Alogliptin added to insulin therapy in patients with type 2 diabetes reduces HbA(1C) without causing weight gain or increased hypoglycaemia

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.

Medical treatment of Cushing's disease with concurrent diabetes mellitus

Cushing's disease (CD) is a severe endocrine disorder characterized by chronic hypercortisolaemia secondary to an overproduction of adrenocorticotropic hormone (ACTH) by a pituitary adenoma. Cortisol excess impairs normal glucose homeostasis through many pathophysiological mechanisms. The varying degrees of glucose intolerance, including impaired fasting glucose, impaired glucose tolerance, and Diabetes Mellitus (DM) are commonly observed in patients with CD and contribute to significant morbidity and mortality. Although definitive surgical treatment of ACTH-secreting tumors remains the most effective therapy to control both cortisol levels and glucose metabolism, nearly one-third of patients present with persistent or recurrent disease and require additional treatments. In recent years, several medical therapies demonstrated prominent clinical efficacy in the management of patients with CD for whom surgery was non-curative or for those who are ineligible to undergo surgical treatment. Cortisol-lowering medications may have different effects on glucose metabolism, partially independent of their role in normalizing hypercortisolaemia. The expanding therapeutic landscape offers new opportunities for the tailored therapy of patients with CD who present with glucose intolerance or DM, however, additional clinical studies are needed to determine the optimal management strategies. In this article, we discuss the pathophysiology of impaired glucose metabolism caused by cortisol excess and review the clinical efficacy of medical therapies of CD, with particular emphasis on their effects on glucose homeostasis.

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.

Novel approaches to hypoglycemia and burnt-out diabetes in chronic kidney disease

PURPOSE OF REVIEW

Diabetes mellitus is a leading cause of chronic kidney disease (CKD) that confers faster kidney disease progression, higher mortality, and various metabolic derangements including hypoglycemia.

RECENT FINDINGS

Even in the absence of diabetes mellitus, growing research demonstrates that CKD patients are at heightened risk for hypoglycemia via multiple pathways. In CKD patients transitioning to end-stage renal disease (ESRD), spontaneous resolution of hyperglycemia and frequent hypoglycemia resulting in reduction and/or cessation of glucose-lowering medications are frequently observed in a phenomenon described as 'burnt-out diabetes'. In non-CKD patients, it is well established that hypoglycemia is causally associated with mortality, with pathways including arrhythmias, sudden cardiac death, stroke, and seizures. Increasing evidence shows that, in CKD and ESRD patients with and without diabetes mellitus, hypoglycemia is associated with cardiovascular complications and mortality risk.

SUMMARY

Given the high prevalence of hypoglycemia in CKD patients and the morbidity and mortality associated with this metabolic complication, a multimodal strategy is needed to prevent dysglycemia, including individualization of glycemic targets, selection of glucose-lowering medications less likely to induce hypoglycemia, medical nutrition therapy administered by trained dietitians, and accurate and precise hypoglycemia detection methods, such as self-monitored blood glucose or continuous glucose monitoring including during dialysis treatment.

Novel mechanistic insights towards the repositioning of alogliptin in Parkinson's disease

Parkinson's disease (PD) is a progressive neurodegenerative disease that impairs people's lives tremendously. The development of innovative treatment modalities for PD is a significant unmet medical need. The critical function of glucagon-like peptide-1 (GLP-1) in neurodegenerative diseases has raised impetus in investigating the repositioning of a dipeptidyl peptidase IV inhibitor, alogliptin (ALO), as an effective treatment for PD. As a result, the focus of this research was to assess the effect of ALO in a rat rotenone (ROT) model of PD. For 21 days, ROT (1.5 mg/kg) was delivered subcutaneously every other day. ALO (30 mg/kg/day), delivered by gavage for 21 days, recovered motor performance and improved motor coordination in the open-field and rotarod testing. These impacts were highlighted by restoring striatal dopamine content and correcting histological changes that occurred concurrently. The ALO molecular signaling was determined by increasing the quantity of GLP-1 and the protein expression of its downstream signaling pathway, pT172-AMPK/SIRT1/PGC-1α. Furthermore, it curbed neuroinflammation via hampering HMGB1/TLR4/NLRP3 inflammasome activation and conquered striatal microglia activation. Pre-administration of dorsomorphin reversed the neuroprotective effects. In conclusion, the promising neuroprotective effect of ALO highlights the repositioning of ALO as a prospective revolutionary candidate for combating PD.

Comparison of New Glucose-Lowering Drugs on Risk of Pancreatitis in Type 2 Diabetes: A Network Meta-Analysis

BACKGROUND & AIMS

Whether new glucose-lowering drugs increases the risk of pancreatitis in individuals with type 2 diabetes remains controversial. This present network meta-analysis aims to investigate the risk of pancreatitis associated with the use of glucagon-like peptide (GLP)-1 agonists and dipeptidyl peptidase (DPP)-4 inhibitors in the treatment of type 2 diabetes mellitus.

METHODS

PubMed, Web of Science, EMBASE and the Cochrane Library were searched. The literature was published from the date of their inception to July 21, 2021, including placebo-controlled or head-to-head trials of 2 new glucose-lowering drugs. Relative ratio (RR) and 95% confidence interval (CI) were used to assess the risk of GLP-1 agonists and DPP-4 inhibitors for pancreatitis or pancreatic cancer among patients with type 2 diabetes.

RESULTS

Seventeen studies were identified, covered 102257 participants. The pooled results showed a neutral relationship between GLP-1 agonists and pancreatitis (Overall RR, 0.96; 95% CI, 0.31-3.00) or pancreatic cancer (Overall RR, 1.10; 95% CI, 0.31-4.10) compared to placebo. Meanwhile, DPP-4 inhibitors were not be associated with the increased risk of pancreatitis (Overall RR, 1.60; 95% CI, 0.25-11.00) or pancreatic cancer (Overall RR, 0.79; 95% CI, 0.26-2.40). Among them, lixisenatide and saxagliptin may be the safest drug compared to other drugs according to the ranking of probability. Sensitivity and subgroup analysis confirmed the stability of the core results.

CONCLUSION

The most obvious finding to emerge from this study is that GLP-1 agonists and DPP-4 inhibitors are safe with respect to pancreatitis and pancreatic cancer risk compared to placebo. This conclusion may provide useful evidence for correlated clinical researches.

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

A randomized, placebo-controlled study to evaluate the efficacy and safety of adding omarigliptin to insulin therapy in Japanese patients with type 2 diabetes and inadequate glycaemic control

AIM

To evaluate the efficacy and safety of adding the once-weekly oral dipeptidyl peptidase-4 inhibitor omarigliptin to treatment of Japanese patients with type 2 diabetes and inadequate glycaemic control on insulin monotherapy.

MATERIALS AND METHODS

In a 52-week clinical trial, Japanese patients on insulin monotherapy were randomized to once-weekly omarigliptin 25 mg (N = 123) or placebo (N = 61) for a 16-week, double-blind, placebo-controlled period. After Week 16, patients continued or switched to omarigliptin for a 36-week open-label period.

RESULTS

From a mean baseline of approximately 8.8%, the Week 16 least squares mean changes in HbA1c were -0.61% (omarigliptin) and 0.29% (placebo); the between-group difference was -0.90% (p < .001). At Week 52, the mean change from baseline in HbA1c was -0.57% in both the group on omarigliptin for 52 weeks and the group on omarigliptin for 36 weeks (switched from placebo at Week 16). During the first 16 weeks of treatment, the incidences of adverse events (AEs), serious AEs, drug-related AEs and discontinuation from trial medication because of an AE were similar in both groups. A slight increase in incidence of symptomatic hypoglycaemia was observed in the omarigliptin group (n = 13 [10.6%]) compared with placebo (n = 4 [6.6%]). No severe hypoglycaemia was reported during the study. No new safety signals emerged with treatment beyond Week 16 through Week 52.

CONCLUSION

The addition of once-weekly omarigliptin to insulin therapy for up to 52 weeks was generally well tolerated and provided clinically meaningful improvement in glycaemic control throughout the trial period. ClinicalTrials.gov: NCT02906709.

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.

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.

Benefit-Risk Assessment of Alogliptin for the Treatment of Type 2 Diabetes Mellitus

The dipeptidyl peptidase-4 inhibitor (DPP-4i) alogliptin is an oral, antidiabetic treatment that is approved in many countries to treat patients with type 2 diabetes mellitus (T2DM), including the USA, Europe, and Japan. Alogliptin is efficacious both as monotherapy and as add-on/combination therapy with other commonly prescribed T2DM treatments, such as metformin and pioglitazone. Overall, alogliptin is well-tolerated in patients with T2DM, including older patients, those with renal and/or hepatic impairment, and those at high risk of cardiovascular events. There is a low risk of hypoglycemia, weight gain, acute pancreatitis, and gastrointestinal adverse events with alogliptin treatment, as demonstrated in long-term trials (lasting up to 4.5 years) and in a real-world setting. Additionally, alogliptin has a generally favorable or similar safety profile in comparison to other antidiabetic agents (metformin, thiazolidinediones, sulfonylureas, glucagon-like peptide-1 receptor agonists, sodium-glucose cotransporter 2 inhibitors, α-glucosidase inhibitors, and insulin). However, further evaluation would be required to determine the mechanism and effect of alogliptin on heart failure, bullous pemphigoid, and inflammatory bowel disease. Of note, due to the ethnic diversity in the epidemiology of T2DM, alogliptin has been shown to be more efficacious in Asian patients than in non-Asian patients with T2DM, but with a similar tolerability profile. These data indicate that DPP-4is, including alogliptin, are important treatment options, especially for Asian patients with T2DM, for whom they have potential as a first-line therapy. This benefit-risk assessment aims to place alogliptin within the current armamentarium of T2DM and aid physicians when choosing optimal diabetes treatment for their patients.

Efficacy and safety of gemigliptin as add-on therapy to insulin, with or without metformin, in patients with type 2 diabetes mellitus (ZEUS II study)

The objective of this study was to evaluate the efficacy and safety of gemigliptin added to a stable dose of insulin alone or of insulin in combination with metformin in patients with type 2 diabetes mellitus. After a two-week run-in period, patients were randomized 2:1 to receive gemigliptin 50 mg or placebo once daily as add-on to background therapy with insulin or insulin plus metformin for 24 weeks. The primary endpoint was change in haemoglobin A1c (HbA1c) from baseline at Week 24. Baseline characteristics were similar between the gemigliptin (n = 188) and placebo (n = 95) groups in terms of HbA1c (8.1%). At Week 24, the gemigliptin group showed a statistically significant reduction in mean HbA1c from baseline as compared with placebo (between-group mean difference, -0.7% [95% CI, -0.9% to -0.4%]; P-value < 0.0001). The incidence of overall adverse events and the number of hypoglycaemic adverse events were similar between the study groups. Gemigliptin added to insulin alone or to insulin in combination with metformin resulted in superior glycaemic control compared to that in the placebo group and was well tolerated for 24 weeks in patients with type 2 diabetes mellitus, without causing weight gain or increasing the incidence of hypoglycaemia.

Meta-Analysis of 11 Heterogeneous Studies regarding Dipeptidyl Peptidase 4 Inhibitor Add-On Therapy for Type 2 Diabetes Mellitus Patients Treated with Insulin

BACKGROUND

Several clinical trials have addressed the therapeutic strategy of adding dipeptidyl peptidase 4 (DPP-4) inhibitors to the treatment of type 2 diabetes mellitus (DM) inadequately controlled by insulin therapy. However, there is a high degree of heterogeneity in these studies, and the cause of which has not been identified.

METHODS

We conducted a meta-analysis of randomized controlled trials, which compared the efficacy and safety of adding DPP-4 inhibitors or placebo to insulin therapy; the level of hemoglobin A1c (HbA1c) in the patients was >7.0%, and the duration of treatment was ≥8 weeks. We focused on the mean changes in HbA1c from the baseline (ΔHbA1c) and the incidence of hypoglycemia. We assumed that five baseline parameters (HbA1c, fasting blood glucose, body mass index (BMI), duration of type 2 DM, and duration of treatment) could affect ΔHbA1c. Regarding the incidence of hypoglycemia, we suspected that the heterogeneity was caused by differences in the definition of hypoglycemia among the studies.

RESULTS

Data obtained from 11 studies (n = 4654 patients) were included in the analysis. The mean ΔHbA1c between the DPP-4 inhibitor and placebo groups was -0.61% (95% confidence interval (CI): -0.74 to -0.48, I ² = 73.4%). There was substantial heterogeneity among the 11 studies, but 74.1% of this variability was explained by the difference in BMI. The odds ratio for the incidence of hypoglycemia was 1.02 (95% CI: 0.74 to 1.42, I ² = 63.8%), with substantial heterogeneity due to differences in the definition of hypoglycemia among the studies. There was no apparent effect of publication bias.

CONCLUSIONS

The addition of DPP-4 inhibitors to insulin therapy for adult patients with type 2 DM can significantly reduce HbA1c levels without increasing the occurrence of hypoglycemia. BMI and hypoglycemia definition could explain the heterogeneity in the clinical trials. This trial is registered with PROSPERO #CRD42016035994.

Efficacy and safety of linagliptin to improve glucose control in older people with type 2 diabetes on stable insulin therapy: A randomized trial

AIM

To assess the addition of linagliptin as an alternative to insulin uptitration in older people with type 2 diabetes on stable insulin therapy.

MATERIALS AND METHODS

This phase 4, randomized, multicentre, double-blinded, placebo-controlled, 24-week study recruited individuals on stable insulin, with baseline HbA1c 7.0%-10.0%, aged ≥60 years and body mass index ≤45 kg/m² . HbA1c and fasting plasma glucose were measured at study visits, and participants assessed glycaemic control with a self-monitoring blood glucose device. Adverse events (AEs) were reported during the study.

RESULTS

Three hundred and two participants were randomized 1:1 to linagliptin 5 mg qd and placebo, with one third of patients from Japan. Study population age and HbA1c (baseline mean ± SD) were 72.4 ± 5.4 years and 8.2 ± 0.8%, respectively; ~80% of participants were aged ≥70 years; 80% had macrovascular complications, one third had a baseline estimated glomerular filtration rate <60 mL/min/1.73 m² ; and half had been diagnosed with diabetes for >15 years. Linagliptin significantly improved glucose control at 24 weeks (HbA1c-adjusted mean change vs. placebo: -0.63%; P <0.0001) and the probability of achieving predefined HbA1c targets without hypoglycaemia (HbA1c <8.0%: OR 2.02; P <0.05 and HbA1c <7.0%: OR 2.44; P <0.01). Linagliptin versus placebo was well tolerated, with similar incidences of AEs, including clinically important hypoglycaemia (blood glucose <54 mg/dL) or severe hypoglycaemia.

CONCLUSIONS

Addition of linagliptin improves glucose control without an excess of hypoglycaemia in older patients with type 2 diabetes on stable insulin therapy.

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.

Post-marketing Study of Linagliptin: A Pilot Study

INTRODUCTION

Linagliptin is a high-cost oral antidiabetic that has been widely used, and studies on its effectiveness and safety for the treatment of type 2 diabetes mellitus (DM2) in the real world is rare and necessary.

OBJECTIVE

To analyze the values of glycated hemoglobin (HbA1c) and adverse events before and after the use of linagliptin in the post-marketing context of a pilot study.

METHODS

This is a descriptive observational and exploratory study with a retrospective longitudinal approach, conducted between January 2014 and December 2016. All patients who participated in the study were over 18 years of age, with DM2, assisted by the Brazilian Public Health System (Sistema Único de Saúde - SUS) and had been indicated for use of linagliptin. The users were followed up and the variables of interest were collected from a computerized health information system (sistema informatizado de saúde - SIS) and patient records. For effectiveness analysis, HbA1c before (T0) and after (T1) the use of linagliptin was considered in patients registered as having collected linagliptin at the pharmacy for at least three consecutive months. For safety analysis, registered adverse events (AE) were verified in patients' records. The sample was stratified according to the pharmacotherapeutic scheme of the users. To compare the means before (T0) and after (T1), a paired t-test (data with normal distribution) and Wilcoxon Signed Rank Sum test (non-normal distribution data) were performed.

RESULTS

Considering the total population of the study, in a different pharmacotherapeutic regimen, a median reduction in HbA1c of -0.86% (p < 0.05) was observed. After stratification by pharmacotherapeutic regimen, the most significant reduction of HbA1c was -1.07% (p = 0.014) for the linagliptin group associated with insulins and oral antidiabetic agents (n = 13). On the other hand, patients taking linagliptin in monotherapy had the lowest HbA1c reduction, -0.48% (p > 0.05). AE occurred in 12 (36.4%) patients, and 16.7% were in monotherapy.

CONCLUSION

Linagliptin did not presented, in real world, the desired performance as showed in randomized premarketing clinical trials and it should be carefully evaluated in public health services.

Double-blind, randomized clinical trial comparing the efficacy and safety of continuing or discontinuing the dipeptidyl peptidase-4 inhibitor sitagliptin when initiating insulin glargine therapy in patients with type 2 diabetes: The CompoSIT-I Study

AIMS

To compare the effects of continuing versus discontinuing sitagliptin when initiating and intensively titrating insulin glargine.

MATERIALS AND METHODS

Eligible patients had inadequately controlled type 2 diabetes on metformin (≥1500 mg/d) in combination with a dipeptidyl peptidase-4 (DPP-4) inhibitor and/or a sulphonylurea. Those on metformin + sitagliptin were directly randomized; all others were switched to metformin + sitagliptin (discontinuing other DPP-4 inhibitors and sulphonylureas) and stabilized during a run-in period. At randomization, patients were allocated to continuing sitagliptin or discontinuing sitagliptin, with both groups initiating insulin glargine and titrating to a target fasting glucose of 4.0 to 5.6 mmol/L.

RESULTS

A total of 743 participants (mean glycated haemoglobin [HbA1c] 72.6 mmol/mol [8.8%], disease duration 10.8 years), were treated. After 30 weeks, the mean HbA1c and least squares (LS) mean change from baseline in HbA1c were 51.4 mmol/mol (6.85%) and -20.5 mmol/mol (-1.88%) in the sitagliptin group and 56.4 mmol/mol (7.31%) and -15.5 mmol/mol (-1.42%) in the placebo group; the difference in LS mean changes from baseline HbA1c was -5.0 mmol/mol (-0.46%; P < 0.001). The percentage of participants with HbA1c <53 mmol/mol (<7.0%) was higher (54% vs. 35%) and the mean daily insulin dose was lower (53 vs. 61 units) in the sitagliptin group. Despite lower HbA1c, event rates and incidences of hypoglycaemia were not higher in the sitagliptin group. Adverse events overall and changes from baseline in body weight were similar between the two treatment groups.

CONCLUSION

When initiating insulin glargine therapy, continuation of sitagliptin, compared with discontinuation, resulted in a clinically meaningful greater reduction in HbA1c without an increase in hypoglycaemia. ClinicalTrials.gov Identifier: NCT02738879.

DPP-4 Inhibition and the Path to Clinical Proof

In the 1990s it was discovered that the enzyme dipeptidyl peptidase-4 (DPP-4) inactivates the incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). DPP-4 inhibition results in raised levels of the two incretin hormones which in turn result in lowering of circulating glucose through stimulation of insulin secretion and inhibition of glucagon secretion. Since then, several small orally available molecules have been developed with DPP-4 inhibitory action. Early studies in the 1990s showed that the DPP-4 inhibitors improve glycemia in animals. Subsequent clinical studies during the 2000s showed a glucose-lowering action of DPP-4 inhibitors also in human subjects with type 2 diabetes. This action was seen when DPP-4 inhibitors were used both as monotherapy and as add-on to other therapies, i.e., metformin, sulfonylureas, tiazolidinediones or exogenous insulin. The DPP-4 inhibitors were also found to have a low risk of adverse events, including hypoglycemia. Five of the DPP-4 inhibitors (sitagliptin, vildagliptin, alogliptin, saxagliptin and linagliptin) were approved by regulatory authorities and entered the market between 2006 and 2013. DPP-4 inhibitors have thereafter undergone long-term cardiovascular outcome trials, showing non-inferiority for risk of major acute cardiovascular endpoints. Also the risk of other potential adverse events is low in these long-term studies. DPP-4 inhibitors are at present included in guidelines as a glucose-lowering concept both as monotherapy and in combination therapies. This article summarizes the development of the DPP-4 inhibition concept from its early stages in the 1990s. The article underscores that the development has its basis in scientific studies on pathophysiology of type 2 diabetes and the importance of targeting the islet dysfunction, that the development has been made possible through academic science in collaboration with the research-oriented pharmaceutical industry, and that the development of a novel concept takes time and requires focused efforts, persistence and long-term perserverance.

Dipeptidyl peptidase-4 inhibitors as add-on therapy to insulin in patients with type 2 diabetes mellitus: a meta-analysis of randomized controlled trials

PURPOSE

Addition of the dipeptidyl peptidase-4 (DPP4) inhibitors to insulin in patients with type 2 diabetes mellitus (T2DM) may achieve better glycemic control. However, results of pilot randomized controlled trials (RCTs) are inconsistent. We aimed to perform a meta-analysis of RCTs to evaluate efficacy and safety of DPP4 inhibitors compared with placebo/no treatment as add-on therapy to insulin in T2DM patients.

MATERIALS AND METHODS

Relevant studies were identified via a search of PubMed, Cochrane Library, and Embase databases. A fixed or random effect model was applied according to the heterogeneity.

RESULTS

Overall, 22 RCTs with 6,957 T2DM patients were included. Addition of DPP4 inhibitors to insulin was associated with significantly reduced HbA1c as compared with controls (weighed mean difference [WMD]: -0.54%, p<0.001). The benefits of DPP4 inhibitors as add-on therapy on HbA1c were independent of study design, follow-up duration, categories of DPP4 inhibitors used, and using of fixed/adjustable insulin doses as indicated by predefined subgroup analyses. Moreover, addition of DPP4 inhibitors to insulin was associated with significantly reduced fasting blood glucose (WMD: -0.47mmol/L, p<0.001), postprandial glucose at 2 hrs (WMD: -2.03 mmol/L, p<0.001), and daily dose of insulin (WMD: -2.73U/d, p<0.001), while body weight (WMD: 0.02 g, p=0.81) or risk of symptomatic hypoglycemia (risk ratio: 0.92, p=0.37) were not affected.

CONCLUSIONS

Addition of DPP4 inhibitors to insulin significantly improved the glycemic control in T2DM patients without further increasing the risk of weight gain and hypoglycemia.

Safety and Efficacy of DPP4 Inhibitor and Basal Insulin in Type 2 Diabetes: An Updated Review and Challenging Clinical Scenarios

The safety and efficacy of dipeptidyl peptidase-4 (DPP4) inhibitors as monotherapy or in combination with other oral antidiabetic agents or basal insulin are well established. DPP4 inhibitors stimulate glucose-dependent insulin secretion and inhibit glucagon production. As monotherapy, they reduce the hemoglobin A1c level by about 0.6-0.8%. The addition of a DPP4 inhibitor to basal insulin is an attractive option, because they lower both postprandial and fasting plasma glucose concentrations without increasing the risk of hypoglycemia or weight gain. The present review summarizes the extensive evidence on the combination therapy of DPP4 inhibitors and insulin-based regimens in patients with type 2 diabetes. We focus our discussion on challenging clinical scenarios including patients with chronic renal impairment, elderly persons and hospitalized patients. The evidence indicates that these drugs are highly effective and safe in the elderly and in the presence of mild, moderate and severe renal failure improving glycemic control with low risk of hypoglycemia. In addition, several randomized-controlled trials have shown that the use of DPP4 inhibitors in combination with basal insulin represents an alternative to the basal-bolus insulin regimen in hospitalized patients with type 2 diabetes.

A practical approach and algorithm for intensifying beyond basal insulin in type 2 diabetes

Despite the availability of long-term data demonstrating the benefits of timely and aggressive intensification of antihyperglycaemic regimens among individuals with type 2 diabetes, intensification beyond basal insulin continues to be suboptimal and a global challenge. This review summarizes the evidence surrounding the various options of advancing glucose-lowering management beyond basal insulin and provides a practical algorithm to assist in optimizing patient care and enhancing glycaemic target achievements.

Addition of dipeptidyl peptidase-4 inhibitors to insulin treatment in type 2 diabetes patients: A meta-analysis

AIMS/INTRODUCTION

To evaluate the efficacy and safety of combining insulin therapy with dipeptidyl peptidase-4 (DPP-4) inhibitors compared with combining insulin therapy with a placebo or other antihyperglycemic agents.

MATERIALS AND METHODS

A literature search was carried out via electronic databases. The inclusion criteria were randomized controlled trials comparing the addition of DPP-4 inhibitors to insulin with the addition of a placebo or other active hypoglycemic agents to insulin therapy, study duration of no less than 12 weeks carried out in type 2 diabetes patients and the availability of outcome data to evaluate a change in the glycated hemoglobin.

RESULTS

The glycated hemoglobin-lowering efficacy was significantly greater with DPP-4 inhibitor/insulin (DPP-4i/INS) than with placebo/insulin (weighted mean difference -0.53%, 95% confidence interval -0.63, -0.43, P < 0.01). The postprandial plasma glucose-lowering efficacies was also significantly greater with DPP-4i/INS than with placebo/insulin (weighted mean difference -1.65 mmol/L, 95% CI: -2.34, -0.96, P < 0.05). The risk of hypoglycemia or severe hypoglycemia was similar for DPP4i/INS and placebo/insulin treatments. There was no significant difference in the glycemia-lowering efficacy between DPP-4i/INS and alpha-glucosidase inhibitors/insulin, thiazolidinedione/insulin and glucagon-like peptide-1 receptor agonist/insulin. Sodium-glucose cotransporter 2 inhibitor/insulin treatment achieved better placebo-corrected efficacy in lowering postprandial plasma glucose, with less weight gain and no higher risk of hypoglycemia.

CONCLUSIONS

Treatment with DPP-4 inhibitors combined with insulin improved glycemic control without an increased risk of hypoglycemia or weight gain compared with insulin treatment alone.

Comparison of non-insulin antidiabetic agents as an add-on drug to insulin therapy in type 2 diabetes: a network meta-analysis

We aimed to evaluate the comparative efficacy and safety of dipeptidyl peptidase-4 inhibitors (DPP4i), glucagon-like peptide-1 receptor agonists (GLP-1RA), sodium-glucose co-transporter 2 inhibitors (SGLT2i), or thiazolidinedione (TZD) as an adjunctive treatment in patients with poorly controlled type 2 diabetes mellitus (T2DM) on insulin therapy. We searched Medline, Embase, the Cochrane Library, and ClinicalTrials.gov through April 2016. Bayesian network meta-analyses were performed with covariate adjustment. The primary outcome was the change in glycated hemoglobin A1c (HbA1c) from baseline. Fifty randomized controlled trials covering 15,494 patients were included. GLP-1RA showed the greatest HbA1c-lowering effect compared to the control (−0.84%; 95% credible interval, −1.00% to −0.69%), followed by TZD (−0.73%; −0.93 to −0.52%), SGLT2i (−0.66%; −0.84% to −0.48%), and DPP4i (−0.54%; −0.68% to −0.39%). SGLT2i showed the greatest fasting plasma glucose reduction. GLP-1RA and SGLT2i showed greater body weight reduction, whereas TZD increased body weight. TZD was ranked the highest in terms of insulin dose reduction. The risk of hypoglycemia was increased with TZD or GLP-1RA. The study provides the best available evidence on the comparative efficacy and safety of non-insulin anti-diabetic agents on top of pre-existing insulin therapy for inadequately controlled T2DM patients.

A review of dipeptidyl peptidase-4 inhibitors. Hot topics from randomized controlled trials

The first clinical study to investigate effects of dipeptidyl peptidase-4 (DPP-4) inhibition was published in 2002, and since then, numerous randomized controlled trials (RCTs) have shown that DPP-4 inhibitors are efficacious, safe and well-tolerated. This review will focus upon RCTs which have investigated DPP-4 inhibitors in patient groups which are often under-represented or excluded from typical phase 3 clinical trials. Large cardiovascular (CV) safety outcome trials in patients with established CV disease have confirmed that DPP-4 inhibitors are not associated with any additional CV risk in these already-at-high-risk individuals, while raising awareness of any uncommon adverse events, such as heart failure hospitalization seen in one of the trials. Studies in patients with kidney disease have shown DPP-4 inhibitors to be efficacious without increasing the risk of hypoglycaemia, irrespective of the degree of renal impairment, while data from the large CV trials as well as smaller RCTs have even pointed towards potential renoprotective effects such individuals. The use of DPP-4 inhibitors with insulin when therapy requires intensification may be beneficial without affecting the incidence or severity of hypoglycaemia, with these effects also being replicated in patients with chronic kidney disease, for whom other agents may not be suitable. Attention is now turning towards exploring the potential utility of DPP-4 inhibitors in other circumstances, including for in-hospital management of hyperglycaemia and in other metabolic disorders. Together, these RCTs raise the possibility that in the future, DPP-4 inhibitors may have a broader use which may extend beyond glycaemic control in the typical type 2 diabetes mellitus (T2DM) patient seen in general practice and may encompass conditions other than T2DM.

Ethnic Differences in Efficacy and Safety of Alogliptin: A Systematic Review and Meta-Analysis

INTRODUCTION

Alogliptin is a highly selective, potent, and orally available dipeptidyl peptidase-4 (DPP-4) inhibitor. This study compared the glucose-lowering efficacy and safety of alogliptin between Asian and non-Asian patients with type 2 diabetes.

METHODS

We systematically searched MEDLINE, EMBASE, Cochrane Library, and ISI Web of Science databases for articles published June 2017 and earlier in English. We identified randomized controlled trials (RCTs) of adults with type 2 diabetes that compared alogliptin with placebo as either monotherapy or add-on therapy. We divided subgroups by ethnicity, and compared the results of alogliptin use in Asian and non-Asian-dominant studies.

RESULTS

A total of 15 RCTs with 4456 patients with type 2 diabetes were included in this study. Alogliptin lowered glycated hemoglobin (HbA1c) to a much greater extent in Asian-dominant studies [- 0.75% (95% CI - 0.84 to - 0.65)] than in non-Asian-dominant studies [- 0.61% (95% CI - 0.68 to - 0.54)] (P = 0.02). The risk ratio of achieving HbA1c goal was larger in Asian-dominant studies [2.88 (95% CI 2.15-3.87)] than in non-Asian-dominant studies [1.93 (95% CI 1.55-2.41)] (P = 0.03). The postprandial blood glucose-lowering efficacy was higher in Asian-dominant studies [- 2.42 mmol/l (95% CI - 2.99 to - 1.85)] than in non-Asian-dominant studies [- 0.60 mmol/l (95% CI - 1.60 to 0.40)] (P = 0.002), while the fasting blood glucose and body weight changes were similar between the two subgroups. The incidence of adverse events, including hypoglycemia, nasopharyngitis, upper respiratory tract infection, headache, and diarrhea, were comparable between the two groups.

CONCLUSIONS

Alogliptin is more effective in improving glycemic levels in Asians than in other ethnic populations. Future studies are required to explore the potential mechanisms.

Improving postprandial hyperglycemia in patients with type 2 diabetes already on basal insulin therapy: Review of current strategies

A large number of patients with type 2 diabetes (T2D) on basal insulin do not reach their HbA1c goals and require additional therapy to address postprandial hyperglycemia. Guidelines from expert bodies have outlined several approaches to accomplish postprandial glucose (PPG) control, and recent literature suggests several more. This article provides strategies for primary care physicians caring for patients with T2D who do not achieve glycemic control with basal insulin alone. Current treatment guidelines and strategies for improving PPG control are reviewed, including the efficacy, safety, and cost-effectiveness of rapid-acting insulin (RAI) analogs, premixed insulin, glucagon-like peptide-1 (GLP-1) receptor agonists (RAs), dipeptidyl peptidase 4 inhibitors, sodium-glucose cotransporter 2 inhibitors, and α-glucosidase inhibitors. Other approaches, such as combinations of newer basal insulin plus RAI and a fixed-ratio combination of basal insulin and a GLP-1 RA, are also described.

The effect of concomitant DPPIVi use on glycaemic control and hypoglycaemia with insulin glargine 300 U/mL (Gla-300) versus insulin glargine 100 U/mL (Gla-100) in people with type 2 diabetes: A patient-level meta-analysis of EDITION 2 and 3

Aims

To evaluate the effect of concomitant dipeptidyl peptidase IV inhibitor (DPPIVi) use on efficacy and safety of insulin glargine 300 U/mL (Gla-300) versus glargine 100 U/mL (Gla-100) in people with type 2 diabetes on oral antihyperglycaemic drugs.

Methods

A post hoc patient-level meta-analysis was performed using data from EDITION 2 (basal insulin [N = 811]) and EDITION 3 (insulin-naïve [N = 878]), multicentre, randomised, open-label, parallel-group, phase 3a trials of similar design. Endpoints analysed included HbA_1c, hypoglycaemia and adverse events, investigated in subgroups of participants with and without concomitant DPPIVi use.

Results

Of 1689 participants randomised, 107 (13%, Gla-300) and 133 (16%, Gla-100) received DPPIVi therapy. The least squares mean change in HbA_1c (baseline to month 6) was comparable between treatment groups, irrespective of DPPIVi use (no evidence of heterogeneity of treatment effect across subgroups, p = 0.753), although group sizes were unbalanced. The cumulative mean number of confirmed (≤3.9 mmol/L [≤70 mg/dL]) or severe hypoglycaemic events, and the risk and annualised rate of such events, were consistently lower for Gla-300 than Gla-100 during the night (between 00:00 and 05:59 h) or at any time of day (24 h period), irrespective of DPPIVi use. Severe hypoglycaemia occurred in 8/838 and 10/844 participants in the Gla-300 and Gla-100 groups, respectively, and was not affected by DPPIVi use. The adverse event profile was similar between treatment groups and DPPIVi subgroups.

Conclusions

Glycaemic control with Gla-300 was comparable to Gla-100, with less hypoglycaemia during the night and at any time of day (24 h), irrespective of concomitant DPPIVi use.

Trial registration

ClinicalTrials.gov NCT01499095; NCT01676220

Diabetes Mellitus Secondary to Cushing's Disease

Associated with important comorbidities that significantly reduce patients' overall wellbeing and life expectancy, Cushing's disease (CD) is the most common cause of endogenous hypercortisolism. Glucocorticoid excess can lead to diabetes, and although its prevalence is probably underestimated, up to 50% of patients with CD have varying degrees of altered glucose metabolism. Fasting glycemia may nevertheless be normal in some patients in whom glucocorticoid excess leads primarily to higher postprandial glucose levels. An oral glucose tolerance test should thus be performed in all CD patients to identify glucose metabolism abnormalities. Since diabetes mellitus (DM) is a consequence of cortisol excess, treating CD also serves to alleviate impaired glucose metabolism. Although transsphenoidal pituitary surgery remains the first-line treatment for CD, it is not always effective and other treatment strategies may be necessary. This work examines the main features of DM secondary to CD and focuses on antidiabetic drugs and how cortisol-lowering medication affects glucose metabolism.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Efficacy and safety of alogliptin in patients with type 2 diabetes mellitus: A multicentre randomized double-blind placebo-controlled Phase 3 study in mainland China, Taiwan, and Hong Kong

BACKGROUND

This study determined the efficacy and safety of once-daily oral alogliptin in patients from mainland China, Taiwan, and Hong Kong with type 2 diabetes mellitus.

METHODS

In this Phase 3 multicenter double-blind placebo-controlled 16-week trial, 506 patients were randomized to receive once-daily alogliptin 25 mg or placebo: 185 in the monotherapy group, 197 in the add-on to metformin group, and 124 in the add-on to pioglitazone group. The primary efficacy variable was the change from baseline (CFB) in HbA1c at Week 16; other efficacy measures included CFB to Week 16 in fasting plasma glucose (FPG), incidence of marked hyperglycemia (FPG ≥11.1 mmol/L), and the incidence of clinical HbA1c ≤6.5 % (48 mmol/mol) and ≤7.0 % (53 mmol/mol) at Week 16. Safety was assessed throughout the trial.

RESULTS

Alogliptin monotherapy provided a significantly greater decrease in HbA1c from baseline to Week 16 compared with placebo (-0.58 %; 95 % confidence interval [CI] -0.78 %, -0.37 %; P < 0.001). As an add-on to metformin or pioglitazone, alogliptin also significantly decreased HbA1c compared with placebo (-0.69 % [95 % CI -0.87 %, -0.51 %; P < 0.001] and -0.52 % [95 % CI -0.75 %, -0.28 %; P < 0.001], respectively). In any treatment group versus placebo, alogliptin led to greater decreases in FPG (P ≤ 0.004) and a higher percentage of patients who achieved an HbA1c target of ≤6.5 % and ≤7.0 % (P ≤ 0.003). No weight gain was observed in any treatment group. A similar percentage of patients experienced drug-related, treatment-emergent adverse events in the alogliptin and placebo arms. Four and two patients in the alogliptin and placebo arms, respectively, experienced mild or moderate hypoglycemia.

CONCLUSIONS

Alogliptin 25 mg once daily reduced HbA1c and FPG and enhanced clinical response compared with placebo when used as monotherapy or as an add-on to metformin or pioglitazone. Therapy with alogliptin was well tolerated.

Basal insulin treatment intensification in patients with type 2 diabetes mellitus: A comprehensive systematic review of current options

AIM

As type 2 diabetes mellitus progresses, most patients require treatment with basal insulin in combination with another agent to achieve recommended glycaemic targets. The purpose of this systematic review was to examine the evidence supporting the use of the available add-on treatments [rapid-acting insulin (RAI), glucagon-like peptide-1 receptor agonists (GLP-1 RAs), dipeptidyl peptidase (DPP)-4 inhibitors and sodium-glucose cotransporter-2 (SGLT-2) inhibitors] to basal insulin.

METHODS

MEDLINE, EMBASE and EBSCOhost were searched for English-language articles, and all those captured were original articles (case studies and narrative reviews were omitted). Data on study design, population demographics, interventions and outcomes were tabulated. The extracted outcome data included changes in glycated haemoglobin (HbA_1c), fasting plasma glucose (FPG) and postprandial plasma glucose (PPG), as well as body weight and safety data.

RESULTS

A total of 88 publications were deemed relevant. All treatments reduced HbA_1c and FPG. The most pronounced reductions in PPG, an unmet need in patients not controlled by basal insulin, were seen following administration of RAIs and short-acting GLP-1 RAs, although data for this outcome are generally lacking. Body weight benefits were observed with GLP-1 RAs and SGLT-2 inhibitors. However, as only articles in English were included, the result was a possible publication bias, while the diversity of study designs and drug combinations limited comparisons between studies.

CONCLUSION

The evidence supports effectiveness of the available add-on treatments to basal insulin. However, other factors, such as potential body-weight increases, convenience/compliance and adverse events, particularly hypoglycaemia, should be considered on a patient-by-patient basis to optimalize treatment outcomes.

Relationship between frequency of hypoglycemic episodes and changes in carotid atherosclerosis in insulin-treated patients with type 2 diabetes mellitus

The effect of hypoglycemia on the progression of atherosclerosis in patients with type 2 diabetes mellitus (T2DM) remains largely unknown. This is a post hoc analysis of a randomized trial to investigate the relationship between hypoglycemic episodes and changes in carotid intima-media thickness (IMT). Among 274 study subjects, 104 patients experienced hypoglycemic episodes. Increases in the mean IMT and left maximum IMT of the common carotid arteries (CCA) were significantly greater in patients with hypoglycemia compared to those without hypoglycemia. Classification of the patients into three groups according to the frequency of hypoglycemic episodes showed that high frequency of hypoglycemic events was associated with increases in mean IMT-CCA, and left max-IMT-CCA and right max-IMT-CCA. In addition, repetitive episodes of hypoglycemia were associated with a reduction in the beneficial effects of sitagliptin on carotid IMT. Our data suggest that frequency of hypoglycemic episodes was associated with changes in carotid atherosclerosis.

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.

Comparison between SGLT2 inhibitors and DPP4 inhibitors added to insulin therapy in type 2 diabetes: a systematic review with indirect comparison meta-analysis

BACKGROUND

Both sodium glucose cotransporter 2 (SGLT2) inhibitors and dipeptidyl peptidase-4 (DPP4) inhibitors can be used to treat patients with type 2 diabetes mellitus (T2DM) that is inadequately controlled with insulin therapy, and yet there has been no direct comparison of these two inhibitors.

METHODS

We searched MEDLINE, EMBASE, LILACS, the Cochrane Central Register of Controlled Trials and ClinicalTrials.gov through June 2015. Randomized controlled trials published in English that compare SGLT2 inhibitor plus insulin (SGLT2i/INS) with placebo plus insulin or DPP4 inhibitor plus insulin (DPP4i/INS) with placebo plus insulin in patients with T2DM were selected. Data on the study characteristics, efficacy and safety outcomes were extracted. We compared the efficacy and safety between SGLT2i/INS and DPP4i/INS indirectly with covariates adjustment. Risk of potential bias was assessed.

RESULTS

Fourteen eligible randomized controlled trials comprising 6980 patients were included (five SGLT2 inhibitor studies and nine DPP4 inhibitor studies). Covariate-adjusted indirect comparison using meta-regression analyses revealed that SGLT2i/INS achieved greater reduction in HbA_1c [weighted mean difference (WMD) -0.24%, 95% confidence interval (CI) -0.43 to -0.05%], fasting plasma glucose (WMD -18.0 mg/dL, 95% CI -28.5 to -7.6 mg/dL) and body weight (WMD -2.38 kg, 95% CI -3.18 to -1.58 kg) from baseline than DPP4i/INS without increasing the risk of hypoglycaemia (relative risks 1.19, 95% CI 0.78 to 1.82).

CONCLUSIONS

Sodium glucose cotransporter 2 inhibitors achieved better glycaemic control and greater weight reduction than DPP4 inhibitors without increasing the risk of hypoglycaemia in patients with T2DM that is inadequately controlled with insulin. There has been no direct comparison of SGLT2 inhibitors and DPP4 inhibitors in patients with T2DM inadequately controlled with insulin therapy. In this study, we performed indirect meta-analysis comparing SGLT2 inhibitors and DPP4 inhibitors added to insulin therapy. Without increasing hypoglycaemia, SGLT2 inhibitors showed better glycaemic control and greater weight reduction than DPP4 inhibitors in patients with T2DM inadequately controlled with insulin. The results of the current study could serve as the best available evidence in selecting oral agents to improve glycaemic control in insulin-treated T2DM patients. Copyright © 2016 John Wiley & Sons, Ltd.

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.

An update on the clinical pharmacology of the dipeptidyl peptidase 4 inhibitor alogliptin used for the treatment of type 2 diabetes mellitus

Alogliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor that is a class of relatively new oral hypoglycaemic drugs used in patients with type 2 diabetes (T2DM), can be used as monotherapy or in combination with other anti-diabetic agents, including metformin, pioglitazone, sulfonylureas and insulin with a considerable therapeutic effect. Alogliptin exhibits favorable pharmacokinetic and pharmacodynamic profiles in humans. Alogliptin is mainly metabolized by cytochrome P450 (CYP2D6) and CYP3A4. Dose reduction is recommended for patients with moderate or worse renal impairment. Side effects of alogliptin include nasopharyngitis, upper-respiratory tract infections and headache. Hypoglycaemia is seen in about 1.5% of the T2DM patients. Rare but severe adverse reactions such as acute pancreatitis, serious hypersensitivity including anaphylaxis, angioedema and severe cutaneous reactions such as Stevens-Johnson syndrome have been reported from post-marketing monitoring. Pharmacokinetic interactions have not been observed between alogliptin and other drugs including glyburide, metformin, pioglitazone, insulin and warfarin. The present review aimed to update the clinical information on pharmacodynamics, pharmacokinetics, adverse effects and drug interactions, and to discuss the future directions of alogliptin.

An update on the 'gliptins'

Progressive impairment of insulin secretion in people with type 2 diabetes leads to blood glucose concentrations worsening over time, often resulting in escalation of blood glucose lowering therapy.¹ In 2015/2016, more money was spent on dipeptidyl peptidase-4 (DPP-4) inhibitors ('gliptins') than on any other class of antidiabetic drug except for insulins.² In 2008, we reviewed sitagliptin and vildagliptin.³ Here, we briefly review three other DPP-4 inhibitors, saxagliptin (Onglyza-AstraZeneca), linagliptin (Trajenta-Boehringer Ingelheim) and ▼alogliptin (Vipidia-Takeda), and consider data from recent cardiovascular outcomes studies.

Physiological aspects of the combination of insulin and GLP-1 in the regulation of blood glucose control

Combining insulin with glucagon-like peptide-1 (GLP-1) receptor agonists or dipeptidyl peptidase-4 (DPP-4) inhibitors as glucose-lowering therapy for type 2 diabetes is a promising strategy that has gained considerable interest over the past few years. One advantage of this combination is the complementary mechanistic actions of insulin and GLP-1. Insulin increases glucose utilization and retards hepatic glucose production through direct actions in muscle, adipose tissue and the liver. On the other hand, GLP-1 stimulates insulin secretion, inhibits glucagon secretion and retards gastric emptying. Combining these effects results in powerful reductions in both fasting and postprandial glucose through diminished glucose entry into the bloodstream after food consumption, reduced hepatic production of glucose and increased glucose utilization. In addition, GLP-1 receptor agonists induce satiety, leading to decreases in food intakes and body weight, thereby preventing the weight gain often seen with insulin therapy. Clinical trials have verified that these physiological effects as a result of combining insulin with GLP-1 receptor agonists or DPP-4 inhibitors can indeed result in improved glycaemia, with limited risks of hypoglycaemia and weight gain.

Adverse effects of incretin-based therapies on major cardiovascular and arrhythmia events: meta-analysis of randomized trials

BACKGROUND

Recent cardiovascular outcome trials of incretin-based therapies (IBT) in type 2 diabetes have not demonstrated either benefit or harm in terms of major adverse cardiovascular events (MACE). Earlier meta-analyses showed conflicting results but were limited in methodology. We aimed to perform an updated meta-analysis of all available incretin therapies on the incidence of MACE plus arrhythmia and heart failure.

METHODS

We identified studies published through November 2014 by searching electronic databases and reference lists. We included RCTs in which the intervention group received incretin-based therapies and the control group received placebo or standard treatment; enrolled >100 participants in each group; interventions lasted >24 weeks; and reported data on one or more primary major adverse cardiovascular events endpoints plus terms for arrhythmia and heart failure. We used the Peto method for each CV event for individual IBT treatment.

RESULTS

In this meta-analysis of 100 RCTs involving 54,758 incretin-based therapies users and 48,175 controls, exenatide was associated with increased risk of arrhythmia (OR 2.83; 95% CI, 1.06-7.57); saxagliptin was associated with an increased risk of heart failure (OR 1.23; 95% CI, 1.03-1.46), and sitagliptin was associated with a significantly decreased risk of all cause death compared to active controls (OR 0.39, 95% CI 0.18-0.82).

CONCLUSIONS

In type 2 diabetes, exenatide may increase the risk of arrhythmia, and sitagliptin may reduce the risk of all cause death; however, the subgroup of patients most likely to experience harm or benefit is unclear. Copyright © 2016 John Wiley & Sons, Ltd.

Alogliptin for the treatment of type 2 diabetes: a drug safety evaluation

INTRODUCTION

Dipeptidyl peptidase-4 (DPP-4) inhibitors such as alogliptin are becoming more widely established as treatment options for patients with type 2 diabetes (T2DM) because of their ability to improve glycemic control without increasing the risk of hypoglycemia or weight gain. New therapies with improved safety profiles are needed, especially because of the chronic and progressive nature of T2DM.

AREAS COVERED

In this article, the overall safety and tolerability of alogliptin are evaluated based upon a review of the literature. In particular, adverse events (AEs) that have been of interest for the DPP-4 class of drugs, such as the risk of major cardiovascular (CV) events and acute pancreatitis, will be investigated in detail.

EXPERT OPINION

Alogliptin is generally well-tolerated in a broad range of patient populations including different ethnic groups and the elderly. In the pivotal EXAMINE clinical trial, alogliptin was found not to be associated with an increased risk of major CV events or acute pancreatitis/pancreatic cancer.

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.

Insulin monotherapy compared with the addition of oral glucose-lowering agents to insulin for people with type 2 diabetes already on insulin therapy and inadequate glycaemic control

BACKGROUND

It is unclear whether people with type 2 diabetes mellitus on insulin monotherapy who do not achieve adequate glycaemic control should continue insulin as monotherapy or can benefit from adding oral glucose-lowering agents to the insulin therapy.

OBJECTIVES

To assess the effects of insulin monotherapy compared with the addition of oral glucose-lowering agents to insulin monotherapy for people with type 2 diabetes already on insulin therapy and inadequate glycaemic control.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, ClinicalTrials.gov, the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) and reference lists of articles. The date of the last search was November 2015 for all databases.

SELECTION CRITERIA

Randomised controlled clinical trials of at least two months' duration comparing insulin monotherapy with combinations of insulin with one or more oral glucose-lowering agent in people with type 2 diabetes.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials, assessed risk of bias, extracted data and evaluated overall quality of the evidence using GRADE. We summarised data statistically if they were available, sufficiently similar and of sufficient quality. We performed statistical analyses according to the statistical guidelines in the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

We included 37 trials with 40 treatment comparisons involving 3227 participants. The duration of the interventions ranged from 2 to 12 months for parallel trials and two to four months for cross-over trials.The majority of trials had an unclear risk of bias in several risk of bias domains. Fourteen trials showed a high risk of bias, mainly for performance and detection bias. Insulin monotherapy, including once-daily long-acting, once-daily intermediate-acting, twice-daily premixed insulin, and basal-bolus regimens (multiple injections), was compared to insulin in combination with sulphonylureas (17 comparisons: glibenclamide = 11, glipizide = 2, tolazamide = 2, gliclazide = 1, glimepiride = 1), metformin (11 comparisons), pioglitazone (four comparisons), alpha-glucosidase inhibitors (four comparisons: acarbose = 3, miglitol = 1), dipeptidyl peptidase-4 inhibitors (DPP-4 inhibitors) (three comparisons: vildagliptin = 1, sitagliptin = 1, saxagliptin = 1) and the combination of metformin and glimepiride (one comparison). No trials assessed all-cause mortality, diabetes-related morbidity or health-related quality of life. Only one trial assessed patients' treatment satisfaction and showed no substantial differences between the addition of either glimepiride or metformin and glimepiride to insulin compared with insulin monotherapy.Insulin-sulphonylurea combination therapy (CT) compared with insulin monotherapy (IM) showed a MD in glycosylated haemoglobin A1c (HbA1c) of -1% (95% confidence interval (CI) -1.6 to -0.5); P < 0.01; 316 participants; 9 trials; low-quality evidence. Insulin-metformin CT compared with IM showed a MD in HbA1c of -0.9% (95% CI -1.2 to -0.5); P < 0.01; 698 participants; 9 trials; low-quality evidence. We could not pool the results of adding pioglitazone to insulin. Insulin combined with alpha-glucosidase inhibitors compared with IM showed a MD in HbA1c of -0.4% (95% CI -0.5 to -0.2); P < 0.01; 448 participants; 3 trials; low-quality evidence). Insulin combined with DPP-4 inhibitors compared with IM showed a MD in HbA1c of -0.4% (95% CI -0.5 to -0.4); P < 0.01; 265 participants; 2 trials; low quality evidence. In most trials the participants with CT needed less insulin, whereas insulin requirements increased or remained stable in participants with IM.We did not perform a meta-analysis for hypoglycaemic events because the included studies used different definitions.. In most trials the insulin-sulphonylurea combination resulted in a higher number of mild episodes of hypoglycaemia, compared to the IM group (range: 2.2 to 6.1 episodes per participant in CT versus 2.0 to 2.6 episodes per participant in IM; low-quality evidence). Pioglitazone CT also resulted in more mild to moderate hypoglycaemic episodes compared with IM (range 15 to 90 episodes versus 9 to 75 episodes, respectively; low-quality evidence. The trials that reported hypoglycaemic episodes in the other combinations found comparable numbers of mild to moderate hypoglycaemic events (low-quality evidence).The addition of sulphonylureas resulted in an additional weight gain of 0.4 kg to 1.9 kg versus -0.8 kg to 2.1 kg in the IM group (220 participants; 7 trials; low-quality evidence). Pioglitazone CT caused more weight gain compared to IM: MD 3.8 kg (95% CI 3.0 to 4.6); P < 0.01; 288 participants; 2 trials; low-quality evidence. Metformin CT was associated with weight loss: MD -2.1 kg (95% CI -3.2 to -1.1), P < 0.01; 615 participants; 7 trials; low-quality evidence). DPP-4 inhibitors CT showed weight gain of -0.7 to 1.3 kg versus 0.6 to 1.1 kg in the IM group (362 participants; 2 trials; low-quality evidence). Alpha-glucosidase CT compared to IM showed a MD of -0.5 kg (95% CI -1.2 to 0.3); P = 0.26; 241 participants; 2 trials; low-quality evidence.Users of metformin CT (range 7% to 67% versus 5% to 16%), and alpha-glucosidase inhibitors CT (14% to 75% versus 4% to 35%) experienced more gastro-intestinal adverse effects compared to participants on IM. Two trials reported a higher frequency of oedema with the use of pioglitazone CT (range: 16% to 18% versus 4% to 7% IM).

AUTHORS' CONCLUSIONS

The addition of all oral glucose-lowering agents in people with type 2 diabetes and inadequate glycaemic control who are on insulin therapy has positive effects on glycaemic control and insulin requirements. The addition of sulphonylureas results in more hypoglycaemic events. Additional weight gain can only be avoided by adding metformin to insulin. Other well-known adverse effects of oral glucose-lowering agents have to be taken into account when prescribing oral glucose-lowering agents in addition to insulin therapy.

Update on the treatment of type 2 diabetes mellitus

To achieve good metabolic control in diabetes and keep long term, a combination of changes in lifestyle and pharmacological treatment is necessary. Achieving near-normal glycated hemoglobin significantly, decreases risk of macrovascular and microvascular complications. At present there are different treatments, both oral and injectable, available for the treatment of type 2 diabetes mellitus (T2DM). Treatment algorithms designed to reduce the development or progression of the complications of diabetes emphasizes the need for good glycaemic control. The aim of this review is to perform an update on the benefits and limitations of different drugs, both current and future, for the treatment of T2DM. Initial intervention should focus on lifestyle changes. Moreover, changes in lifestyle have proven to be beneficial, but for many patients is a complication keep long term. Physicians should be familiar with the different types of existing drugs for the treatment of diabetes and select the most effective, safe and better tolerated by patients. Metformin remains the first choice of treatment for most patients. Other alternative or second-line treatment options should be individualized depending on the characteristics of each patient. This article reviews the treatments available for patients with T2DM, with an emphasis on agents introduced within the last decade.

Differential HbA1c response in the placebo arm of DPP-4 inhibitor clinical trials conducted in China compared to other countries: a systematic review and meta-analysis

BACKGROUND

It has been observed that the efficacy of dipeptidyl peptidase-4 (DPP-4) inhibitors as compared to the placebo groups in some clinical trials conducted in China is weaker than that in trials conducted outside China, leading to the suspicion that this may be caused by differential Glycosylated Hemoglobin (HbA1c) response in the placebo arm of DPP-4 inhibitor clinical trials conducted in China compared to other countries.

METHODS

We searched published articles and other documents related to phase III placebo-control trials of DPP-4 inhibitors in Type 2 diabetes mellitus (T2DM). We included studies from different countries and compared those conducted in China to those conducted in other countries. Meta-regression analysis was used to analyze the HbA1c response in the placebo arms.

RESULTS

A total of 66 studies met the inclusion criteria and 10 were conducted within China. There were a total of 8303 participants (mean age 56, male 57 %) in placebo groups. The pooled change in HbA1c for the placebo groups of 10 trials conducted in patients with T2DM in China was 0.26 % (95 % CI [-0.36 %, -0.16 %], p-value < 0.001), compared to 0.015 % (95 % CI [-0.05 %, 0.08 %], p-value is 0.637) for 56 trials conducted outside of China. The difference of placebo effect between trials conducted in and outside China is -0.273 % (95 % CI [-0.42 %, -0.13 %], p-value is less than 0.001) while after excluding trials conducted in Japan, the difference is -0.203 % (95 % CI [-0.35 %, -0.06 %], p-value is 0.005). They are both statistically significant.

CONCLUSIONS

The meta-analysis in the article demonstrates that there is statistically significant difference in the HbA1c response in the placebo arm of DPP-4 inhibitor clinical trials conducted in China compared to other countries. This differential HbA1c response in the placebo arm should be taken into consideration by both experimenters and medical decision makers when future DPP-4 studies are conducted in China.

Positioning SGLT2 Inhibitors/Incretin-Based Therapies in the Treatment Algorithm

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are the most recent addition to the therapeutic options available for the treatment of type 2 diabetes and became available after the introduction of incretin-based therapies, dipeptidyl peptidase 4 inhibitors and glucagon-like peptide 1 receptor agonists (GLP-1 RAs). These agents have potential advantages with regard to their weight loss-promoting effect, low risk of hypoglycemia, reduction in blood pressure, and reduction in cardiovascular events in high-risk patients (with empagliflozin). Apart from these clinically important outcomes, they may also correct core defects present in type 2 diabetes (i.e., improvement in β-cell function and insulin sensitivity). They do, however, have some adverse effects, notably, nausea with GLP-1 RAs and genital tract infections and potential for volume depletion with SGLT2i. Whether incretin-based therapies are associated with an increased risk of pancreatitis is unclear. Most recently, diabetic ketoacidosis has been reported with SGLT2i. Therefore, a key clinical question in relation to guidelines is whether these clinical advantages, in the context of the adverse effect profile, outweigh the additional cost compared with older, more established therapies. This article reviews the therapeutic rationale for the use of these newer drugs for diabetes treatment, considers their place in current guidelines, and discusses how this may change as new data emerge about their long-term efficacy and safety from ongoing outcome trials.

Role of incretin-based therapies and sodium-glucose co-transporter-2 inhibitors as adjuncts to insulin therapy in Type 2 diabetes, with special reference to IDegLira

The progressive nature of Type 2 diabetes necessitates treatment intensification over time in order to maintain glycaemic control, with many patients ultimately requiring insulin therapy. While insulin has unlimited potential efficacy, its initiation is often delayed and improvements in glycaemic control are typically accompanied by weight gain and an increased risk of hypoglycaemia, particularly as HbA1c approaches and falls below target levels. This may account for the sub-optimal control often achieved after insulin initiation. Combining insulin with antihyperglycaemic therapies that have a low risk of hypoglycaemia and are weight-neutral or result in weight loss is a therapeutic strategy with the potential to improve Type 2 diabetes management. Although the effects differ with each individual class of therapy, clinical trials have shown that adding a glucagon-like peptide-1 receptor agonist, dipeptidyl peptidase-4 inhibitor or sodium-glucose co-transporter-2 inhibitor to insulin regimens can offer a significant reduction in HbA1c without substantially increasing hypoglycaemia risk, or weight. The evidence and merit of each approach are reviewed in this paper. Once-daily co-formulations of a basal insulin and a glucagon-like peptide-1 receptor agonist have been developed (insulin degludec/liraglutide) or are under development (lixisenatide/insulin glargine). Insulin degludec/liraglutide phase III trials and a lixisenatide/insulin glargine phase II trial have shown robust HbA1c reductions, with weight loss and a low risk of hypoglycaemia. With insulin degludec/liraglutide now approved in Europe, an important consideration will be the types of patients who may benefit most from a fixed-ratio combination; this is discussed in the present review, and we also take a look toward future developments in the field.

Clinical pharmacology of dipeptidyl peptidase 4 inhibitors indicated for the treatment of type 2 diabetes mellitus

Dipeptidyl peptidase-4 (DPP-4) inhibitors are a class of oral antidiabetic drugs that improve glycaemic control without causing weight gain or increasing hypoglycaemic risk in patients with type 2 diabetes mellitus (T2DM). The eight available DPP-4 inhibitors, including alogliptin, anagliptin, gemigliptin, linagliptin, saxagliptin, sitagliptin, teneligliptin, and vildagliptin, are small molecules used orally with identical mechanism of action and similar safety profiles in patients with T2DM. DPP-4 inhibitors may be used as monotherapy or in double or triple combination with other oral glucose-lowering agents such as metformin, thiazolidinediones, or sulfonylureas. Although DPP-4 inhibitors have the same mode of action, they differ by some important pharmacokinetic and pharmacodynamic properties that may be clinically relevant in some patients. The main differences between the eight gliptins include: potency, target selectivity, oral bioavailability, elimination half-life, binding to plasma proteins, metabolic pathways, formation of active metabolite(s), main excretion routes, dosage adjustment for renal and liver insufficiency, and potential drug-drug interactions. The off-target inhibition of selective DPP-4 inhibitors is responsible for multiorgan toxicities such as immune dysfunction, impaired healing, and skin reactions. As a drug class, the DPP-4 inhibitors have become accepted in clinical practice due to their excellent tolerability profile, with a low risk of hypoglycaemia, a neutral effect on body weight, and once-daily dosing. It is unknown if DPP-4 inhibitors can prevent disease progression. More clinical studies are needed to validate the optimal regimens of DPP-4 inhibitors for the management of T2DM when their potential toxicities are closely monitored.

Efficacy and safety of the addition of a dipeptidyl peptidase-4 inhibitor to insulin therapy in patients with type 2 diabetes: A systematic review and meta-analysis

AIMS

To compare the efficacy and safety of the addition of a dipeptidyl peptidase-4 (DPP-4) inhibitor or a placebo in patients with type 2 diabetes inadequately controlled with insulin.

METHODS

We searched randomised controlled trials (RCTs) from MEDLINE, EMBASE, LILACS, the Cochrane Central Register of Controlled Trials and the ClinicalTrials.gov online registry. Studies of at least 12week treatment duration were eligible if they were RCTs in patients with type 2 diabetes comparing addition of a DPP-4 inhibitor to insulin therapy (INS/DPP4i) with addition of a placebo to insulin therapy (INS/PCB) and contained information on the change in glycated haemoglobin (HbA1c) from baseline.

RESULTS

Of 3105 potentially relevant published articles and 206 registered trials, 9 studies were included for meta-analysis. Compared to INS/PCB, INS/DPP4i exhibited a greater reduction in HbA1c (weighted mean difference [WMD] -0.58%; 95% CI -0.70, -0.46) and fasting plasma glucose (WMD -0.59mmol/L; 95% CI -0.79, -0.40) with less daily insulin doses (WMD -1.86IU; 95% CI -3.27, -0.45) and with no difference in weight gain (WMD -0.04kg; 95% CI -0.25, 0.16). The risk of hypoglycaemia was similar between INS/DPP-4i and INS/PCB (the RR in favour of INS/PCB was 0.94; 95% CI 0.84, 1.05).

CONCLUSIONS

Compared to placebo, DPP-4 inhibitors exhibit a better glycaemic control without further increasing the risk of weight gain and hypoglycaemia in patients with type 2 diabetes inadequately controlled with insulin.