A randomized, double-blind, comparative therapy evaluating sitagliptin versus glibenclamide in type 2 diabetes patients already treated with pioglitazone and metformin: a 3-year study

Systematic review and meta-analysis of head-to-head trials comparing sulfonylureas and low hypoglycaemic risk antidiabetic drugs

BACKGROUND

Safety of sulfonylurea drugs in the treatment of Type 2 Diabetes is still under debate. The aim of this study was to compare the all-cause mortality and cardiovascular adverse events of sulfonylureas and drugs with a low risk for hypoglycaemia in adults with type 2 diabetes.

METHODS

Systematic review and meta-analysis of randomised controlled trials.

DATA SOURCES

MEDLINE (PubMed, OVID), Embase, Cochrane Central Register of Controlled Trials, CINAHL, WOS and Lilacs.

STUDY SELECTION

Randomised controlled head-to-head trials that compared sulfonylureas with active control with low hypoglycaemic potential in adults (≥ 18 years old) with type 2 diabetes published up to August 2015. The drug classes involved in the analysis were metformin, dipeptidyl peptidase-4 (DPP-4) inhibitors, sodium-glucose co-transporter-2 (SGLT-2) inhibitors and glucagon-like peptide-1 (GLP-1) receptor agonists.

OUTCOMES

The primary endpoint was all-cause mortality. The secondary endpoints were MACE, cardiovascular events and severe hypoglycaemia.

SYNTHESIS OF RESULTS

Two reviewers checked study eligibility, independently extracted data and assessed quality with disagreements resolved through discussion. We assessed the risk of bias of the included studies using the Cochrane risk of bias tool for randomized trials v2. Pooled odds ratios (ORs) were estimated by using fixed effects model. The study is registered on PROSPERO (26/05/2016 CRD42016038780).

RESULTS

Our final analysis comprised 31 studies (26,204 patients, 11,711 patients given sulfonylureas and 14,493 given comparator drugs). In comparison to drugs with low hypoglycaemic potential, sulfonylureas had higher odds for all-cause mortality (OR 1.32, 95% CI 1.00-1.75), MACE (OR 1.32, 95% CI 1.07-1.61), myocardial infarction (fatal and non-fatal) (OR 1.67, 95% CI 1.17-2.38) and hypoglycaemia (OR 5.24, 95% CI 4.20-6.55). Subsequent sensitivity analysis revealed differences in the effect of sulfonylureas, with an increased risk of all-cause mortality with glipizide but not the other molecules.

CONCLUSION

Our meta-analysis raises concern about the safety of SUs compared to alternative drugs involved in current analysis. Important differences may exist within the drug class, and glimepiride seems to have best safety profile.

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.

Comparative Effectiveness of DPP-4 Inhibitors Versus Sulfonylurea for the Treatment of Type 2 Diabetes in Routine Clinical Practice: A Retrospective Multicenter Real-World Study

INTRODUCTION

DPP-4 inhibitors (DPP4i) and sulfonylureas are popular second-line therapies for type 2 diabetes (T2D), but there is a paucity of real-world studies comparing their effectiveness in routine clinical practice.

METHODS

This was a multicenter retrospective study on diabetes outpatient clinics comparing the effectiveness of DPP4i versus gliclazide extended release. The primary endpoint was change from baseline in HbA1c. Secondary endpoints were changes in fasting plasma glucose, body weight, and systolic blood pressure. Automated software extracted data from the same clinical electronic chart system at all centers. Propensity score matching (PSM) was used to generate comparable cohorts to perform outcome analysis.

RESULTS

We included data on 2410 patients starting DPP4i and 1590 patients starting gliclazide (mainly 30-60 mg/day). At baseline, the two groups differed in disease duration, body weight, blood pressure, HbA1c, fasting glucose, HDL cholesterol, triglycerides, liver enzymes, eGFR, prevalence of microangiopathy, and use of metformin. Among DPP4i molecules, no difference in glycemic effectiveness was detected. In matched cohorts (n = 1316/group), patients starting DPP4i, as compared with patients starting gliclazide, experienced greater reductions in HbA1c (- 0.6% versus - 0.4%; p < 0.001), fasting glucose (- 14.1 mg/dl versus - 8.8 mg/dl; p = 0.007), and body weight (- 0.4 kg versus - 0.1 kg; p = 0.006) after an average 6 months follow-up. DPP4i improved glucose control more than gliclazide, especially in patients who had failed with other glucose-lowering medications or were on basal insulin.

CONCLUSIONS

This large retrospective real-world study shows that, in routine clinical practice, starting a DPP4i allows better glycemic control than starting low-dose gliclazide.

FUNDING

The Italian Diabetes Society, with external support from AstraZeneca.

Practical strategies for improving outcomes in T2DM: The potential role of pioglitazone and DPP4 inhibitors

T2DM is a complex disease underlined by multiple pathogenic defects responsible for the development and progression of hyperglycaemia. Each of these factors can now be tackled in a more targeted manner thanks to glucose-lowering drugs that have been made available in the past 2 to 3 decades. Recognition of the multiplicity of the mechanisms underlying hyperglycaemia calls for treatments that address more than 1 of these mechanisms, with more emphasis placed on the earlier use of combination therapies. Although chronic hyperglycaemia contributes to and amplifies cardiovascular risk, several trials have failed to show a marked effect from intensive glycaemic control. During the past 10 years, the effect of specific glucose-lowering agents on cardiovascular risk has been explored with dedicated trials. Overall, the cardiovascular safety of the new glucose-lowering agents has been proven with some of the trials summarized in this review, showing significant reduction of cardiovascular risk. Against this background, pioglitazone, in addition to exerting a sustained glucose-lowering effect, also has ancillary metabolic actions of potential interest in addressing the cardiovascular risk of T2DM, such as preservation of beta-cell mass and function. As such, it seems a logical agent to combine with other oral anti-hyperglycaemic agents, including dipeptidyl peptidase-4 inhibitors (DPP4i). DPP4i, which may also have a potential to preserve beta-cell function, is available as a fixed-dose combination with pioglitazone, and could, potentially, attenuate some of the side effects of pioglitazone, particularly if a lower dose of the thiazolidinedione is used. This review critically discusses the potential for early combination of pioglitazone and DPP4i.

Cost-effectiveness analysis of different dipeptidyl-peptidase 4 inhibitor drugs for treatment of type 2 diabetes mellitus

INTRODUCTION

Type 2 diabetes mellitus (T2DM) has burdened health systems in the world to the value of 500 billion dollars/year. Dipeptidyl peptidase 4 inhibitors (DPP-4 Inhibitors) have been strongly associated with spending on the treatment of T2DM by the courts in Brazil. The aim of this study was to estimate the most cost-effective DPP-4 Inhibitor for T2DM treatment. A pharmacoeconomic study of cost-effectiveness was performed in a medium-sized municipality in Minas Gerais state, Brazil.

METHODS

The data are from legalization in municipal health in 2013. The effectiveness of DPP-4 Inhibitors was measured by the reduction in glycated hemoglobin (A1c). The direct medical costs of drug and adverse drug reactions were identified. With these data, a cost-effectiveness ratio (CER) and construction of the decision tree for sensitivity analysis were performed.

RESULTS

The representative of the most effective in reducing A1c gliptins was sitagliptin in combination with metformin, it was able to reduce A1c by 1.16% (1.09 to 1.22, CI 95%). The drug with the lowest cost was linagliptin, with a cost per patient/year of US$ 481.42. Sensitivity analysis performed by the decision tree shows that sitagliptin in association with metformin had the CER of US$ 1,506.75 per patient/year, to reduce A1c by 1%.

CONCLUSION

The most cost-effective DPP-4 Inhibitor was sitagliptin with metformin.

A systematic literature review on the efficacy-effectiveness gap: comparison of randomized controlled trials and observational studies of glucose-lowering drugs

Aim

To identify a potential efficacy–effectiveness gap and possible explanations (drivers of effectiveness) for differences between results of randomized controlled trials (RCTs) and observational studies investigating glucose-lowering drugs.

Methods

A systematic literature review was conducted in English language articles published between 1 January, 2000 and 31 January, 2015 describing either RCTs or observational studies comparing glucagon-like peptide-1 analogs (GLP-1) with insulin or comparing dipeptidyl peptidase-4 inhibitors (DPP-4i) with sulfonylurea, all with change in glycated hemoglobin (HbA1c) as outcome. Medline, Embase, Current Content, and Biosis were searched. Information on effect estimates, baseline characteristics of the study population, publication year, study duration, and number of patients, and for observational studies, characteristics related to confounding adjustment and selection- and information bias were extracted.

Results

From 312 hits, 11 RCTs and 7 observational studies comparing GLP-1 with insulin, and from 474 hits, 16 RCTs and 4 observational studies comparing DPP-4i with sulfonylurea were finally included. No differences were observed in baseline characteristics of the study populations (age, sex, body mass index, time since diagnosis of type 2 diabetes mellitus, and HbA1c) or effect sizes across study designs. Mean effect sizes ranged from −0.43 to 0.91 and from −0.80 to 1.13 in RCTs and observational studies, respectively, comparing GLP-1 with insulin, and from −0.13 to 2.70 and −0.20 to 0.30 in RCTs and observational studies, respectively, comparing DPP-4i and sulfonylurea. Generally, the identified observational studies held potential flaws with regard to confounding adjustment and selection- and information bias.

Conclusions

Neither potential drivers of effectiveness nor an efficacy–effectiveness gap were identified. However, the limited number of studies and potential problems with confounding adjustment, selection- and information bias in the observational studies, may have hidden a true efficacy-effectiveness gap.

Pharmacology and therapeutic implications of current drugs for type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is a global epidemic that poses a major challenge to health-care systems. Improving metabolic control to approach normal glycaemia (where practical) greatly benefits long-term prognoses and justifies early, effective, sustained and safety-conscious intervention. Improvements in the understanding of the complex pathogenesis of T2DM have underpinned the development of glucose-lowering therapies with complementary mechanisms of action, which have expanded treatment options and facilitated individualized management strategies. Over the past decade, several new classes of glucose-lowering agents have been licensed, including glucagon-like peptide 1 receptor (GLP-1R) agonists, dipeptidyl peptidase 4 (DPP-4) inhibitors and sodium/glucose cotransporter 2 (SGLT2) inhibitors. These agents can be used individually or in combination with well-established treatments such as biguanides, sulfonylureas and thiazolidinediones. Although novel agents have potential advantages including low risk of hypoglycaemia and help with weight control, long-term safety has yet to be established. In this Review, we assess the pharmacokinetics, pharmacodynamics and safety profiles, including cardiovascular safety, of currently available therapies for management of hyperglycaemia in patients with T2DM within the context of disease pathogenesis and natural history. In addition, we briefly describe treatment algorithms for patients with T2DM and lessons from present therapies to inform the development of future therapies.

Comparative review of dipeptidyl peptidase-4 inhibitors and sulphonylureas

Type 2 diabetes (T2DM) is a progressive disease, and pharmacotherapy with a single agent does not generally provide durable glycaemic control over the long term. Sulphonylurea (SU) drugs have a history stretching back over 60 years, and have traditionally been the mainstay choice as second-line agents to be added to metformin once glycaemic control with metformin monotherapy deteriorates; however, they are associated with undesirable side effects, including increased hypoglycaemia risk and weight gain. Dipeptidyl peptidase (DPP)-4 inhibitors are, by comparison, more recent, with the first compound being launched in 2006, but the class now globally encompasses at least 11 different compounds. DPP-4 inhibitors improve glycaemic control with similar efficacy to SUs, but do not usually provoke hypoglycaemia or weight gain, are relatively free from adverse side effects, and have recently been shown not to increase cardiovascular risk in large prospective safety trials. Because of these factors, DPP-4 inhibitors have become an established therapy for T2DM and are increasingly being positioned earlier in treatment algorithms. The present article reviews these two classes of oral antidiabetic drugs (DPP-4 inhibitors and SUs), highlighting differences and similarities between members of the same class, as well as discussing the potential advantages and disadvantages of the two drug classes. While both classes have their merits, the choice of which to use depends on the characteristics of each individual patient; however, for the majority of patients, DPP-4 inhibitors are now the preferred choice.

Dipeptidyl peptidase-4 inhibition and narrow-band ultraviolet-B light in psoriasis (DINUP): study protocol for a randomised controlled trial

BACKGROUND

Moderate to severe psoriasis is a systemic inflammatory disease associated with insulin resistance, obesity and type 2 diabetes (T2DM). Sitagliptin is a dipeptidyl peptidase-4 (DPP-4) inhibitor that improves glycaemia and has a marketing authorisation for the treatment of T2DM. Non-immunosuppressive therapies that are effective for psoriasis and its associated comorbidities would be a significant advance in the treatment of this chronic disease.

METHODS/DESIGN

This is a single centre, 39-week, prospective, randomised, open label, clinical trial of oral sitagliptin (Januvia(®)) in psoriasis patients who are due to undergo a course of narrow-band ultraviolet-B (NB-UVB) phototherapy. We plan to enrol 120 participants and allocate participants on a random and 1:1 basis to receive sitagliptin 100 mg daily for 24 weeks combined with NB-UVB or NB-UVB monotherapy. Participants will be followed up for 12 weeks after sitagliptin therapy is discontinued. The primary endpoint is the change in Psoriasis Area and Severity Index (PASI) 24 weeks after treatment initiation. Secondary endpoints include cumulative NB-UVB dose, number of NB-UVB treatments required to clear psoriasis, proportions of participants who achieve PASI-50 (50 % reduction in PASI from baseline), PASI-75, PASI-90 and the proportion of participants who relapse in each group. We will also analyse changes in cardiovascular disease risk factors, serum cytokine and hormone levels and peripheral blood mononuclear expression of immune proteins at 24 and 36 weeks. A subgroup of participants will have skin biopsies taken and analysed for skin levels and expression of immune cells, receptors, hormones and immune proteins. The genetic or epigenetic profile that predicts best response to DPP-4 inhibitor therapy will be analysed. The safety endpoints include the rate and severity of adverse events.

DISCUSSION

This is the first randomised clinical trial assessing dipeptidyl peptidase-4 inhibition therapy in psoriasis. We hypothesise that sitagliptin therapy in combination with NB-UVB improves psoriasis severity compared to NB-UVB monotherapy.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT02347501 (Date of registration: 27 January 2015).

Dipeptidyl peptidase-4 inhibitors in triple oral therapy regimens in patients with type 2 diabetes mellitus

OBJECTIVE

There is no clear consensus regarding treatment of patients with type 2 diabetes mellitus (T2DM) that is inadequately controlled using dual combination therapy. Recommended agents for triple combination therapy should have complementary mechanisms of action with minimal risk of added side effects such as weight gain and hypoglycemia. We discuss considerations in selecting triple oral therapy regimens in patients with T2DM, and review clinical trial data regarding triple oral therapy using dipeptidyl peptidase-4 (DPP-4) inhibitors.

METHODS

A search of the PubMed database was conducted to identify clinical trials of triple oral therapy incorporating a DPP-4 inhibitor (November 2013 to January 2015), using the following search terms: 'type 2 diabetes' AND 'alogliptin OR linagliptin OR saxagliptin OR sitagliptin OR vildagliptin' AND 'metformin'. Trials had to include adult patients with T2DM who received triple oral therapy with a DPP-4 inhibitor for ≥18 weeks. The bibliographies of retrieved articles were also searched to identify any other relevant trials.

RESULTS

A total of 17 clinical trials evaluating metformin and a DPP-4 inhibitor combined with a sulfonylurea (SU), thiazolidinedione (TZD), or sodium-glucose cotransporter 2 (SGLT2) inhibitor were identified and included in this review. Consistently, the addition of a DPP-4 inhibitor to metformin and SU, TZD, or SGLT2 inhibitor therapy improved glycemic measures, and these combinations were generally well tolerated. An increased incidence of hypoglycemia was reported for combinations that included an SU.

CONCLUSIONS

Triple oral therapy that includes a DPP-4 inhibitor is a valid option for patients with T2DM not adequately controlled with dual combination therapy, and offers an alternative to insulin therapy. Triple oral therapy with a DPP-4 inhibitor, metformin, and a TZD or SGLT2 inhibitor should be considered when avoidance of hypoglycemia is a primary goal.

Comparative effects of sitagliptin and metformin in patients with type 2 diabetes mellitus: a meta-analysis

BACKGROUND

Sitagliptin has been widely used in the treatment of type 2 diabetes mellitus (T2DM); however, the therapeutic efficacy of sitagliptin remains inconclusive in randomized controlled studies on T2DM in which metformin has served as a control.

OBJECTIVES

The present meta-analysis aimed to compare the therapeutic efficacy of sitagliptin and metformin in the treatment of T2DM.

METHODS

We searched the following databases (Medline, Embase, Cochrane databases, Chinese Medical Journal Database, and the Chinese National Knowledge Infrastructure from inception until April 2013), and identified randomized controlled trials (RCTs) involving sitagliptin and metformin for T2DM. Two independent authors determined whether or not these trials met the inclusion criteria. Then, the variance of results from each study was calculated, and I(2) was employed for evaluation of heterogeneity.

RESULTS

One hundred and twenty-one studies were identified, of which seven were included for further analysis. For T2DM, the therapeutic efficacy of sitagliptin and metformin was comparable in reducing HbA1c (P = 0.148, standard mean difference [SMD] = 0.13, 95% confidence interval [CI] = -0.05, 0.30), decreasing BMI (P = 0.063, SMD = 0.26, 95% CI = -0.01, 0.54), and improving the homeostasis model assessment (HOMA)-β (P = 0.285, SMD = -0.05, 95% CI = -0.15, 0.04), but sitagliptin was inferior to metformin in improving HOMA-IR (P = 0.003, SMD = 0.16, 95% CI = 0.06, 0.27).

CONCLUSIONS

Sitagliptin is similar to metformin in reducing HbA1c, decreasing body weight, and improving the function of beta cells, but is inferior to metformin in improving insulin sensitivity. More RCTs with large sample sizes are required to provide evidence for the rational application of sitagliptin.