Dipeptidyl peptidase-4 inhibitors and HbA1c target of <7% in type 2 diabetes: meta-analysis of randomized controlled trials

Effects of SGLT2 Inhibitors and DPP-4 Inhibitors on Advanced Glycation End Products

Clinical trials have revealed that sodium glucose cotransporter 2 (SGLT2) inhibitors suppress the onset of heart failure and cardiovascular death in diabetic patients. On the other hand, few reports have been published concerning such effects of dipeptidyl peptidase-4 (DPP-4) inhibitors. We undertook the present study to evaluate the effects of SGLT2 inhibitors and DPP-4 inhibitors on the advanced glycation end products (AGEs), well known as a risk factor for the development of cardiovascular disorders.Type 2 diabetes mellitus were divided into two groups and treated with either SGLT2 inhibitors or DPP-4 inhibitors for 3 months. Before and after the 3-month treatment period with each drug, the AGEs and diabetes-related parameters were measured. Methylglyoxal-derived hydroimidazolone-1 (MG-H1) was measured as one of the AGEs.In the SGLT2 inhibitor group, both the blood HbA1c and MG-H1 levels decreased significantly after the 3-month treatment period. In the DPP-4 inhibitor group, only the blood HbA1c level decreased significantly, with no significant change of the blood MG-H1 level.SGLT2 inhibitor reduced both the blood levels of HbA1c and AGEs (MG-H1). Considering that the blood levels of AGEs are associated with the risk of heart failure and cardiovascular disorders, the results of the present study suggest that the effect of SGLT2 inhibitors in suppressing cardiovascular death might be mediated by the reduction in the blood levels of AGEs induced by this class of drugs. DPP-4 inhibitors showed no significant effects on the blood levels of AGEs.

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

BACKGROUND AND AIM

There are efficacy and safety concerns related to teneligliptin treatment. A systematic review of randomized controlled trials (RCTs) was undertaken to comprehensively profile the efficacy and safety of teneligliptin in the treatment of type 2 diabetes mellitus (T2DM).

METHODS

Thirteen studies were chosen from a search of scientific databases for RCTs using teneligliptin as a monotherapy or as an adjunct to other glycemic agents with pre-specified inclusion criteria. We calculated weighted mean differences (WMDs) and 95% confidence intervals (CIs) in each included trial and pooled the data using a random-effects model.

RESULTS

Thirteen studies enrolled 2853 patients were identified. Teneligliptin treatment was associated with weight gain (vs. placebo, weighted mean difference (WMD) 0.28 kg; 95% CI - 0.20-0.77 kg; I² = 86%; P = 0.25). Compared to monotherapy, add on therapy with teneligliptin showed significant improvement in FPG mg/dl levels (WMD - 16.75 mg/dl; 95% CI - 19.38 to - 14.13 mg/dl), HOMA-β (WMD 7.91; 95% CI 5.38-10.45) and HOMA-IR (WMD - 0.27; 95% CI - 0.46 to - 0.07). The improvement in HbA1c was greater with monotherapy (WMD - 8.88 mmol/mol; 95% CI - 9.59 to - 8.08 mmol/mol). There was no significant risk of any hypoglycemia with teneligliptin compared to placebo (OR 0.84; 95% CI 0.44-1.60; I² = 0%; P = 0.60). However, the risk was 1.84 times high when combined with other glycemic agents. The risk of cardiovascular events was comparable, regardless of treatment duration when compared to placebo or any other active comparator (OR 0.79; 95% CI 0.40-1.57; I² = 0%; P = 0.50). [PROSPERO, CRD42022360785].

CONCLUSIONS

Teneligliptin is an effective and safe therapeutic option for patients with T2DM, both as monotherapy and as add-on therapy. However, additional large-scale, high-quality, long-term follow-up clinical trials with diverse ethnic populations are required to confirm its long-term efficacy and safety.

Heterocyclic Compounds as Dipeptidyl Peptidase-IV Inhibitors with Special Emphasis on Oxadiazoles as Potent Anti-Diabetic Agents

Dipeptidyl peptidase-IV (DPP-IV) inhibitors, often known as gliptins, have been used to treat type 2 diabetes mellitus (T2DM). They may be combined with other medications as an additional treatment or used alone as a monotherapy. In addition to insulin, sulfonylureas, thiazolidinediones, and metformin, these molecules appear as possible therapeutic options. Oxadiazole rings have been employed in numerous different ways during drug development efforts. It has been shown that including them in the pharmacophore increases the amount of ligand that may be bound. The exceptional hydrogen bond acceptor properties of oxadiazoles and the distinct hydrocarbon bonding potential of their regioisomers have been established. Beside their anti-diabetic effects, oxadiazoles display a wide range of pharmacological properties. In this study, we made the assumption that molecules containing oxadiazole rings may afford a different approach to the treatment of diabetes, not only for controlling glycemic levels but also for preventing atherosclerosis progression and other complications associated with diabetes. It was observed that oxadiazole fusion with benzothiazole, 5-(2,5,2-trifluoroethoxy) phenyl, β-homophenylalanine, 2-methyl-2-{5-(4-chlorophenyl), diamine-bridged bis-coumarinyl, 5-aryl-2-(6′-nitrobenzofuran-2′-yl), nitrobenzofuran, and/or oxindole leads to potential anti-diabetic activity.

Role of Dipeptidyl Peptidase 4 Inhibitors in Antidiabetic Treatment

In recent years, important changes have occurred in the field of diabetes treatment. The focus of the treatment of diabetic patients has shifted from the control of blood glucose itself to the overall management of risk factors, while adjusting blood glucose goals according to individualization. In addition, regulators need to approve new antidiabetic drugs which have been tested for cardiovascular safety. Thus, the newest class of drugs has been shown to reduce major adverse cardiovascular events, including sodium-glucose transporter 2 (SGLT2) and some glucagon like peptide 1 receptor (GLP1) analog. As such, they have a prominent place in the hyperglycemia treatment algorithms. In recent years, the role of DPP4 inhibitors (DPP4i) has been modified. DPP4i have a favorable safety profile and anti-inflammatory profile, do not cause hypoglycemia or weight gain, and do not require dose escalation. In addition, it can also be applied to some types of chronic kidney disease patients and elderly patients with diabetes. Overall, DPP4i, as a class of safe oral hypoglycemic agents, have a role in the management of diabetic patients, and there is extensive experience in their use.

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

Registration:

PROSPERO: CRD42020210645

Introduction:

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

Methods:

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

Results:

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

Conclusion:

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

Plain language summary

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

Clinical associations of an updated medication effect score for measuring diabetes treatment intensity

OBJECTIVES

The medication effect score reflects overall intensity of a diabetes regimen by consolidating dosage and potency of agents used. Little is understood regarding how medication intensity relates to clinical factors. We updated the medication effect score to account for newer agents and explored associations between medication effect score and patient-level clinical factors.

METHODS

Cross-sectional analysis of baseline data from a randomized controlled trial involving 263 Veterans with type 2 diabetes and hemoglobin A1c levels ≥8.0% (≥7.5% if under age 50). Medication effect score was calculated for all patients at baseline, alongside additional measures including demographics, comorbid illnesses, hemoglobin A1c, and self-reported psychosocial factors. We used multivariable regression to explore associations between baseline medication effect score and patient-level clinical factors.

RESULTS

Our sample had a mean age of 60.7 (SD = 8.2) years, was 89.4% male, and 57.4% non-White. Older age and younger onset of diabetes were associated with a higher medication effect score, as was higher body mass index. Higher medication effect score was significantly associated with medication nonadherence, although not with hemoglobin A1c, self-reported hypoglycemia, diabetes-related distress, or depression.

DISCUSSION

We observed several expected associations between an updated medication effect score and patient-level clinical factors. These associations support the medication effect score as an appropriate measure of diabetes regimen intensity in clinical and research contexts.

Efficacy and safety profile of Sitagliptin, vildagliptin, and metformin in newly diagnosed type 2 diabetic subjects

Type-2 diabetes mellitus is a chronic and progressive disease that requires long-term management. Thus, Dipeptidyl peptidase-4 inhibitors (DPP-4) need more investigations about their efficacy and safety profile as there is still no evidence of whether DPP-4 inhibitors can be used as 1st line option for type2 diabetes drug naïve patients. In this randomized case-controlled study, 60 drug-naïve type 2 diabetic subjects were randomized into 3 groups, each group comprising 20 subjects. Group 1 was given sitagliptin 100 mg once daily, Group 2 was given vildagliptin 50 mg twice daily, and Group 3 served as the control group and was given Metformin 1gm twice daily. Efficacy endpoints included changes in glycosylated hemoglobin (HbA1c), fasting plasma glucose (FPG), and 2-hr postprandial plasma glucose (PPG), and the secondary endpoints were related to safety profile were the assessment of liver and kidney function tests and complete blood count (CBC). All treatment regimens had comparable efficacy and safety profiles with the non-significant relative superiority of vildagliptin in lowering HbA1c more than sitagliptin but significant (p=0.011) regarding FPG reduction, vildagliptin significantly decreased HbA1c by -1.02 % (P< 0.001), sitagliptin significantly decreased HbA1c by -0.96% (P< 0.001), and control significantly decreased HbA1c by -0.90% (P< 0.001) compared with baseline. The studied drugs showed moderate efficacy in lowering HbA1c levels with the non-significant relative higher efficacy of DPP-4 inhibitors. DPP-4 inhibitors and metformin showed favorable effects on improving metabolic syndrome by decreasing blood pressure, serum triglycerides (TG), low-density lipoprotein (LDL), total cholesterol, and increasing high-density lipoprotein (HDL), plus their positive impacts on weight. As a final conclusion, the three medications are highly comparable.

Dipeptidyl peptidase 4 inhibitors in the treatment of type 2 diabetes mellitus

Dipeptidyl peptidase 4 inhibitors (DPP4i) have been available for treating type 2 diabetes mellitus since 2006. Although they are a diverse group, DPP4i are all small, orally available molecules that interact with the catalytic site of DPP4 without disturbing any of its other known functions, including its effects on the immune system. DPP4i have no intrinsic glucose-lowering activity, so their efficacy as anti-diabetic agents is related directly to their ability to inhibit DPP4 activity and is mediated through the effects of the substrates they protect. Of these, the incretin hormone, glucagon-like peptide 1, is probably the most important. As the effects of glucagon-like peptide 1 are glucose-dependent, the risk of hypoglycaemia with DPP4i is low. Class effects, which are directly related to the mechanism of action, are common to all DPP4i; these include their overall good safety profile and tolerability, as well as their efficacy in improving glycaemic control, but also, potentially, a small increased risk of acute pancreatitis. Compound-specific effects are those related to their differing chemistries and/or pharmacokinetic profiles. These compound-specific effects could affect the way in which individual DPP4i are used therapeutically and potentially explain off-target adverse effects, such as hospitalization for heart failure, which is seen only with one DPP4i. Overall, DPP4i have a favourable therapeutic profile and are safe and effective in the majority of patients with type 2 diabetes mellitus.

Effect of Dipeptidyl Peptidase 4 Inhibitors Used in Combination with Insulin Treatment in Patients with Type 2 Diabetes: A Systematic Review and Meta-analysis

INTRODUCTION

To evaluate the efficacy and safety of dipeptidyl peptidase 4 inhibitors (DPP4i) used in combination with insulin in patients with type 2 diabetes mellitus (T2DM).

METHODS

We searched the MEDLINE, Embase, and Cochrane library databases for randomized controlled trials (RCTs) published through June 2018. Studies with at least a 12-week treatment period were included to compare the addition of DPP4i to insulin with insulin control therapy. Meanwhile, groups on a stable insulin dosage (insulin-stable subgroup) or titrating insulin dosage (insulin-flexible subgroup) were analyzed separately.

RESULTS

Twenty-one RCTs with 3697 patients randomized to a DPP4i/insulin treatment arm and 3538 to an insulin control arm were included. DPP4i, when added to insulin therapy, led to a significantly greater reduction in HbA1c (- 0.57%, 95% CI - 0.66, - 0.48) and provided significantly greater odds of achieving the HbA1c target < 7% (OR 3.45; 95% CI 2.58, 4.63). These effects were achieved in the context of a decrease in the daily insulin requirement, without increases in hypoglycemia risk and body weight, compared with the control treatment. Subgroup analysis showed control-adjusted reductions in HbA1c from baseline in the insulin-stable subgroup (-  0.64%; 95% CI - 0.74, - 0.53) and the insulin-flexible subgroup (- 0.43%; 95% CI - 0.56, - 0.30). Other results occurred similarly in both subgroups.

CONCLUSIONS

The addition of DPP4i to insulin is associated with a statistically significant reduction in glycemic control as measured by HbA1c, fasting plasma glucose, and 2-h postprandial glucose, without increasing the risk of hypoglycemia and weight gain. These conclusions were also observed in both stable-dose and flexible-dose insulin subgroups.

Real-World Glycemic Lowering Effectiveness of Linagliptin Among Adults with Type 2 Diabetes by Age, Renal Function, and Race

INTRODUCTION

To assess real-world effectiveness of linagliptin in persons with type 2 diabetes mellitus (T2DM) across a range of ages and renal function. Effectiveness was assessed in different races, with a focus on African Americans (AA).

METHODS

This was a non-interventional retrospective cohort study using data in the Optum clinical database from adults with T2DM initiating linagliptin. Date of the first linagliptin prescription was the index date. Outcomes included change in glycated hemoglobin (HbA1c) and the percentage of persons achieving an HbA1c < 7% (53 mmol/mol) during the 60-180 days following linagliptin initiation. Analyses of age by renal function were conducted. Multivariate regression analysis was performed to assess change in HbA1c, controlling for an a priori list of covariates.

RESULTS

Overall, 11,001 persons were included. Mean pre-index HbA1c value was 8.2% (66 mmol/mol), with higher levels in younger versus older persons and AAs versus other race groups. Persons initiating linagliptin had an average HbA1c reduction of 0.51% (5.6 mmol/mol). Without adjusting for age, renal function, race, and pre-index HbA1c, greater reductions in HbA1c were observed in younger versus older persons, persons with higher versus lower estimated glomerular filtration rate (eGFR), and AAs versus white or Asians. After multivariate analysis, variables significantly associated with a greater HbA1c reduction included higher pre-index HbA1c and older age.

CONCLUSIONS

These results support the HbA1c-lowering effectiveness of linagliptin across age, race, and renal function categories among a large real-world population of adults with T2DM.

Risk of any hypoglycaemia with newer antihyperglycaemic agents in patients with type 2 diabetes: A systematic review and meta-analysis

OBJECTIVES

For patients with type 2 diabetes, newer antihyperglycaemic agents (AHA), including the dipeptidyl peptidase IV inhibitors (DPP4i), glucagon-like peptide-1 receptor agonists (GLP1RA) and sodium glucose co-transporter 2 inhibitors (SGLT2i) offer a lower risk of hypoglycaemia relative to sulfonylurea or insulin. However, it is not clear how AHA compare to placebo on risk of any hypoglycaemia. This study evaluates the risk of any and severe hypoglycaemia with AHA and metformin relative to placebo.

DESIGN

A systematic review and meta-analysis was conducted of randomized, placebo-controlled trials ≥12 weeks in duration. MEDLINE, Embase and the Cochrane Library were searched up to April 16, 2019. Studies allowing use of other diabetes medications were excluded. Mantel-Haenszel risk ratio with 95% confidence intervals were used to pool estimates based on class of AHA and number of concomitant therapies used.

PATIENTS

Eligible studies enrolled patients with type 2 diabetes ≥18 years of age.

RESULTS

144 studies met our inclusion criteria. Any hypoglycaemia was not increased with AHA when used as monotherapy (DPP4i (RR 1.12; 95% CI 0.81-1.56), GLP1RA (1.77; 0.91-3.46), SGLT2i (1.34; 0.83-2.15)), or as add-on to metformin (DPP4i (0.95; 0.67-1.35), GLP1RA (1.24; 0.80-1.91), SGLT2i (1.29; 0.91-1.83)) or as triple therapy (1.13; 0.67-1.91). However, metformin monotherapy (1.73; 1.02-2.94) and dual therapy initiation (3.56; 1.79-7.10) was associated with an increased risk of any hypoglycaemia. Severe hypoglycaemia was rare not increased for any comparisons.

CONCLUSIONS

Metformin and the simultaneous initiation of dual therapy, but not AHA used alone or as single add-on combination therapy, was associated with an increased risk of any hypoglycaemia relative to placebo.

Effectiveness and Safety of Adding Basal Insulin Glargine in Patients with Type 2 Diabetes Mellitus Exhibiting Inadequate Response to Metformin and DPP-4 Inhibitors with or without Sulfonylurea

BACKGROUND

We aimed to investigate the effectiveness and safety of adding basal insulin to initiating dipeptidyl peptidase-4 (DPP-4) inhibitor and metformin and/or sulfonylurea (SU) in achieving the target glycosylated hemoglobin (HbA1c) in patients with type 2 diabetes mellitus (T2DM).

METHODS

This was a single-arm, multicenter, 24-week, open-label, phase 4 study in patients with inadequately controlled (HbA1c ≥7.5%) T2DM despite the use of DPP-4 inhibitor and metformin. A total of 108 patients received insulin glargine while continuing oral antidiabetic drugs (OADs). The primary efficacy endpoint was the percentage of subjects achieving HbA1c ≤7.0%. Other glycemic profiles were also evaluated, and the safety endpoints were adverse events (AEs) and hypoglycemia.

RESULTS

The median HbA1c at baseline (8.9%; range, 7.5% to 11.1%) decreased to 7.6% (5.5% to 11.7%) at 24 weeks. Overall, 31.7% subjects (n=33) achieved the target HbA1c level of ≤7.0%. The mean differences in body weight and fasting plasma glucose were 1.2±3.4 kg and 56.0±49.8 mg/dL, respectively. Hypoglycemia was reported in 36 subjects (33.3%, 112 episodes), all of which were fully recovered. There was no serious AE attributed to insulin glargine. Body weight change was significantly different between SU users and nonusers (1.5±2.5 kg vs. -0.9±6.0 kg, P=0.011).

CONCLUSION

The combination add-on therapy of insulin glargine, on metformin and DPP-4 inhibitors with or without SU was safe and efficient in reducing HbA1c levels and thus, is a preferable option in managing T2DM patients exhibiting dysglycemia despite the use of OADs.

Efficacy and Safety of Switching to Teneligliptin in Patients with Type 2 Diabetes Inadequately Controlled with Dipeptidyl Peptidase-4 Inhibitors: A 12-Week Interim Report

INTRODUCTION

Teneligliptin, an antidiabetic agent classified as a class III dipeptidyl peptidase-4 (DPP-4) inhibitor, has a unique structural feature that provides strong binding to DPP-4 enzymes. We investigated the efficacy and safety of switching patients with type 2 diabetes mellitus (T2DM) who had inadequate glycemic control on a stable dose of other DPP-4 inhibitors to teneligliptin.

METHODS

Patients with T2DM whose glycosylated hemoglobin (HbA1c) levels were ≥ 7% despite taking DPP-4 inhibitors other than teneligliptin, with or without other hypoglycemic agents, for at least 3 months were enrolled. The DPP-4 inhibitors taken before participating in the study were switched to 20 mg qd teneligliptin, and this was to be maintained for 52 weeks. The primary end point was the change in HbA1c levels after 12 weeks. Metabolic parameters including fasting plasma glucose (FPG) and blood lipids were assessed also. To assess safety, adverse and hypoglycemic events were monitored. The data from baseline to week 12 were used for analysis in this interim report.

RESULTS

The mean change in HbA1c levels from baseline to week 12 was - 0.44%. At week 12, the percentage of patients achieving HbA1c < 7.0% was 31.6% and that of achieving HbA1c < 6.5% was 11.4%, respectively. In 41.2% of patients, the HbA1c levels decreased by at least 0.5% at 12 weeks. The mean change in FPG levels from baseline to week 12 was - 11.5 mg/dl. No severe hypoglycemia was reported.

CONCLUSION

After switching to teneligliptin, HbA1c levels decreased significantly in patients with T2DM inadequately controlled with other DPP-4 inhibitors.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03793023.

FUNDING

Handok Inc.

Ten years of experience with DPP-4 inhibitors for the treatment of type 2 diabetes mellitus

Achieving and maintaining recommended glycemic targets without causing adverse e ffects, including hypoglycemia, is challenging, especially in older patients with type 2 diabetes mellitus (T2DM). The introduction of dipeptidyl peptidase-4 (DPP-4) inhibitors, more than 10 years ago, has provided an alternative to conventional medications for the intensification of glucose-lowering treatment after failure of metformin monotherapy, and therefore, marked an important advance in the management of T2DM. By prolonging the activity of incretin hormones, DPP-4 inhibitors induce insulin release and decrease glucagon secretion in a glucose-dependent manner. This results in a more physiologic glycemic control as compared to that ensured by insulin secretagogues (sulfonylureas and glinides). Overall, DPP-4 inhibitors have a favorable safety profile and can be used without dose adjustments in older adults and in patients with mild renal impairment; they have a neutral effect on body weight and do not cause hypoglycemia by themselves. Safety issues, reported mainly in post-marketing surveillance programs and including cardiovascular outcomes and the risk of acute pancreatitis, are being extensively investigated. The aim of this review is to discuss the impact of DPP-4 inhibitors on the treatment of T2DM, after 10 years of experience, with an emphasis on diabetes care in Italy. We will first describe T2DM treatment in Italy and then provide an overview of the main findings from randomized controlled trials, real-world studies and post-marketing surveillance programs with DPP-4 inhibitors.

Understanding the impact of commonly utilized, non-insulin, glucose-lowering drugs on body weight in patients with type 2 diabetes

INTRODUCTION

The majority of patients with type 2 diabetes also have obesity. Obesity increases the risk of developing diabetes and is associated with worsened glycemic control and increased morbidity and mortality in individuals with diabetes. Sustained weight loss is associated with improved glycemic control, potential for diabetes remission, and decreased medical expenditures.

AREAS COVERED

Herein, the impact of commonly utilized, non-insulin, glucose-lowering drugs on body weight in patients with type 2 diabetes is discussed. The weight change magnitudes, mechanisms, and any within-class differences are also explored.

EXPERT OPINION

The weight impact of diabetes medications should be considered when designing treatment regimens, especially in patients who are overweight or have obesity. Lifestyle modification is paramount for optimal diabetes management. Therapeutic regimens should ideally be designed to maximize weight loss and at least minimize or avoid weight gain. Future glucose-lowering medications should continue to offer improvement in cardiovascular risk factors, including weight, in order to be accepted into the armamentarium of diabetes therapy. Therapeutic regimens should be designed to help patients with diabetes and obesity achieve both glycemic and weight goals. Management of these disease states is expected to become increasingly integrated.

Efficacy and safety of teneligliptin added to canagliflozin monotherapy in Japanese patients with type 2 diabetes mellitus: A multicentre, randomized, double-blind, placebo-controlled, parallel-group comparative study

Dipeptidyl peptidase-4 (DPP-4) inhibitors and sodium glucose co-transporter 2 (SGLT2) inhibitors are frequently used in combination for the treatment of type 2 diabetes mellitus (T2DM). We examined the efficacy and safety of teneligliptin (a DPP-4 inhibitor) added to canagliflozin (an SGLT2 inhibitor) monotherapy in Japanese patients with poorly controlled T2DM as part of the development of a fixed-dose combination of teneligliptin and canagliflozin. Japanese patients treated with canagliflozin (100 mg) for ≥12 weeks were randomized to receive add-on teneligliptin (20 mg; C + T group) or placebo (C + P group) for 24 weeks. The primary endpoint was change in glycated haemoglobin (HbA1c) from baseline to Week 24. The between-group differences in reductions from baseline to Week 24 were significantly greater in the C + T group for HbA1c (-0.94%; P < .001). The incidence of adverse events was similar in both groups (55.8% and 49.4% in the C + T and C + P groups, respectively). No episodes of hypoglycaemia were reported. Teneligliptin added to ongoing canagliflozin monotherapy improved glycaemic control and was well tolerated in Japanese patients with inadequately controlled T2DM.

Effects of Vildagliptin Add-on Insulin Therapy on Nocturnal Glycemic Variations in Uncontrolled Type 2 Diabetes

INTRODUCTION

To investigate whether vildagliptin add-on insulin therapy improves glycemic variations in patients with uncontrolled type 2 diabetes (T2D) compared to patients with placebo therapy.

METHODS

This was a 24-week, single-center, double-blind, placebo-controlled trial. Inadequately controlled T2D patients treated with insulin therapy were recruited between June 2012 and April 2013. The trial included a 2-week screening period and a 24-week randomized period. Subjects were randomly assigned to a vildagliptin add-on insulin therapy group (n = 17) or a matched placebo group (n = 16). Scheduled visits occurred at weeks 4, 8, 12, 16, 20, and 24. Continuous glucose monitoring (CGM) was performed before and at the endpoint of the study.

RESULTS

A total of 33 subjects were admitted, with 1 patient withdrawing from the placebo group. After 24 weeks of therapy, HbA1c values were significantly reduced at the endpoint in the vildagliptin add-on group. CGM data showed that patients with vildagliptin add-on therapy had a significantly lower 24-h mean glucose concentration and mean amplitude of glycemic excursion (MAGE). At the endpoint of the study, patients in the vildagliptin add-on group had a significantly lower MAGE and standard deviation compared to the control patients during the nocturnal period (0000-0600). A severe hypoglycemic episode was not observed in either group.

CONCLUSION

Vildagliptin add-on therapy to insulin has the ability to improve glycemic variations, especially during the nocturnal time period, in patients with uncontrolled T2D.

Gastrointestinal Adverse Events of Dipeptidyl Peptidase 4 Inhibitors in Type 2 Diabetes: A Systematic Review and Network Meta-analysis

PURPOSE

The purpose of this study was to systematically evaluate the effect of dipeptidyl peptidase 4 inhibitors on gastrointestinal adverse events in patients with type 2 diabetes.

METHODS

MEDLINE, Embase, the Cochrane Library, and ClinicalTrials.gov were searched from inception through April 28, 2016. Randomized controlled trials that compared dipeptidyl peptidase 4 inhibitor-based therapies with placebo and other hypoglycemic agents in type 2 diabetes were included. The duration of studies was at least 4 weeks.

FINDINGS

A total of 165 randomized controlled trials and 122,072 patients were included in the study. Dipeptidyl peptidase 4 inhibitors did not increase the incidence of gastrointestinal adverse events after the treatment with alogliptin (odds ratio [OR] = 0.83; 95% CI, 0.59-1.15), linagliptin (OR = 1.11; 95% CI, 0.92-1.35), saxagliptin (OR = 0.96; 95% CI, 0.80-1.15), sitagliptin (OR = 0.95; 95% CI, 0.64-1.14), teneligliptin (OR = 1.50; 95% CI, 0.81-2.77), and vildagliptin (OR = 0.80; 95% CI, 0.63-1.01) compared with placebo. Compared with glucagon-like peptide 1 receptor agonists, dipeptidyl peptidase 4 inhibitors significantly decreased the incidence of gastrointestinal adverse events with alogliptin (OR = 0.26; 95% CI, 0.15-0.44), linagliptin (OR = 0.43; 95% CI, 0.25-0.74), saxagliptin (OR = 0.28; 95% CI, 0.17-0.46), sitagliptin (OR = 0.24; 95% CI, 0.17-0.35), and vildagliptin (OR = 0.27; 95% CI, 0.18-0.41). Dipeptidyl peptidase 4 inhibitors were not associated with an increased risk of gastrointestinal adverse events relative to metformin and α-glucosidase inhibitors, respectively.

IMPLICATIONS

The network meta-analysis found that compared with glucagon-like peptide 1 receptor agonists, metformin, and α-glucosidase inhibitor, dipeptidyl peptidase 4 inhibitors are associated with a lower incidence of gastrointestinal adverse events.

Long-term efficacy and safety of vildagliptin add-on therapy in type 2 diabetes mellitus with insulin treatment

BACKGROUND

The use of dipeptidyl peptidase (DPP)-4 inhibitors in patients with type 2 diabetes treated with insulin may be beneficial. However, the long-term efficacy and safety of vildagliptin add-on therapy in these patients remains unclear.

SUBJECTS AND METHODS

A total of 73 patients with type 2 diabetes treated with insulin were randomly assigned to receive either add-on therapy of vildagliptin (n=37) or conventional therapy without DPP-4 inhibitors (n=36) for glucose control. Hemoglobin A1c (HbA1c) levels, dose and number of insulin injections, number of hypoglycemia episodes, and liver and renal function were monitored for 2years.

RESULTS

The baseline characteristics of subjects, including age, dose of insulin injections, or HbA1c levels, did not differ between the two groups. In the vildagliptin group, HbA1c levels significantly decreased and the significance of HbA1c reduction was maintained for 24months (from 8.0±1.2% to 7.4±1.0%, p<0.05, at the end of observational period). In addition, the dose and number of insulin injections significantly reduced (-5.6units, p<0.01, and -0.9 times, p<0.001). However, these parameters were unchanged in the control group. The number of patients who experienced three or more episodes of hypoglycemia per year was significantly lower in the vildagliptin group (n=4) than in the control group (n=11) (odds ratio, 0.28; 95% confidence interval, 0.08-0.97; p<0.05).

CONCLUSION

Vildagliptin as an add-on to insulin treatment for 24months was well tolerated and led to sustained reductions in HbA1c, the dose and number of insulin injections, and the risk of hypoglycemia.

Blood Glucagon Levels Predict the Hemoglobin A1c Response to Saxagliptin in Patients with Type 2 Diabetes Inadequately Controlled with Metformin

BACKGROUND

Dipeptidyl peptidase-4 (DPP-4) inhibitors are widely used as second-option medications when metformin fails. Variance of the glycated hemoglobin (HbA1c) response to DPP-4 inhibitions in patients with type 2 diabetes mellitus (T2DM) has been observed, but the characteristics which predict the response to DPP-4 inhibitor therapy are unclear. The aim of this study was to investigate the characteristics of α- and β-cell functions which might predict the efficacy of saxagliptin and facilitate personalization of treatment.

METHODS

We studied 60 patients with T2DM who had inadequate glycemic control [HbA1c7.0-13.0% (53-119 mmol/mol)) with metformin alone. The patients were treated with saxagliptin (5 mg, daily) and metformin (1000-2000 mg as former) for 12 weeks. Oral glucose tolerance tests were carried out at baseline and endpoint to evaluate α- and β-cell functions, and blood C-peptide, insulin, glucagon levels were tested. Blood glucose, HbA1c and weight were also observed.

RESULTS

Significant reduction of weight, HbA1c and glucagon was observed after 12-week treatment, while C-peptide, insulin and homeostasis model assessment-β increased (P < 0.05). Linear regression and receiver operating characteristic analysis showed that baseline HbA1c and 30 min-glucagon were correlated with the HbA1c response to saxagliptin, while the weight loss was correlated with gender, age and fasting-insulin level. Further analysis showed the 30 min-glucagon of 49.1 pmol/L was the optimal cutoff value to predict the efficacy of saxagliptin.

CONCLUSIONS

Saxagliptin added to metformin significantly improved glycemic control and α- and β-cell function. Blood glucagon level was a good predicting factor for the HbA1c response to saxagliptin, and it will help appropriate patient selection.

TRIAL REGISTRATION

Chinese Clinical Trial Register identifier, ChiCTR-PPR-15007045.

Comparative effects of vildagliptin and sitagliptin determined by continuous glucose monitoring in patients with type 2 diabetes mellitus

The dipeptidyl peptidase-4 inhibitors vildagliptin and sitagliptin are effective in treating patients with type 2 diabetes mellitus. Patients receiving standard doses of sitagliptin plus insulin may require increased doses of sitagliptin or switching to vildagliptin to improve blood glucose control. This study compared the effects of increasing sitagliptin and switching to vildagliptin in type 2 diabetes patients receiving standard doses of sitagliptin plus insulin. This prospective, randomized, parallel-group comparison trial enrolled 33 type 2 diabetes patients receiving 50 mg sitagliptin once daily plus insulin. Seventeen patients were randomized to 50 mg vildagliptin twice daily, and 16 to 100 mg sitagliptin once daily, and evaluated by continuous glucose monitoring at baseline and after 8 weeks. The primary end-point was the change in mean amplitude of glycemic excursions (MAGE). MAGE decreased from baseline in both the vildagliptin (-13.4 ± 35.7 mg/dL) and sitagliptin (-8.4 ± 24.3 mg/dL) groups, but neither within- nor between-group changes were statistically significant. Similarly, the areas under the curve for blood glucose levels ≥180 mg/dL and <70 mg/dL tended to improve in both groups, but these differences were not statistically significant. In contrast, HbA1c was significantly reduced only in the vildagliptin group, from 7.1 ± 0.6% at baseline to 6.8 ± 0.6% at 8 weeks (p=0.006). Increasing sitagliptin dose and switching to vildagliptin had limited effects in improving MAGE in type 2 diabetic patients treated with standard doses of sitagliptin.

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.

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.

Options for empagliflozin in combination therapy in type 2 diabetes mellitus

Objective

To update clinicians with an overview of empagliflozin for the treatment of type 2 diabetes mellitus (T2DM), with focus on use in combination regimens.

Methods

Keyword searches were conducted in the Medline database to identify literature reporting clinical trials of at least 12 weeks’ duration using empagliflozin treatment in patients with T2DM.

Results

When given as monotherapy or in combination therapy (as add-on or single-pill therapy) with metformin, pioglitazone, sulfonylurea, linagliptin, and insulin, empagliflozin produced clinically meaningful reductions in glycated hemoglobin levels, plasma glucose concentrations, bodyweight, and blood pressure. These changes were sustained during long-term treatment. In a dedicated cardiovascular event trial, empagliflozin on top of standard of care demonstrated a significant reduction in the risk of cardiovascular mortality and all-cause mortality. Across the clinical trials, empagliflozin combination therapies were well tolerated, and empagliflozin used alone was not associated with increased risk of hypoglycemia versus placebo. Indeed, the combination of empagliflozin and metformin had a significantly reduced rate of hypoglycemia compared with the combination of metformin and a sulfonylurea. On the other hand, empagliflozin treatment did have increased risk of genital infections compared with placebo. In clinical trials to date, diabetic ketoacidosis was not seen more frequently with empagliflozin than with placebo, but physicians should be alert to the possibility of this rare event.

Conclusion

Empagliflozin has the potential to make an important contribution to the treatment of patients with T2DM. In some patients, empagliflozin may be used as monotherapy, but it is most likely to be used in combination with other therapies. Given the reduced risk of mortality seen when empagliflozin was added to standard care in patients at high cardiovascular risk, as well as the lack of alternative options for patients at lower cardiovascular risk, empagliflozin may be added to ongoing regimens for a significant proportion of patients.

Type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is an expanding global health problem, closely linked to the epidemic of obesity. Individuals with T2DM are at high risk for both microvascular complications (including retinopathy, nephropathy and neuropathy) and macrovascular complications (such as cardiovascular comorbidities), owing to hyperglycaemia and individual components of the insulin resistance (metabolic) syndrome. Environmental factors (for example, obesity, an unhealthy diet and physical inactivity) and genetic factors contribute to the multiple pathophysiological disturbances that are responsible for impaired glucose homeostasis in T2DM. Insulin resistance and impaired insulin secretion remain the core defects in T2DM, but at least six other pathophysiological abnormalities contribute to the dysregulation of glucose metabolism. The multiple pathogenetic disturbances present in T2DM dictate that multiple antidiabetic agents, used in combination, will be required to maintain normoglycaemia. The treatment must not only be effective and safe but also improve the quality of life. Several novel medications are in development, but the greatest need is for agents that enhance insulin sensitivity, halt the progressive pancreatic β-cell failure that is characteristic of T2DM and prevent or reverse the microvascular complications. For an illustrated summary of this Primer, visit: http://go.nature.com/V2eGfN.

Gut-brain connection: The neuroprotective effects of the anti-diabetic drug liraglutide

Long-acting glucagon-like peptide-1 (GLP-1) analogues marketed for type 2 diabetes (T2D) treatment have been showing positive and protective effects in several different tissues, including pancreas, heart or even brain. This gut secreted hormone plays a potent insulinotropic activity and an important role in maintaining glucose homeostasis. Furthermore, growing evidences suggest the occurrence of several commonalities between T2D and neurodegenerative diseases, insulin resistance being pointed as a main cause for cognitive decline and increased risk to develop dementia. In this regard, it has also been suggested that stimulation of brain insulin signaling may have a protective role against cognitive deficits. As GLP-1 receptors (GLP-1R) are expressed throughout the central nervous system and GLP-1 may cross the blood-brain-barrier, an emerging hypothesis suggests that they may be promising therapeutic targets against brain dysfunctional insulin signaling-related pathologies. Importantly, GLP-1 actions depend not only on the direct effect mediated by its receptor activation, but also on the gut-brain axis involving an exchange of signals between both tissues via the vagal nerve, thereby regulating numerous physiological functions (e.g., energy homeostasis, glucose-dependent insulin secretion, as well as appetite and weight control). Amongst the incretin/GLP-1 mimetics class of anti-T2D drugs with an increasingly described neuroprotective potential, the already marketed liraglutide emerged as a GLP-1R agonist highly resistant to dipeptidyl peptidase-4 degradation (thereby having an increased half-life) and whose systemic GLP-1R activity is comparable to that of native GLP-1. Importantly, several preclinical studies showed anti-apoptotic, anti-inflammatory, anti-oxidant and neuroprotective effects of liraglutide against T2D, stroke and Alzheimer disease (AD), whereas several clinical trials, demonstrated some surprising benefits of liraglutide on weight loss, microglia inhibition, behavior and cognition, and in AD biomarkers. Herein, we discuss the GLP-1 action through the gut-brain axis, the hormone’s regulation of some autonomic functions and liraglutide’s neuroprotective potential.

Efficacy of dipeptidyl-peptidase-4 inhibitors and impact on β-cell function in Asian and Caucasian type 2 diabetes mellitus patients: A meta-analysis

BACKGROUND

This work aimed to compare the efficacy of dipeptidyl peptidase-IV (DPP-4) inhibitors and their impact on β-cell function in Asian and Caucasian patients with type 2 diabetes mellitus.

METHODS

Databases were systematically searched and qualifying studies that compared DPP-4 inhibitors with other antidiabetic medications in type 2 diabetes were included.

RESULTS

A total of 68 studies were included in the meta-analysis. Comparison of DPP-4 inhibitors with placebo in Asian patients showed a decrease in glycosylated hemoglobin (HbA1c ) favoring DPP-4 inhibitors (weighted mean difference [WMD], -0.81%; 95% confidence interval [CI], -0.95% to -0.68%; P < 0.001). Comparison of HbA1c changes between Asian and Caucasian patients showed a significant between-group difference of -0.18% (95% CI, -0.32% to -0.04%; P = 0.011) when compared with placebo. In Asian patients, the homeostatic model assessment for β-cell function (HOMA-β) was increased with DPP-4 inhibitors compared with placebo (WMD, 7.90; 95% CI, 4.29 to 11.51; P < 0.001), although to a lesser extent in Caucasian patients. Comparisons between Asian and Caucasian patients showed a significant between-group difference of -4.97 (95% CI, -9.86 to -0.09; P = 0.046) compared with placebo. Body weight increase with DPP-4 inhibitors compared with placebo was comparable in Asian and Caucasian studies (WMD, 0.37 kg and 0.45 kg and 95% CI, 0.04-0.69 and 0.27-0.62, respectively).

CONCLUSIONS

The glucose-lowering efficacy of DPP-4 inhibitors was greater in Asian patients than in Caucasian patients, although the effect on β-cell function was inferior in Asian patients. The effect of DPP-4 inhibitors on insulin resistance and body weight in Asian patients was comparable with that observed in Caucasian patients.

Optimal candidates for the switch from glimepiride to sitagliptin to reduce hypoglycemia in patients with type 2 diabetes mellitus

BACKGROUND

Sitagliptin is a novel antidiabetic agent with a low risk for hypoglycemia. We investigated the efficacy and safety of sitagliptin when patients switched from a sulfonylurea to sitagliptin and identified good candidates for the switch.

METHODS

Sixty-one patients with type 2 diabetes switched from glimepiride with metformin to sitagliptin with metformin due to clinical hypoglycemia. Serum glycated hemoglobin (HbA1c), fasting plasma glucose (FPG), and 2-hour postprandial plasma glucose (2h-PPG) before and 12 and 24 weeks after the drug switch were checked.

RESULTS

HbA1c and FPG levels did not change 12 or 24 weeks after the switch; however, the 2h-PPG level decreased from 218.0±67.5 mg/dL at baseline to 197.1±69.9 mg/dL at 12 weeks and 192.3±67.4 mg/dL at 24 weeks after switching drugs (P=0.045, P=0.018, respectively). All but one patient no longer experienced hypoglycemia after discontinuing glimepiride. In a multivariate logistic regression analysis, a high homeostasis model assessment of insulin resistance and low baseline HbA1c level were independent predictors of an HbA1c ≤7% after switching to sitagliptin.

CONCLUSION

Glycemic control was not aggravated in patients 24 weeks after the drug switch, and symptomatic hypoglycemia decreased significantly. Patients with dominant insulin resistance may be good candidates for switching from a sulfonylurea to sitagliptin to reduce hypoglycemia.

Cardiometabolic Effects of a New Class of Antidiabetic Agents

PURPOSE

Within the past decade, many new classes of drugs have received approval from the US Food and Drug Administration for treatment of type 2 diabetes mellitus, including glucagon-like peptide-1agonists, dipeptidyl peptidase-4 inhibitors, and the sodium-glucose cotransporter-2 inhibitors. Many trials have been performed, and several more are currently ongoing to evaluate these drugs. This review addresses the broad therapeutic and pleiotropic effects of these drugs. The review also discusses the role of these drugs in the treatment paradigm for type 2 diabetes and identifies patients who would be suitable candidates for treatment with these drugs.

METHODS

In this comprehensive evidence-based review, the following databases were searched from 1990 to the present: PubMed/MEDLINE, Scopus, CINAHL, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Portal, and the American Diabetes Association and European Association for the Study of Diabetes abstract databases. Randomized clinical trials (RCTs) were only included for the main therapeutic and cardiovascular (CV) effects of these drug classes. For pleiotropic effects, RCTs were included unless no RCTs exist, in which case other studies as specified in the detailed Methods section were included.

FINDINGS

All 3 drug classes are effective in lowering hemoglobin A1c between 0.4% and 1.4%, depending on the drug class and population selected. These drug classes have beneficial effects on CV risk factors, such as weight, lipids, and blood pressure, in addition to lowering blood glucose levels. The CV tolerability of some drugs has been evaluated and found to be neutral; however, most trials are currently ongoing to assess CV tolerability. There are no concrete guidelines to determine where these drugs fit in the diabetes management paradigm, and there are ongoing trials to determine the best combination drug with metformin.

IMPLICATIONS

These 3 drug classes will potentially increase the armamentarium against hyperglycemia. However, the specific combinations with other antidiabetic drugs and populations that will best benefit from these drugs are still being tested. Future research is also being conducted on the use of glucagon-like peptide-1 receptor agonists and sodium-glucose cotransporter-2 inhibitors in patients with type 1 diabetes.

A nomogram to estimate the HbA1c response to different DPP-4 inhibitors in type 2 diabetes: a systematic review and meta-analysis of 98 trials with 24 163 patients

OBJECTIVES

To develop a nomogram for estimating the glycated haemoglobin (HbA1c) response to different dipeptidyl peptidase-4 (DPP-4) inhibitors in type 2 diabetes.

DESIGN

A systematic review and meta-analysis of randomised controlled trials (RCTs) of DPP-4 inhibitors (vildagliptin, sitagliptin, saxagliptin, linagliptin and alogliptin) on HbA1c were conducted. Electronic searches were carried out up to December 2013. Trials were included if they were carried out on participants with type 2 diabetes, lasted at least 12 weeks, included at least 30 participants and had a final assessment of HbA1c. A random effect model was used to pool data. A nomogram was used to represent results of the metaregression model.

PARTICIPANTS

Adults with type 2 diabetes.

INTERVENTIONS

Any DPP-4 inhibitor (vildagliptin, sitagliptin, saxagliptin, linagliptin or alogliptin).

OUTCOME MEASURES

The HbA1c response to each DPP-4 inhibitor within 1 year of therapy.

RESULTS

We screened 928 citations and reviewed 98 articles reporting 98 RCTs with 100 arms in 24 163 participants. There were 26 arms with vildagliptin, 37 with sitagliptin, 13 with saxagliptin, 13 with linagliptin and 11 with alogliptin. For all 100 arms, the mean baseline HbA1c value was 8.05% (64 mmol/mol); the decrease of HbA1c from baseline was -0.77% (95% CI -0.82 to -0.72%), with high heterogeneity (I(2)=96%). Multivariable metaregression model that included baseline HbA1c, type of DPP-4 inhibitor and fasting glucose explained 58% of variance between studies, with no significant interaction between them. Other factors, including age, previous diabetes drugs and duration of treatment added low predictive power (<1%). The nomogram estimates the absolute HbA1c reduction from baseline using the type of DPP-4 inhibitor, baseline values of HbA1c and fasting glucose.

CONCLUSIONS

Baseline HbA1c level and fasting glucose explain most of the variance in HbA1c change in response to DPP-4 inhibitors: each increase of 1.0% units HbA1c provides a 0.4-0.5% units greater fall.

Alogliptin benzoate for the treatment of type 2 diabetes

INTRODUCTION

Type 2 diabetes mellitus continues to be a global problem, placing an enormous burden on healthcare systems and resources. Effective treatment options to minimize the effects of hyperglycemia are essential. Most patients eventually need to take multiple drugs to maintain glycemic control, and many antidiabetic drugs are associated with adverse effects, such as hypoglycemia, weight gain or gastrointestinal effects. Dipeptidyl peptidase (DPP)-4 inhibitor is one of the newer classes of oral antidiabetic drug, and alogliptin is the most recently approved drug in this class.

AREAS COVERED

This paper reviews the pharmacodynamic and pharmacokinetic properties of alogliptin and the results of clinical trials evaluating its efficacy at improving glycemic control in patients with type 2 diabetes both as monotherapy and in combination with other antidiabetic drugs. The drug's tolerability and safety profiles are also considered.

EXPERT OPINION

Alogliptin is a DPP-4 inhibitor that can help in improving glycemic control in patients with type 2 diabetes, including the elderly. It is generally well tolerated and does not increase the risk of hypoglycemia or weight gain.

Vildagliptin vs liraglutide as a second-line therapy switched from sitagliptin-based regimens in patients with type 2 diabetes: A randomized, parallel-group study

Introduction

A step-up strategy for dipeptidyl peptidase (DPP)-4 inhibitor-based regimens has not yet been established. In addition, similarities and differences between DPP-4 inhibitors and glucagon-like peptide (GLP)-1 receptor agonists remain to be elucidated in humans. We investigated the pleiotropic effects of vildagliptin vs liraglutide in patients with type 2 diabetes on sitagliptin-based regimens in an open-label, randomized, clinical trial.

Materials and Methods

A total of 122 patients with type 2 diabetes that was inadequately controlled by sitagliptin-based regimens were randomly assigned to either vildagliptin (50 mg, twice daily) or liraglutide treatment (0.9 mg, once daily) for 12 weeks. The primary outcomes were glycated hemoglobin and body mass index.

Results

Both vildagliptin and liraglutide significantly lowered glycated hemoglobin within 12 weeks after switching from sitagliptin, but liraglutide produced a greater reduction (−0.67 ± 0.12% vs −0.36 ± 0.53%). Liraglutide lowered body mass index, whereas vildagliptin did not affect body mass index. Vildagliptin lowered fasting C-peptide immunoreactivity, but liraglutide did not. Vildagliptin increased serum levels of adiponectin, arachidonic acid, eicosapentaenoic acid and docosahexaenoic acid, whereas liraglutide had no effect on these levels. Quality of life, assessed using the diabetes treatment satisfaction questionnaire, was not impaired in either group. The most common adverse events were gastrointestinal symptoms, which occurred with similar frequencies in both groups.

Conclusions

Vildagliptin-mediated improvements in glycemic control did not correlate with indices for insulin secretion and insulin sensitivity. Switching from sitagliptin to liraglutide is useful in managing hyperglycemia and weight. Each agent exerts unique pleiotropic effects. This trial was registered with the University Hospital Medical Information Network Clinical Trials Registry (no. 000004953).

Alogliptin: A new dipeptidyl peptidase-4 inhibitor for the management of type 2 diabetes mellitus

PURPOSE

The pharmacology, pharmacodynamics, pharmacokinetics, safety, efficacy, and place in therapy of alogliptin and its combinations for managing type 2 diabetes mellitus are reviewed.

SUMMARY

Alogliptin is a selective, orally bioavailable inhibitor of the enzymatic activity of dipeptidyl peptidase-4 (DPP-4). It works by slowing the inactivation of the incretin hormones, thereby increasing their concentrations in the bloodstream and reducing fasting and postprandial glucose concentrations in a glucose-dependent manner in patients with type 2 diabetes mellitus. Alogliptin has a moderate degree of absorption, estimated to exceed 75%, and its absorption is not affected by food. No drug interactions are known to be associated with alogliptin monotherapy. It is indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. The clinical efficacy and safety of alogliptin have been demonstrated in several clinical trials, reducing patients' glycosylated hemoglobin level by 0.4-1.0% in 26 weeks. Alogliptin does not require any dosage adjustment when coadministered with ketoconazole, fluconazole, gemfibrozil, warfarin, metformin, glyburide, and pioglitazone. Alogliptin selectively binds to and inhibits DPP-4 in vitro at concentrations approximating therapeutic exposures. The most common adverse events associated with alogliptin are nasopharyngitis, headache, and upper respiratory tract infection. As with the other DPP-4 inhibitors, use of alogliptin may be associated with the development of pancreatitis during therapy.

CONCLUSION

Alogliptin, a selective DPP-4 inhibitor, does not differ greatly from the other DPP-4 inhibitors currently available. It can be used as monotherapy or in combination with metformin for the management of type 2 diabetes.

Comparison of GLP-1 analogues versus sitagliptin in the management of type 2 diabetes: systematic review and meta-analysis of head-to-head studies

Background

Incretin–based therapies which include glucagon-like peptide-1 (GLP-1) receptor agonists and dipeptidyl peptidase-4 (DPP-4) inhibitors are recommended by several practice guidelines as second-line agents for add-on therapy to metformin in patients with type 2 diabetes (T2DM) who do not achieve glycemic control with metformin plus lifestyle interventions alone. The purpose of this study is to perform a systematic review with meta-analysis of existing head to head studies to compare the efficacy and safety of GLP-1 analogues with DPP-4 inhibitors.

Methods

We performed a systematic review and meta-analysis of head-to-head studies to compare GLP-1 analogues with DPP-4 inhibitors in the management of type 2 diabetes. A random effects model was selected to perform the meta-analyses, results were expressed as weighted mean differences for continuous outcomes and relative risks for dichotomous outcomes, both with 95% confidence intervals, and with I² values and P values as markers of heterogeneity.

Results

Four head-to-head randomized controlled studies with 1755 patients were included. Compared to sitagliptin, GLP-1 analogues are more effective in reducing HbA1C (weight mean difference −0.41%, 95% CI −0.51 to −0.31) and body weight (weight mean difference −1.55 kg, 95% CI −1.98 to −1.12). Conversely, GLP-1 analogues are associated with a higher incidence of gastrointestinal adverse events compared to sitagliptin: nausea (relative risk 3.14, 95% CI 2.15 to 4.59), vomiting (relative risk 2.60, 95% CI 1.48 to 4.56), diarrhea (relative risk 1.82, 95% CI 1.24 to 2.69), and constipation (relative risk 2.50, 95% CI 1.33 to 4.70).

Conclusions

The result of this meta-analysis demonstrates that compared to sitagliptin, GLP-1 analogues are more effective for glycemic control and weight loss, but have similar efficacy in reducing blood pressure and lipid parameters, however, GLP-1 analogues are associated with a higher incidence of gastrointestinal adverse events and a similar incidence of hypoglycemia compared to sitagliptin.

Comparative effectiveness of dipeptidylpeptidase-4 inhibitors in type 2 diabetes: a systematic review and mixed treatment comparison

OBJECTIVE

To compare the safety and efficacy of the dipeptidylpeptidase-4 (DPP-4) inhibitors in patients with type 2 diabetes and inadequate glycemic control.

DESIGN

Systematic review of randomized controlled trials (RCTs), health economic evaluation studies, systematic reviews, and meta-analyses, followed by primary Bayesian mixed treatment comparison meta-analyses (MTCs), and secondary frequentist direct-comparison meta-analyses using a random-effects model. Outcomes were reported as weighted mean change from baseline, or odds ratio (OR) with 95% credible interval.

DATA SOURCES

MEDLINE, MEDLINE In-Process, EMBASE, and BIOSIS via Dialog ProQuest; Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews via EBSCO; four diabetes and two technical congress abstracts; and health technology assessment organization websites.

ELIGIBILITY CRITERIA

Patients with type 2 diabetes and inadequate glycemic control receiving any pharmacological anti-diabetic treatment.

DATA EXTRACTION AND ANALYSIS

Title/abstracts were reviewed for eligibility, followed by full-text review of publications remaining after first pass. A three-person team filtered articles and an independent reviewer checked a random selection (10%) of filtered articles. Data extraction and quality assessment of studies were also independently reviewed. Five DPP-4 inhibitors (alogliptin, linagliptin, saxagliptin, sitagliptin, and vildagliptin) were compared via meta-analysis (where data were available) as monotherapy, dual therapy (plus metformin, sulfonylurea, pioglitazone, or insulin), and triple therapy (plus metformin/sulfonylurea).

RESULTS

The review identified 6,601 articles; 163 met inclusion criteria and 85 publications from 83 RCTs contained sufficient or appropriate data for analysis. MTCs demonstrated no differences between DPP-4 inhibitors in mean change from baseline in glycosylated hemoglobin (HbA1c) or body weight, or the proportions of patients achieving HbA1c <7% or experiencing a hypoglycemic event, apart from in patients on alogliptin plus metformin, who achieved HbA1c <7% more frequently than those treated with saxagliptin plus metformin [OR 6.41 (95% CI 3.15-11.98) versus 2.17 (95% CI 1.56-2.95)].

CONCLUSIONS

This systematic review and MTC showed similar efficacy and safety for DPP-4 inhibitors as treatment for type 2 diabetes, either as monotherapy or combination therapy.

Efficacy and safety of sitagliptin monotherapy and combination therapy in Japanese type 2 diabetes patients

(J Diabetes Invest, doi: 10.1111/j.2040-1124.2012.00221.x, 2012) Aims/Introduction:  To determine the efficacy and safety of sitagliptin monotherapy and combination therapy in Japanese type 2 diabetes patients after 3 months' therapy.

MATERIALS AND METHODS

  A retrospective, observational study of 741 type 2 diabetes patients was carried out; 110 received sitagliptin monotherapy, and 631 received combination therapy with sitagliptin when other oral medications were insufficient. The primary outcome measure was glycated hemoglobin (HbA1c) measured at 0, 4 and 12 weeks of sitagliptin therapy.

RESULTS

  In the monotherapy and combination therapy groups, HbA1c decreased significantly after 12 weeks. Target HbA1c (<7%) was achieved in 39.1% overall. On logistic regression analysis, baseline HbA1c was the strongest contributing factor for achieving target HbA1c; baseline body mass index and duration of diabetes were also significant factors. A total of 82 patients (11%) were unresponsive to sitagliptin. These patients' baseline body mass index was significantly higher and their baseline HbA1c was significantly lower than those of patients who responded to sitagliptin. The most commonly co-administered drugs were sulfonylureas (508 patients). In these patients, the dose of sulfonylurea decreased with time. In 66 patients whose sulfonylurea dosage was reduced when sitagliptin was started, HbA1c and bodyweight decreased significantly after 12 weeks. A total of 24 patients receiving sulfonylureas had mild hypoglycemia, but none discontinued sitagliptin.

CONCLUSIONS

  Sitagliptin was effective and safe as both monotherapy and combination therapy in Japanese type 2 diabetes patients. When sulfonylureas were ineffective, sitagliptin improved glycemic control. In patients whose sulfonylurea dose was reduced at the start of sitagliptin, blood glucose improved and bodyweight decreased after 12 weeks.

A nomogram to estimate the proportion of patients at hemoglobin A1c target <7% with noninsulin antidiabetic drugs in type 2 diabetes: a systematic review of 137 randomized controlled trials with 39,845 patients

We assessed the efficacy of noninsulin antidiabetic medications used in current clinical practice (metformin, sulfonylureas, α-glucosidase inhibitors, thiazolidinediones, glinides, dipeptidyl peptidase-4 inhibitors, glucagon-like peptide-1 agonists) to reach the HbA1c target <7% in people with type 2 diabetes. MEDLINE, EMBASE, and the Cochrane CENTRAL were searched from inception through April 2011 for randomized controlled trials (RCTs) involving noninsulin antidiabetic drugs. RCTs had to report the effect of any diabetes medication on the HbA1c levels, to include at least 30 subjects in every arm of the study, and to last at least 12 weeks. Data were summarized across studies using random-effects meta-regression. We found 137 RCTs with 205 arms and 39,845 patients. The proportion of patients who achieved the HbA1c goal ranged from 25.9% (95% CI 18.5-34.9) with α-glucosidase inhibitors to 48.6% (95% CI, 53.6) with GLP-1 analogs. Baseline HbA1c was the major determinant of the proportion of patients at HbA1c goal. The meta-regression model with mean baseline HbA1c value, concomitant drug use, and class of drugs as covariates explained almost 67% of the between-study variability. A nomogram was developed to estimate the proportion of patients at target for each noninsulin drug class: for a baseline HbA1c level of 7.5%, all noninsulin drugs, except α-glucosidase inhibitors, achieved the HbA1c goal <7% in more than 50% of patients. Starting or intensifying pharmacological therapy at baseline HbA1c 8% or less was associated with more than 50% of patients at HbA1c goal for most noninsulin drugs.

Head-to-head comparison of dipeptidyl peptidase-IV inhibitors and sulfonylureas - a meta-analysis from randomized clinical trials

BACKGROUND

Dipeptidyl peptidase-IV (DPP-4) inhibitors and sulfonylureas are two important second-line anti-diabetic agents. The objective of this research was to evaluate the efficacy and safety of DPP-4 inhibitors compared with sulfonylureas by meta-analytic approach of available randomized studies.

METHODS

We searched MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials databases up to 30 June 2013, collecting all randomized clinical trials with a treatment duration of ≥18weeks. Data on glycated haemoglobin (HbA1c ), body weight, hypoglycaemia, total adverse events, and cardiovascular events were retrieved and analysed.

RESULTS

The analysis included 12 randomized studies comprising 10 982 patients with type 2 diabetes mellitus. On the basis of meta-analysis, sulfonylureas lowered HbA1c significantly more than DPP-4 inhibitors with weighted mean difference (WMD) of 0.105 [95% confidence interval (CI) 0.103 to 0.107]. The results were consistent in trials with longer (>32 weeks) or shorter (≤32 weeks) duration; however, DPP-4 inhibitors showed greater reduction in HbA1c compared with the second-generation sulfonylureas and in patients with baseline eGFR < 50 mL/min/1.73 m(2) . Patients treated with DPP-4 inhibitors are less likely to achieve HbA1c  < 7% compared with sulfonylureas [Mantel-Haenszel odds ratio (MH-OR) 0.91; 95% CI 0.84 to 0.99]. DPP-4 xinhibitors were associated with a reduction in body weight (WMD -1.652; 95% CI -1.658 to -1.646) and lower risk of hypoglycaemia (MH-OR, 0.13; 95% CI 0.11 to 0.16), total adverse events (MH-OR, 0.79; 95% CI 0.72 to 0.87), and cardiovascular events (MH-OR, 0.53; 95% CI 0.32 to 0.87) compared with sulfonylureas.

CONCLUSION

Although DPP-4 inhibitors are less efficacious compared with sulfonylureas, they demonstrate a beneficial effect on body weight, episodes of hypoglycaemia, and total adverse events.

Drug treatment of type 2 diabetes mellitus in patients for whom metformin is contraindicated

Metformin is considered an initial drug of choice for type 2 diabetes mellitus by leading recommendations. When contraindications to its use exist or patients cannot tolerate it due to adverse effects, clinicians have a variety of other classes of agents to treat hyperglycemia associated with type 2 diabetes mellitus. Each class of agent has its own benefit and safety profile. There are numerous factors to consider when selecting another agent in lieu of metformin including, but not limited to, overall efficacy in A1c reduction, adverse effect profile, cost, and patient preference. The number of factors influencing the decision process presents challenges and often no one specific agent is ideal. Each pharmacotherapeutic class of agents alternative to metformin for the treatment of hyperglycemia in type 2 diabetes mellitus as initial monotherapy is reviewed.

The gut-renal axis: do incretin-based agents confer renoprotection in diabetes?

Diabetic nephropathy is the leading cause of end-stage renal disease worldwide, and is associated with a high risk of cardiovascular morbidity and mortality. Intensive control of glucose levels and blood pressure is currently the mainstay of both prevention and treatment of diabetic nephropathy. However, this strategy cannot fully prevent the development and progression of diabetic nephropathy, and an unmet need remains for additional novel therapies. The incretin-based agents--agonists of glucagon-like peptide 1 receptor (GLP-1R) and inhibitors of dipeptidyl peptidase 4 (DPP-4), an enzyme that degrades glucagon-like peptide 1--are novel blood-glucose-lowering drugs used in the treatment of type 2 diabetes mellitus (T2DM). Therapeutic agents from these two drug classes improve pancreatic islet function and induce extrapancreatic effects that ameliorate various phenotypic defects of T2DM that are beyond glucose control. Agonists of GLP-1R and inhibitors of DPP-4 reduce blood pressure, dyslipidaemia and inflammation, although only GLP-1R agonists decrease body weight. Both types of incretin-based agents inhibit renal tubular sodium reabsorption and decrease glomerular pressure as well as albuminuria in rodents and humans. In rodents, incretin-based therapies also prevent onset of the morphological abnormalities of diabetic nephropathy.