Saxagliptin given in combination with metformin as initial therapy improves glycaemic control in patients with type 2 diabetes compared with either monotherapy: a randomized controlled trial

The Role and Mechanism of Probiotics Supplementation in Blood Glucose Regulation: A Review

With economic growth and improved living standards, the incidence of metabolic diseases such as diabetes mellitus caused by over-nutrition has risen sharply worldwide. Elevated blood glucose and complications in patients seriously affect the quality of life and increase the economic burden. There are limitations and side effects of current hypoglycemic drugs, while probiotics, which are safe, economical, and effective, have good application prospects in disease prevention and remodeling of intestinal microecological health and are gradually becoming a research hotspot for diabetes prevention and treatment, capable of lowering blood glucose and alleviating complications, among other things. Probiotic supplementation is a microbiologically based approach to the treatment of type 2 diabetes mellitus (T2DM), which can achieve anti-diabetic efficacy through the regulation of different tissues and metabolic pathways. In this study, we summarize recent findings that probiotic intake can achieve blood glucose regulation by modulating intestinal flora, decreasing chronic low-grade inflammation, modulating glucagon-like peptide-1 (GLP-1), decreasing oxidative stress, ameliorating insulin resistance, and increasing short-chain fatty acids (SCFAs) content. Moreover, the mechanism, application, development prospect, and challenges of probiotics regulating blood glucose were discussed to provide theoretical references and a guiding basis for the development of probiotic preparations and related functional foods regulating blood glucose.

Initial Combination Therapy in Type 2 Diabetes

Type 2 diabetes (T2D) is a progressive disease in which it is challenging to achieve long-term durable glycemic control. However, intensive glycemic control is crucial for preventing diabetes-related complications. Previous studies showed that monotherapy with a stepwise add-on approach was seldom effective for long-term durable glycemic control. Combination therapy, which refers to the use of two or more drugs to control hyperglycemia, has multiple benefits, including the ability to target a variety of pathophysiological processes underlying hyperglycemia. In clinical trials, initial combination therapy showed better glycemic control than monotherapy or a stepwise approach. Emerging evidence indicates that initial combination therapy is associated with preserved β-cell function and fewer complications in T2D. However, cost-effectiveness and adverse events with combination therapy are issues that should be considered. Therefore, initial combination therapy is an important option for patients with T2D that clinicians should consider with a view toward balancing benefits and potential harms. In this review, we summarize the literature addressing initial combination therapy in T2D, and we suggest optimal strategies based on clinical situations and patient characteristics.

Adipose tissue inflammation linked to obesity: A review of current understanding, therapies and relevance of phyto-therapeutics

Obesity is a current global challenge affecting all ages and is characterized by the up-regulated secretion of bioactive factors/pathways which result in adipose tissue inflammation (ATI). Current obesity therapies are mainly focused on lifestyle (diet/nutrition) changes. This is because many chemosynthetic anti-obesogenic medications cause adverse effects like diarrhoea, dyspepsia, and faecal incontinence, among others. As such, it is necessary to appraise the efficacies and mechanisms of action of safer, natural alternatives like plant-sourced compounds, extracts [extractable phenol (EP) and macromolecular antioxidant (MA) extracts], and anti-inflammatory peptides, among others, with a view to providing a unique approach to obesity care. These natural alternatives may constitute potent therapies for ATI linked to obesity. The potential of MA compounds (analysed for the first time in this review) and extracts in ATI and obesity management is elucidated upon, while also highlighting research gaps and future prospects. Furthermore, immune cells, signalling pathways, genes, and adipocyte cytokines play key roles in ATI responses and are targeted in certain therapies. As a result, this review gives an in-depth appraisal of ATI linked to obesity, its causes, mechanisms, and effects of past, present, and future therapies for reversal and alleviation of ATI. Achieving a significant decrease in morbidity and mortality rates attributed to ATI linked to obesity and related comorbidities is possible as research improves our understanding over time.

Benefits and risks of drug combination therapy for diabetes mellitus and its complications: a comprehensive review

Diabetes is a chronic metabolic disease, and its therapeutic goals focus on the effective management of blood glucose and various complications. Drug combination therapy has emerged as a comprehensive treatment approach for diabetes. An increasing number of studies have shown that, compared with monotherapy, combination therapy can bring significant clinical benefits while controlling blood glucose, weight, and blood pressure, as well as mitigating damage from certain complications and delaying their progression in diabetes, including both type 1 diabetes (T1D), type 2 diabetes (T2D) and related complications. This evidence provides strong support for the recommendation of combination therapy for diabetes and highlights the importance of combined treatment. In this review, we first provided a brief overview of the phenotype and pathogenesis of diabetes and discussed several conventional anti-diabetic medications currently used for the treatment of diabetes. We then reviewed several clinical trials and pre-clinical animal experiments on T1D, T2D, and their common complications to evaluate the efficacy and safety of different classes of drug combinations. In general, combination therapy plays a pivotal role in the management of diabetes. Integrating the effectiveness of multiple drugs enables more comprehensive and effective control of blood glucose without increasing the risk of hypoglycemia or other serious adverse events. However, specific treatment regimens should be tailored to individual patients and implemented under the guidance of healthcare professionals.

DPP-4 inhibitors for treating T2DM - hype or hope? an analysis based on the current literature

DPP-4 inhibition is an interesting line of therapy for treating Type 2 Diabetes Mellitus (T2DM) and is based on promoting the incretin effect. Here, the authors have presented a brief appraisal of DPP-4 inhibitors, their modes of action, and the clinical efficiency of currently available drugs based on DPP-4 inhibitors. The safety profiles as well as future directions including their potential application in improving COVID-19 patient outcomes have also been discussed in detail. This review also highlights the existing queries and evidence gaps in DPP-4 inhibitor research. Authors have concluded that the excitement surrounding DPP-4 inhibitors is justified because in addition to controlling blood glucose level, they are good at managing risk factors associated with diabetes.

Comparative analysis of the efficacies of probiotic supplementation and glucose-lowering drugs for the treatment of type 2 diabetes: A systematic review and meta-analysis

The aim of this systematic review and meta-analysis was to evaluate the effects of probiotics and glucose-lowering drugs (thiazolidinedione [TZD], glucagon-like pep-tide-1 receptor agonists [GLP-1 RA], dipeptidyl peptidase IV inhibitors, and sodium glucose co-transporter 2 inhibitors [SGLT-2i]) in patients with type 2 diabetes from randomized con-trolled trials (RCTs). The PubMed, Web of science, Embase, and Cochrane Library databases were searched on the treatment effects of probiotics and glucose-lowering drugs on glycemia, lipids, and blood pressure metabolism published between Jan 2015 and April 2021. We performed meta-analyses using the random-effects model. We included 25 RCTs (2,843 participants). Overall, GLP-1RA, SGLT-2i, and TZD significantly reduce fasting blood sugar (FBS) and glycated hemoglobin (HbA1c), whereas GLP-1 RA increased the risk of hypoglycaemia. Multispecies probiotics decrease FBS, total cholesterol (TC), and systolic and diastolic blood pressure (SBP, DBP). Moreover, subgroup analyses indicated that participants aged >55 years, BMI ≥30 kg/m2, longer duration of intervention, and subjects from Eastern countries, showed significantly higher reduction in FBS and HbA1c, TC, TG and SBP. This meta-analysis revealed that including multiple probiotic rather than glucose-lowering drugs might be more beneficial regarding T2D prevention who suffering from simultaneously hyperglycemia, hypercholesterolemia, and hypertension.

Dipeptidyl peptidase-4 inhibitors and gallbladder or biliary disease in type 2 diabetes: systematic review and pairwise and network meta-analysis of randomised controlled trials

OBJECTIVE

To examine the association between dipeptidyl peptidase-4 inhibitors and gallbladder or biliary diseases.

DESIGN

Systematic review and pairwise and network meta-analysis.

DATA SOURCES

PubMed, EMBASE, Web of Science, and CENTRAL from inception until 31 July 2021.

ELIGIBILITY CRITERIA

Randomised controlled trials of adult patients with type 2 diabetes who received dipeptidyl peptidase-4 inhibitors, glucagon-like peptide-1 receptor agonists, and sodium-glucose cotransporter-2 inhibitors compared with placebo or other antidiabetes drugs.

MAIN OUTCOME MEASURES

Composite of gallbladder or biliary diseases, cholecystitis, cholelithiasis, and biliary diseases.

DATA EXTRACTION AND DATA SYNTHESIS

Two reviewers independently extracted the data and assessed the quality of the studies. The quality of the evidence for each outcome was assessed using the Grading of Recommendations, Assessment, Development and Evaluations framework (GRADE) approach. The meta-analysis used pooled odds ratios and 95% confidence intervals.

RESULTS

A total of 82 randomised controlled trials with 104 833 participants were included in the pairwise meta-analysis. Compared with placebo or non-incretin drugs, dipeptidyl peptidase-4 inhibitors were significantly associated with an increased risk of the composite of gallbladder or biliary diseases (odds ratio 1.22 (95%confidence interval 1.04 to 1.43); risk difference 11 (2 to 21) more events per 10 000 person years) and cholecystitis (odds ratio 1.43 (1.14 to 1.79); risk difference 15 (5 to 27) more events per 10 000 person years) but not with the risk of cholelithiasis and biliary diseases. The associations tended to be observed in patients with a longer duration of dipeptidyl peptidase-4 inhibitor treatment. In the network meta-analysis of 184 trials, dipeptidyl peptidase-4 inhibitors increased the risk of the composite of gallbladder or biliary diseases and cholecystitis compared with sodium-glucose cotransporter-2 inhibitors but not compared with glucagon-like peptide-1 receptor agonists.

CONCLUSIONS

Dipeptidyl peptidase-4 inhibitors increased the risk of cholecystitis in randomised controlled trials, especially with a longer treatment duration, which requires more attention from physicians in clinical practice.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42021271647.

Effect of dipeptidyl peptidase-4 inhibitors on postprandial glucagon level in patients with type 2 diabetes mellitus: A systemic review and meta-analysis

AIMS

Hyperglucagonemia occurs in the pathogenesis of type 2 diabetes mellitus (T2DM). In this meta-analysis, we summarized the effects of DPP4 inhibitors on glucagon levels in patients with T2DM.

MATERIALS AND METHODS

Randomized controlled trials (RCTs) comparing the influence of DPP4 inhibitors on circulating glucagon levels with placebo or other oral antidiabetic drugs (OADs) in patients with T2DM were identified by searches of Medline (PubMed), Embase (Ovid), and CENTER (Cochrane Library). Only studies reporting changes in glucagon level presented as total area under the curve (AUC_glucagon) using a meal or oral glucose tolerance test were included. Results were combined using a random-effects model that incorporated potential heterogeneity among the included studies.

RESULTS

A total of 36 RCTs with moderate to high quality were included. Overall, the numbers of T2DM patients included for the meta-analyses comparing DPP4 inhibitors with placebo and other OADs were 4266 and 1652, respectively. Compared to placebo, DPP4 inhibitors significantly reduced circulating glucagon levels (standard mean difference [SMD]: -0.32, 95% CI: -0.40 to -0.24, P<0.001; I^{2 =} 28%). Analysis of subgroups revealed that study characteristics had no significant effect on results, such as study design (parallel group or crossover), number of patients, mean patient age, proportion of men, baseline HbA1c, duration of diabetes, background therapy, treatment duration, or methods for glucagon measurement (all P for subgroup differences >0.05). Moreover, DPP4 inhibitors significantly reduced glucagon levels compared to other OADs (SMD: -0.35, 95% CI: -0.53 to -0.16, P<0.001; I² = 66%), and the reduction in glucagon was greater in comparison with insulin secretagogues than in comparison with non-insulin secretagogues (P for subgroup difference =0.03).

SYSTEMATIC REVIEW REGISTRATION

https://inplasy.com/, identifier INPLASY202280104.

CONCLUSIONS

DPP4 inhibitors are effective at reducing the circulating postprandial glucagon level in T2DM patients.

In Silico Prediction of Potential Drug Combinations for Type 2 Diabetes Mellitus by an Integrated Network and Transcriptome Analysis

Type 2 diabetes mellitus (T2DM) is a heterogeneous disorder, so achieving the desired therapeutic efficacy through monotherapy is tricky. Drug combinations play a vital role in treating multiple complex diseases by providing increased efficacy and reduced toxicity. Here, we adopted a computational framework to discover potential drugs and drug pairs for T2DM. Firstly, we collected T2DM-associated genes and constructed the disease module for T2DM. Then, by quantifying the proximity between drugs and the disease module, we found out potential drugs. Based on the drug-induced gene expression profiles, we further performed Gene Set Enrichment Analysis (GSEA) on these drugs and identified several potential candidates. In addition, through network-based separation, potential drug combinations for T2DM were predicted. Results from this study could provide insights for anti-T2DM drug discovery and rational drug use of existing agents. As a useful computational framework, our approach could also be applied in drug research for other complex diseases.

Dipeptidyl peptidase-4 inhibitor treatment and the risk of bullous pemphigoid and skin-related adverse events: A systematic review and meta-analysis of randomized controlled trials

AIMS

This meta-analysis aimed to evaluate the risk of developing bullous pemphigoid (BP) and other skin-related adverse events (AEs) in patients with type 2 diabetes (T2DM) undergoing dipeptidyl peptidase-4 inhibitor (DPP-4i) treatment in randomized controlled trials (RCTs).

METHODS

In this meta-analysis, the MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases were searched for RCTs, which involve patients with T2DM reporting skin-related AEs. RCTs that comparatively evaluated the effects of DPP-4i treatment and placebo on patients with T2DM and reported skin-related AEs were included in the analysis. The odds ratio (OR) and 95% confidence interval (CI) were calculated using the Peto's methods. The GRADE approach was used to rate the quality of evidence.

RESULTS

A total of 46 randomized placebo-controlled trials, including 3 trials with reports of BP (n = 38 011), that reported skin-related AEs were included (n = 59 332). Compared to the placebo group, the risk of developing BP was significantly higher in the DPP-4i treatment group (OR = 7.38, 95% CI 2.00-27.25, I² = 0%, P = .003; quality rating: very low). Additionally, DPP-4i treatment was associated with an increased overall risk of developing skin-related AEs (OR = 1.22, 95% CI 1.02-1.46, I² = 32%, P = .03; quality rating: moderate).

CONCLUSIONS

This meta-analysis suggested that treatment with DPP-4is, including sitagliptin, saxagliptin, and linagliptin, was associated with an increased risk of developing BP. Additionally, the risk of developing skin-related AEs increased when all DPP-4is were combined. Skin lesion, especially BP, should be monitored in patients with diabetes undergoing DPP-4i treatment. Future studies should evaluate the susceptible population and develop strategies for early detection of skin-related AEs.

Early combination versus initial metformin monotherapy in the management of newly diagnosed type 2 diabetes: An East Asian perspective

Type 2 diabetes (T2D) in the East Asian population is characterized by phenotypes such as low body mass index, an index of β-cell dysfunction, and higher percentage of body fat, an index of insulin resistance. These phenotypes/pathologies may predispose people to early onset of diabetes with increased risk of stroke and renal disease. Less than 50% of patients with T2D in East Asia achieve glycaemic targets recommended by national or regional guidelines, which may be attributable to knowledge and/or implementation gaps. Herein, we review the latest evidence with special reference to East Asian patients with T2D and present arguments for the need to use early combination therapy to intensify glycaemic control. This strategy is supported by the 5-year worldwide VERIFY study, which reported better glycaemic durability in newly diagnosed patients with T2D with a mean HbA1c of 6.9% treated with early combination therapy of vildagliptin plus metformin versus those treated with initial metformin monotherapy followed by addition of vildagliptin only with worsening glycaemic control. This paradigm shift of early intensified treatment is now recommended by the American Diabetes Association and the European Association for the Study of Diabetes. In order to translate these evidence to practice, increased awareness and strengthening of the healthcare system are needed to diagnose and manage patients with T2D early for combination therapy.

Optimizing the treatment of newly diagnosed type 2 diabetes mellitus with combination of dipeptidyl peptidase-4 inhibitors and metformin: An expert opinion

The expanding burden of Type 2 Diabetes Mellitus (T2DM) in today's world, with respect to incidence, prevalence, and cost incurred, is an existential risk to society. Various guidelines recommend individualization of treatment. This expert opinion aims to review the recent evidences and reach a consensus on the preferable combination therapy for use in newly diagnosed Indian T2DM patients with HbA_1C >7.5%. The core committee included seventeen diabetes specialists. Three statements were developed, discussed, and rated by specialists and recommendations were noted. Specialists were requested to rate the statements using a 9-point Likert's scale with score of 1 being “Strongly Disagree” and 9 being “Strongly Agree”. Statement-specific scores of all the specialists were added and mean score of ≥7.00 was considered to have achieved a consensus. Statements used to meet the consensus were: Statement 1. Majority of newly-diagnosed Indian diabetics have HbA_1C >7.5%; Statement 2. Patients with HbA_1C >7.5% may be initiated with dual therapy of dipeptidyl peptidase-4 inhibitors (DPP4Is) + Metformin; and Statement 3. In Indian patients with HbA_1C >7.5% at diagnosis, DPP4Is + Metformin may be considered as a first-line therapy. Literature review revealed that HbA_1C level at the time of diagnosis in majority of Indian T2DM patients is >7.5%. Consensus was reached that dual anti-diabetic therapy should be initiated in patients with HbA_1C >7.5%. DPP4Is + Metformin is the preferred cost-effective option and may be considered as a first-line therapy in Indian T2DM patients with HbA_1C >7.5% at diagnosis.

Incretin mimetics and sodium-glucose co-transporter 2 inhibitors as monotherapy or add-on to metformin for treatment of type 2 diabetes: a systematic review and network meta-analysis

PURPOSE

Although there are many different methods of treating type 2 diabetes (T2D), it is still difficult to draw coincident conclusions concerning the efficacy and safety of different classes of new drugs, and the recommendation level of them has still kept uncertain as second anti-diabetic agents. Therefore, the aim of this study was to summarize evidence on the efficacy and safety of DPP-4is, GLP-1RAs and SGLT-2is as monotherapy or add-on to metformin (Met) for treatment of T2D.

MATERIALS AND METHODS

We searched PubMed, Embase, Cochrane library and ClinicalTrials.gov for relevant articles in keeping with established methods using terms associated with anti-diabetic agents up to February, 2020, with no start date restriction. Weighted mean difference and risk ratios with 95% confidence intervals were calculated within traditional and network meta-analysis. Primary outcomes were the mean change in hemoglobin A1c (HbA1c), fasting plasma glucose (FPG) change and the frequency of hypoglycemic events from baseline after 12 weeks of treatment.

RESULTS

In total, 64 eligible studies comprising 37,780 patients and 7 treatment strategies were included. The results of primary outcomes showed that GLP-1RAs were significantly more effective than DPP-4is or SGLT-2is in reducing HbA1c when add-on to Met. For FPG, both GLP-1RAs and SGLT-2is significantly reduced FPG compared with DPP-4is whether add-on to Met or not. For hypoglycemia, monotherapy has a lower risk than combination therapy except for SGLT-2is. Ranking probability analysis indicated that GLP-1RAs and SGLT-2is, respectively, reduced HbA1c and FPG most when add-on to Met. Meanwhile, GLP-1RAs took the lowest risk to induce the hypoglycemia, whereas GLP-1RAs plus Met the highest.

CONCLUSIONS

Both GLP-1RAs and SGLT-2is have their own advantages in efficacy and safety. Monotherapy is beneficial for reducing the risk of hypoglycemia. The recommendation should be a patient-centered approach when selecting treatment choices.

Age, sex, disease severity, and disease duration difference in placebo response: implications from a meta-analysis of diabetes mellitus

BACKGROUND

The placebo response in patients with diabetes mellitus is very common. A systematic evaluation needs to be updated with the current evidence about the placebo response in diabetes mellitus and the associated factors in clinical trials of anti-diabetic medicine.

METHODS

Literature research was conducted in Medline, Embase, the Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov for studies published between the date of inception and June 2019. Randomized placebo-controlled trials conducted in type 1and type 2 diabetes mellitus (T1DM/T2DM) were included. Random-effects model and meta-regression analysis were accordingly used. This meta-analysis was registered in PROSPERO as CRD42014009373.

RESULTS

Significantly weight elevation (effect size (ES) = 0.33 kg, 95% CI, 0.03 to 0.61 kg) was observed in patients with placebo treatments in T1DM subgroup while significantly HbA1c reduction (ES = - 0.12%, 95% CI, - 0.16 to - 0.07%) and weight reduction (ES = - 0.40 kg, 95% CI, - 0.50 to - 0.29 kg) were observed in patients with placebo treatments in T2DM subgroup. Greater HbA1c reduction was observed in patients with injectable placebo treatments (ES = - 0.22%, 95% CI, - 0.32 to - 0.11%) versus oral types (ES = - 0.09%, 95% CI, - 0.14 to - 0.04%) in T2DM (P = 0.03). Older age (β = - 0.01, 95% CI, - 0.02 to - 0.01, P < 0.01) and longer diabetes duration (β = - 0.02, 95% CI, - 0.03 to - 0.21 × 10^-2, P = 0.03) was significantly associated with more HbA1c reduction by placebo in T1DM. However, younger age (β = 0.02, 95% CI, 0.01 to 0.03, P = 0.01), lower male percentage (β = 0.01, 95% CI, 0.22 × 10^-2, 0.01, P < 0.01), higher baseline BMI (β = - 0.02, 95% CI, - 0.04 to - 0.26 × 10^-2, P = 0.02), and higher baseline HbA1c (β = - 0.09, 95% CI, - 0.16 to - 0.01, P = 0.02) were significantly associated with more HbA1c reduction by placebo in T2DM. Shorter diabetes duration (β = 0.06, 95% CI, 0.06 to 0.10, P < 0.01) was significantly associated with more weight reduction by placebo in T2DM. However, the associations between baseline BMI, baseline HbA1c, and placebo response were insignificant after the adjusted analyses.

CONCLUSION

The placebo response in diabetes mellitus was systematically outlined. Age, sex, disease severity (indirectly reflected by baseline BMI and baseline HbA1c), and disease duration were associated with placebo response in diabetes mellitus. The association between baseline BMI, baseline HbA1c, and placebo response may be the result of regression to the mean.

Impact of baseline characteristics on glycemic effects of add-on saxagliptin or acarbose to metformin therapy: Subgroup analysis of the SMART study in Chinese patients with type 2 diabetes mellitus

AIMS/INTRODUCTION

This secondary analysis of the 24-week SMART study examined the efficacy of add-on saxagliptin or acarbose to metformin across different patient subgroups with type 2 diabetes mellitus, based on baseline characteristics.

MATERIALS AND METHODS

Randomized patients (n = 481) were classified into subgroups based on their baseline age (<65, ≥65 years), body mass index (BMI; <24, 24-<28, ≥28 kg/m2 ), glycated hemoglobin (HbA1c; <8%, 8-<9%, 9-<10%, ≥10%) and renal function (creatinine clearance 50-<80, ≥80 mL/min). Treatment effects on primary outcome (HbA1c) and key secondary outcomes of fasting plasma glucose (FPG), 2-h postprandial glucose and homeostatic model assessment of β-cell function were assessed across patient subgroups.

RESULTS

For saxagliptin, reductions in HbA1c from baseline to week 24 were consistent across different subgroups regardless of baseline age, body mass index, HbA1c and renal function (range -0.66 to -1.16%). Saxagliptin was associated with consistent reductions in FPG (-0.60 to -1.33 mmol/L) and 2-h postprandial glucose (-0.48 to -1.95 mmol/L) across the majority of subgroups studied. The efficacy of acarbose on FPG attenuated progressively with increasing baseline HbA1c (+0.86 to -1.43 mmol/L); an increase from baseline FPG was observed in patients with HbA1c >9%. The effect of acarbose on postprandial glucose was also variable (+0.23 to -3.38 mmol/L).

CONCLUSIONS

As add-on to metformin, both saxagliptin and acarbose reduced HbA1c regardless of baseline HbA1c, age, body mass index and renal function; however, only saxagliptin was effective at a stable glycemic control (FPG and PPG). The efficacy of acarbose on FPG and PPG was significantly attenuated in patients with higher baseline HbA1c (≥8%).

Metformin monotherapy for adults with type 2 diabetes mellitus

BACKGROUND

Worldwide, there is an increasing incidence of type 2 diabetes mellitus (T2DM). Metformin is still the recommended first-line glucose-lowering drug for people with T2DM. Despite this, the effects of metformin on patient-important outcomes are still not clarified.

OBJECTIVES

To assess the effects of metformin monotherapy in adults with T2DM.

SEARCH METHODS

We based our search on a systematic report from the Agency for Healthcare Research and Quality, and topped-up the search in CENTRAL, MEDLINE, Embase, WHO ICTRP, and ClinicalTrials.gov. Additionally, we searched the reference lists of included trials and systematic reviews, as well as health technology assessment reports and medical agencies. The date of the last search for all databases was 2 December 2019, except Embase (searched up 28 April 2017).

SELECTION CRITERIA

We included randomised controlled trials (RCTs) with at least one year's duration comparing metformin monotherapy with no intervention, behaviour changing interventions or other glucose-lowering drugs in adults with T2DM.

DATA COLLECTION AND ANALYSIS

Two review authors read all abstracts and full-text articles/records, assessed risk of bias, and extracted outcome data independently. We resolved discrepancies by involvement of a third review author. For meta-analyses we used a random-effects model with investigation of risk ratios (RRs) for dichotomous outcomes and mean differences (MDs) for continuous outcomes, using 95% confidence intervals (CIs) for effect estimates. We assessed the overall certainty of the evidence by using the GRADE instrument.

MAIN RESULTS

We included 18 RCTs with multiple study arms (N = 10,680). The percentage of participants finishing the trials was approximately 58% in all groups. Treatment duration ranged from one to 10.7 years. We judged no trials to be at low risk of bias on all 'Risk of bias' domains. The main outcomes of interest were all-cause mortality, serious adverse events (SAEs), health-related quality of life (HRQoL), cardiovascular mortality (CVM), non-fatal myocardial infarction (NFMI), non-fatal stroke (NFS), and end-stage renal disease (ESRD). Two trials compared metformin (N = 370) with insulin (N = 454). Neither trial reported on all-cause mortality, SAE, CVM, NFMI, NFS or ESRD. One trial provided information on HRQoL but did not show a substantial difference between the interventions. Seven trials compared metformin with sulphonylureas. Four trials reported on all-cause mortality: in three trials no participant died, and in the remaining trial 31/1454 participants (2.1%) in the metformin group died compared with 31/1441 participants (2.2%) in the sulphonylurea group (very low-certainty evidence). Three trials reported on SAE: in two trials no SAE occurred (186 participants); in the other trial 331/1454 participants (22.8%) in the metformin group experienced a SAE compared with 308/1441 participants (21.4%) in the sulphonylurea group (very low-certainty evidence). Two trials reported on CVM: in one trial no CVM was observed and in the other trial 4/1441 participants (0.3%) in the metformin group died of cardiovascular reasons compared with 8/1447 participants (0.6%) in the sulphonylurea group (very low-certainty evidence). Three trials reported on NFMI: in two trials no NFMI occurred, and in the other trial 21/1454 participants (1.4%) in the metformin group experienced a NFMI compared with 15/1441 participants (1.0%) in the sulphonylurea group (very low-certainty evidence). One trial reported no NFS occurred (very low-certainty evidence). No trial reported on HRQoL or ESRD. Seven trials compared metformin with thiazolidinediones (very low-certainty evidence for all outcomes). Five trials reported on all-cause mortality: in two trials no participant died; the overall RR was 0.88, 95% CI 0.55 to 1.39; P = 0.57; 5 trials; 4402 participants). Four trials reported on SAE, the RR was 0,95, 95% CI 0.84 to 1.09; P = 0.49; 3208 participants. Four trials reported on CVM, the RR was 0.71, 95% CI 0.21 to 2.39; P = 0.58; 3211 participants. Three trial reported on NFMI: in two trials no NFMI occurred and in one trial 21/1454 participants (1.4%) in the metformin group experienced a NFMI compared with 25/1456 participants (1.7%) in the thiazolidinedione group. One trial reported no NFS occurred. No trial reported on HRQoL or ESRD. Three trials compared metformin with dipeptidyl peptidase-4 inhibitors (one trial each with saxagliptin, sitagliptin, vildagliptin with altogether 1977 participants). There was no substantial difference between the interventions for all-cause mortality, SAE, CVM, NFMI and NFS (very low-certainty evidence for all outcomes). One trial compared metformin with a glucagon-like peptide-1 analogue (very low-certainty evidence for all reported outcomes). There was no substantial difference between the interventions for all-cause mortality, CVM, NFMI and NFS. One or more SAEs were reported in 16/268 (6.0%) of the participants allocated to metformin compared with 35/539 (6.5%) of the participants allocated to a glucagon-like peptide-1 analogue. HRQoL or ESRD were not reported. One trial compared metformin with meglitinide and two trials compared metformin with no intervention. No deaths or SAEs occurred (very low-certainty evidence) no other patient-important outcomes were reported. No trial compared metformin with placebo or a behaviour changing interventions. Four ongoing trials with 5824 participants are likely to report one or more of our outcomes of interest and are estimated to be completed between 2018 and 2024. Furthermore, 24 trials with 2369 participants are awaiting assessment.

AUTHORS' CONCLUSIONS

There is no clear evidence whether metformin monotherapy compared with no intervention, behaviour changing interventions or other glucose-lowering drugs influences patient-important outcomes.

Possible mechanisms of direct cardiovascular impact of GLP-1 agonists and DPP4 inhibitors

Diabetes mellitus is a leading cause of cardiovascular morbidity and mortality worldwide. Traditional antidiabetic therapies targeting hyperglycemia reduce diabetic microvascular complications but have minor effects on macrovascular complications, including cardiovascular disease. Instead, cardiovascular complications are improved by antidiabetic medications (metformin) and other therapies (statins, antihypertensive medications) ameliorating insulin resistance and other associated metabolic abnormalities. Novel classes of antidiabetic drugs have proven efficacious in improving glycemia, while at the same time exert beneficial effects on pathophysiologic mechanisms of diabetes-related cardiovascular disease. In the present review, we will present current evidence of the cardiovascular effects of two new classes of antidiabetic medications, glucagon-like peptide 1 (GLP-1) agonists and dipeptidyl peptidase-4 (DPP4) inhibitors, focusing from mechanistic preclinical and clinical investigation to late-phase clinical testing.

Disparities in the Efficacy of Metformin in Combination with Dipeptidyl Peptidase-4 Inhibitor as Initial Treatment Stratified by Dosage and Ethnicity: A Meta-Analysis

BACKGROUND

As initial combination therapy of metformin and dipeptidyl peptidase-4 (DPP-4) inhibitor, the efficacy and safety for the use of high dose of metformin or low dose of metformin and the efficacy and safety for the combination use for Asian and Caucasian patients were not clear.

METHODS

Double-blind randomized controlled trials comparing the efficacy of initial combination therapy of metformin and DPP-4 inhibitors with metformin monotherapy were included. The primary outcome was a result of comparisons between high-dose combination therapy and low-dose combination therapy in terms of efficacy and safety.

RESULTS

A total of 11 studies were included. The results indicated that the high-dose combination therapy showed significant decreases in hemoglobin A_1c (HbA_1c) (-0.32%, P < 0.05), fasting plasma glucose (FPG) (-0.63 mmol/L, P < 0.05), and postprandial glucose (PPG) (-0.99 mmol/L, P < 0.05), but less increase in body weight (-0.54 kg, P < 0.05) when compared with low-dose combination therapy, corrected by metformin monotherapy. Moreover, the high-dose combination therapy exhibited significant decreases in HbA_1c (-0.24%, P < 0.05), FPG (-0.54 mmol/L, P < 0.05), and PPG (-0.94 mmol/L, P < 0.05) in the Caucasian population than in the Asian population, corrected by metformin monotherapy.

CONCLUSION

As an initial treatment, the high dose of metformin in combination with DPP-4 inhibitors not only provided better glycemic control but also had less effect on weight gain compared with the low-dose combination therapy through the correction of metformin monotherapy. Moreover, initial combination therapy in the Caucasian population showed better glycemic control and less increase in body weight compared with the Asian population.

Efficacy and Safety of Initial Combination Therapy in Treatment-Naïve Type 2 Diabetes Patients: A Systematic Review and Meta-analysis

INTRODUCTION

The aim of this study was to evaluate the efficacy and safety of initial combination therapy compared with monotherapy in drug-naïve type 2 diabetes patients.

METHODS

MEDLINE, Embase and the Cochrane Central Register of Controlled Trials were searched for randomized clinical trials of initial combination therapy with hypoglycemic agents compared with monotherapy. Those which satisfied the search criteria were included in the meta-analysis. Weighted mean difference and relative risks were calculated.

RESULTS

A total of 36 studies were included in the meta-analysis. Compared with metformin monotherapy, initial combination therapy with metformin plus another anti-diabetes drug exhibited significant reductions in glycated hemoglobin (HbA1c) (p < 0.001). Most of the combination therapies had a similar risk of hypoglycemia (p > 0.05), with the exception of combinations of sulfonylurea/glinide and metformin or combinations of thiazolidinedione and metformin. Compared with dipeptidyl peptidase-4 (DPP-4) inhibitor monotherapy, initial combination therapy with DPP-4 inhibitor plus another anti-diabetes drug showed a significant decrease in HbA1c (p < 0.001) and a similar risk of hypoglycemia (p > 0.05). Compared with monotherapy with other anti-diabetes drugs, initial combination therapies also resulted in significant HbA1c reductions, a similar risk of hypoglycemia and similar risks of other adverse events.

CONCLUSION

Compared with monotherapy, all initial combination therapies resulted in significant HbA1c reductions. Compared with metformin monotherapy, initial combination therapies with DPP-4 inhibitors plus metformin, sodium/glucose cotransporter 2 inhibitors and metformin, respectively, were associated with similar risks of hypoglycemia, but initial combination therapies with sulfonylurea plus metformin, thiazolidinedione and metformin, respectively, were associated with higher risks of hypoglycemia.

FUNDING

AstraZeneca Ltd. (China).

TRIAL REGISTRATION

Registration number CRD42017060717 in PROSPERO.

Cell Death Pathways in Mutant Rhodopsin Rat Models Identifies Genotype-Specific Targets Controlling Retinal Degeneration

Retinitis pigmentosa (RP) is a group of inherited neurological disorders characterized by rod photoreceptor cell death, followed by secondary cone cell death leading to progressive blindness. Currently, there are no viable treatment options for RP. Due to incomplete knowledge of the molecular signaling pathways associated with RP pathogenesis, designing therapeutic strategies remains a challenge. In particular, preventing secondary cone photoreceptor cell loss is a key goal in designing potential therapies. In this study, we identified the main drivers of rod cell death and secondary cone loss in the transgenic S334ter rhodopsin rat model, tested the efficacy of specific cell death inhibitors on retinal function, and compared the effect of combining drugs to target multiple pathways in the S334ter and P23H rhodopsin rat models. The primary driver of early rod cell death in the S334ter model was a caspase-dependent process, whereas cone cell death occurred though RIP3-dependent necroptosis. In comparison, rod cell death in the P23H model was via necroptotic signaling, whereas cone cell loss occurred through inflammasome activation. Combination therapy of four drugs worked better than the individual drugs in the P23H model but not in the S334ter model. These differences imply that treatment modalities need to be tailored for each genotype. Taken together, our data demonstrate that rationally designed genotype-specific drug combinations will be an important requisite to effectively target primary rod cell loss and more importantly secondary cone survival.

Efficacy and safety of saxagliptin in patients with type 2 diabetes: A systematic review and meta-analysis

OBJECTIVE

To evaluate the comparative efficacy and safety of saxagliptin for type 2 diabetes (T2D).

METHODS

A systematic search of PubMed, Embase, the Cochrane Library, Web of Science, ClinicalTrials.gov and two Chinese databases for randomized controlled trials (RCTs) comparing saxagliptin with placebo or active comparators was performed up to July 2017. A complementary search was done to cover literature until March 2018. For continuous data, estimates were pooled using inverse variance methodology to calculate weighted mean differences (WMDs). Dichotomous data were presented as Mantel-Haenzel risk ratios (RRs).

RESULTS

Thirty-nine references of 30 RCTs involving 29,938 patients were analyzed. Compared with placebo, saxagliptin significantly reduced glycated hemoglobin (HbA1c, WMD -0.52%, 95% CI -0.60 to -0.44) and fasting plasma glucose (WMD -13.78 mg/dL, 95% CI -15.31 to -12.25), and increased the proportion of patients achieving HbA1c <7% (RR 1.64, 95% CI 1.53 to 1.75). When combined with submaximal-dose metformin, saxagliptin significantly increased the proportion of patients achieving HbA1c <7% compared with acarbose (RR 2.38, 95% CI 1.17 to 4.83) and uptitrated metformin (RR 1.30, 95% CI 1.04 to 1.63). Saxagliptin was similar to other DPP-4 inhibitors but inferior to liraglutide and dapagliflozin on glycemic control. Saxagliptin significantly decreased the incidences of overall adverse events compared with acarbose (RR 0.71, 95% CI 0.57 to 0.89) and liraglutide (RR 0.41, 95% CI 0.24 to 0.71) when added to metformin. Weight gain and hypoglycemia with saxagliptin was slightly but significantly higher than placebo and lower than sulfonylureas. Saxagliptin did not increase the risk of arthralgia, heart failure, pancreatitis and other adverse events.

CONCLUSIONS

Generally, saxagliptin has similar efficacy compared with most oral antidiabetic drugs and may be more effective than acarbose, while having a better safety profile than both acarbose and sulfonylureas.

Efficacy and safety of saxagliptin in combination with metformin as initial therapy in Chinese patients with type 2 diabetes: Results from the START study, a multicentre, randomized, double-blind, active-controlled, phase 3 trial

AIM

To assess the efficacy and safety of saxagliptin plus metformin over 24 weeks in pharmacotherapy-naïve Chinese patients with type 2 diabetes mellitus and inadequate glycaemic control (HbA1c, 8.0%-12.0%).

RESEARCH DESIGN AND METHODS

In this multicentre, double-blind, active-controlled study (The START study: NCT02273050, clinicaltrials.gov), patients were randomized (1:1:1) to saxagliptin 5 mg plus metformin, saxagliptin 5 mg plus placebo or metformin plus placebo. Saxagliptin was taken once daily; metformin was taken once/twice daily and was titrated from 500 mg to a maximum of 2000 mg/d over 8 weeks. The primary end point was change in HbA1c from baseline to Week 24.

RESULTS

Data from 630 patients (66.5% men; mean age, 50.1 years; mean body mass index, 26.6 kg/m2 ; mean HbA1c, 9.4%; mean diabetes duration, 0.81 years) were analysed. Mean reduction in HbA1c was greater with saxagliptin plus metformin (-3.0%) than with saxagliptin plus placebo (-2.1%; P < .001) or metformin plus placebo (-2.8%; P = .034). Changes in mean fasting plasma glucose, 120-minute postprandial glucose, and 180-minute postprandial glucose area under the curve were greater, and more patients achieved a therapeutic glycaemic response, with saxagliptin plus metformin than with either monotherapy. Hypoglycaemic events were infrequent (<2%). Incidence of adverse events was similar among groups; upper respiratory tract infection and diarrhoea were most common.

CONCLUSIONS

Saxagliptin 5 mg plus metformin significantly improved glycaemic control compared with either monotherapy in treatment-naïve Chinese patients with type 2 diabetes, and was well tolerated.

The Role of Glucagon in the Pathophysiology and Treatment of Type 2 Diabetes

Type 2 diabetes is a disease involving both inadequate insulin levels and increased glucagon levels. While glucagon and insulin work together to achieve optimal plasma glucose concentrations in healthy individuals, the usual regulatory balance between these 2 critical pancreatic hormones is awry in patients with diabetes. Although clinical discussion often focuses on the role of insulin, glucagon is equally important in understanding type 2 diabetes. Furthermore, an awareness of the role of glucagon is essential to appreciate differences in the mechanisms of action of various classes of glucose-lowering therapies. Newer drug classes such as dipeptidyl peptidase-4 inhibitors and glucagon-like peptide-1 receptor agonists improve glycemic control, in part, by affecting glucagon levels. This review provides an overview of the effect of glucose-lowering therapies on glucagon on the basis of an extensive PubMed literature search to identify clinical studies of glucose-lowering therapies in type 2 diabetes that included assessment of glucagon. Clinical practice currently benefits from available therapies that impact the glucagon regulatory pathway. As clinicians look to the future, improved treatment strategies are likely to emerge that will either use currently available therapies whose mechanisms of action complement each other or take advantage of new therapies based on an improved understanding of glucagon pathophysiology.

Efficacy and safety of sodium-glucose cotransporter-2 inhibitors versus dipeptidyl peptidase-4 inhibitors as monotherapy or add-on to metformin in patients with type 2 diabetes mellitus: A systematic review and meta-analysis

AIMS

To compare the efficacy and safety of dipeptidyl peptidase-4 inhibitors (DPP-4is) and sodium-glucose cotransporter-2 inhibitors (SGLT-2is) as monotherapy or add-on to metformin (Met) in patients with type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

PubMed, Embase and ClinicalTrials.gov sites were systematically searched for randomized controlled trials to assess the efficacy and safety of DPP-4is and SGLT-2is in patients with T2DM. Risk ratio (RR) and weighted mean difference (WMD) were used to evaluate outcomes.

RESULTS

In the analysis of 25 randomized trials, which involved 14 619 patients, SGLT-2is were associated with a significantly stronger reduction in haemoglobin A1c (HbA1c) (WMD 0.13%, 95% credible interval [CI], 0.04%-0.22%, P = .005) and fasting plasma glucose (FPG) (WMD 0.80 mmol/L, 95% CI, 0.58-1.01 mmol/L, P < .00001) than were DPP-4is. However, no significant difference between the 2 drug categories was found in the risk of hypoglycaemic events (RR, 0.99; 95% CI, 0.78-1.26, P = .92). SGLT-2is plus Met was associated with a more significant decrease in FPG (WMD 0.71 mmol/L, 95% CI, 0.43-1.00 mmol/L, P < .00001) than was DPP-4is plus Met. However, no differences were found in the reduction of HbA1c (WMD 0.11%, 95% CI, -0.03%-0.25%, P = .12) or the risk of hypoglycaemic events (RR, 1.02; 95% CI, 0.80-1.31, P = .86).

CONCLUSIONS

This review revealed that, compared to DPP-4is, SGLT-2is significantly reduced HbA1c, FPG and body weight without increasing the risk of hypoglycaemia in diabetes treatment.

Incretin-based therapy in type 2 diabetes: An evidence based systematic review and meta-analysis

Incretin based therapies such as dipeptidyl peptidase-4 inhibitors (DPP-4i) and glucagon-like peptide-1 receptor agonists (GLP-1Ra) are increasingly used for the treatment of Type 2 diabetes mellitus. In clinical practice and in previously performed clinical trials, these agents are often used in combination with other oral anti-diabetic agents (OADs) and Insulin. Prior meta-analytic reviews however do not adequately address the impact of background therapy and active comparator arms. Accordingly, we aimed to further investigate the efficacy of incretin based therapies by updating existing reviews by including clinical trial evidence after 2008; estimating the pooled effect of incretin therapies on glycemic efficacy and weight-loss, stratified by comparator therapy (placebo, mono-therapy, etc.), estimating the impact of background OADs and within class (GLP-1Ra or DPP-4i) comparative efficacy, on glycemia control. 82 randomized controlled trials after 2008 with glycemic control and weight loss as primary end-points were included. Both DPP-4i and GLP-1Ra reduced HbA1c, but only GLP-1Ra caused weight loss when compared to either active comparator drugs or placebo. GLP-1Ra were more effective than DPP-4i in glycemia lowering. Long acting GLP-1Ra were more effective in HbA1c lowering than short-acting agents but with similar weight loss effect. The effect of DPP-4i incretin glycemic efficacy was not modified by background therapy used in the study.

Glycemic Improvement with a Fixed-dose combination of DPP-4 inhibitor + metformin in patients with Type 2 diabetes (GIFT study)

This study investigates changes in A1C following a switch from dual therapy of metformin and DPP-4 inhibitor to a fixed-dose combination (FDC) of metformin + DPP-4 inhibitor following the introduction of the FDC in the provincial formulary. The LMC Diabetes Registry was queried retrospectively for patients with type 2 diabetes, aged between 18 and 80 years with at least one A1C recorded prior and ≥3 months post-switch. Five hundred and sixty-eight subjects with mean age 64 ± 12 years and mean A1C 7.7% ± 1.2% met study criteria. Overall, A1C was 0.3% lower post-switch to FDC (P < .01). In stratified analysis, subjects with baseline A1C between 7% and 10% had 0.4% lower A1C (P < .01), with 31% of these subjects reaching target A1C ≤7%, post-switch. A1C reduction was greater among patients with a higher baseline pill burden: 0.4% among those using ≥10 pills/day vs. 0.1% for those with <10 pills/day (P = .02). In this real-world study, switching to FDC of metformin + DPP-4 inhibitor was associated with a significant improvement in A1C. Switching to FDC, especially in patients with high pill burden, can improve A1C goal achievement in clinical practice.

The Use of Saxagliptin in People with Type 2 Diabetes in France: The Diapazon Epidemiological Study

INTRODUCTION

Saxagliptin is a potent, reversible inhibitor of dipeptidyl peptidase-4 that is indicated for the treatment of type 2 diabetes. The DIAPAZON study was a multicenter observational study intended to document the effectiveness, safety and patterns of saxagliptin use in France, including the saxagliptin retention rate, over 2 years of follow-up.

METHODS

A geographically representative sample of 304 French physicians (general practitioners and specialist endocrinologists or diabetologists) recruited 1131 adults with type 2 diabetes into an ambispective cohort; 1033 fulfilled the inclusion criteria. All had started saxagliptin during the previous 6 months or at study inclusion, and follow-up was for 24 ± 3 months after starting saxagliptin.

RESULTS

The mean age of the study population when starting saxagliptin was 61 years, and the mean HbA1c level was 8.0%; 79% had an HbA1c level ≥7%. Prior to starting saxagliptin treatment, most participants (91%) were receiving treatment with oral glucose-lowering drugs alone. The most commonly prescribed regimen at starting saxagliptin (53% of participants) was a combination of saxagliptin and metformin. The overall saxagliptin retention rate at 2 years was 79%, as estimated by the Kaplan-Meier method. The most common reasons for discontinuation were inadequate glycemic control (52%) and intolerance (22%). During the course of the study, the mean HbA1c level decreased to 7.0%, and the percentage of people with HbA1c <7% increased from 21% to 49%. The mean change in body weight was -1.8 kg. A total of 294 hypoglycemic episodes were reported in 70 participants (6.8%) during the follow-up period. Of these, 143 episodes in 41 participants (4.0%) occurred when saxagliptin was used in combination with agents associated with hypoglycemia, such as insulin, sulfonylureas or glinides.

CONCLUSION

Saxagliptin is efficacious and well tolerated in a real-world practice setting, with almost 80% of participants remaining on treatment after 2 years.

FUNDING

AstraZeneca, France.

Cardiovascular Actions and Clinical Outcomes With Glucagon-Like Peptide-1 Receptor Agonists and Dipeptidyl Peptidase-4 Inhibitors

Potentiation of glucagon-like peptide-1 (GLP-1) action through selective GLP-1 receptor (GLP-1R) agonism or by prevention of enzymatic degradation by inhibition of dipeptidyl peptidase-4 (DPP-4) promotes glycemic reduction for the treatment of type 2 diabetes mellitus by glucose-dependent control of insulin and glucagon secretion. GLP-1R agonists also decelerate gastric emptying, reduce body weight by reduction of food intake and lower circulating lipoproteins, inflammation, and systolic blood pressure. Preclinical studies demonstrate that both GLP-1R agonists and DPP-4 inhibitors exhibit cardioprotective actions in animal models of myocardial ischemia and ventricular dysfunction through incompletely characterized mechanisms. The results of cardiovascular outcome trials in human subjects with type 2 diabetes mellitus and increased cardiovascular risk have demonstrated a cardiovascular benefit (significant reduction in time to first major adverse cardiovascular event) with the GLP-1R agonists liraglutide (LEADER trial [Liraglutide Effect and Action in Diabetes: Evaluation of Cardiovascular Ourcome Results], -13%) and semaglutide (SUSTAIN-6 trial [Trial to Evaluate Cardiovascular and Other Long-term Outcomes with Semaglutide], -24%). In contrast, cardiovascular outcome trials examining the safety of the shorter-acting GLP-1R agonist lixisenatide (ELIXA trial [Evaluation of Lixisenatide in Acute Coronary Syndrom]) and the DPP-4 inhibitors saxagliptin (SAVOR-TIMI 53 trial [Saxagliptin Assessment of Vascular Outcomes Recorded in Patients With Diabetes Mellitus-Thrombolysis in Myocardial Infarction 53]), alogliptin (EXAMINE trial [Examination of Cardiovascular Outcomes With Alogliptin Versus Standard of Care in Patients With Type 2 Diabetes Mellitus and Acute Coronary Syndrome]), and sitagliptin (TECOS [Trial Evaluating Cardiovascular Outcomes With Sitagliptin]) found that these agents neither increased nor decreased cardiovascular events. Here we review the cardiovascular actions of GLP-1R agonists and DPP-4 inhibitors, with a focus on the translation of mechanisms derived from preclinical studies to complementary findings in clinical studies. We highlight areas of uncertainty requiring more careful scrutiny in ongoing basic science and clinical studies. As newer more potent GLP-1R agonists and coagonists are being developed for the treatment of type 2 diabetes mellitus, obesity, and nonalcoholic steatohepatitis, the delineation of the potential mechanisms that underlie the cardiovascular benefit and safety of these agents have immediate relevance for the prevention and treatment of cardiovascular disease.

Value-Based Payments and Incentives to Improve Care: A Case Study of Patients with Type 2 Diabetes in Medicare Advantage

OBJECTIVES

To estimate the impact of increased glycated hemoglobin (A1C) monitoring and treatment intensification for patients with type 2 diabetes (T2D) on quality measures and reimbursement within the Medicare Advantage Star (MA Star) program.

METHODS

The primary endpoint was the share of patients with T2D with adequate A1C control (A1C ≤ 9%). We conducted a simulation of how increased A1C monitoring and treatment intensification affected this end point using data from the National Health and Nutrition Examination Survey and clinical trials. Using the estimated changes in measured A_1C levels, we calculated corresponding changes in the plan-level A_1C quality measure, overall star rating, and reimbursement.

RESULTS

At baseline, 24.4% of patients with T2D in the average plan had poor A1C control. The share of plans receiving the highest A1C rating increased from 27% at baseline to 49.5% (increased monitoring), 36.2% (intensification), and 57.1% (joint implementation of both interventions). However, overall star ratings increased for only 3.6%, 1.3%, and 4.8% of plans, respectively, by intervention. Projected per-member per-year rebate increases under the MA Star program were $7.71 (monitoring), $2.66 (intensification), and $10.55 (joint implementation).

CONCLUSIONS

The simulation showed that increased monitoring and treatment intensification would improve A1C levels; however, the resulting average increases in reimbursement would be small.

Assessment of Saxagliptin Efficacy: Meta-Analysis of 14 Phase 2 and 3 Clinical Trials

INTRODUCTION

This meta-analysis of data from 14 phase 2 and 3, double-blind, randomized, controlled 12- and 24-week studies (N = 4632) summarizes saxagliptin efficacy in patients with type 2 diabetes (T2D) across treatment regimens.

METHODS

Patients received saxagliptin 5 mg/d or control as either monotherapy (n = 1196 vs placebo), add-on therapy (n = 2139 vs placebo and n = 514 vs uptitrated sulfonylurea), or initial combination therapy (n = 619 vs control monotherapy). Patients with renal impairment received saxagliptin 2.5 mg/d or placebo (n = 164).

RESULTS

Mean baseline glycated hemoglobin (A1C) ranged from 8.07% to 9.43% for the saxagliptin and control groups across treatment regimens. A1C reduction from baseline was greater with saxagliptin versus control for all studies combined (mean treatment difference [95% CI]: -0.55% [-0.63%, -0.47%]) and when used as monotherapy (-0.52% [-0.63, -0.40%]), add-on (-0.55% [-0.69%, -0.40%] vs placebo; -0.72% [-0.88%, -0.56%] vs uptitrated sulfonylurea), initial combination therapy (-0.54% [-0.73%, -0.35%] vs control monotherapy), and in patients with renal impairment (-0.42% [-0.75%, -0.09%]). Similar reductions in A1C versus control were noted for patients <65 years (-0.55% [-0.67%, -0.43%]) and ≥65 years (-0.54% [-0.69%, -0.38%]) and for men (-0.54% [-0.69%, -0.40%]) and women (-0.55% [-0.64%, -0.47%]) across treatment regimens. More patients achieved A1C <7% (39% vs 23%) and A1C ≤6.5% (24% vs 14%) with saxagliptin than with placebo or active-control treatment. Saxagliptin versus control was associated with a reduction in glucagon area under the curve (AUC) from baseline and increases in insulin AUC, C-peptide AUC, and the homeostasis model assessment of β-cell function.

CONCLUSION

Results of this meta-analysis demonstrate the consistency of saxagliptin efficacy in different subgroups of patients with T2D across treatment regimens.

FUNDING

AstraZeneca.

Early Combination Therapy with Oral Glucose-Lowering Agents in Type 2 Diabetes

Despite the considerable burden of disease associated with type 2 diabetes mellitus (T2DM), most patients are not at, or are unable to achieve, recommended glycemic targets. This is partly because of the relentless progressive nature of the disease, but it may also be attributable to the current diabetes treatment paradigm. The recommended stepwise approach may lead to frequent early treatment failure with prolonged periods of elevated glucose as a consequence of clinical inertia and delays in achieving optimal glycemic control. Thus, it is most appropriate to consider the current treatment paradigm for T2DM in the context of a more aggressive initial therapy with early combination therapy. Current guidelines advise that initial combination therapy should be used for patients presenting with elevated glycated hemoglobin (HbA_1c). However, several studies and recent meta-analyses suggest a potential benefit from initial combination therapy on glycemic outcomes in diabetes compared with metformin monotherapy across a wide range of baseline HbA_1c levels. Indeed, combination therapy can increase the number of patients achieving glycemic goals, and the newer glucose-lowering agents may reduce the risk of hypoglycemia and body weight gain. Moreover, our improving understanding of the complex pathophysiology of T2DM and the availability of treatments tackling specific mechanisms contributing to hyperglycemia should lead to more pathophysiologically sound combination therapy. We discuss the rationale behind and evidence for early combination therapy as well as what is needed in the future to better understand its potential.

Efficacy and safety of initial combination therapy with gemigliptin and metformin compared with monotherapy with either drug in patients with type 2 diabetes: A double-blind randomized controlled trial (INICOM study)

BACKGROUND

Gemigliptin is a new dipeptidyl peptidase-IV inhibitor. We investigated the efficacy and safety of initial combination therapy with gemigliptin and metformin compared with monotherapy with either drug in patients with type 2 diabetes (T2D).

METHODS

A total of 433 T2D patients with a glycosylated haemoglobin (HbA1c) level of 7.5% to 11.0% and a fasting plasma glucose (FPG) concentration <270 mg/dL were randomly assigned to 3 groups: (1) gemigliptin 50 mg qd + metformin 1000 to 2000 mg qd (titrated individually), (2) gemigliptin 50 mg qd, or (3) metformin 1000 to 2000 mg qd. The primary end-point was the change in HbA1c level after 24 weeks. Secondary end-points were the changes in FPG, insulin, proinsulin and C-peptide levels. The percentages of responders who achieved an HbA1c level <7% (or <6.5%) were compared between treatment groups.

RESULTS

Baseline HbA1c levels were 8.7% in all groups. The mean changes in HbA1c level from baseline to week 24 were -2.06%, -1.24% and -1.47% in the combination, gemigliptin monotherapy and metformin monotherapy groups, respectively. The 95% confidence intervals for between-group differences in HbA1c changes were -1.02 to -0.63 in the combination group vs the gemigliptin group and -0.82 to -0.41 vs the metformin group, which confirmed the superiority of combination therapy. A significantly higher percentage of patients in the combination therapy group reached the target HbA1c level <7% (or <6.5%) compared with the monotherapy groups. No severe side effects were observed.

CONCLUSIONS

In T2D patients, the initial combination of gemigliptin and metformin had superior efficacy without safety concerns compared with monotherapy with either drug.

Dipeptidyl peptidase-4 inhibitors and the risk of heart failure: a systematic review and meta-analysis

BACKGROUND

Given recent discrepant results from randomized controlled trials (RCTs), we examined the totality of RCT evidence assessing the association between dipeptidyl peptidase-4 (DPP-4) inhibitors and heart failure.

METHODS

MEDLINE, Embase and ClinicalTrials.gov were searched without language restrictions to August 2016 for RCTs comparing DPP-4 inhibitors to placebo or no therapy for a period of 24 weeks or more. We included all heart failure outcomes when listed either as a serious adverse event or adverse event. Pooled analyses used random-effects.

RESULTS

We identified 100 RCTs (n = 79 867) - 3 large cardiovascular-safety RCTs (SAVOR-TIMI 53[saxagliptin]/n = 16 492, EXAMINE[alogliptin]/n = 5380, and TECOS[sitagliptin]/n = 14 735), and 97 smaller RCTs with a primary outcome that was usually change in glycated hemoglobin. Virtually all RCTs were high-quality, multicentre, placebo-controlled trials. A total of 96% (1192/1244) of heart failure events were prespecified, blindly adjudicated and required hospital admission. Pooled results suggested a 13% increase in heart failure (relative risk [RR] 1.13, 95% confidence interval [CI] 1.01-1.26, I2 = 0%; 32 RCTs, n = 54 640, 1244 events). When including only the 3 large RCTs, the increase was similar, but not significant (RR 1.14, 95% CI 0.97-1.32; 3 RCTs, n = 36 543, 1169 adjudicated events; number needed to harm 246) owing to heterogeneity (I2 = 42%), which lead to wider CIs, because SAVOR-TIMI 53 showed increased heart failure (RR 1.26, 95% CI 1.06-1.49) and TECOS showed no effect (RR 1.00, 95% CI 0.83-1.19).

INTERPRETATION

Despite pooled data from 79 867 patients, whether DPP-4 inhibitors increase heart failure overall or exhibit within-class differences remains unresolved. Our results highlight the importance of ongoing trials that are comparing DPP-4 inhibitors to placebo, although no large cardiovascular-safety RCTs are comparing different DPP-4 inhibitors to each other; consequently, these will address the overall but not class-difference question.

Emerging use of combination therapies for the management of type 2 diabetes - focus on saxagliptin and dapagliflozin

AIMS

The aim of this article is to review the safety and efficacy data of dapagliflozin, saxagliptin, and their combination in the management of patients with type 2 diabetes. Evidence for the use of the single-tablet combination formulation is also presented.

METHODS

A nonsystematic literature review was performed using the Ovid, PubMed, and Google Scholar databases.

RESULTS

The addition of dapagliflozin/saxagliptin to metformin can lower mean hemoglobin A1c by as much as 1.47% and lead to weight loss of 0.5-2.0 kg. The risk of genital infections with combination therapy is lower than observed with dapagliflozin alone, suggestive of a protective effect. Adverse event risk at 52-week follow-up was not increased beyond that seen with either monotherapy.

CONCLUSION

Dapagliflozin/saxagliptin combination is generally well tolerated and is an effective tool in helping patients with diabetes improve glycemic control.

NRF2 activation by antioxidant antidiabetic agents accelerates tumor metastasis

Cancer is a common comorbidity of diabetic patients; however, little is known about the effects that antidiabetic drugs have on tumors. We discovered that common classes of drugs used in type 2 diabetes mellitus, the hypoglycemic dipeptidyl peptidase-4 inhibitors (DPP-4i) saxagliptin and sitagliptin, as well as the antineuropathic α-lipoic acid (ALA), do not increase tumor incidence but increase the risk of metastasis of existing tumors. Specifically, these drugs induce prolonged activation of the nuclear factor E2-related factor 2 (NRF2)-mediated antioxidant response through inhibition of KEAP1-C151-dependent ubiquitination and subsequent degradation of NRF2, resulting in up-regulated expression of metastasis-associated proteins, increased cancer cell migration, and promotion of metastasis in xenograft mouse models. Accordingly, knockdown of NRF2 attenuated naturally occurring and DPP-4i-induced tumor metastasis, whereas NRF2 activation accelerated metastasis. Furthermore, in human liver cancer tissue samples, increased NRF2 expression correlated with metastasis. Our findings suggest that antioxidants that activate NRF2 signaling may need to be administered with caution in cancer patients, such as diabetic patients with cancer. Moreover, NRF2 may be a potential biomarker and therapeutic target for tumor metastasis.

Incretin-Based Therapy and Risk of Pancreatic Cancer in Patients with Type 2 Diabetes Mellitus: A Meta-analysis of Randomized Controlled Trials

INTRODUCTION

The present study aims to evaluate the risk of pancreatic cancer with incretin-based therapy among patients with type 2 diabetes mellitus (T2DM).

METHODS

We searched EMBASE, MEDLINE, the Cochrane Central Register of Controlled Trials and ClinicalTrials.gov for eligible studies published up to March 06 2016. This meta-analysis includes all studies reporting adverse events of pancreatic cancer with use of incretin-based therapies compared with placebo or non-incretin anti-diabetic drugs in patients with T2DM. We used fixed-effect model to compare pooled relative risk (RR) with related 95% confidence intervals (CI).

RESULTS

A total of 159 randomized trials were identified. Out of these, 135 studies were excluded as pancreatic cancer occurrence had not been included as an end point. The remaining 24 trials enrolling 47,904 participants were further assessed. Overall, no increased risk of pancreatic cancer were detected in association with incretin-based treatment (RR = 0.7, 95% CI 0.37-1.05). The incidence of pancreatic neoplasm was even lower among incretin-based groups than controls (RR = 0.50, 95% CI 0.29-0.87) in trials with duration more than 104 weeks. There was even decreased risk of pancreatic cancer within groups paralleled by incretin-matched placebos (RR = 0.55, 95% CI 0.32-0.93) than by non-incretin anti-diabetic drugs. Neither monotherapy (RR = 0.62, 95% CI 0.38-1.01) nor combination regimen (RR = 0.92, 95% CI 0.45-1.90) of incretin mimetics increased the risk of pancreatic cancer.

CONCLUSION

This meta-analysis shows that incretin-based therapies are not associated with increase in the risk of pancreatic cancer. Interestingly, subgroup analyses suggested lower risk of pancreatic cancer in incretin groups than placebo in long-term studies (>104 weeks). Considering the inconsistent results among randomized trials and previous epidemiological investigations, more such studies should be conducted to clarify the existence or non-existence of this association.

FUNDING

This work was supported by grants from the National Natural Science Foundation of China (Nos. 81270476 and 81470830).

Efficacy and safety of saxagliptin monotherapy or added to metformin in Chinese patients with type 2 diabetes mellitus: results from the 24-week, post-marketing SUNSHINE study

BACKGROUND

The aim of the present study was to explore the efficacy and safety of saxagliptin in a large Chinese population with type 2 diabetes mellitus (T2DM).

METHODS

In all, 1423 T2DM patients from 92 research centers, either drug naïve or uncontrolled by metformin, were enrolled in this single-arm cohort study; patients were treated with saxagliptin 5 mg once daily for 24 weeks. The primary efficacy endpoint was the change from baseline in HbA1c at 24 weeks in the per-protocol analysis set. Secondary endpoints included the proportion of patients achieving HbA1c <7% and changes from baseline in fasting plasma glucose (FPG) and 2-h postprandial plasma glucose (PPG) concentrations at 24 weeks. Safety endpoints included adverse events (AEs) and the incidence of hypoglycemia.

RESULTS

Among 1210 patients in the per-protocol analysis set, mean HbA1c, FPG and 2-h PPG decreased by 1.61 ± 0.04%, 0.55 ± 0.07 mmol/L, and 2.83  ±  0.27 mmol/L, respectively, at week 24. The proportion of patients achieving HbA1c <7% was 44.1%. No new (previously unreported) AEs occurred. The incidence of serious AEs and hypoglycemia was low (1.8% and 1.2%, respectively). There were no significant differences in efficacy endpoints in subgroup analyses by age, creatinine clearance, body mass index, or treatment background. In elderly patients (≥65 years) and those with mild renal impairment (50 < CCr ≤ 80 mL/min), the incidence of AEs was similar to that of the entire study population.

CONCLUSIONS

Saxagliptin significantly improved glycemic control and was well tolerated in Chinese T2DM patients, including the elderly and patients with mild renal impairment.

Gemigliptin: An Update of Its Clinical Use in the Management of Type 2 Diabetes Mellitus

Dipeptidyl peptidase-4 (DPP-4) inhibitors are a new class of oral antidiabetic agent for the treatment of type 2 diabetes mellitus. They increase endogenous levels of incretin hormones, which stimulate glucose-dependent insulin secretion, decrease glucagon secretion, and contribute to reducing postprandial hyperglycemia. Although DPP-4 inhibitors have similar benefits, they can be differentiated in terms of their chemical structure, pharmacology, efficacy and safety profiles, and clinical considerations. Gemigliptin (brand name: Zemiglo), developed by LG Life Sciences, is a potent, selective, competitive, and long acting DPP-4 inhibitor. Various studies have shown that gemigliptin is an optimized DPP-4 inhibitor in terms of efficacy, safety, and patient compliance for treatment of type 2 diabetes mellitus. In this review, we summarize the characteristics of gemigliptin and discuss its potential benefits in clinical practice.

Efficacy, safety and impact on β-cell function of dipeptidyl peptidase-4 inhibitors plus metformin combination therapy in patients with type 2 diabetes and the difference between Asians and Caucasians: a meta-analysis

BACKGROUND

To assess the efficacy, safety and impact on β-cell function of DPP-4 inhibitors plus metformin in T2DM patients and their difference between Asians and Caucasians.

METHODS

We conducted a literature search (from 1 January 2000 to 14 April 2015) for RCTs of DPP-4 inhibitors plus metformin combination therapy in T2DM.

RESULTS

A total of 27 RCTs were included. Compared with metformin, DPP-4 inhibitor plus metformin therapy was associated with higher reduction in HbA1c [-0.61 %, -0.69 to -0.52], FPG [-1.10 mmol/l, -1.29 to -0.92], TC [-0.11 mmol/l, -0.20 to -0.02], TG [-0.21 mmol/l, -0.33 to -0.10], HOMA-IR [-0.19, -0.36 to -0.02], gastrointestinal adverse events [OR 0.86, 0.77-0.97] and higher increment in HOMA-β [10.21, 7.73-12.69]. Comparison of HbA1c, FPG, body weight and HOMA-IR changes between Asian and Caucasian patients did not show a significant between-group difference of -0.05 % (-0.30, 0.20; P = 0.69), 0.17 mmol/l (-0.52, 0.85; P = 0.62), -0.15 kg (-0.64, 0.35; P = 0.53) and 0.27 (-0.98, 1.53; P = 0.64) compared with metformin. Comparisons of HOMA-β between Asian and Caucasian patients showed a significant between-group difference of -7.68 (-14.95, -0.42; P = 0.04).

CONCLUSION

DPP-4 inhibitors and metformin therapy was effective and safe for T2DM patients. The glucose-lowering efficacy of DPP-4 inhibitors was same in Asian and Caucasian patients, although the effect on HOMA-β was inferior in Asian patients. The effect of DPP-4 inhibitors on HOMA-IR and body weight in Asian patients was comparable with that observed in Caucasian patients.

Dipeptidyl peptidase-4 inhibitors and fracture risk: an updated meta-analysis of randomized clinical trials

Data on the effects of dipeptidyl peptidase-4 (DPP-4) inhibitors on fracture risk are conflicting. Here, we performed a systematic review and meta-analysis of randomized controlled trials (RCTs) assessing the effects of DPP-4 inhibitors. Electronic databases were searched for relevant published articles, and unpublished studies presented at ClinicalTrials.gov were searched for relevant clinical data. Eligible studies included prospective randomized trials evaluating DPP-4 inhibitors versus placebo or other anti-diabetic medications in patients with type 2 diabetes. Study quality was determined using Jadad scores. Statistical analyses were performed to calculate the risk ratios (RRs) and 95% confidence intervals (CIs) using fixed-effects models. There were 62 eligible RCTs with 62,206 participants, including 33,452 patients treated with DPP-4 inhibitors. The number of fractures was 364 in the exposed group and 358 in the control group. The overall risk of fracture did not differ between patients exposed to DPP-4 inhibitors and controls (RR, 0.95; 95% CI, 0.83–1.10; P = 0.50). The results were consistent across subgroups defined by type of DPP-4 inhibitor, type of control, and length of follow-up. The study showed that DPP-4 inhibitor use does not modify the risk of bone fracture compared with placebo or other anti-diabetic medications in patients with type 2 diabetes.