Efficacy and safety of treatment with sitagliptin or glimepiride in patients with type 2 diabetes inadequately controlled on metformin monotherapy: a randomized, double-blind, non-inferiority trial

Efficacy and Safety of DPP-4 Inhibitors and Metformin Combinations in Type 2 Diabetes: A Systematic Literature Review and Network Meta-Analysis

Objective

Several oral antidiabetic regimens are available for treating type 2 diabetes mellitus (T2DM), dipeptidyl peptidase-4 inhibitors (DPP4i) being one of them. We conducted a network meta-analysis (NMA) comparing DPP4i plus metformin (Met) combination with other Met-based oral antidiabetic drug (OAD) combinations used in treating patients with T2DM.

Methods

We searched PubMed and Embase from inception until 19th April, 2022 for phase II and phase III trials in patients with T2DM on Met-based traditional OADs. The primary outcome was assessed by change in glycated hemoglobin (HbA1c), fasting plasma glucose (FPG), and 2-hour post-prandial blood glucose (2h-PPG). The secondary safety outcomes assessed were hypoglycemic events, serious adverse events (SAEs), cardiovascular (CV) events, and gastrointestinal (GI) events.

Results

Sixty-two trials were included in the analysis. The combination of DPP4i + Met revealed a comparable mean reduction in HbA1c levels to the glinides (Gli) + Met combination (mean difference [MD]: -0.03%, 95% CI: 0.69, -0.65), although the difference was not statistically significant. The mean HbA1c reduction with DPP4i + Met was greater than with sulfonylureas (SU) + Met (MD: -0.05, 95% CI: -0.29, 0.39), thiazolidinedione (TZD) + Met (MD: -0.69, 95% CI: -1.39, -0.02), and SU + TZD (MD: 0.21; 95% CI: -1.30, 1.71), with no statistical significance. DPP4i + Met demonstrated a non-significant lower incidence of CV events in comparison to TZD + Met (RR: 1.01, 95% CI: 0.46, 2.45) and SU + Met (RR: 1.06, 95% CI: 0.61, 2.06).

Conclusion

DPP4i in combination with Met was efficacious and had a well-tolerated safety profile compared with other traditional OADs. This combination can be considered as a suitable treatment option for patients with T2DM.

Pharmacokinetic comparison of sitagliptin and metformin HCl extended-release tablets versus JANUMET® XR in healthy volunteers under fasting and fed conditions

Background and Objectives: Janumet^® XR is the combination of sitagliptin and extended metformin hydrochloride produced by Merck Sharp & Dohme. It is specially designed for diabetes mellitus patients taking both drugs already. Janumet^® XR exhibited clinically significant blood glucose lowering efficacy and long-term use safety. However, no generic form of Janumet^® XR has been approved in western countries. The relatively high cost made the medication less prescribed. A more affordable form of this drug may benefit an immense diabetes mellitus population. The current study compared the bioequivalence (BE) of sitagliptin 100 mg and metformin 1000 mg produced by Nanjing Chia-Tai Tianqing Pharmaceutical Company to Janumet^® XR in healthy Chinese subjects. Methods: Twenty-eight healthy Chinese subjects were enrolled in Study 1 and 2, respectively. Both studies were conducted with an open, randomized, two-period crossover design using the test (T) or the reference (R) drug. Study 1 is conducted under the fasting state, and Study 2 is under the fed state. Subjects received an oral dose of sitagliptin 100 mg and metformin 1000 mg, and plasma concentrations of sitagliptin and metformin were determined up to 72 h post-dose. Pharmacokinetic (PK) parameters, including maximum serum concentration (C_max) and area under the concentration-time curve up to the last quantifiable concentration (AUC_0-t) of both sitagliptin and metformin, were calculated and compared between the T and R treatments. Results: In the fasting study, the geometric mean ratios of C_max, AUC_0-t, and AUC_0-∞ for sitagliptin were 109.42%, 101.93%, and 101.95%, respectively; the corresponding ratios for metformin were 98.69%, 94.12%, and 93.42%, respectively. In the fed study, the geometric mean ratios of C_max, AUC_0-t, and AUC_0-∞ for sitagliptin were 98.41%, 100.30%, and 100.24%, respectively; the corresponding ratios for metformin were 97.79%, 99.28%, and 100.69%, respectively. The 90% CIs of C_max, AUC_0-t, and AUC_0-∞ in both studies were all within acceptance limits (80.00%-125.00%). Conclusion: The results demonstrated for the first time that sitagliptin 100 mg and metformin 1000 mg produced by Nanjing Chia-Tai Tianqing Pharmaceutical Company was bioequivalent to the branded Janumet^® XR, and both drugs were well tolerated.

Reduction of Severe Hypoglycemic Events Among Outpatients with Type 2 Diabetes Following Sodium-Glucose Cotransporter 2 Inhibitor Marketing in Japan

Recently, oral hypoglycemic agents with newer glucose lowering mechanisms have been on release. This is mostly to meet the diabetic patient's need to avoid hypoglycemia, which is profoundly important for better long-term outcome of the treatment. In this study, we quantified the annual number of patients with type 2 diabetes who experienced hypoglycemia needing the third-party assistance who had random sample plasma glucose<59.4 mg/dl (3.3 mmol/l) on the one hand and analyzed the prescription trend of hypoglycemic agents all over Japan on the other. Analysis of the annual number of hypoglycemic patients visited ER was performed at Aizawa Hospital, a medical center located in the midst of a city. The study duration was over 10 years from 2008 to 2019. We found a clear-cut decreasing trend of hypoglycemia over the 10 years, ca. 61/year to 39/year. Immediately after the release of sodium-glucose co-transporter-2 inhibitors, since 2013 to 2017, the decrease was rather sharp as 81/year to 31/year, and the change of the national number of its prescription inversely correlated with the change of the number of the patients with hypoglycemia. This was not the case immediately after the introduction of dipeptidyl peptidase-4 inhibitors in the Japanese market since 2008 to 2012. There was no significant correlation between its prescription and the number of patients with hypoglycemia. The data strongly suggested that there was a causal relationship exclusively between the introduction of sodium-glucose cotransporter-2 inhibitor, and the reduction of hypoglycemic events among patients with type 2 diabetes.

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.

Safety, feasibility and efficacy of metformin and sitagliptin in patients with a TIA or minor ischaemic stroke and impaired glucose tolerance

INTRODUCTION

Impaired glucose tolerance (IGT) is highly prevalent after stroke and is associated with recurrent stroke and unfavourable outcome.

OBJECTIVES

We aimed to assess the feasibility, safety and effects on glucose metabolism of metformin or sitagliptin in patients with transient ischaemic attack (TIA) or minor ischaemic stroke and IGT.

DESIGN

We performed a multicentre, randomised, controlled, open-label phase II trial with blinded outcome assessment.

INTERVENTIONS

Patients were randomised in a 2:1:1 ratio to 'no medication', sitagliptin or metformin.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcome measures were baseline adjusted differences of 2-hour postload glucose; secondary outcome measures fasting glucose, glycosylated haemoglobin 1c (HbA1c) levels, tolerability and safety of metformin and sitagliptin at 6 months. Patients on metformin or sitagliptin were contacted by telephone for recording of possible adverse events and to support continuation of treatment at 2 weeks, 6 weeks and 3 months after inclusion. These events were not analysed as outcome measures.

RESULTS

Fifty-three patients were randomised to control group, 26 to metformin and 22 to sitagliptin. We found no significant differences in 2-hour postload glucose between patients on antidiabetic drugs and controls ((-0.04 mmol/L (95% CI -0.53 to 0.45)). Patients in the treatment arms had reduced fasting glucose: ((-0.21 mmol/L (95% CI -0.36 to -0.06)) and HbA1c levels ((-1.16 mmol/mol (95% CI -1.84 to -0.49)). Thirteen patients (50%) on metformin and 7 (32%) on sitagliptin experienced side effects. Sixteen patients (61%) in the metformin and 13 (59%) in the sitagliptin group were still on treatment after 6 months.

CONCLUSIONS

Metformin and sitagliptin were both effective in reducing fasting glucose and HbA1c levels in patients with recent TIA or minor ischaemic stroke and IGT. However, the reduction of glucose levels and sample size was relatively small. The clinical relevance, therefore, needs to be tempered. A phase III trial is needed to investigate whether medical treatment, compared with lifestyle intervention or a combination of both, not only improves glucose metabolism in IGT, but also leads to reduction of recurrent TIA or ischaemic stroke in these patients.

TRIAL REGISTRATION NUMBER

NL3048.

First-in-Human, Double-Blind, Randomized, Placebo-Controlled Trial of TQ-F3083, a New Dipeptidyl Peptidase-4 Inhibitor, in Healthy Chinese Adults

Background: As a novel dipeptidyl peptidase-4 (DPP-4) inhibitor, TQ-F3083 represents a promising new drug for type 2 diabetes mellitus (T2DM). This phase I, first-in-human study evaluated the tolerability, pharmacokinetics, and pharmacodynamics of TQ-F3083 in healthy Chinese adults.

Methods: Sixty healthy participants total were enrolled in the single-ascending dose, multiple-dose, and food-effect studies. Safety endpoints included adverse events (AEs), vital signs, 12-lead electrocardiogram, abdominal ultrasound, chest X-ray, physical examination, and clinical laboratory tests. Blood, urine, and feces samples were collected for pharmacokinetic analyses. Pharmacodynamic parameters were evaluated based on DPP-4 activity and the active glucagon-like peptide-1 concentration.

Results: In total, 22 treatment-related AEs, mostly grade 1 or 2, were reported in 14 individuals. No deaths, serious AEs, or grade ≥4 AEs occurred, and no dose-dependent AEs were demonstrated. For pharmacokinetic characteristics, dose linearity was analyzed using power model. The slopes (90% CIs) were 1.08 (1.02–1.13) and 1.05 (0.99–1.11) for AUC_0-t and AUC_0-∞, suggesting liner pharmacokinetic characteristic after oral dose TQ-F3083 from 2 to 160 mg. The accumulation factor was 1.39 after multiple dose for 7 days. Decreased plasma exposure (84.87% decrease in C_max, 49.23% in AUC_0-t, and 47.77% in AUC_0-∞) was observed with administration after a high-fat and high-calorie standardized breakfast. The 0–72 h TQ-F3083 excretion recovery percentages were 7.84% in urine and 5.76% in feces. Over 80% DPP-4 inhibition for 24 h was observed in the 20–160 mg cohorts, and the model-estimated 50% effective concentration was 1.10 ng/ml. The concentration of active glucagon-like peptide-1 increased after TQ-F3083 administration, but no obvious dose dependency was observed.

Conclusion: TQ-F3083 was well tolerated in healthy Chinese adults, and the pharmacokinetic and pharmacodynamic characteristics support further evaluation of TQ-F3083 in a trial in T2DM patients.

3-point major cardiovascular event outcome for patients with T2D treated with dipeptidyl peptidase-4 inhibitor or glucagon-like peptide-1 receptor agonist in addition to metformin monotherapy

Background

The global incidence of type 2 diabetes (T2D) continues to increase annually, and persons with T2D typically require regular changes in pharmacologic invention for achieving glycemic targets. Healthcare providers must consider multiple factors when selecting a 2nd line. This retrospective cohort study evaluates impact of two common anti-diabetes medication classes (dipeptidyl peptidase-4 inhibitors and glucagon-like peptide-1 receptor agonists) on the well-known composite 3-point major cardiovascular events outcome (3P-MACE, comprised of cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke). No significant impact was found. Persons with T2D face increased risks of many adverse cardiovascular outcomes. This study duplicated common inclusion and exclusion criteria to create an observational cohort from a large healthcare system's electronic health records for testing DPP-4i and GLP-1RA against each other to evaluate impact on likelihood to develop 3P-MACE.

Methods

The statistical model and analyses were based on a cohort of 5,518 adult patients with T2D who were prescribed metformin and either DPP-4i or GLP-1RA to control glycemia during clinic visits between January 2005 and September 2019. A Cox proportional hazards model was developed from the cohort to predict the 3P-MACE endpoint.

Results

The model did not show a meaningful difference in likelihood of developing the 3P-MACE outcome between patients treated with DPP-4i compared to patients treated with GLP-1RA.

Conclusions

Prior history of cardiovascular disease (CVD) did not impact this small difference between the two classes of drug.

Reduction in HbA1c with SGLT2 inhibitors vs. DPP-4 inhibitors as add-ons to metformin monotherapy according to baseline HbA1c: A systematic review of randomized controlled trials

AIMS

This study compared the reduction of glycated haemoglobin (HbA1c) with sodium-glucose cotransporter type-2 inhibitors (SGLT2is) vs. dipeptidyl peptidase-4 inhibitors (DPP-4is) as add-ons to metformin in patients with type 2 diabetes mellitus (T2DM), with a specific focus on HbA1c changes according to baseline HbA1c.

MATERIALS AND METHODS

Electronic databases were scrutinized for randomized controlled trials (RCTs) evaluating the reduction of HbA1c from baseline (Δ HbA1c) with an SGLT2i or DPP-4i in patients with T2DM not well controlled by metformin monotherapy. The endpoint was Δ HbA1c using both indirect and direct comparisons.

RESULTS

Overall, Δ HbA1c was slightly greater with SGLT2is (-0.80±0.20% from 8.03±0.35%; 44 analyses, 29 RCTs, 15 with two doses, n=9321) than with DPP-4is (-0.71±0.23% from 8.05±0.43%; 61 analyses, 59 RCTs, n=17,914; P=0.0354). When the mean baseline HbA1c was<8% ([64mmol/mol] 7.79±0.15% vs. 7.71±0.23%), Δ HbA1c averaged -0.735±0.17% vs. -0.62±0.16% (P=0.0117) with SGLT2is vs. DPP-4is, respectively. However, this difference vanished when the mean baseline HbA1c was≥8% (-0.87±0.22% from 8.27±0.32% with SGLT2is vs. -0.80±0.24% from 8.35±0.33% with DPP-4is; P=0.2756). The relationship between Δ HbA1c and baseline HbA1c was only slightly stronger with SGLT2is (slope: -0.39, r²=-0.43; P<0.0001) than with DPP-4is (slope: -0.26, r²=-0.25; P<0.0001).

CONCLUSION

Because of the small difference in Δ HbA1c whatever the baseline HbA1c level with SGLT2is vs. DPP-4is as add-ons to metformin, choosing between these glucose-lowering agents in clinical practice should be based on other efficacy criteria (such as weight and blood pressure changes, cardiovascular and renal protection) or on safety profiles rather than on HbA1c levels.

Outcomes for Inappropriate Renal Dose Adjustment of Dipeptidyl Peptidase-4 Inhibitors in Patients With Type 2 Diabetes Mellitus: Population-Based Study

OBJECTIVES

To estimate inappropriate dosing of dipeptidyl peptidase-4 (DPP-4) inhibitors and to assess the risk of emergency department visits, hypoglycemia, and mortality in patients with type 2 diabetes mellitus (T2DM) and chronic kidney disease (CKD) prescribed inappropriate DPP-4 inhibitor doses because limited real-world information is available regarding rates of DPP-4 inhibitor dose adjustment and its safety in patients with T2DM and CKD.

PATIENTS AND METHODS

We performed a retrospective observational cohort study of 82,332 patients aged 30 to 75 years with T2DM and CKD being treated with DPP-4 inhibitors from January 1, 2012, through December 31, 2014, using the Korean National Health Information Database. We divided the patients according to the prescription of DPP-4 inhibitor with or without dose adjustment according to estimated glomerular filtration rate. The incidences of emergency department visits, hypoglycemia, and mortality were assessed using hazard ratios estimated using Cox proportional hazards regression modeling.

RESULTS

Approximately 40% of patients with T2DM and CKD were prescribed an inappropriate dose of DPP-4 inhibitor from 2009 through 2011; this proportion decreased to 24.4% in 2015. Hazard ratios (95% CIs) for inappropriate vs appropriate dosing of DPP-4 inhibitors were 1.115 (1.005-1.237) for mortality, 1.074 (1.018-1.133) for emergency department visits, and 1.192 (1.054-1.349) for severe hypoglycemia after multivariable adjustment for confounding factors.

CONCLUSION

One of every 3 patients with T2DM and CKD received inappropriate dosing of DPP-4 inhibitor, which was associated with high risk of emergency department visits, severe hypoglycemia, and mortality.

The efficacy and safety of luseogliflozin and sitagliptin depending on the sequence of administration in patients with type 2 diabetes mellitus: a randomized controlled pilot study

Background: The efficacy and safety of SGLT-2 and DPP-4 inhibitor monotherapies in T2DM is well established; however, data on the effect of combination therapies and sequence of administration are lacking. We investigated the efficacy and safety of the sequence of SGLT-2 and DPP-4 inhibitor administration in Japanese T2DM patients.Research design and methods: In this single-institution, open-label, randomized controlled study, T2DM patients inadequately controlled (HbA1c ≥6.5%) with conventional therapy were randomized to receive luseogliflozin-sitagliptin (LS; luseogliflozin 2.5 mg for 0-12 weeks, then luseogliflozin plus sitagliptin 50 mg for 12-24 weeks) or sitagliptin-luseogliflozin (SL; sitagliptin 50 mg for 0-12 weeks, then sitagliptin plus luseogliflozin 2.5 mg for 12-24 weeks). The main outcome was the difference in mean change in HbA1c at 24 weeks relative to baseline between both groups.Results: Of the 41 enrolled and randomized patients, 34 completed the study. Mean ± SD HbA1c at baseline was 10.35 ± 1.04% and 10.02 ± 1.40% in the LS and SL groups, respectively, and mean ± SD change in HbA1c at 24 weeks from baseline was -3.81 ± 1.21% vs -2.46 ± 1.42% (P < 0.01), respectively. No drug-related adverse events were reported.Conclusion: Over the 24-week period, LS was more effective in reducing HbA1c levels than SL in Japanese T2DM patients.

Cardiovascular risk of sitagliptin in treating patients with type 2 diabetes mellitus

Patients with type 2 diabetes mellitus (T2DM) have a very high risk of cardiovascular related events, and reducing complications is an important evaluation criterion of efficacy and safety of hypoglycemic drugs. Previous studies have shown that the dipeptidyl peptidase-4 (DPP-4) inhibitors (DPP4i), such as sitagliptin, might reduce the incidence of major cardiovascular events (MACEs). However, the safety and efficacy of sitagliptin remains controversial, especially the safety for cardiovascular related events. Here, a systematic review was conducted to assess the cardiovascular safety of sitagliptin in T2DM patients. The literature research dating up to October 2018 was performed in the electronic database. The clinical trials about sitagliptin for T2DM patients were included. Two reviewers independently screened literature according to the inclusion and exclusion criteria. The primary outcome was the MACE, and the secondary outcome was all-cause mortality. Finally, 32 clinical trials composed of 16082 T2DM patients were included in this meta-analysis. The results showed that: there was no significant difference between sitagliptin group and the control group on MACE (odds ratio (OR) = 0.85, 95% confidence intervals (CIs) = 0.63–1.15), myocardial infarction (MI) (OR = 0.66, 95% CI = 0.38–1.16), stroke (OR = 0.83, 95% CI = 0.44–1.54) and mortality (OR = 0.52, 95% CI = 0.26–1.07). These results demonstrated that sitagliptin did not increase the risk of cardiovascular events in patients with T2DM.

Double-blind, randomized clinical trial assessing the efficacy and safety of early initiation of sitagliptin during metformin uptitration in the treatment of patients with type 2 diabetes: The CompoSIT-M study

AIMS

To characterize the glycaemic efficacy and safety of initiation of the dipeptidyl peptidase-4 inhibitor sitagliptin during metformin dose escalation in people with type 2 diabetes (T2D) not at glycated haemoglobin (HbA1c) goal on a sub-maximal dose of metformin.

MATERIALS AND METHODS

Study participants with HbA1c ≥58 mmol/mol and ≤97 mmol/mol (≥7.5% and ≤11.0%) while on 1000 mg/d metformin were randomized to sitagliptin 100 mg once daily or placebo. All were to uptitrate metformin to 2000 mg/d. A longitudinal data analysis model was used to test the primary hypothesis that sitagliptin is superior to placebo when initiated during uptitration of metformin in reducing HbA1c at week 20. [ClinicalTrials.gov Identifier: NCT02791490, EudraCT: 2015-004224-59] RESULTS: A total of 458 participants (mean HbA1c 71.1 mmol/mol [8.7%], T2D duration 6.3 years) were treated. After 20 weeks, the least squares (LS) mean changes from baseline in HbA1c were -12.1 mmol/mol (-14.0, -10.1) (-1.10% [-1.28, -0.93]) and -7.6 mmol/mol (-9.6, -5.6) (-0.69% [-0.88, -0.51]) with sitagliptin and placebo, respectively; the between-group difference in LS mean changes from baseline HbA1c was -4.5 mmol/mol (-6.5, -2.5) (-0.41% [-0.59, -0.23]); P < 0.001. The likelihood of having HbA1c <53 mmol/mol (<7.0%) at week 20 was higher in the sitagliptin group than in the placebo group in the overall population (relative risk 1.7, P = 0.002) and in those with a baseline HbA1c ≥69 mmol/mol (≥8.5%) (relative risk 2.4, P = 0.026). There were no notable differences between groups with regard to adverse events overall, hypoglycaemia events, changes in body weight or other safety variables.

CONCLUSION

In participants not at HbA1c goal on a sub-maximal dose of metformin, addition of sitagliptin at the time of metformin dose uptitration improved glycaemic response and HbA1c goal attainment, with similar safety and tolerability, compared to metformin uptitration alone.

Comparative effect of saxagliptin and glimepiride with a composite endpoint of adequate glycaemic control without hypoglycaemia and without weight gain in patients uncontrolled with metformin therapy: Results from the SPECIFY study, a 48-week, multi-centre, randomized, controlled trial

AIMS

To compare the efficacy and safety of saxagliptin and glimepiride in type 2 diabetes (T2D) patients who are inadequately controlled with metformin monotherapy.

MATERIALS AND METHODS

In this 48-week, multi-centre, open-label, randomized, parallel trial (NCT02280486, clinicaltrials.gov), a total of 388 T2D patients were randomized 1:1 to saxagliptin or glimepiride groups. The primary endpoint was achievement of HbA1c <7.0%, without hypoglycaemia, defined as blood glucose <3.9 mmol/L and weight gain <3.0% after 48 weeks of treatment.

RESULTS

Over 48 weeks, a greater proportion of patients achieved the primary endpoint with saxagliptin compared with glimepiride (43.3% vs 31.3%; odds ratio, 1.38, 95% CI, 1.05-1.82; P = 0.019), especially among patients with baseline HbA1c <8.0%, duration <5 years or baseline BMI ≥25 kg/m² . Mean reduction in HbA1c was similar in the two treatment groups at Week 48 (-0.94% with saxagliptin vs -0.98% with glimepiride; P = 0.439). Bodyweight decreased with saxagliptin, but increased with glimepiride over the treatment period, and the treatment difference was -1.6 kg (P < 0.001) at Week 48. The proportion of patients experiencing hypoglycaemia was much lower with saxagliptin vs glimepiride (3.1% vs 12.8%; P < 0.001).

CONCLUSIONS

This study provides evidence that, compared to glimepiride, saxagliptin more effectively achieves a composite endpoint of adequate glycaemic control without hypoglycaemia and without weight gain in T2D patients who are inadequately controlled with metformin monotherapy, especially in overweight patients with moderate hyperglycaemia and a relatively short duration of diabetes.

Effects of Sitagliptin on Pancreatic Beta-Cells in Type 2 Diabetes With Sulfonylurea Treatment: A Prospective Randomized Study

Background

This prospective randomized, multicenter, open-label, comparative study was performed to analyze the effects of sitagliptin on glycemic control and maintenance of beta-cell function in patients with poorly controlled type 2 diabetes treated with low-dose glimepiride.

Methods

Forty-one patients with type 2 diabetes mellitus treated with low-dose glimepiride (≤ 2 mg/day) were prospectively enrolled in this study (age: 20 - 75 years; hemoglobin A1c (HbA1c): 7.4- 9.4%). The patients were randomized into two groups: the glimepiride (G) group, in which glimepiride dose was increased gradually to 6 mg/day, and the sitagliptin (S) group, in which sitagliptin was added at a dose of 50 mg/day.

Results

HbA1c level was significantly decreased after 24 weeks, but not 12 weeks, in the G group, while a significant decrease was seen after 12 weeks in the S group. Although there were no significant differences in HbA1c level at 24 weeks between the two groups (P = 0.057). The overall trend of changes in HbA1c level suggested that the glucose-lowering effects were superior in the S group. Furthermore, a significant change in fasting glucose was seen in the S group, but not in the G group. Glycemic control target was achieved in 36.7% and 16.7% patients in the S group and the G group, respectively. The proinsulin/insulin (P/I) ratio was significantly increased in the G group, whereas it tended to decrease in the S group. After 24 weeks of treatment, no significant difference was observed in the P/I ratio between the two groups, whereas a significant difference was noted in the ΔP/I (amount of change). Albuminuria tended to increase in the G group compared with the S group.

Conclusion

The results of the present study suggested that sitagliptin effectively lowered hyperglycemia and that it may have a protective effect on pancreatic beta-cells when combined with a low dose of glimepiride. Therefore, sitagliptin may represent a useful combination therapy with low-dose sulfonylurea, not only for achieving glycemic control but also for protection of pancreatic beta-cells.

Clinical Use of DPP-4 Inhibitors

DPP-4 inhibitors were introduced for the treatment of type 2 diabetes in 2006. They stimulate insulin secretion and inhibit glucagon secretion by elevating endogenous GLP-1 concentrations without an intrinsic hypoglycaemia risk. Their efficacy potential to lower HbA1c is in the range between 0.5 and 1.0% and their safety profile is favorable. DPP-4 inhibitors are body weight neutral and they have demonstrated cardiovascular safety. Most compounds can be used in impaired renal function. Guidelines suggest the additional use of DPP-4 inhibitors after metformin failure in patients that do not require antidiabetic therapy with proven cardiovascular benefit. Recently, DPP-4 inhibitors have increasingly replaced sulfonylureas as second line therapy after metformin failure and many metformin/DPP-4 inhibitor fixed dose combinations are available. In later stages of type 2 diabetes, DPP-4 inhibitors are also recommended in the guidelines in triple therapies with metformin and SGLT-2 inhibitors or with metformin and insulin. A treatment with DPP-4 inhibitors should be stopped when GLP-1 receptor agonists are used. DPP-4 inhibitors can be used as monotherapy when metformin is contraindicated or not tolerated. Some studies have shown value of initial metformin-DPP-4 inhibitor combination therapy in special populations. This article gives an overview on the clinical use of DPP-4 inhibitors.

Observational studies of treatment effectiveness: worthwhile or worthless?

Observational studies which evaluate effectiveness are often viewed with skepticism owing to the fact that patients are not randomized to treatment, meaning that results are more prone to bias. Therefore, randomized controlled trials remain the gold standard for evaluating treatment effectiveness. However, it is not always possible to conduct randomized trials. This may be due to financial constraints, for example, in identifying funding for a randomized trial for medicines that have already gained market authorization. There can also be challenges with recruitment, for example, of people with rare conditions or in hard-to-reach population subgroups. This is why observational studies are still needed. In this manuscript, we discuss how researchers can mitigate the risk of bias in the most common type of observational study design for evaluation of treatment effectiveness, the cohort study. We outline some key issues that warrant careful consideration at the outset when the question is being developed and the cohort study is being designed. We focus our discussion on the importance of deciding when to start follow-up in a study, choosing a comparator, managing confounding and measuring outcomes. We also illustrate the application of these considerations in a more detailed case study based on an examination of comparative effectiveness of two antidiabetic treatments using data collected during routine clinical practice.

Blood glucose reduction by diabetic drugs with minimal hypoglycaemia risk for cardiovascular outcomes: Evidence from meta-regression analysis of randomized controlled trials

AIMS

To investigate the effects of blood glucose control with antihyperglycaemic agents with minimal hypoglycaemia risk on cardiovascular outcomes in patients with type 2 diabetes (T2D).

MATERIALS AND METHODS

Randomized controlled trials (RCTs) comparing the relative efficacy and safety of antidiabetic drugs with less hypoglycaemia risk were comprehensively researched in MEDLINE, Embase and the Cochrane Library up to January 27, 2018. Mixed-effects meta-regression analysis was conducted to explore the relationship between haemoglobin A1c (HbA1c) reduction and the risk of major adverse cardiovascular events (MACE), myocardial infarction, stroke, cardiovascular death, all-cause death, and hospitalization for heart failure.

RESULTS

Ten RCTs comprising 92 400 participants with T2D were included and provided information on 9773 MACE during a median follow-up of 2.6 years. The mean HbA1c concentration was 0.42% lower (range, 0.27%-0.86%) for participants given antihyperglycaemic agents than those given placebo. The meta-regression analysis demonstrated that HbA1c reduction was significantly associated with a decreased risk of MACE (β value, -0.39 to -0.55; P < 0.02) even after adjusting for possible confounding factors including age, sex, baseline HbA1c, duration of follow-up, difference in achieved systolic blood pressure, difference in achieved body weight, and risk difference in hypoglycaemia. Lowering HbA1c by 1% conferred a significant risk reduction of 30% (95% confidence interval, 17%-40%) for MACE. By contrast, the meta-regression analysis for trials using conventional agents failed to demonstrate a significant relationship between achieved HbA1c difference and MACE risk (P > 0.74).

CONCLUSIONS

Compared with placebo, newer T2D agents with less hypoglycaemic hazard significantly reduced the risk of MACE. The MACE reduction appears to be associated with HbA1c reduction in a linear relationship.

A randomized controlled trial to compare the effects of sulphonylurea gliclazide MR (modified release) and the DPP-4 inhibitor vildagliptin on glycemic variability and control measured by continuous glucose monitoring (CGM) in Brazilian women with type 2 diabetes

AIMS

This study aims to evaluate whether there is a difference between the effects of vildagliptin and gliclazide MR (modified release) on glycemic variability (GV) in women with type 2 diabetes (T2DM) as evaluated by continuous glucose monitoring (CGM).

METHODS

An open-label, randomized study was conducted in T2DM women on steady-dose metformin monotherapy which were treated with 50 mg vildagliptin twice daily or 60-120 mg of gliclazide MR once daily. CGM and GV indices calculation were performed at baseline and after 24 weeks.

RESULTS

In total, 42 patients (age: 61.9 ± 5.9 years, baseline glycated hemoglobin (HbA1c): 7.3 ± 0.56) were selected and 37 completed the 24-week protocol. Vildagliptin and gliclazide MR reduced GV, as measured by the mean amplitude of glycemic excursions (MAGE, p = 0.007 and 0.034, respectively). The difference between the groups did not reach statistical significance. Vildagliptin also significantly decreased the standard deviation of the mean glucose (SD) and the mean of the daily differences (MODD) (p = 0.007 and 0.030).

CONCLUSIONS

Vildagliptin and gliclazide MR similarly reduced the MAGE in women with T2DM after 24 weeks of treatment. Further studies are required to attest differences between vildagliptin and gliclazide MR regarding glycemic variability.

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

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

Cost-consequence analysis of sitagliptin versus sulfonylureas as add-on therapy for the treatment of diabetic patients in Italy

Objective

Diabetes mellitus is a chronic disease related to a significant impact in both epidemiologic and economic terms. In Italy, around 3.6 million people are affected by diabetes and this number is expected to increase significantly in the next few years. As recommended by current national and international guidelines, metformin (Met) is prescribed as first-line pharmacological treatment, and many pharmacological alternatives are available for patients uncontrolled with Met monotherapy. Despite the availability of many innovative oral antidiabetic drugs (OADs), such as dipeptidyl peptidase 4 inhibitors (DPP4-i) and its first-in-class sitagliptin (SITA), which entered the Italian market in the last 10 years, their usage is consistently lower than traditional drugs such as sulfonylureas (SUs). In fact, due to higher acquisition costs, the prescription of innovative OADs in Italy is restricted to specialist, resulting in a prominent usage of traditional OAD that can be prescribed also by general practitioners (GPs). A cost consequence analysis (CCA) was performed in order to compare SITA with SU, as second-line therapy in add-on to Met, in terms of costs and related clinical events over 36 months.

Methods

A CCA was conducted on a hypothetical cohort of 100,000 type 2 diabetes mellitus (T2DM) patients uncontrolled with Met monotherapy, from both the Italian National Health Service (INHS) and societal perspective. Therefore, both direct (drugs, self-monitoring, hypoglycemia, major cardiovascular events [MACEs], and switch to insulin) and indirect costs (expressed in terms of productivity losses) were evaluated. Clinical and economic data were collected through Italian national tariffs, literature, and experts' opinions. Three expert clinicians finally validated data inputs. To assess robustness of base case results, a one-way sensitivity analysis (OWSA) and a conservative scenario analysis - excluding MACEs - were carried out.

Results

In the base case analysis, the higher drug costs related to SITA were offset by other management costs (ie, lower use of devices for glycemia self-monitoring, lower incidence of hypoglycemia and MACE, and delay to insulin switch). As a result, the economic evaluation showed that, compared to SU, SITA was cost saving from both societal (-€61,217,723) and INHS (-€51,846,442) perspectives over 3 years as add-on to Met. The base case results were also confirmed by the scenario analysis and by the OWSA performed on the key parameters. The adoption of SITA, in a cohort of 100,000 diabetes patients, would avoid 26,882 non-severe hypoglycemic events, 6,528 severe hypoglycemic events, and 1,562 MACEs.

Conclusion

This analysis suggests that, compared to SU, SITA could be a sustainable and cost-saving alternative for the management of T2DM patients uncontrolled with Met monotherapy from both clinical and economic perspectives.

Network meta-analysis of lorcaserin and oral hypoglycaemics for patients with type 2 diabetes mellitus and obesity

In addition to weight loss, randomized controlled trials have shown improvement in glycaemic control in patients taking lorcaserin. The aim of this study aim was to compare adding lorcaserin or other glucose lowering medications to metformin on weight and glycaemic control. A systematic review and network meta-analysis of randomized controlled trials were conducted. Included studies (published 1990-2014) were of lorcaserin or glucose lowering medications in type 2 diabetic patients compared to placebo or different active treatments. Studies had to report ≥1 key outcome (change in weight or HbA1c, % HbA1c <7, hypoglycaemia). Direct meta-analysis was performed using DerSimonian and Laird random effects models, and network meta-analysis with Bayesian Markov-chain Monte Carlo random effects models; 6552 articles were screened and 41 included. Lorcaserin reduced weight significantly more than thiazolidinediones, glinides, sulphonylureas and dipeptidyl peptidase-4 inhibitors, some of which may have led to weight gain. There were no significant differences in weight change between lorcaserin and alpha-glucoside inhibitors, glucagon-like peptide-1 agonists and sodium/glucose cotransporter 2 inhibitors. Network meta-analysis showed lorcaserin was non-inferior to all other agents on HbA1c reduction and % achieving HbA1c of <7%. The risk of hypoglycaemia was not significantly different among studied agents except that sulphonylureas were associated with higher risk of hypoglycaemia than lorcaserin. Although additional studies are needed, this analysis suggests in a population of patients with a body mas index of ≥27 who do not achieve glycaemic control on a single agent, lorcaserin may be added as an alternative to an add-on glucose lowering medication.

Understanding the Gap Between Efficacy in Randomized Controlled Trials and Effectiveness in Real-World Use of GLP-1 RA and DPP-4 Therapies in Patients With Type 2 Diabetes

OBJECTIVE

The objective of this study was to estimate and explain the gap between clinical efficacy and real-world (RW) effectiveness of type 2 diabetes medications.

RESEARCH DESIGN AND METHODS

This mixed-methods quasi-experimental study used retrospective claims (Optum/Humedica) to compare the change in HbA_1c of RW patients with type 2 diabetes 12 months after starting a glucagon-like peptide 1 receptor agonist (GLP-1 RA) or dipeptidyl peptidase 4 (DPP-4) inhibitor with published findings from randomized controlled trials (RCTs) evaluating these drugs. Selected RW patients were similar to RCT patients, and regression analysis was used in the RW data to adjust for differences between poorly adherent and adherent patients to explain why RCT and RW findings may differ.

RESULTS

RW patients initiating a GLP-1 RA (n = 221) or a DPP-4 (n = 652) experienced smaller reductions in HbA_1c (GLP-1 RA: -0.52% [-6 mmol/mol], DPP-4: -0.51% [-6 mmol/mol])than reported in RCTs (-1.30% [-14 mmol/mol] from seven GLP-1 RA RCTs, n = 2,600; -0.68% [-8 mmol/mol] from four DPP-4 RCTs, n = 1,889). Baseline HbA_1c, additional medications, and adherence were significant explanatory factors in the RW HbA_1c change. Modeled estimates of RCT efficacy (-1.04% GLP-1 RA [-12 mmol/mol], -0.69% DPP-4 [-8 mmol/mol]) were within the RCTs' reported range (GLP-1 RA: -0.84% to -1.60% [-9 to -18 mmol/mol], DPP-4: -0.47% to -0.90% [-5 to -10 mmol/mol]). Poor medication adherence accounted for approximately three-fourths of the gap between RW and expected RCT results (gap = 0.51% [6 mmol/mol] GLP-1 RA; 0.18% [3 mmol/mol] DPP-4).

CONCLUSIONS

Poor medication adherence is primarily why RW effectiveness is significantly less than RCT efficacy, suggesting an urgent need to effectively address adherence among patients with type 2 diabetes.

Type 2 Diabetes in the Real World: The Elusive Nature of Glycemic Control

Despite U.S. Food and Drug Administration (FDA) approval of over 40 new treatment options for type 2 diabetes since 2005, the latest data from the National Health and Nutrition Examination Survey show that the proportion of patients achieving glycated hemoglobin (HbA_1c) <7.0% (<53 mmol/mol) remains around 50%, with a negligible decline between the periods 2003-2006 and 2011-2014. The Healthcare Effectiveness Data and Information Set reports even more alarming rates, with only about 40% and 30% of patients achieving HbA_1c <7.0% (<53 mmol/mol) in the commercially insured (HMO) and Medicaid populations, respectively, again with virtually no change over the past decade. A recent retrospective cohort study using a large U.S. claims database explored why clinical outcomes are not keeping pace with the availability of new treatment options. The study found that HbA_1c reductions fell far short of those reported in randomized clinical trials (RCTs), with poor medication adherence emerging as the key driver behind the disconnect. In this Perspective, we examine the implications of these findings in conjunction with other data to highlight the discrepancy between RCT findings and the real world, all pointing toward the underrealized promise of FDA-approved therapies and the critical importance of medication adherence. While poor medication adherence is not a new issue, it has yet to be effectively addressed in clinical practice-often, we suspect, because it goes unrecognized. To support the busy health care professional, innovative approaches are sorely needed.

Sitagliptin 100 mg vs glimepiride 1-3 mg as an add-on to insulin and metformin in type 2 diabetes (SWIM)

OBJECTIVE

To compare the effect of sitagliptin (100 mg) vs glimepiride (1-3 mg) as add-on therapy in Indian type 2 diabetes (T2DM) patients on treatment with insulin and metformin (SWIM study).

RESEARCH DESIGN AND METHODS

This 24-week, controlled, open-label study randomized T2DM patients (n = 440) receiving a stable dose of metformin and insulin combination therapy to sitagliptin (100 mg) or glimepiride (1-3 mg) as add-on therapy. Baseline HbA1c was ≥7.3% and ≤8.5%. After a 6-week titration period for glimepiride (dose titrated every 2 weeks by 1 mg up to a maximum of 3 mg daily), patients were continued for 18 weeks on their respective tolerable doses of glimepiride (ranging from 1 mg to 3 mg) or sitagliptin (100 mg) along with metformin and insulin.

RESULTS

Greater reductions in HbA1c and TDD of insulin were achieved with sitagliptin compared to glimepiride. HbA1c targets and reductions in TDD were achieved by more patients on sitagliptin than on glimepiride. Reductions in both body weight and BMI were also noted among patients on sitagliptin when compared to those on glimepiride, and more hypoglycemic events occurred with glimepiride treatment than with sitagliptin.

CONCLUSIONS

Sitagliptin (100 mg), when compared to glimepiride (1-3 mg), bestowed beneficial effects to T2DM patients in terms of achieving greater glycemic control and also brought significant reductions in total daily dose of insulin required, bodyweight, BMI and hypoglycemic events. Overall, the results suggest that sitagliptin (100 mg) is a superior agent over glimepiride (1-3 mg) as an add-on to insulin-metformin therapy among Asian Indians with T2DM.

Effectiveness of sitagliptin compared to sulfonylureas for type 2 diabetes mellitus inadequately controlled on metformin: a systematic review and meta-analysis

OBJECTIVE

To assess the effectiveness of sitagliptin compared to sulfonylureas as add-on to metformin in adults with type 2 diabetes mellitus from both randomised controlled trials (RCTs) and 'real-world' non-randomised studies.

METHODS AND ANALYSES

We conducted a systematic review of EMBASE, MEDLINE, CENTRAL and grey literature for RCTs and non-randomised studies. We reported outcomes relating to change in HbA1c, fasting glucose, weight, blood pressure and lipids from baseline and need for treatment change. No study investigating macrovascular and microvascular diabetes complications was found. Meta-analysis was used where studies were sufficiently homogenous.

RESULTS

Seven RCTs and five non-randomised studies were eligible for inclusion from 1335 articles retrieved. Meta-analysis of three homogenous RCTs revealed a statistically significant decrease in weight with sitagliptin when compared to sulfonylureas (weighted mean difference (WMD) -2.05 kg; 95% CI -2.38 to -1.71); however, a similar change from baseline in HbA1c (WMD 0.05; 95% CI -0.03 to 0.12), fasting glucose (WMD 0.11; 95% CI -0.08 to -0.29), blood pressure, lipids and the proportion achieving HbA1c <7% by study end (OR 0.98; 95% CI 0.85 to 1.13) was observed.Non-randomised studies identified consisted of four prospective and one retrospective cohort study. Three of these five studies were of moderate/high quality, and results though less precise suggested similar real-world comparative glycaemic and weight effectiveness for both treatments. Data from two cohort studies suggested that treatment change (HR 0.65; 95% CI 0.57 to 0.73) and insulin initiation (HR 0.76; 95% CI 0.65 to 0.90) were less likely among those prescribed sitagliptin; however, inadequate reporting of HbA1c at time of treatment change made interpreting results challenging.

CONCLUSION

Sitagliptin users experienced modest weight loss compared to gain with sulfonylureas; however, this difference was around 2 kg, which may not be of major clinical significance for most individuals. Similar change was observed across most other effectiveness outcomes reported. Further studies are needed to address longer-term effectiveness outcomes for sitagliptin compared to sulfonylureas as add-on to metformin.

PROSPERO REGISTRATION NUMBER

CRD42016033983.

Linagliptin versus sitagliptin in patients with type 2 diabetes mellitus: a network meta-analysis of randomized clinical trials

Background

Diabetes is one of the most common chronic and costly diseases worldwide and type 2 diabetes is the most common type which accounts for about 90% of cases with diabetes. New medication-therapy regimens such as those containing linagliptin alone or in combination with other medications (within the category of DDP-4 inhibitors) must be evaluated in terms of efficacy and compared with other currently used drugs and then enter the medication list of the country. Hence, this study aimed to compare the clinical efficacy of the two drugs, i.e. linagliptin and sitagliptin, in patients with type 2 diabetes.

Methods

A systematic review was conducted to identify all clinical trials published by 2015 which compared the two drugs in patients with type 2 diabetes. Using keywords such as “linagliptin”, “type 2 diabetes mellitus”, “sitagliptin” and related combinations, we searched databases including Scopus, PubMed, and Web of Science. The quality of the selected studies was evaluated using the Jadad score. Considering primary and secondary outcomes extracted from the reviewed studies, a network meta-analysis was used to conduct a systematic comparison between the two studied drugs.

Results

This network meta-analysis included 32 studies (Linagliptin vs PLB: n = 8, Sitagliptin vs PLB: n = 13, Linagliptin + MET vs PLB + MET: n = 4, and Sitagliptin + MET vs PLB + MET: n = 7) and a total of 13,747 patients. The results showed no significant difference between linagliptin and sitagliptin in terms of key efficacy and safety outcomes such as HbA1c changes from baseline, body weight change from baseline, percentage of patients achieving HbA1c <7, and percentage of patients experiencing hypoglycemic events (p > 0.05). The results showed that the efficacy of the two drug regimens was the same.

Conclusions

Based on the results, there was no significant difference between the two drugs, i.e. linagliptin and sitagliptin, in terms of efficacy; in other words, the efficacy of the two drugs was the same. Therefore, the use of these two drugs depends on their availability and cost.

Graphical abstract

Graphical abstract of the network meta-analysis performed to evaluate the alternatives under the study.

Electronic supplementary material

The online version of this article (10.1186/s40199-017-0189-6) contains supplementary material, which is available to authorized users.

A randomized, double-blind, non-inferiority trial evaluating the efficacy and safety of omarigliptin, a once-weekly DPP-4 inhibitor, or glimepiride in patients with type 2 diabetes inadequately controlled on metformin monotherapy

OBJECTIVE

To evaluate the efficacy and safety of adding the once-weekly DPP-4 inhibitor omarigliptin or the sulfonylurea glimepiride to the treatment regimen of patients with type 2 diabetes (T2DM) and inadequate glycemic control on metformin monotherapy.

METHODS

Patients with T2DM and HbA1c ≥6.5% to ≤9.0% while on a stable dose of metformin (≥1500 mg/day) were randomized to omarigliptin 25 mg once-weekly (n = 376) or glimepiride up to 6 mg once daily (n = 375) for 54 weeks. The primary hypothesis was that omarigliptin is non-inferior to glimepiride in reducing HbA1c at week 54.

RESULTS

The mean baseline HbA1c was 7.5% in the omarigliptin group and 7.4% in the glimepiride group. After 54 weeks, the least squares (LS) mean change from baseline in HbA1c was -0.30% in the omarigliptin group and -0.48% in the glimepiride group, with a between-group difference (95% CI) of 0.18% (0.06, 0.30), which met the pre-specified criterion for declaring non-inferiority. The incidence of symptomatic hypoglycemia was 5.3% in the omarigliptin group and 26.7% in the glimepiride group. With the exception of hypoglycemia, the incidences of adverse events and discontinuations were similar between treatment groups. Relative to baseline, omarigliptin was associated with a mean weight loss (-0.4 kg) and glimepiride a mean weight gain (+1.5 kg).

CONCLUSIONS

After 54 weeks, as add-on therapy to metformin, once-weekly omarigliptin was generally well tolerated and non-inferior to glimepiride in improving glycemic control, with a lower incidence of hypoglycemia and with weight loss vs weight gain.

Rhabdomyolysis and AKI with Atorvastatin and Sitagliptin Use in the Setting of Low 25-Hydroxyvitamin D Levels

We report a case of an 86-year-old woman admitted to the hospital with rhabdomyolysis and acute kidney injury 3 weeks after starting sitagliptin while on long-term atorvastatin therapy. She also had low levels of 25-hydroxyvitamin D and mild chronic kidney disease, which may have contributed to the development of rhabdomyolysis. A review of the literature reveals four previous reports of this drug interaction in elderly patients, some with underlying kidney disease.

Metformin: clinical use in type 2 diabetes

Metformin is one of the most popular oral glucose-lowering medications, widely considered to be the optimal initial therapy for patients with type 2 diabetes mellitus. Interestingly, there still remains controversy regarding the drug's precise mechanism of action, which is thought to involve a reduction in hepatic glucose production. It is now recommended as first-line treatment in various guidelines, including that of the EASD and ADA. Its favoured status lies in its efficacy, low cost, weight neutrality and good safety profile. Other benefits have also been described, including improvements in certain lipids, inflammatory markers, and a reduction in cardiovascular events, apparently independent from the drug's glucose-lowering effect. Data have emerged questioning the previous reluctance to use this agent in those with mild to moderate chronic kidney disease. Regulations guiding its use in patients with stable, modest renal dysfunction have, as a result, become more lenient in recent years. With no long-term studies comparing it against newer glucose-lowering drugs, some of which have more robust evidence for cardioprotection, metformin's established role as 'foundation therapy' in type 2 diabetes may justifiably be challenged.

Evaluating the costs of glycemic response with canagliflozin versus dapagliflozin and empagliflozin as add-on to metformin in patients with type 2 diabetes mellitus in the United Arab Emirates

OBJECTIVE

This study evaluates the cost of achieving glycemic control with three sodium glucose co-transporter 2 (SGLT2) inhibitors, canagliflozin, dapagliflozin, and empagliflozin, in patients with type 2 diabetes mellitus (T2DM) from the payer perspective in the United Arab Emirates (UAE).

METHODS

A systematic literature review identified randomized controlled trials of antihyperglycemic agents as add-on to metformin in patients with T2DM of 26 ± 4 weeks in duration, published by 10 September 2014. A Bayesian network-meta analysis (NMA) compared HbA1c changes with canagliflozin 100 and 300 mg versus dapagliflozin 10 mg and empagliflozin 10 and 25 mg. The cost associated with a 1% placebo-adjusted HbA1c reduction with each SGLT2 inhibitor as add-on to metformin was calculated based on NMA results and UAE drug costs.

RESULTS

In the NMA, canagliflozin 100 and 300 mg were associated with HbA1c reductions (-0.67% and -0.79%) compared with dapagliflozin 10 mg (-0.41%) and empagliflozin 10 and 25 mg (-0.57% and -0.64%). Probabilities of canagliflozin 100 mg performing better were 79%, 60%, and 53% versus dapagliflozin 10 mg and empagliflozin 10 and 25 mg, respectively; probabilities for canagliflozin 300 mg performing better were 88%, 72%, and 65%, respectively. The cost per 1%-point reduction in HbA1c was projected to be lower with canagliflozin 100 and 300 mg ($448 and $422) compared with dapagliflozin 10 mg ($785) and empagliflozin 10 and 25 mg ($527 and $563).

CONCLUSIONS

Canagliflozin may provide a greater glycemic response at a lower effective cost than dapagliflozin or empagliflozin for patients with T2DM inadequately controlled with metformin from the payer perspective in the UAE.

NRF2 activation by antioxidant antidiabetic agents accelerates tumor metastasis

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

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

FUNDING

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

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.

Addition of sulphonylurea to metformin does not relevantly change body weight: a prospective observational cohort study (ZODIAC-39)

AIM

To investigate changes in body weight trajectories after the addition of individual sulphonylureas (SUs) to metformin in patients with type 2 diabetes.

MATERIALS AND METHODS

We conducted a retrospective observational cohort study, in a primary care setting in the Netherlands. Patients aged ≥18 years with type 2 diabetes who were included in the ZODIAC cohort between 1998 and 2012 and who received metformin monotherapy at inclusion (n = 29 195), and had used metformin as monotherapy for at least 1 year before receiving dual therapy through the addition of an SU for at least 1 year were eligible for inclusion. The primary outcome was within-drug yearly change in body weight after receiving add-on therapy with individual SUs during 5 years of follow-up. The secondary outcome was within-drug yearly change in glycated haemoglobin (HbA1c). Annual changes in weight and HbA1c were estimated with linear mixed models, adjusted for age, gender and diabetes duration.

RESULTS

A total of 2958 patients were included. No significant weight changes were observed within and between any of the individual SUs after treatment intensification (p = 0.24). In addition, no significant difference in weight between the add-on therapy combinations was observed (p = 0.26). The average HbA1c the year before intensification was 7.2% (55 mmol/mol) and dropped below 7.0% (53 mmol/mol) the year after.

CONCLUSIONS

In patients with type 2 diabetes treated in primary care, strict glycaemic control can be maintained with SUs used as add-on therapy to metformin, without the offset of relevant weight changes.

Incretin-Based Therapy for Diabetes: What a Cardiologist Needs to Know

Incretin-based therapies are effective glucose-lowering drugs that have an increasing role in the treatment of type 2 diabetes because of their efficacy, safety, and ease of use. Both glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors are commonly used for glycemic control as adjuncts to metformin, other oral antiglycemic agents, or insulin. Glucagon-like peptide-1 receptor agonists may have additional effects, such as weight loss, that may be advantageous in obese patients. There is a large body of evidence from randomized controlled clinical trials supporting the cardiovascular safety of dipeptidyl peptidase-4 inhibitors and some glucagon-like peptide-1 receptor agonists, at least in the short term. However, concerns have been raised, particularly regarding their safety in patients with heart failure. In this review, the authors provide a brief but practical evidence-based analysis of the use of incretin-based agents in patients with diabetes, their efficacy, and cardiovascular safety.

Cerebrovascular Safety of Sulfonylureas: The Role of KATP Channels in Neuroprotection and the Risk of Stroke in Patients With Type 2 Diabetes

Sulfonylureas are ATP-sensitive potassium (KATP) channel blockers commonly used in the treatment of type 2 diabetes mellitus (T2DM). Activation of KATP channels plays a neuroprotective role in ischemia; thus, whether sulfonylureas affect the outcomes of stroke in patients with T2DM needs to be further studied. In our study, streptozotocin (STZ)-induced diabetic mice subjected to transient middle cerebral artery occlusion (MCAO) showed larger areas of brain damage and poorer behavioral outcomes. Blocking the KATP channel by tolbutamide increased neuronal injury induced by oxygen-glucose deprivation (OGD) in vitro and permanent MCAO (pMCAO) in vivo. Activating the KATP channel by diazoxide reduced the effects of both the OGD and pMCAO. Western blot analysis in STZ mouse brains indicated an early increase in protein levels of N-methyl-d-aspartate receptor 2B and postsynaptic density protein-95, followed by a decrease in phosphorylation of glycogen synthase kinase 3β. Our systematic meta-analysis indicated that patients with T2DM treated with sulfonylureas had a higher odds ratio for stroke morbidity than those who received comparator drugs. Taken together, these results suggest that sulfonylurea treatment in patients with T2DM may inhibit the neuroprotective effects of KATP channels and increase the risk of stroke.

A randomized clinical trial evaluating the safety and efficacy of sitagliptin added to the combination of sulfonylurea and metformin in patients with type 2 diabetes mellitus and inadequate glycemic control

BACKGROUND

Type 2 diabetes mellitus (T2DM) treatment generally requires multiple antihyperglycemic agents. When diet, exercise, and treatment with sulfonylurea and metformin do not achieve glycemic goals, several options are available. The present study evaluated the efficacy and tolerability of sitagliptin 100 mg/day added to therapy with sulfonylurea and metformin.

METHODS

Patients with HbA1c ≥7.5% and ≤10.5% while on a sulfonylurea and metformin were randomized 1: 1 to sitagliptin 100 mg/day or placebo for 24 weeks. At Week 24, patients in the placebo group switched to pioglitazone 30 mg/day and both groups continued treatment for another 30 weeks.

RESULTS

Of 427 patients randomized, 339 (79.4%) completed the study. At Week 24, significantly greater (P < 0.001) mean reductions from baseline were seen in the sitagliptin versus placebo group for HbA1c (-0.84% vs -0.16%, respectively), 2-h post-meal glucose (-2.0 vs -0.2 mmol/L, respectively) and fasting plasma glucose (-0.7 vs 0.3 mmol/L, respectively). At Week 54, improvements in glycemic control continued. At Week 24, the incidence of adverse events (AEs) was numerically greater with sitagliptin than placebo, primarily because of a higher incidence of hypoglycemia. At Week 54, the incidence of AEs was similar in both groups, primarily because of a higher incidence of hypoglycemia and edema in the placebo/pioglitazone group after Week 24. The only meaningful change in body weight was an increase in the placebo/pioglitazone group at Week 54.

CONCLUSIONS

In this study, sitagliptin 100 mg/day was generally well tolerated and provided improvement in glycemic control when added to the combination of sulfonylurea and metformin in patients with T2DM.

Hypoglycaemia when adding sulphonylurea to metformin: a systematic review and network meta-analysis

AIMS

The risk of hypoglycaemia may differ among sulphonylureas (SUs), but evidence from head-to-head comparisons is sparse. Performing a network meta-analysis to use indirect evidence from randomized controlled trials (RCTs), we compared the relative risk of hypoglycaemia with newer generation SUs when added to metformin.

METHODS

A systematic review identified RCTs lasting 12-52 weeks and evaluating SUs added to inadequate metformin monotherapy (≥1000 mg/day) in type 2 diabetes. Adding RCTs investigating the active comparators from the identified SU trials, we established a coherent network. Hypoglycaemia of any severity was the primary end point.

RESULTS

Thirteen trials of SUs and 14 of oral non-SU antihyperglycaemic agents (16 260 patients) were included. All reported hypoglycaemia only as adverse events. Producing comparable reductions in HbA_1C of -0.66 to -0.84% (-7 to -9 mmol/mol), the risk of hypoglycaemia was lowest with gliclazide compared to glipizide (OR 0.22, CrI: 0.05 to 0.96), glimepiride (OR 0.40, CrI: 0.13 to 1.27), and glibenclamide (OR 0.21, CrI: 0.03 to 1.48). A major limitation is varying definitions of hypoglycaemia across studies.

CONCLUSIONS

When added to metformin, gliclazide was associated with the lowest risk of hypoglycaemia between the newer generation SUs. Clinicians should consider the risk of hypoglycaemia agent-specific when selecting an SU agent.

Sitagliptin/metformin fixed-dose combination in type 2 diabetes mellitus: an evidence-based review of its place in therapy

Type 2 diabetes mellitus is a progressive disease associated with significant morbidity and mortality. There is good evidence showing that intensive glycemic control reduces the development and progression of complications. In order to achieve glycemic targets, patients often require a combination of oral therapy and/or insulin in addition to lifestyle modification. Unfortunately, many of the traditional therapies for type 2 diabetes are associated with weight gain and hypoglycemia, resulting in poor compliance and subsequent worsening of glycemic control. The dipeptidyl peptidase-4 inhibitor sitagliptin is a therapy for type 2 diabetes and is available as a fixed-dose combination with metformin. Phase III clinical trials have demonstrated beneficial effects on glycemic control and minimal untoward effects with this combination. In this article, we provide an overview of the pharmacology, efficacy, and safety and examine the role of this combination within current practice.

Comparative studies of dipeptidyl peptidase 4 inhibitor vs sulphonylurea among Muslim Type 2 diabetes patients who fast in the month of Ramadan: A systematic review and meta-analysis

AIM

To systematically review the literature to compare the use of DPP4 inhibitors vs sulphonylurea in type 2 diabetic Muslim patients who fast in Ramadan, with regards to its safety, tolerability, glycemic control, and body weight changes.

METHODS

All English-language medical literature published from inception till October 2014 which met the inclusion criteria were reviewed and analyzed.

RESULTS

A total of nine papers were included, reviewed and analyzed. The total sample size was 4276 patients. All studies used either of the two DPP4 inhibitors - Vildagliptin or Sitagliptin, vs sulphonylurea or meglitinides. Patients receiving DPP4 inhibitors were less likely to develop symptomatic hypoglycemia (risk ratio 0.46; 95% CI, 0.30-0.70), confirmed hypoglycemia (risk ratio 0.36; 95% CI, 0.21-0.64) and severe hypoglycemia (risk ratio 0.22; 95% CI, 0.10-0.53) compared with patients on sulphonylureas. There was no statistically significant difference in HbA1C changes comparing Vildagliptin and sulphonylurea.

CONCLUSION

DPP4 inhibitor is a safer alternative to sulphonylurea in Muslim patients with type 2 diabetes mellitus who fast during the month of Ramadan as it is associated with lower risk of symptomatic, confirmed and severe hypoglycemia, with efficacy comparable to sulphonylurea.

DPP-4 inhibitor therapy and bone fractures in people with Type 2 diabetes - A systematic review and meta-analysis

AIM

Fracture risk is higher in older adults with Type 2 diabetes mellitus (T2DM). Oral glucose-lowering medications have different effects on bone metabolism. The purpose of this study is to appraise the evidence from literature and determine the effect of dipeptidyl peptidase-4 (DPP-4) inhibitor on the risk of developing bone fractures.

METHODS

Using Boolean search terms, the search strategy combined synonyms of 'fracture' and 'DPP-4 inhibitor'. Comprehensive electronic databases which include EMBASE, MEDLINE, the EMA and the WHO ICTRP databases were searched for randomised controlled trial (RCT) studies which compared a DPP-4 inhibitor with an active comparator or placebo amongst patients with T2DM. Meta-analysis was performed to compare DPP-4 inhibitor with either an active comparator or a placebo. The outcome measure was the presence or absence of fracture.

RESULTS

The search yielded 5061 records relating to fractures and DPP-4 inhibitor, from which 51 eligible RCTs were selected for meta-analysis (N=36,402). Thirty-seven (37) studies compared DPP-4 inhibitor with placebo (n=23,974), while fourteen (14) studies (n=12,428) compared DPP-4 inhibitor with an active comparator. The mean age of patients was 57.5±5.4years, the average glycated haemoglobin (HbA1c) was 8.2%, while the average BMI was 30±2kg/m(2). Overall, there was no significant association of fracture events with the use of DPP-4 inhibitor when compared with placebo (OR; 0.82, 95% CI 0.57-1.16, P=0.9) or when DPP-4 inhibitor was compared against an active comparator (OR; 1.59, 95% CI 0.91-2.80, P=0.9).

CONCLUSION

This study offers a larger, up-to-date review of the subject. The meta-analysis showed that there was no significant association between DPP-4 inhibitor use and the incidence of fractures.

DPP-4 inhibitors and risk of infections: a meta-analysis of randomized controlled trials

BACKGROUND

To evaluate the risk of infections in the treatment of type 2 diabetes patients with dipeptidyl-peptidase 4 (DPP-4) inhibitors.

METHODS

A literature search was conducted through electronic databases. The inclusion criteria included study duration of no less than 12 weeks developed in type 2 diabetes patients, the use of a randomized control group receiving a DPP-4 inhibitor and the availability of outcome data for infections. Out of 2181 studies, 74 studies were finally included.

RESULTS

The risk of overall infection for DPP-4 inhibitors treatment was comparable to placebo (odds ratio (OR) = 0.97, 95% confidence interval (CI), 0.91 to 1.04, p = 0.40), metformin treatment (OR = 1.22, 95% CI, 0.95 to 1.56, p = 0.12), sulphonylurea treatment (OR = 1.09, 0.93 to 1.29, p = 0.29), thiazolidinedione treatment (OR = 0.86, 95% CI, 0.65 to 1.14, p = 0.29) and alpha glucosidase inhibitor treatment (OR = 1.03, 95% CI, 0.33 to 3.22, p = 0.96). When compared different DPP-4 inhibitors with placebo treatment, risks of infections were comparable for alogliptin, linagliptin, sitagliptin, saxagliptin and vildagliptin. Compared with placebo or active comparator treatment, risks of infection in different systems for DPP-4 inhibitors were all comparable.

CONCLUSIONS

The overall risk of infections of DPP-4 inhibitor was not increased compared with control groups.

Efficacy, Safety and Treatment Satisfaction of Glimepiride vs Sitagliptin in Combination with Metformin in Type 2 Diabetes Mellitus

INTRODUCTION

Metformin is a preferred drug for starting treatment in type 2 diabetes mellitus. But, eventually most of the patients need additional drug to control blood sugar level. The choice of drug depends upon several factors including patient specific criteria, economical factors and treatment satisfaction.

AIM

The aim of the present study is to investigate the effects of adding sitagliptin or glimepiride on efficacy, safety and treatment satisfaction in patients with type 2 diabetes mellitus.

MATERIALS AND METHODS

It was a retrospective observational study on 50 patients each in sitagliptin and glimepiride group, who are receiving treatment for at least 12 weeks and are stable on respective treatment regimen. Glycated haemoglobin (HBA1c) was the primary measure of efficacy. Safety was assessed by checking weight gain/loss, hypoglycaemia episodes and other laboratory investigations. Patient satisfaction was assessed by Diabetes Treatment Satisfaction Questionnaire.

RESULTS

The HbA1c level after 12-24 weeks of treatment was not found to be significant compared to each other or from baseline. Compared to baseline fasting plasma glucose & postprandial plasma glucose were lower in glimepiride group. Sitagliptin was associated with less episodes of hypoglycaemia. Weight gain was associated with glimepiride but it was non-significant (p=0.08). Overall treatment satisfaction score were better for sitagliptin but were not statistically significant.

CONCLUSION

The efficacy of sitagliptin was comparable. Sitagliptin had superior adverse effect profile with less chances of hypoglycaemia and weight gain. Questionnaire scores were higher for sitagliptin indicating better treatment satisfaction compared to glimepiride.

Effectiveness and Safety of Newer Antidiabetic Medications for Ramadan Fasting Diabetic Patients

Hypoglycemia is the most common side effects for most glucose-lowering therapies. It constitutes a serious risk that faces diabetic patients who fast during Ramadan (the 9th month in the Islamic calendar). New glucose-lowering classes like dipeptidyl peptidase-4 (DPP-4) inhibitors, glucagon-like peptide 1 receptor agonist (GLP-1 RA), and sodium-glucose cotransporter-2 (SGLT-2) inhibitors are efficacious in controlling blood glucose level with less tendency to induce hypoglycemia and thus may constitute a good choice for diabetic patients during Ramadan. This study reviews the safety and efficacy of newer glucose-lowering therapies during Ramadan. This study was accomplished through a careful literature search about studies that assess the benefit and side effects of these new glucose-lowering therapies during Ramadan during September 2015. Vildagliptin, sitagliptin, liraglutide, exenatide, and dapagliflozin were the only studied glucose-lowering therapies. All of the studied newer glucose-lowering therapies except dapagliflozin were associated with reduced risk to induce hypoglycemia. Gastrointestinal upset was common with the usage of liraglutide while increased thirst sensation was common with dapagliflozin. In conclusion DPP-4 inhibitors such as vildagliptin and sitagliptin may form a suitable glucose-lowering therapy option for Ramadan fasting patients.

Gliptins and Cardiovascular Outcomes: A Comparative and Critical Analysis after TECOS

The issue related to macrovascular outcomes and intensive glycemic control was hotly debated after the publication of landmark trials like ACCORD, ADVANCE, and VADT. The only benefits seem to come from intervening early on in the disease process as indicated by the 10-year UKPDS follow-up. To complicate matters USFDA made it mandatory for modern drugs to conduct cardiovascular safety trials in high-risk populations after the 2008 rosiglitazone scare. This led to all the modern group of drugs designing cardiovascular safety trials (gliptins, GLP-1 agonists, and SGLT-2 inhibitors) to meet USFDA regulatory requirements. We saw publication of the first 2 randomized trials with gliptins published a year and a half back. On the face value SAVOR TIMI and EXAMINE satisfied the primary composite CV end-points. However, issues related to significant increase in heart failure and all-cause 7-day on-treatment mortality created a lot of confusion. FDA reanalysis of these data (especially SAVOR) raises a lot of doubts as far as CV safety of these groups of drugs was concerned. Hence, all eyes were on TECOS, which was published this year. We take a microscopic look at these trials trying to understand where we stand as from now on this issue.

Risk of pancreatic adverse events associated with the use of glucagon-like peptide-1 receptor agonist and dipeptidyl peptidase-4 inhibitor drugs: A systematic review and meta-analysis of randomized trials

AIM: To systematically assess risk of pancreatic adverse events with glucagon-like peptide-1 (GLP-1) receptor agonist and dipeptidyl peptidase-4 (DPP-4) inhibitor drugs.

METHODS: We searched PubMed, Embase, CINAHL, Cochrane review of clinical trials, pharmaceutical company clinical trials register, United States Food and Drug Administration website, European Medicines Agency website and ClinicalTrials.gov for randomized controlled trials from inception to October 2013. Randomized control trial studies were selected for inclusion if they reported on pancreatic complication events and/or changes in pancreatic enzyme levels (serum amylase and serum lipase) as adverse events or as serious adverse events for patients who were on GLP-1 receptor agonist and DPP-4 inhibitor drugs. Two independent reviewers extracted data directly. We performed Peto odds ratio (OR) fixed effect meta-analysis of pancreatic adverse events a, and assessed heterogeneity with the I² statistic.

RESULTS: Sixty-eight randomized controlled trials were eligible. A total of 60720 patients were included in our analysis of the association of risk of pancreatic complication events with GLP-1 agents. A total of 89 pancreatic related adverse events occurred among the GLP-1 agents compared to 74 events among the controls. There was a statistically significant increased risk of elevation of pancreatic enzymes associated with GLP-1 agents compared with control (Peto OR = 3.15, 95%CI: 1.56-6.39, P = 0.001, I² = 0%). There was no statistically significant difference in the risk of pancreatic adverse event associated with GLP-1 agent compared with controls (Peto OR = 1.00, 95%CI: 0.73-1.37, P = 1.00, I² = 0%). There were a total of 71 pancreatitis events in patients on GLP-1 agents and 56 pancreatitis events occurred in the control patients. There were 36 reports of pancreatic cancer in these studies. Of these cases, 2 used linagliptin, 2 used alogliptin, 1 used vildagliptin, 7 used saxagliptin while 6 used sitagliptin. The remaining 18 cases occurred among controls.

CONCLUSION: Although GLP-1 based agents are associated with pancreatic enzyme elevation, we were unable to confirm a significant risk of pancreatitis or pancreatic cancer.

Metformin and sitAgliptin in patients with impAired glucose tolerance and a recent TIA or minor ischemic Stroke (MAAS): study protocol for a randomized controlled trial

Background

Impaired glucose tolerance is present in one third of patients with a TIA or ischemic stroke and is associated with a two-fold risk of recurrent stroke. Metformin improves glucose tolerance, but often leads to side effects.

The aim of this study is to explore the feasibility, safety, and effects on glucose metabolism of metformin and sitagliptin in patients with TIA or minor ischemic stroke and impaired glucose tolerance. We will also assess whether a slow increase in metformin dose and better support and information on this treatment will reduce the incidence of side effects in these patients.

Methods/Design

The Metformin and sitAgliptin in patients with impAired glucose tolerance and a recent TIA or minor ischemic Stroke trial (MAAS trial) is a phase II, multicenter, randomized, controlled, open-label trial with blinded outcome assessment. Non-diabetic patients (n = 100) with a recent (<6 months) TIA, amaurosis fugax or minor ischemic stroke (modified Rankin scale ≤ 3) and impaired glucose tolerance, defined as 2-hour post-load glucose levels between 7.8 and 11.0 mmol/L after repeated standard oral glucose tolerance test, will be included. Patients with renal or liver impairment, heart failure, chronic hypoxic lung disease stage III–IV, history of lactate acidosis or diabetic ketoacidosis, pregnancy or breastfeeding, pancreatitis and use of digoxin will be excluded. The patients will be randomly assigned in a 1:1:2 ratio to metformin, sitagliptin or “no treatment.” Patients allocated to metformin will start with 500 mg twice daily, which will be slowly increased during a 6-week period to a twice daily dose of 1000 mg. Patients allocated to sitagliptin will be treated with a daily fixed dose of 100 mg. The study has been registered as NTR 3196 in The Netherlands Trial Register. Primary outcomes include percentage still on treatment, percentage of (serious) adverse events, and the baseline adjusted difference in 2-hour post-load glucose levels at 6 months.

Discussion

This study will give more information about the feasibility and safety of metformin and sitagliptin as well as the effect on 2-hour post-load glucose levels at 6 months in patients with TIA or ischemic stroke and impaired glucose tolerance.

Trial registration number

NTR3196, Date of registration: 15 December 2011.

Effects of sulfonylureas on lipids in type 2 diabetes mellitus: a meta-analysis of randomized controlled trials

OBJECTIVE

Previous studies suggested that dyslipidemia was potentially associated with anti-diabetic medications of sulfonylureas (SUs). The results were, however, inconsistent. Therefore, we conducted a meta-analysis of randomized controlled trials (RCTs) to assess the effects of SUs on the level of lipids in patients with type 2 diabetes mellitus (T2DM).

METHODS

We searched PubMed, EMBASE, and CENTRAL databases for RCTs that addressed the effects of second- and/or third-generation SUs used in T2DM patients on lipids profiles with study duration of at least 12 weeks. Two reviewers independently screened literature, collected data, and assessed methodological quality of included studies. The meta-analysis was performed by using the RevMan5.1 software.

RESULTS

A total of 59 RCTs were included, of which 52 were included for final meta-analysis. The results suggested that SUs statistically increased the levels of FFA (SMD = 0.24, 95%CI 0.06 to 0.42) and TG (MD = 0.06, 95%CI 0.02 to 0.10), but decreased HDL-C (MD = -0.07, 95%CI -0.11 to -0.04) and LDL-C (MD = -0.11, 95%CI -0.17 to -0.04); but the SUs had no effect on TC (MD = 0.01, 95%CI -0.05 to 0.08), ApoA1 (MD = 0.01, 95%CI -0.03 to 0.04), and Apo B (MD = -0.01, 95%CI -0.05 to 0.03). When compared to metformin, SUs could increase TC and LDL-C; compared to glinides, SUs increased TC and lowered HDL-C; compared to thiazolidinediones, SUs reduced TC, LDL-C, HDL-C, and increase TG.

CONCLUSIONS

SUs have a small effect on lipids, although they may statistically increase the level of FFA and TG, and decrease LDL-C and HDL-C.