular outcomes. Firm evidence that in T2DM cardiovascular disease can be reversed or prevented by improving glycaemic control is still incomplete and must await large, long-term clinical trials in patients at low risk using modern treatment strategies, i.e., drug combinations designed to maximize HbA1c reduction while minimizing hypoglycaemia and excessive weight gain.

Dipeptidyl Peptidase 4: A New Link between Diabetes Mellitus and Atherosclerosis?

Type 2 diabetes mellitus (T2DM) has become one of the most prevalent noncommunicable diseases in the past years. It is undoubtedly associated with atherosclerosis and increased risk for cardiovascular diseases. Incretins, which are intestinal peptides secreted during digestion, are able to increase insulin secretion and its impaired function and/or secretion is involved in the pathophysiology of T2DM. Dipeptidyl peptidase 4 (DPP4) is an ubiquitous enzyme that regulates incretins and consequently is related to the pathophysiology of T2DM. DPP4 is mainly secreted by endothelial cells and acts as a regulatory protease for cytokines, chemokines, and neuropeptides involved in inflammation, immunity, and vascular function. In T2DM, the activity of DPP4 seems to be increased and there are a growing number of in vitro and in vivo studies suggesting that this enzyme could be a new link between T2DM and atherosclerosis. Gliptins are a new class of pharmaceutical agents that acts by inhibiting DPP4. Thus, it is expected that gliptin represents a new pharmacological approach not only for reducing glycemic levels in T2DM, but also for the prevention and treatment of atherosclerotic cardiovascular disease in diabetic subjects. We aimed to review the evidences that reinforce the associations between DPP4, atherosclerosis, and T2DM.

Cardiovascular safety of linagliptin in type 2 diabetes: a comprehensive patient-level pooled analysis of prospectively adjudicated cardiovascular events

BACKGROUND

The cardiovascular (CV) safety of linagliptin was evaluated in subjects with type 2 diabetes (T2DM).

METHODS

Pre-specified patient-level pooled analysis of all available double-blind, randomized, controlled trials, ≥ 12 weeks' duration (19 trials, 9459 subjects) of linagliptin versus placebo/active treatment. Primary end point: composite of prospectively adjudicated CV death, non-fatal myocardial infarction, non-fatal stroke, and hospitalization for unstable angina (4P-MACE). Hospitalization for congestive heart failure (CHF) was also evaluated; adjudication of CHF was introduced during the phase 3 program (8 trials; 3314 subjects). 4P-MACE was assessed in placebo-controlled trials (subgroup of 18 trials; 7746 subjects). Investigator-reported events suggestive of CHF from 24 placebo-controlled trials (including trials <12 weeks' duration, 8778 subjects) were also analyzed.

RESULTS

5847 patients received linagliptin (5 mg: 5687, 10 mg: 160) and 3612 comparator (glimepiride: 775, voglibose: 162, placebo: 2675); cumulative exposure, 4421.3 and 3254.7 patient-years, respectively. 4P-MACE incidence rates: 13.4 per 1000 patient-years, linagliptin (60 events), 18.9, total comparators (62 events); overall hazard ratio (HR), 0.78 (95% confidence interval [CI], 0.55-1.12). HR for adjudicated hospitalization for CHF (n = 21): 1.04 (0.43-2.47). For placebo-controlled trials, 4P-MACE incidence rates: 14.9 per 1000 patient-years, linagliptin (43 events), 16.4, total comparators (29 events); overall HR, 1.09 (95% CI, 0.68-1.75). Occurrence of investigator-reported events suggestive of CHF was low for linagliptin- (26 events, 0.5%; serious: 16 events, 0.3%) and placebo-treated (8 events, 0.2%; serious: 6 events, 0.2%) patients.

CONCLUSIONS

Linagliptin is not associated with increased CV risk versus pooled active comparators or placebo in patients with T2DM.

Cardiovascular effects of dipeptidyl peptidase-4 inhibitors in patients with type 2 diabetes

Cardiovascular (CV) disease is the leading cause of mortality and morbidity in patients with type 2 diabetes mellitus (T2DM). However, improving glycaemic control alone has not decreased CV events. Therapies that improve glycaemic control, CV disease risk factors and CV function are more likely to be successful. Dipeptidyl peptidase-4 (DPP-4) inhibitors prevent breakdown of incretin hormones glucagon-like peptide-1(GLP-1) and glucose-dependent insulinotropic peptide and improve glycaemic control in patients with T2DM. DPP-4 acts on other substrates, many associated with cardioprotection. Thus, inhibition of DPP-4 may lead to elevations in these potentially beneficial substrates. Data from animal studies and small observational studies in humans suggest that DPP-4 inhibitors may potentially reduce CV risk. However, recently completed CV outcome trials in patients with T2DM and CV disease or at high risk of adverse CV events have shown that the DPP-4 inhibitors saxagliptin and alogliptin neither increased nor decreased major adverse CV events.

DPP-4 inhibitors: pharmacological differences and their clinical implications

INTRODUCTION

Recently, incretin-based therapy was introduced for the treatment of type 2 diabetes (T2D). In particular, dipeptidyl peptidase-4 inhibitors (DPP-4i) (sitagliptin, vildagliptin, saxagliptin, linagliptin and alogliptin) play an increasing role in the management of T2D.

AREAS COVERED

An extensive literature search was performed to analyze the pharmacological characteristics of DPP-4i and their clinical implications.

EXPERT OPINION

DPP-4i present significant pharmacokinetic differences. They also differ in chemical structure, in the interaction with distinct subsites of the enzyme and in different levels of selectivity and potency of enzyme inhibition. Moreover, disparities in the effects on glycated hemoglobin, glucagon-like peptide-1 and glucagon levels and on glucose variability have been observed. However, indirect comparisons indicate that all DPP-4i have a similar safety and efficacy profiles. DPP-4i are preferred in overweight/obese and elderly patients because of the advantages of minimal or no influence on weight gain and low risk of hypoglycemia. For the same reasons, DPP-4i can be safely combined with insulin. However, currently cardiovascular outcomes related to DPP-4i are widely debated and the available evidence is controversial. Today, long-term studies are still in progress and upcoming results will allow us to better define the strengths and limits of this therapeutic class.