Comparison of vildagliptin and metformin monotherapy in elderly patients with type 2 diabetes: a 24-week, double-blind, randomized trial

Dipeptidyl peptidase-4 inhibitors and pancreatitis risk: a meta-analysis of randomized clinical trials

AIM

Some observational studies reporting an increased risk of pancreatitis in association with Dipeptidyl Peptidase-4 inhibitors (DPP4i) have raised concerns on the overall safety of this class. Aim of the present meta-analysis is the systematic collection of information on pancreatitis in randomized clinical trials with DPP4i.

DATA SOURCES

an extensive Medline, Embase and Cochrane Database search for 'vildagliptin', 'sitagliptin', 'saxagliptin', 'alogliptin', 'linagliptin' and 'dutogliptin' was performed up to 1 March 2013.

STUDY SELECTION

studies were included if they satisfied the following criteria: (i) randomized trials, (ii) duration ≥12 weeks, (iii) on type 2 diabetes and (iv) comparison of DPP4i with placebo or active drugs. The identification and the selection of studies, and the subsequent data extraction were performed independently by two authors. Mantel-Haenszel odds ratio with 95% Confidence Interval (MH-OR) was calculated for all the adverse events defined below. The principal outcome was the effect of DPP4i on the incidence of pancreatitis.

RESULTS

A total of 134 eligible trials were identified. The overall risk of pancreatitis and pancreatic cancer was not different between DPP4i and comparators (MH-OR: 0.93[0.51-1.69]; p = 0.82).

CONCLUSIONS

It should be recognized that the number of observed cases of incident pancreatitis is small and the confidence intervals of risk estimates are wide. However, the present meta-analysis do not suggest any increase in the risk of pancreatitis with DPP4i.

Efficacy and safety of dipeptidyl peptidase-4 inhibitors and metformin as initial combination therapy and as monotherapy in patients with type 2 diabetes mellitus: a meta-analysis

AIMS

This meta-analysis was performed to provide an update on the efficacy and safety of dipeptidyl peptidase-4 (DPP-4) inhibitors and metformin as initial combination therapy and as monotherapy in patients with type 2 diabetes mellitus (T2DM).

METHODS

We conducted a search on MEDLINE, Embase and Cochrane Collaborative database for randomized controlled trials (RCTs) of DPP-4 inhibitors and metformin as initial combination therapy or as monotherapy in patients with T2DM by the end of December 2012, using the key words 'alogliptin', 'dutogliptin', 'linagliptin', 'saxagliptin', 'sitagliptin', 'vildagliptin' and 'metformin'. RCTs were selected for meta-analysis if (1) they were RCTs comparing DPP-4 inhibitors plus metformin as initial combination therapy or DPP-4 inhibitor monotherapy to metformin monotherapy, (2) duration of treatment was ≥12 weeks and (3) reported data on haemoglobin A1c (HbA1c) change, fasting plasma glucose (FPG) change, weight change, adverse cardiovascular (CV) events, hypoglycaemia or gastrointestinal adverse events (AEs).

RESULTS

A total of eight RCTs were included. Compared with metformin monotherapy, DPP-4 inhibitors monotherapy was associated with lower reduction in HbA1c level [weighted mean differences (MD) = 0.28, 95% confidence intervals (CIs) (0.17, 0.40), p < 0.00001], lower reduction in FPG level [MD = 0.81, 95% CI(0.60, 1.02), p <0.00001], lower weight loss [MD = 1.51, 95% CI (0.89, 2.13), p < 0.00001], but lower risk of adverse CV events [risk ratio (RR) = 0.36, 95% CI (0.15, 0.85), p = 0.02], lower risk of hypoglycaemia [RR = 0.44, 95% CI (0.27, 0.72), p = 0.001] and lower risk of gastrointestinal AEs [RR = 0.63, 95% CI(0.55, 0.70), p <0.00001]. Compared with metformin monotherapy, DPP-4 inhibitors plus metformin as initial combination therapy was associated with higher reduction in HbA1c level [MD = -0.49, 95% CI (-0.57, -0.40), p < 0.00001], higher reduction in FPG level [MD = -0.80, 95% CI (-0.87, -0.74), p < 0.00001], lower weight loss [MD = 0.44, 95% CI (0.22, 0.67), p = 0.0001]; but was not associated with a further reduction in adverse CV events [RR=0.54, 95% CI (0.25, 1.19), p = 0.13], nor the higher risk of hypoglycaemia [RR = 1.04, 95% CI (0.72, 1.50), p = 0.82], nor the prolonged risk of gastrointestinal AEs [RR = 0.98, 95% CI (0.88, 1.10), p = 0.77].

CONCLUSIONS

DPP-4 inhibitors, which are safe and effective in controlling the blood glucose, may possibly decrease the risk of CV events in patients with T2DM. It could be a credible alternative for T2DM patients who, for some reason, cannot use metformin, or are in high risk of CV exposure. High-quality, large sample and long-term follow-up clinical trails are needed to confirm the long-term conclusions.

The dipeptidyl peptidase (DPP)-4 inhibitors for type 2 diabetes mellitus in challenging patient groups

Treating hyperglycemia is a critical aspect of managing type 2 diabetes mellitus (T2DM), but can be especially challenging in patients from vulnerable groups such as those with chronic kidney disease, African Americans, and older people. The dipeptidyl peptidase (DPP)-4 inhibitors are relatively new oral antidiabetes drugs that have been incorporated into treatment algorithms over the past few years and have also been studied in these vulnerable patients. Clinical trials with DPP-4 inhibitors have now been reported for all these patient groups and have demonstrated significant improvements in measures of hyperglycemia, with a good safety profile. Based on the current evidence, it appears that the DPP-4 inhibitors are worthy of consideration not only for the most straightforward patients with T2DM, but also for these vulnerable patients.

Linagliptin for patients aged 70 years or older with type 2 diabetes inadequately controlled with common antidiabetes treatments: a randomised, double-blind, placebo-controlled trial

BACKGROUND

A substantial proportion of patients with type 2 diabetes are elderly (≥65 years) but this group has been largely excluded from clinical studies of glucose-lowering drugs. We aimed to assess the effectiveness of linagliptin, a dipeptidyl peptidase-4 inhibitor, in elderly patients with type 2 diabetes.

METHODS

In this randomised, double-blind, parallel-group, multinational phase 3 study, patients aged 70 years or older with type 2 diabetes, glycated haemoglobin A1c (HbA1c) of 7·0% or more, receiving metformin, sulfonylureas, or basal insulin, or combinations of these drugs, were randomised (by computer-generated randomisation sequence, concealed with a voice-response system, stratified by HbA1c level [<8·5% vs ≥8·5%] and insulin use [yes vs no], block size four) in a 2:1 ratio to once-daily oral treatment with linagliptin 5 mg or matching placebo for 24 weeks. Investigators and participants were masked to assignment throughout the study. The primary endpoint was change in HbA1c from baseline to week 24. This trial is registered with ClinicalTrials.gov, number NCT01084005.

FINDINGS

241 community-living outpatients were randomised (162 linagliptin, 79 placebo). Mean age was 74·9 years (SD 4·3). Mean HbA1c was 7·8% (SD 0·8). At week 24, placebo-adjusted mean change in HbA1c with linagliptin was -0·64% (95% CI -0·81 to -0·48, p<0·0001). Overall safety and tolerability were much the same between the linagliptin and placebo groups; 75·9% of patients in both groups had an adverse event (linagliptin n=123, placebo n=60). No deaths occurred. Serious adverse events occurred in 8·6% (14) of patients in the linagliptin group and 6·3% (five) patients in the placebo group; none were deemed related to study drug. Hypoglycaemia was the most common adverse event in both groups, but did not differ between groups (24·1% [39] in the linagliptin group, 16·5% [13] in the placebo group; odds ratio 1·58, 95% CI 0·78-3·78, p=0·2083).

INTERPRETATION

In elderly patients with type 2 diabetes linagliptin was efficacious in lowering glucose with a safety profile similar to placebo. These findings could inform treatment decisions for achieving individualised glycaemic goals with minimal risk in this important population of patients.

FUNDING

Boehringer Ingelheim.

Individualised treatment targets for elderly patients with type 2 diabetes using vildagliptin add-on or lone therapy (INTERVAL): a 24 week, randomised, double-blind, placebo-controlled study

BACKGROUND

Guidelines suggest setting individualised targets for glycaemic control in elderly patients with type 2 diabetes, despite no evidence. We aimed to assess the feasibility of setting and achieving individualised targets over 24 weeks along with conventional HbA1c reduction using vildagliptin versus placebo.

METHODS

In this multinational, double-blind, 24 week study, we enrolled drug-naive or inadequately controlled (glycosylated haemoglobin A1c [HbA1c] ≥7·0% to ≤10·0%) patients with type 2 diabetes aged 70 years or older from 45 outpatient centres in Europe. Investigators set individualised treatment targets on the basis of age, baseline HbA1c, comorbidities, and frailty status before a validated automated system randomly assigned patients (1:1) to vildagliptin (50 mg once or twice daily as per label) or placebo. Coprimary efficacy endpoints were proportion of patients reaching their investigator-defined HbA1c target and HbA1c reduction from baseline to study end. The study is registered with ClinicalTrials.gov, number NCT01257451, and European Union Drug Regulating Authorities Clinical Trials database, number 2010-022658-18.

FINDINGS

Between Dec 22, 2010, and March 14, 2012, we randomly assigned 139 patients each to the vildagliptin and placebo groups. 37 (27%) of 137 patients in the placebo group achieved their individualised targets by education and interactions with the study team alone and 72 (52·6%) of 137 patients achieved their target in the vildagliptin group (adjusted odds ratio 3·16, 96·2% CI 1·81-5·52; p<0·0001). This finding was accompanied by a clinically relevant 0·9% reduction in HbA1c from a baseline of 7·9% with vildagliptin and a between-group difference of -0·6% (98·8% CI -0·81 to -0·33; p<0·0001). The overall safety and tolerability was similar in the vildagliptin and placebo groups, with low incidence of hypoglycaemia and no emergence of new safety signals.

INTERPRETATION

This study is the first to introduce and show the feasibility of using individualised HbA1c targets as an endpoint in any type 2 diabetes population. Individualised glycaemic target levels are achievable with vildagliptin without any tolerability issues in the elderly type 2 diabetes population.

FUNDING

Novartis Pharma AG.

Clinically relevant reductions in HbA1c without hypoglycaemia: results across four studies of saxagliptin

BACKGROUND

In four 24-week controlled studies, the antihyperglycaemic efficacy of saxagliptin was demonstrated in patients with type 2 diabetes mellitus as add-on therapy to glyburide, a thiazolidinedione, or metformin, and when used in initial combination with metformin vs. metformin monotherapy in drug-naive patients.

METHODS

Data from these studies were analysed to compare the proportions of patients who achieved specific reductions from baseline in glycated haemoglobin [HbA(1c); reductions of ≥ 0.5% and ≥ 0.7% in all studies (prespecified); reductions ≥ 1.0% in the add-on studies and ≥ 1.0% to ≥ 2.5% in the initial combination study (post hoc)] for saxagliptin vs. comparator at week 24. We report overall rates of glycaemic response defined by these reductions in HbA(1c) and rates of response without experiencing hypoglycaemia.

RESULTS

Large glycaemic response rates were higher with saxagliptin 2.5 and 5 mg/day than with comparator (HbA(1c) ≥ 1.0%, 31.7-50.3% vs. 10.3-20.0%) as add-on therapy and higher with saxagliptin 5 mg/day as initial combination with metformin than with metformin monotherapy (HbA(1c) ≥ 2.0%, 68.3% vs. 49.8%) in drug-naive patients. Addition of saxagliptin was associated with a low incidence of hypoglycaemia; overall response rates and response rates excluding patients who experienced hypoglycaemia were similar. Analysis of several demographic and baseline clinical variables revealed no consistent correlations with response to saxagliptin.

CONCLUSIONS

Whether receiving saxagliptin as an add-on therapy to glyburide, a thiazolidinedione, or metformin or in initial combination with metformin, a greater percentage of patients achieve clinically relevant large reductions in HbA(1c) vs. comparator, with a low incidence of hypoglycaemia.

Tolerability and efficacy of glycemic control with saxagliptin in older patients (aged ≥ 65 years) with inadequately controlled type 2 diabetes mellitus

Purpose

To assess safety and efficacy of saxagliptin in older patients with type 2 diabetes mellitus (T2DM).

Patients and methods

This was a post hoc analysis of pooled data from older patients (≥65 years of age) from five 24-week phase III trials: three studies of saxagliptin versus placebo as an add-on therapy to metformin, glyburide, or a thiazolidinedione; and two studies of saxagliptin versus placebo as monotherapy in drug-naïve patients. Separate analyses were conducted on one study of initial combination therapy with saxagliptin plus metformin versus metformin monotherapy in drug-naïve patients. The safety analysis population for the five-study pool included 428 patients ≥ 65 years of age with baseline glycated hemoglobin (HbA_1c) 7.0% to 10.5% who received saxagliptin 2.5 or 5 mg or placebo, and for the study of initial combination therapy included 69 patients ≥ 65 years of age with baseline HbA_1c 8.0% to 12.0% who received saxagliptin 5 mg in combination with metformin or metformin monotherapy. The primary efficacy endpoint was change from baseline HbA_1c.

Results

In the five-study pool, the differences in the adjusted mean change from baseline HbA_1c among older patients receiving saxagliptin versus placebo were −0.60% (95% confidence interval [CI], −0.99% to −0.21%) for saxagliptin 2.5 mg and −0.55% (−0.97% to −0.14%) for saxagliptin 5 mg; in the initial combination study, the difference was −1.22% (−2.27% to −0.17%) among older patients receiving saxagliptin 5 mg plus metformin versus metformin monotherapy. The results were generally similar in older and younger patients. Saxagliptin was well tolerated; the incidence and types of adverse events were similar for saxagliptin and comparators. Hypoglycemia was reported in 3.0% to 9.4% of patients receiving saxagliptin (0%–8.0% for comparators) and was confirmed (finger stick glucose ≤ 50 mg/dL, with associated symptoms) in 0% to 0.7% (0%–0.7% for comparators); hypoglycemic episodes did not vary by age category and did not require medical intervention.

Conclusion

Saxagliptin was effective and well tolerated, with a low risk of hypoglycemia, when used as monotherapy, add-on therapy, or initial combination therapy with metformin in older patients with T2DM.

Efficacy of vildagliptin in combination with insulin in patients with type 2 diabetes and severe renal impairment

Background

The purpose of this study was to evaluate the efficacy of vildagliptin 50 mg once daily in patients with severe renal impairment (estimated glomerular filtration rate < 30 mL/min/1.73 m²) and longstanding type 2 diabetes not adequately controlled with insulin therapy, which is a difficult-to-treat population, with limited therapeutic options and a high susceptibility to hypoglycemia.

Methods

This was a post hoc subanalysis of data obtained during a previously described randomized, double-blind, parallel-group, 24-week study comparing the efficacy and safety of vildagliptin 50 mg once daily versus placebo in patients with type 2 diabetes and moderate or severe renal impairment. The present data derive from 178 patients with severe renal impairment (baseline estimated glomerular filtration rate approximately 21 mL/min/1.73 m², 100 randomized to vildagliptin, 78 randomized to placebo), all of whom were receiving insulin therapy (alone or in combination with an oral antidiabetic agent) for longstanding type 2 diabetes (mean approximately 19 years).

Results

With vildagliptin in combination with insulin, the adjusted mean change (AMΔ) in HbA_1c from baseline (7.7% ± 0.1%) was −0.9% ± 0.4% and the between-treatment difference (vildagliptin – placebo) was −0.6% ± 0.2% (P < 0.001). The percentage of patients achieving endpoint HbA_1c < 7.0% was significantly higher with vildagliptin than placebo (45.2% versus 22.8%, P = 0.008). When added to insulin, vildagliptin and placebo had comparable hypoglycemic profiles and did not cause weight gain. Both treatments were similarly well tolerated, with comparable incidences of adverse events, serious adverse events, and deaths.

Conclusion

When added to insulin therapy in patients with severe renal impairment and longstanding type 2 diabetes, vildagliptin 50 mg once daily was efficacious, eliciting HbA_1c reductions consistent with those previously reported for a patient population with much more recent onset of type 2 diabetes and normal renal function, and had a hypoglycemic profile comparable with placebo. Accordingly, vildagliptin is a suitable treatment option for patients with advanced type 2 diabetes and impaired renal function who require insulin therapy and present a serious therapeutic challenge in clinical practice.

Managing diabetic patients with moderate or severe renal impairment using DPP-4 inhibitors: focus on vildagliptin

BACKGROUND

Dipeptidyl peptidase-4 (DPP-4) inhibitors are novel classified oral anti-diabetic drugs for the treatment of type 2 diabetes mellitus (T2DM) that provide important reduction in glycated hemoglobin, with a low risk for hypoglycemia and no weight gain. In T2DM patients with reduced renal function, adequate glycemic control is essential to delay the progress of kidney dysfunction, but they are at a greater risk of experiencing hypoglycemic events, especially with longer-acting sulfonylureas and meglitinides.

OBJECTIVE

To evaluate vildagliptin as an option to achieve glycemic control in T2DM patients with moderate or severe chronic kidney disease (CKD).

METHODS

A comprehensive search in the literature was performed using the term "vildagliptin." Original articles and reviews exploring our topic were carefully selected.

RESULTS

Vildagliptin provides effective glycemic control in patients with T2DM and CKD. Dose reductions are required for vildagliptin and other DPP-4 inhibitors, except linagliptin, in T2DM patients with moderate-to-severe CKD. Dose of vildagliptin had to be reduced by half (to 50 mg/day) both for moderate (estimated glomerular filtration rate [eGFR] ≥30 to ≤50 mL/min) and severe CKD (eGFR < 30 mL/min). Available results support a favorable efficacy, safety, and tolerability profile for vildagliptin in T2DM with moderate or severe renal failure. Preliminary data may suggest additional benefits beyond improvement of glycemic control.

CONCLUSION

Vildagliptin can be safely used in T2DM patients with varying degrees of renal impairment. Dose adjustments for renal impairment are required. Potential long-term renal benefit of vildagliptin needs to be further explored.

Challenges in achieving optimal glycemic control in type 2 diabetes patients with declining renal function: The Southeast Asia perspective

It is well recognised that Asia is at the epicenter of the global type 2 diabetes epidemic. Driven by socioeconomic changes involving industrialization, urbanization and adoption of Western lifestyles, the unprecedented increases in the prevalence of diabetes are particularly evident in Southeast Asia. The impact of diabetes is immense, and despite evidence of the benefit of optimal glucose control in reducing the risk of disease progression and development of macrovascular and microvascular complications, many individuals in this region remain poorly controlled. Chronic kidney disease (CKD) is an increasingly common diabetes-associated complication in Asian patients. Furthermore, Southeast Asia has one of the highest rates of end-stage renal disease (ESRD) in the world. Consequently, CKD in diabetes is associated with considerable morbidity and cardiovascular-related mortality, highlighting the need to screen and assess patients early in the course of the disease. The management of type 2 diabetes patients with declining renal function represents a significant challenge. Many of the older antidiabetic agents, such as metformin and sulfonylureas, are limited in their utility in CKD as a result of contraindications or hypoglycemic episodes. In contrast, dipeptidyl-peptidase IV inhibitors have provided a welcome addition to the therapeutic armamentarium for achieving glycemic control in these special populations. With comparable efficacy to and more favorable pharmacokinetic and side-effect profiles than traditional therapies, agents in this drug class, such as linagliptin, offer a more tailored approach to disease control in type 2 diabetes patients with declining renal function.

Longer term safety of dipeptidyl peptidase-4 inhibitors in patients with type 2 diabetes mellitus: systematic review and meta-analysis

Dipeptidyl peptidase-4 (DPP-4) inhibitors are oral antidiabetic agents that hold the potential of slowing the progress of type 2 diabetes mellitus. Their long-term safety is still a subject of debate. A systematic review of randomized, controlled trials was undertaken to comprehensively profile the safety of chronic treatment of type 2 diabetes mellitus with DPP-4 inhibitors. We searched data sources including MEDLINE, CENTRAL, publishers' and manufacturers' databases. Eligible trials were double-blind, randomized, placebo or active-controlled trials with ≥18 weeks duration in patients with type 2 diabetes reporting safety outcomes. Meta-analysis was performed separately for trials in which the control group received placebo (44 studies), another gliptin (3 studies) and any other antidiabetic drug (20 studies). Risk ratios with 95% confidence intervals were computed using a Mantel-Haenszel fixed-effect model for general safety outcomes, hypoglycaemia and adverse events by system organ class. Of 307 publications retrieved, 67 randomized, controlled trials met the eligibility criteria and were included in this review (4 alogliptin, 8 linagliptin, 8 saxagliptin, 20 sitagliptin, and 27 vildagliptin trials). Adverse events with gliptin treatment were at placebo level (relative risk (RR) 1.02 [0.99, 1.04]). No increased risk of infections was detectable (RR 0.98 [0.93, 1.05] compared to placebo and 1.02 [0.97, 1.07] compared to other antidiabetic drugs). Asthenia (RR 1.57 [1.09, 2.27]) as well as cardiac (RR 1.37 [1.00, 1.89]) and vascular disorders (RR 1.74 [1.05, 2.86] for linagliptin) emerged as adverse events associated with DPP-4 inhibitor treatment. The risk of hypoglycaemia was low with DPP-4 inhibitor treatment (RR 0.92 [0.74, 1.15] compared to placebo, RR 0.20 [0.17, 0.24] compared to sulphonylureas) in the absence of sulphonylurea or insulin co-therapy, but significantly elevated for combination therapy of sulphonylurea or insulin with sitagliptin or linagliptin (RR 1.86 [1.46, 2.37] compared to placebo). A large body of data supports the long-term safety of gliptin treatment and refutes an increased risk of infections. Further research is needed to clarify a possible link to asthenia, cardiac and vascular events. For combination therapy with insulin or insulin secretagogues, a careful choice of the agent used may limit the risk of hypoglycaemia.

Efficacy and safety of dipeptidyl peptidase-4 inhibitors in type 2 diabetes: meta-analysis

BACKGROUND

An up-to-date assessment of dipeptidyl peptidase-4 (DPP-4) inhibitors is needed to include newly available data.

OBJECTIVE

To assess the efficacy and safety of DPP-4 inhibitors, including sitagliptin, saxagliptin, vildagliptin, and linagliptin, in type 2 diabetes.

METHODS

We conducted a search of MEDLINE for randomized controlled trials (RCTs) of DPP-4 inhibitors in type 2 diabetes through November 2011, using the key terms sitagliptin, saxagliptin, vildagliptin, and linagliptin. We also searched for completed, but unpublished, trials at relevant web sites. RCTs were selected for meta-analysis if they (1) compared DPP-4 inhibitors with placebo or an antihyperglycemic agent; (2) had study duration of 12 or more weeks; (3) had 1 or more baseline and posttreatment efficacy and/or safety outcome; and (4) were published in English.

RESULTS

In 62 evaluated articles, DPP-4 inhibitors lowered hemoglobin A(1c) (A1C) significantly more than placebo (weighted mean difference [WMD] -0.76%; 95% CI -0.83 to -0.68); however, heterogeneity was substantial (I(2) = 82%). Exclusion of Japanese trials (n = 7) resulted in a reduction of heterogeneity (I(2) = 59%). In the non-Japanese RCTs (n = 55), DPP-4 inhibitors were associated with a reduction in A1C (WMD -0.65%; 95% CI -0.71 to -0.60) but higher risk of hypoglycemia (odds ratio [OR] 1.30; 95% CI 1.00 to 1.68) compared to placebo. The 7 Japanese-specific RCTs showed a greater reduction in A1C (WMD -1.67%; 95% CI -1.89 to -1.44) and a nonsignificant increase in risk of hypoglycemia (OR 1.41; 95% CI 0.51 to 3.88) with DPP-4 inhibitors versus placebo. When comparing DPP-4 inhibitors to active comparators, the I(2) was still high after deleting Japanese studies. In these 17 active comparator trials, there was no significant difference in A1C reduction (WMD 0.04%; 95% CI -0.09 to 0.16) or risk of hypoglycemia (OR 0.60; 95% CI 0.22 to 1.61) for DPP-4 inhibitors compared to other antihyperglycemics. There were similar odds of any or serious adverse events with DPP-4 inhibitors compared to placebo, but a decreased risk compared to other antihyperglycemics.

CONCLUSIONS

DPP-4 inhibitors were associated with a reduction in A1C with comparable safety profiles compared to placebo, but no significant difference in A1C compared to other hyperglycemics. Differences in efficacy and safety were observed between Japanese and non-Japanese patients.

Management of type 2 diabetes mellitus in older adults

In the near future, the majority of patients with diabetes will be adults aged 65 or older. Unlike young adults with diabetes, elderly diabetic people may be affected by a variety of comorbid conditions such as depression, cognitive impairment, muscle weakness (sarcopenia), falls and fractures, and physical frailty. These geriatric syndromes should be considered in the establishment of treatment goals in older adults with diabetes. Although there are several guidelines for the management of diabetes, only a few are specifically designed for the elderly with diabetes. In this review, we present specific conditions of elderly diabetes which should be taken into account in the management of diabetes in older adults. We also present advantages and disadvantages of various glucose-lowering agents that should be considered when choosing a proper regimen for older adults with diabetes.

Meta-analysis of effect of dipeptidyl peptidase-4 inhibitors on cardiovascular risk in type 2 diabetes mellitus

Patients with type 2 diabetes mellitus (DM) have a very high risk for major adverse cardiovascular (CV) events. Previous studies have shown that traditional oral diabetic medications, despite lowering blood glucose levels, generally do not improve CV outcomes. The safety of some oral hypoglycemic medications has been questioned. We aimed to evaluate the CV safety of dipeptidyl peptidase-4 (DPP4) inhibitors, a novel class of oral diabetic medications, by performing a meta-analysis of DPP4 inhibitors for type 2 DM. A search of electronic databases of published and unpublished literature (until September 30, 2011) was performed to identify randomized controlled trials of ≥24 weeks that compared DPP4 inhibitors to other oral diabetic medications. A meta-analysis was performed using fixed and random effects to determine risk ratio (RR) for adverse CV events with DPP4 inhibitor monotherapy compared to other oral diabetic medications or to placebo. Eighteen randomized met our inclusion criteria, comprising 4,998 patients who were randomized to DPP4 inhibitors and 3,546 to a comparator, with a median duration of therapy of 46.4 weeks. In pooled analysis, the RR of any adverse CV event with a DPP4 inhibitor was 0.48 (0.31 to 0.75, p = 0.001), and the RR for nonfatal myocardial infarction or acute coronary syndrome was 0.40 (0.18 to 0.88, p = 0.02). In conclusion, this meta-analysis provides evidence that DPP4 inhibitors are safe from a CV standpoint and may possibly decrease risk of adverse CV events.

Drug-induced hypoglycaemia in type 2 diabetes

INTRODUCTION

Hypoglycaemia is a side effect caused by some therapies for type 2 diabetes, which can cause physical, social and psychological harm. Hypoglycaemia also prevents attainment of treatment goals and satisfactory glycaemic control.

AREAS COVERED

The risk of hypoglycaemia associated with commonly prescribed therapies, including metformin, sulphonylureas, dipeptidyl peptidase-4 enzyme (DPP-4) inhibitors, glucagon-like peptide-1 (GLP-1) agonists and thiazolidinediones, is reviewed in this paper (insulin-induced hypoglycaemia is not included). Other medications that are frequently co-prescribed in type 2 diabetes are also discussed, including anti-hypertensive drugs, antibiotics and fibrates, along with various important patient-related risk factors.

EXPERT OPINION

Hypoglycaemia is a common and potentially dangerous side effect of some medications used for type 2 diabetes. The risk of hypoglycaemia should always be considered when selecting and implementing a therapy, with a focus on the individual. Future research into new therapies should measure the frequency of hypoglycaemia prospectively and accurately. Hypoglycaemia has been shown to be a potentially life-threatening metabolic stress; therefore therapies that effectively manage diabetes without the risk of hypoglycaemia are likely to be favoured in the future.

Evidence to support the use of vildagliptin monotherapy in the treatment of type 2 diabetes mellitus

The efficacy and safety of the dipeptidyl peptidase-4 inhibitor, vildagliptin, as monotherapy have been widely confirmed in a large body of clinical studies of up to 2 years’ duration in various populations with type 2 diabetes mellitus. This paper reviews the data supporting the use of vildagliptin in monotherapy. Consideration based on baseline glycated hemoglobin levels and age is given to patient segments where metformin is not appropriate. In addition, although prediabetes is not an indication, this manuscript briefly reviews some of the existing data showing that the mechanisms at work in diabetic populations are active in patients currently classified as prediabetic, with impaired glucose tolerance or impaired fasting glucose. Finally, the rationale for vildagliptin dosing frequency in monotherapy is discussed. In summary, this review aims to define where in community practice the use of vildagliptin as monotherapy is most desirable, focusing on segments of the population with type 2 diabetes mellitus that might receive the greatest benefit from vildagliptin in the management of their disease.

Dipeptidyl peptidase-4 inhibitors in the elderly: more benefits or risks?

Several studies have shown a high prevalence of type 2 diabetes mellitus (T2DM) in the elderly, characterized by a paucity of symptoms, which represents an obstacle for an early diagnosis. Frequently, T2DM in the elderly is diagnosed when a complication occurs, among which are cognitive disorders and/or affective disturbances. Moreover, hypoglycemia is a frequent side effect of therapeutic treatment with insulin, sulfonylureas or glinides, while other treatments (metformin, acarbose, thiazolidinediones, glucagon-like peptide-1 [GLP-1] receptor agonists, and dipeptidyl peptidase-4 [DPP4] inhibitors) are capable of reducing hyperglycemia without inducing hypoglycemia. Thus, considering that older persons are a very heterogeneous group of individuals, management of T2DM in the elderly is challenging but there are no available specific treatment goals or treatment algorithms for older diabetic patients. Metformin is the recommended first-line therapy in all T2DM patients. When metformin is not sufficient to achieve the desired therapeutic targets, a second drug can be added. Available options include sulfonylureas, meglitinides, alfa-glucosidase inhibitors, pioglitazone, insulin, GLP-1 receptor agonists, and DPP-4 inhibitors. The most intriguing therapy for older patients is the one based on the so-called incretins, i.e., gastrointestinal hormones that, mainly secreted in the postprandial phase, stimulate insulin secretion and inhibit glucagon secretion. The two most important human incretins are GLP-1 and glucose-dependent insulinotropic peptide (GIP). These hormones potentiate the acute effects of glucose on pancreatic alfa and beta cells, thus stimulating insulin secretion, and only GLP-1 inhibits glucagon secretion in a glucose-dependent manner (that is, only when glucose levels are increased); as a result, they reduce hyperglycemia with virtually no hypoglycemic risk. Due to their characteristics, DPP-4 inhibitors seem to be particularly interesting as potential agents for the treatment of older patients with T2DM.

Efficacy and safety of exenatide once weekly versus metformin, pioglitazone, and sitagliptin used as monotherapy in drug-naive patients with type 2 diabetes (DURATION-4): a 26-week double-blind study

OBJECTIVE

To test the safety and efficacy of exenatide once weekly (EQW) compared with metformin (MET), pioglitazone (PIO), and sitagliptin (SITA) over 26 weeks, in suboptimally treated (diet and exercise) drug-naive patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

Patients were randomized to subcutaneous (SC) EQW 2.0 mg + oral placebo (n = 248), MET 2,000 mg/day + SC placebo (n = 246), PIO 45 mg/day + SC placebo (n = 163), or SITA 100 mg/day + SC placebo (n = 163) for 26 weeks. MET and PIO therapies were increased to maximum-tolerated dosages. Injections with EQW or placebo were administered weekly, while oral medication or placebo was administered daily.

RESULTS

Baseline characteristics were as follows: 59% men, 67% Caucasian, mean age 54 years, HbA(1c) 8.5%, fasting serum glucose 9.9 mmol/L, body weight 87.0 kg, and diabetes duration 2.7 years. HbA(1c) reductions (%) at 26 weeks (least-squares means) with EQW versus MET, PIO, and SITA were -1.53 vs. -1.48 (P = 0.620), -1.63 (P = 0.328), and -1.15 (P < 0.001), respectively. Weight changes (kg) were -2.0 vs. -2.0 (P = 0.892), +1.5 (P < 0.001), and -0.8 (P < 0.001), respectively. Common adverse events were as follows: EQW, nausea (11.3%) and diarrhea (10.9%); MET, diarrhea (12.6%) and headache (12.2%); PIO, nasopharyngitis (8.6%) and headache (8.0%); and SIT, nasopharyngitis (9.8%) and headache (9.2%). Minor (confirmed) hypoglycemia was rarely reported. No major hypoglycemia occurred.

CONCLUSIONS

EQW was noninferior to MET but not PIO and superior to SITA with regard to HbA(1c) reduction at 26 weeks. Of the agents studied, EQW and MET provided similar improvements in glycemic control along with the benefit of weight reduction and no increased risk of hypoglycemia.

Pharmacology of dipeptidyl peptidase-4 inhibitors: similarities and differences

The dipeptidyl peptidase (DPP)-4 inhibitors, which enhance glucose-dependent insulin secretion from pancreatic β cells by preventing DPP-4-mediated degradation of endogenously released incretin hormones, represent a new therapeutic approach to the management of type 2 diabetes mellitus. The 'first-in-class' DPP-4 inhibitor, sitagliptin, was approved in 2006; it was followed by vildagliptin (available in the EU and many other countries since 2007, although approval in the US is still pending), saxagliptin (in 2009), alogliptin (in 2010, presently only in Japan) and linagliptin, which was approved in the US in May 2011 and is undergoing regulatory review in Japan and the EU. As the number of DPP-4 inhibitors on the market increases, potential differences among the different members of the class become important when deciding which agent is best suited for an individual patient. The aim of this review is to provide a comprehensive and updated comparison of the pharmacodynamic and pharmacokinetic properties of DPP-4 inhibitors, and to pinpoint pharmacological differences of potential interest for their use in therapy. Despite their common mechanism of action, these agents show significant structural heterogeneity that could translate into different pharmacological properties. At the pharmacokinetic level, DPP-4 inhibitors have important differences, including half-life, systemic exposure, bioavailability, protein binding, metabolism, presence of active metabolites and excretion routes. These differences could be relevant, especially in patients with renal or hepatic impairment, and when considering combination therapy. At the pharmacodynamic level, the data available so far indicate a similar glucose-lowering efficacy of DPP-4 inhibitors, either as monotherapy or in combination with other hypoglycaemic drugs, a similar weight-neutral effect, and a comparable safety and tolerability profile. Data on nonglycaemic parameters are scant at present and do not allow a comparison among DPP-4 inhibitors. Several phase III trials of DPP-4 inhibitors are currently ongoing; these trials, along with post-marketing surveillance data, will hopefully increase our knowledge about the long-term efficacy and safety of DPP-4 inhibitor therapy, the effect on pancreatic cell function and peripheral glucose metabolism, and the effect on cardiovascular outcomes in patients with type 2 diabetes.

The efficacy and safety of vildagliptin in patients with type 2 diabetes: a meta-analysis of randomized clinical trials

WHAT IS KNOWN AND OBJECTIVE

Dipeptidyl peptidase-4 (DPP-4) inhibitors are a relatively new class of drugs for the management of type 2 diabetes (T2DM). Vildagliptin is an oral DPP-4 inhibitor approved in more than 70 countries. The purpose of this meta-analysis is to provide an update on the clinical efficacy and safety of vildagliptin in patients with T2DM.

METHODS

A literature search identified 30 randomized controlled trials comparing vildagliptin with comparators (placebo or other hypoglycaemic agents). Meta-analyses were conducted for HbA1c, weight, fasting plasma glucose (FPG), hypoglycaemia and other adverse events. The outcomes of HbA1c, weight and FPG were analysed as weighted mean differences (WMD), and the number of ADRs events as relative risks (RR).

RESULTS

Compared with placebo, vildagliptin lowered HbA1c {WMD, -0·77% [95% confidence interval (CI), -0·96% to -0·58%] for 100 mg/day of vildagliptin and -0·58% [95% CI, -0·72% to -0·44%] for 50 mg/day of vildagliptin}. The effect was non-inferior to thiazolidinediones, sulfonylureas and α-glycosidase inhibitors, but inferior to metformin. Compared with placebo, treatment with 50 mg/day of vildagliptin caused neutral weight changes, while 100 mg/day of vildagliptin resulted in slight weight gain [0·95 kg (95% CI, 0·73-1·17 kg)]. In addition, compared to comparators, vildagliptin was not associated with an increase in overall risk for any adverse events [RR, 0·97 (95% CI, 0·94-0·99)]. The incidence of hypoglycaemia was low with vildagliptin, and the risk with vildagliptin was not significantly different from the comparators [0·85 (95% CI, 0·49-1·47)]. The use of vildagliptin did not display any increased risks of infection [1·03 (95% CI, 0·94-1·13) for nasopharyngitis and 1·07 (95% CI, 0·90-1·27) for upper respiratory tract infection].

WHAT IS NEW AND CONCLUSION

Vildagliptin is effective in glycaemic control with a low risk of hypoglycaemia and other adverse reactions. This may have an important impact on patient adherence to this medication.

DPP-4 inhibitors in the management of type 2 diabetes: a critical review of head-to-head trials

Dipeptidyl peptidase-4 (DPP-4) inhibitors offer new options for the management of type 2 diabetes. Direct comparisons with active glucose-lowering comparators in drug-naive patients have demonstrated that DPP-4 inhibitors exert slightly less pronounced HbA(1c) reduction than metformin (with the advantage of better gastrointestinal tolerability) and similar glucose-lowering effects as with a thiazolidinedione (TZD; with the advantage of no weight gain). In metformin-treated patients, gliptins were associated with similar HbA(1c) reductions compared with a sulphonylurea (SU; with the advantage of no weight gain, considerably fewer hypoglycaemic episodes and no need for titration) and a TZD (with the advantage of no weight gain and better overall tolerability). DPP-4 inhibitors also exert clinically relevant glucose-lowering effects compared with a placebo in patients treated with SU or TZD (of potential interest when metformin is either not tolerated or contraindicated), and as oral triple therapy with a good tolerability profile when added to a metformin-SU or pioglitazone-SU combination. Several clinical trials also showed a consistent reduction in HbA(1c) when DPP-4 inhibitors were added to basal insulin therapy, with no increased risk of hypoglycaemia. Because of the complex pathophysiology of type 2 diabetes and the complementary actions of glucose-lowering agents, initial combination of a DPP-4 inhibitor with either metformin or a glitazone may be applied in drug-naive patients, resulting in greater efficacy and similar safety compared with either drug as monotherapy. However, DPP-4 inhibitors were less effective than GLP-1 receptor agonists for reducing HbA(1c) and body weight, but offer the advantage of being easier to use (oral instead of injected administration) and lower in cost. Only one head-to-head trial demonstrated the non-inferiority of saxagliptin vs sitagliptin. Clearly, more trials of direct comparisons between different incretin-based therapies are needed. Because of their pharmacokinetic characteristics, pharmacodynamic properties (glucose-dependent glucose-lowering effect) and good overall tolerability profile, DPP-4 inhibitors may have a key role to play in patients with renal impairment and in the elderly. The role of DPP-4 inhibitors in the therapeutic armamentarium of type 2 diabetes is rapidly evolving as their potential strengths and weaknesses become better defined mainly through controlled clinical trials.

Noninsulin treatment of type 2 diabetes mellitus in geriatric patients: a review

BACKGROUND

Currently, 42% of the US population with diabetes is aged ≥65 years.

OBJECTIVE

The aim of this review was to discuss the efficacy and tolerability of noninsulin therapies for type 2 diabetes mellitus (T2DM), with an emphasis on patients aged ≥65 years.

METHODS

PubMed and EMBASE (1977-2010) were searched using the terms geriatric, elderly patients, type 2 diabetes mellitus, metformin, secretagogues, thiazolidinediones (TZDs), alpha-glucosidase inhibitors, dipeptidyl peptidase-4 (DPP-4) inhibitors, and glucagon-like peptide-1 (GLP-1) receptor agonists. Articles were included if they were clinical trials, reviews, or meta-analyses.

RESULTS

More than 10 classes of noninsulin treatments are available for T2DM. However, most treatments have been evaluated only in trials in patients aged <65 years, and trials in older populations are scarce. Therefore, health care providers should consider the overall benefit to risk, with a focus on risk factors in older patients. A1C reductions range from 0.6% to 2%, with similar decreases observed for metformin, TZDs, sulfonylureas (SUs), glinides, and GLP-1 receptor agonists Treatment-associated adverse events vary. The prevalence of hypoglycemia is high with the secretagogues, SUs, and glinides (20% with glibenclamide or glipizide, 16% with repaglinide). The TZDs have been associated with an increased risk for heart failure (adjusted ratio = 1.60; 95% CI, 1.21-2.10; P < 0.001) compared with the other oral therapies. Gastrointestinal adverse events have been commonly reported with metformin (38% of patients), which is contraindicated in cases of renal insufficiency. Use of the GLP-1 RAs liraglutide and exenatide have been associated with comparable weight reductions of ∼3 kg and with a low risk for hypoglycemia (prevalence, 4% with exenatide 10 μg; ∼5% with liraglutide 1.2 or 1.8 mg). Treatment with the GLP-1 RAs has been associated with transient gastrointestinal reactions, mainly nausea.

CONCLUSIONS

The selection of noninsulin treatments in older patients with T2DM should be individualized based on patient assessment and on careful evaluation of the potential benefits (glycemic and extraglycemic) and risks (ie, hypoglycemia, weight gain, cardiovascular risks). More clinical trials in older patients, especially those aged ≥65 years, with T2DM are needed.

Tolerability of dipeptidyl peptidase-4 inhibitors: a review

BACKGROUND

Oral glucose-lowering agents are used to treat patients with type 2 diabetes mellitus (T2DM). Most patients require multiple agents to maintain glycemic targets. Dipeptidyl peptidase-4 (DPP-4) inhibitors are administered as monotherapy and in combination therapy for the treatment of T2DM.

OBJECTIVE

The aim of this article was to provide a thorough review of published tolerability data on 5 DPP-4 inhibitors.

METHODS

PubMed and Web of Science were searched for English-language clinical trials published from January 2000 to June 2001, using the following key words: dipeptidyl peptidase-4 inhibitor, vildagliptin, alogliptin, sitagliptin, saxagliptin, linagliptin, safety, tolerability, efficacy, effect, AE, and adverse effect. Studies were considered for inclusion if they were randomized, double-blind trials performed in patients ≥18 years of age with T2DM and with a hemoglobin A(1c) of ≥6.5%; included ≥1 arm that received monotherapy with DPP-4; and reported adverse events (AEs). Studies in patients with a history of type 1 or secondary forms of diabetes, significant diabetic complications or cardiovascular disease within the 6 months before the start of the study, hepatic disease or abnormalities, and/or renal abnormalities were excluded.

RESULTS

A total of 45 clinical trials, 5 pharmacokinetic studies, and 28 meta-analyses or reviews were included. The duration of studies ranged from 7 days to 104 weeks. The most commonly reported AEs were nasopharyngitis, upper respiratory infections, all-cause infections, headache, gastrointestinal symptoms, and musculoskeletal pain. Based on the findings from the studies, the DPP-4 inhibitors had minimal impact on weight and were not associated with an increased risk for hypoglycemia relative to placebo. Rates of nasopharyngitis were higher with the DDP-4 inhibitors than with placebo. Pancreatitis was reported at lower rates with the DPP-4 inhibitors compared with other oral antihyperglycemic agents. Cardiovascular events were limited, and postmarketing studies are ongoing.

CONCLUSIONS

The tolerability of DPP-4 inhibitors is supported by published clinical trials. The rates of weight gain, gastrointestinal AEs, and hypoglycemia were minimal with the DPP-4 inhibitors studied.

Minimizing the risk of hypoglycemia with vildagliptin: Clinical experience, mechanistic basis, and importance in type 2 diabetes management

Even if the true incidence of hypoglycemia in type 2 diabetes mellitus (T2DM) remains difficult to estimate, with highly variable rates reported in the literature, it is likely more common than previously thought. While most hypoglycemic episodes in T2DM are considered "mild," they still have a substantial clinical impact. Severe hypoglycemia also exists in T2DM, with recent landmark studies prompting much debate about the potential role of severe hypoglycemia in cardiovascular morbidity and mortality, even though there is currently no definitive evidence for causality. The challenge in the treatment of T2DM remains the achievement of optimal glycemic control to lower the risk for long-term complications while avoiding hypoglycemia. Successful treatment strategies should therefore include careful selection of therapies to prevent hypoglycemia, starting early in the disease management process, in order to best preserve counterregulation. The dipeptidyl peptidase-4 inhibitor, vildagliptin, is a good treatment option to minimize the risk of hypoglycemia over time, while maintaining good glucose control. Extensive clinical experience is available for vildagliptin, with data published for all stages of the condition and with the low hypoglycemic potential stemming from a solid mechanistic basis.

Predictors of response to dipeptidyl peptidase-4 inhibitors: evidence from randomized clinical trials

AIM

Dipeptidyl peptidase-4 (DPP-4) inhibitors are used in the treatment of type 2 diabetes. Available sub-group analysis of clinical trials does not allow a clear identification of predictors of therapeutic response to these drugs. The aim of this study is the assessment of predictors of response to DPP-4 inhibitors.

MATERIALS AND METHODS

A meta-analysis was performed, exploring correlation between 24-week effects on HbA(1c) of maximal doses of DPP-4 inhibitors, compared either with placebo or with other active drugs, matches to baseline characteristics of patients enrolled in 63 randomized clinical trials, either published or unpublished but disclosed on different websites were studied.

RESULTS

DPP-4 inhibitors significantly reduce HbA(1c) at 24 weeks [by 0.6 (0.5-0.7)%] when compared with placebo; no difference in HbA(1c) was observed in comparisons with thiazolidinediones and α-glucosidase inhibitors, whereas sulfonylureas and metformin produced a greater reduction of HbA(1c) , at least in the short term. DPP-4 inhibitors produced a smaller weight gain than thiazolidinediones, and showed a lower hypoglycaemia risk than sulfonylureas. The placebo-subtracted effect of DPP-4 inhibitors on HbA(1c) was greater in older patients and in those with lower fasting plasma glucose at baseline. Similar results were obtained in comparisons with thiazolidinediones and metformin.

CONCLUSIONS

Although drugs for type 2 diabetes are studied in heterogeneous samples of patients, their efficacy can be predicted by some clinical parameters. DPP-4 inhibitors appear to be more effective in older patients with mild/moderate fasting hyperglycaemia. These data could be useful for a better definition of the profile of patients who are likely to benefit most from these drugs.

Vildagliptin: a review of its use in type 2 diabetes mellitus

Vildagliptin (Galvus®, Jalra®, Xiliarx®) is an orally administered dipeptidyl peptidase-4 (DPP-4) inhibitor. In patients with type 2 diabetes mellitus, vildagliptin 50 mg twice daily is indicated for use in combination with metformin or a thiazolidinedione, and vildagliptin 50 mg once daily is indicated for use in combination with a sulfonylurea. A fixed-dose combination of vildagliptin/metformin (Eucreas®, Icandra®, Zomarist®) is also available. This article reviews the clinical efficacy and tolerability of vildagliptin in patients with type 2 diabetes, as well as summarizing its pharmacological properties. The efficacy of monotherapy or combination therapy with oral vildagliptin in patients with type 2 diabetes has been examined in randomized, double-blind, multicentre trials. Monotherapy with vildagliptin 50 mg once or twice daily reduced glycosylated haemoglobin (HbA(1c)) from baseline to a significantly greater extent than placebo, according to the results of 12- to 52-week trials in patients with type 2 diabetes. In terms of the reduction from baseline in HbA(1c) seen in active comparator trials of 12-104 weeks' duration, the noninferiority of vildagliptin 50 mg twice daily was established versus acarbose or rosiglitazone, the noninferiority of vildagliptin 100 mg once daily (an off-label dosage) versus metformin was established in elderly patients and vildagliptin 50 mg twice daily was more effective than voglibose; however, the noninferiority of vildagliptin 50 mg twice daily versus metformin or gliclazide was not established in two other trials. Combination therapy with vildagliptin 50 mg twice daily plus metformin improved HbA(1c) to a significantly greater extent than monotherapy with metformin and/or vildagliptin alone in patients with type 2 diabetes whose disease was inadequately controlled by metformin monotherapy or who were treatment naive, according to the results of 12- or 24-week trials. In addition, vildagliptin 50 mg twice daily plus metformin demonstrated noninferiority to pioglitazone plus metformin, glimepiride plus metformin or gliclazide plus metformin in terms of the change from baseline in HbA(1c) after 24 or 52 weeks' therapy in patients with inadequately controlled type 2 diabetes. The addition of vildagliptin 50 mg twice daily to pioglitazone or vildagliptin 50 mg once daily to glimepiride improved HbA(1c) to a significantly greater extent than a thiazolidinedione or glimepiride alone in patients with type 2 diabetes whose disease was inadequately controlled, according to the results of 24-week trials. Oral vildagliptin 50 mg once or twice daily was generally well tolerated in patients with type 2 diabetes. In particular, vildagliptin was associated with a low risk of hypoglycaemia and was weight neutral. Increases in transaminase levels were sometimes observed with a vildagliptin dosage of 100 mg once daily in clinical trials, and liver function should be monitored in patients receiving vildagliptin. However, meta-analyses of clinical trial data suggested that vildagliptin 50 mg once or twice daily was not associated with an increased risk of hepatic adverse events, transaminase elevations ≥3 × the upper limit of normal, pancreatitis, cardiovascular or cerebrovascular events, infections or skin-related toxicity. In conclusion, vildagliptin is an important option for use in combination with metformin, a sulfonylurea or a thiazolidinedione in patients with type 2 diabetes who require combination therapy.

Efficacy and safety of saxagliptin in older patients with type 2 diabetes mellitus

OBJECTIVE

To assess the safety and efficacy of saxagliptin (5 mg once-daily) in older patients (≥65 years of age) with inadequately controlled type 2 diabetes.

RESEARCH DESIGN AND METHODS

In this retrospective subgroup analysis, data from five randomized, double-blind, placebo-controlled, multicenter, 24-week, phase 3 trials were included. The primary studies evaluated saxagliptin 5 mg once-daily (monotherapy or add-on) in patients aged 18-77 years with HbA(1c) ≥7.0% (four studies) or ≥7.5% (add-on to glyburide study) versus placebo.

MAIN OUTCOME MEASURES

The primary efficacy endpoint of each study included in this pooled analysis was HbA(1c) change from baseline to week 24.

RESULTS

In the five-study pooled population, 279 (16.6%) patients were at least 65 years old; 142 received saxagliptin 5 mg once-daily and 137 received placebo. Treatment groups were well-balanced for baseline characteristics within each study. In older patients, the HbA(1c) adjusted mean change from a baseline of 8.1% was -0.73 ± 0.16% (mean ± SEM) with saxagliptin compared with -0.17 ± 0.14% for placebo from a baseline of 8.0%. Adverse event rates were similar with saxagliptin 5 mg once-daily compared with placebo in older patients.

CONCLUSION

The pooled subgroup analysis of saxagliptin 5 mg once-daily monotherapy and add-on therapy trials demonstrated clinically relevant and significant efficacy for reducing HbA(1c) in older (≥65 years) patients. Saxagliptin was well-tolerated in older patients with a low incidence of hypoglycemia and no weight gain.

Clinical evidence and mechanistic basis for vildagliptin's action when added to metformin

Several new oral antidiabetic agents, known as 'gliptins' or 'enzyme dipeptidyl peptidase-IV (DPP-4) inhibitors', have been developed for the treatment of type 2 diabetes and a key clinical use of the gliptins is in combination with metformin. There are important differences in the kinetics of the interaction of different gliptins with the catalytic site of DPP-4, which may lead to varying pharmacokinetics, pharmacodynamics and dosing regimens. Therefore, individual gliptins need to be characterized and here we discuss the extensively studied DPP-4 inhibitor vildagliptin, which has binding characteristics that ensure inhibition of the enzyme beyond the presence of detectable drug levels in plasma. As vildagliptin has been used most often at doses of 50 mg once or twice daily, in combination with metformin, this review focuses on these dose regimens. All clinical trials employing vildagliptin (50 mg once or twice daily) as an add-on therapy to metformin (identified by MEDLINE search using keywords vildagliptin and metformin or known by authors to be in press) are reviewed, as is current knowledge of the mechanism of action of vildagliptin. Vildagliptin added to a stable dose of metformin elicits a dose-related decrease in both HbA1c and fasting plasma glucose. The additional efficacy seen with 50 mg twice daily [ΔHbA1c ∼- 1.1% (-12.1 mmol/mol)] relative to 50 mg once daily [ΔHbA1c ∼- 0.7% (-7.7 mmol/mol)] is attributable to an overnight effect of the evening dose of vildagliptin, with prolonged DPP-4 inhibition and elevated fasting levels of the intact and insulinotropic form of glucagon-like peptide-1 (GLP-1). Vildagliptin's therapeutic actions are primarily mediated by GLP-1 and metformin enhances vildagliptin's effect to raise plasma levels of intact GLP-1. Vildagliptin is weight-neutral and has a very low hypoglycaemic potential, explained by its remarkable ability to enhance both α-cell and β-cell sensitivity to glucose. Therefore, vildagliptin offers a clinically important outcome when added to metformin with a twice daily dose regimen, taking advantage of its tight binding and slow dissociation characteristics that lead to a sustained overnight effect.

Assessing the general safety and tolerability of vildagliptin: value of pooled analyses from a large safety database versus evaluation of individual studies

AIM

Analyzing safety aspects of a drug from individual studies can lead to difficult-to-interpret results. The aim of this paper is therefore to assess the general safety and tolerability, including incidences of the most common adverse events (AEs), of vildagliptin based on a large pooled database of Phase II and III clinical trials.

METHODS

Safety data were pooled from 38 studies of ≥ 12 to ≥ 104 weeks' duration. AE profiles of vildagliptin (50 mg bid; N = 6116) were evaluated relative to a pool of comparators (placebo and active comparators; N = 6210). Absolute incidence rates were calculated for all AEs, serious AEs (SAEs), discontinuations due to AEs, and deaths.

RESULTS

Overall AEs, SAEs, discontinuations due to AEs, and deaths were all reported with a similar frequency in patients receiving vildagliptin (69.1%, 8.9%, 5.7%, and 0.4%, respectively) and patients receiving comparators (69.0%, 9.0%, 6.4%, and 0.4%, respectively), whereas drug-related AEs were seen with a lower frequency in vildagliptin-treated patients (15.7% vs 21.7% with comparators). The incidences of the most commonly reported specific AEs were also similar between vildagliptin and comparators, except for increased incidences of hypoglycemia, tremor, and hyperhidrosis in the comparator group related to the use of sulfonylureas.

CONCLUSIONS

The present pooled analysis shows that vildagliptin was overall well tolerated in clinical trials of up to >2 years in duration. The data further emphasize the value of a pooled analysis from a large safety database versus assessing safety and tolerability from individual studies.

Incretin therapies in the management of elderly patients with type 2 diabetes mellitus

Aging is characterized by a progressive increase in the prevalence of type 2 diabetes mellitus (T2DM), which approaches 20% by age 70 years. Older patients with T2DM are a very heterogeneous group with multiple comorbidities, an increased risk of hypoglycemia, and a greater susceptibility to adverse effects of antihyperglycemic drugs, making treatment of T2DM in this population challenging. The risk of severe hypoglycemia likely represents the greatest barrier to T2DM care in the elderly. Although recent guidelines recommend more flexibility in treating this population with individualized targets, inadequate glycemic control is still closely linked to poor outcome in elderly patients. Incretins (glucose-dependent insulinotropic polypeptide [GIP] and glucagon-like peptide-1 [GLP-1]) are hormones released post-meal from intestinal endocrine cells that stimulate insulin secretion and suppress postprandial glucagon secretion in a glucose-dependent manner. "Incretin therapies," comprising the injectable GLP-1 analogs and oral dipeptidyl peptidase-4 (DPP-4) inhibitors, are promising new therapies for use in older patients because of their consistent efficacy and low risk of hypoglycemia. However, data with these new agents are still scarce in this population, which has not been particularly well represented in clinical trials, highlighting the need for additional specific studies. The objective of this article is to provide an overview of the available data and potential role of these novel incretin therapies in managing T2DM in the elderly. With the exception of the DPP-4 inhibitor vildagliptin, there is no published trial to date dedicated to this population, although a few studies are currently ongoing. Therefore, available data from elderly subgroups of individual studies were also reviewed when available, as well as pooled analyses by age subgroups across clinical programs conducted with incretin therapies.

Severe sulfonylurea-induced hypoglycemia: a problem of uncritical prescription and deficiencies of diabetes care in geriatric patients

OBJECTIVE

Severe sulfonylurea-induced hypoglycemia (SH) remains a life-threatening and under-reported condition. We investigated the incidence of SH and clinical characteristics of patients with type 2 diabetes mellitus (T2DM) to demonstrate typical risk constellations.

METHODS

In a prospective population-based observational study, all consecutive cases of SH in the period 2000 - 2009 in a German area with 200,000 inhabitants were registered. Severe hypoglycemia was defined as a symptomatic event requiring treatment with intravenous glucose and was confirmed by a blood glucose measurement of < 50 mg/dl.

RESULTS

A mean incidence of seven episodes of SH per year and 100,000 inhabitants was registered. The 139 hypoglycemic individuals had been treated with glimepiride (n = 98), glibenclamide (n = 40) or gliquidone (n = 1). No preparation showed a constant dose-effect relationship, SH occurring within a wide dose range. The patients were characterized as follows: age 77.5 + or - 9.4 years, duration of diabetes 11 + or - 7 years, body mass index 26.3 + or - 4.9 kg/m(2), HbA1c 6.6 + or - 1.3%, creatinine clearance 46 + or - 24 ml/min with renal insufficiency in 73% and co-medication 7 + or - 3 drugs. Two-thirds of all subjects lived independently at home whereas a third were cared for by a home nursing service or received care in nursing homes. In all, 30% had participated in diabetes education programs. In 31%, systematic blood glucose monitoring was performed.

CONCLUSIONS

Uncritical prescription of sulfonylureas neglecting crucial contraindications - particularly renal insufficiency - and deficiencies of diabetes care contributed substantially to the risk of SH in the mainly geriatric patients. There is a need for alternative therapeutic concepts that minimize the risk of hypoglycemia in geriatric patients with T2DM.

Clinical experience with vildagliptin in the management of type 2 diabetes in a patient population ≥75 years: a pooled analysis from a database of clinical trials

AIM

To report the experience with vildagliptin in a patient population with type 2 diabetes mellitus (T2DM) ≥75 years.

METHODS

Efficacy data from seven monotherapy and three add-on therapy to metformin studies, respectively, of ≥24 weeks duration were pooled; effects of 24 weeks of treatment with vildagliptin (50 mg bid) in patients ≥75 years were assessed in these two pooled datasets. Safety data were pooled from 38 studies of ≥12 to ≥104 weeks duration; adverse events (AEs) profiles of vildagliptin (50 mg bid) were evaluated relative to a pool of comparators; 301 patients ≥75 years were analysed. Data in patients <75 years are provided as a reference.

RESULTS

Mean age of the elderly population was 77 years. Changes in haemoglobin A1c (HbA1c) with vildagliptin in the patient group ≥75 years were -0.9% from a baseline of 8.3% in monotherapy (p < 0.0001) and -1.1% from a baseline of 8.5% in add-on therapy to metformin (p = 0.0004), and these reductions were similar to those seen in the younger patients. The corresponding weight changes in the elderly patients were -0.9 kg (p = 0.0277) and -0.2 kg [not significant (NS)], respectively, and no confirmed hypoglycaemic events, including no severe events, were reported. AEs, drug-related AEs, serious adverse events (SAEs) and deaths were reported with a lower frequency in older patients receiving vildagliptin than comparators [133.9 vs. 200.6, 14.5 vs. 21.8, 8.8 vs. 16.5 and 0.0 vs. 1.7 events per 100 subject year exposure (SYE), respectively], and the incidence of discontinuations due to AEs was similar in the two groups (7.2 vs. 7.5 events per 100 SYE, respectively). The safety profile of vildagliptin was overall similar in younger and older patients.

CONCLUSIONS

Vildagliptin was effective and well-tolerated in type 2 diabetic patients ≥75 years (mean age 77 years).

Dipeptidyl peptidase-4 inhibitors in the treatment of type 2 diabetes: a comparative review

The dipeptidyl peptidase (DPP)-4 inhibitors are a new class of antihyperglycaemic agents which were developed for the treatment of type 2 diabetes by rational drug design, based on an understanding of the underlying mechanism of action and knowledge of the structure of the target enzyme. Although they differ in terms of their chemistry, they are all small molecules which are orally available. There are some differences between them in terms of their absorption, distribution, metabolism and elimination, as well as in their potency and duration of action, but their efficacy, both in terms of inhibiting plasma DPP-4 activity and as antidiabetic agents, appears to be similar. They improve glycaemic control, reducing both fasting and postprandial glucose levels to lower HbA1c levels, without weight gain and with an apparently benign adverse event profile. At present, there seems to be little to distinguish between the different inhibitors in terms of their efficacy as antidiabetic agents and their safety. Long-term accumulated clinical experience will reveal whether compound-related characteristics lead to any clinically relevant differences.

Safety and tolerability of vildagliptin vs. thiazolidinedione as add-on to metformin in type 2 diabetic patients with and without mild renal impairment: a retrospective analysis of the GALIANT study

OBJECTIVE

This retrospective analysis assessed safety and tolerability of vildagliptin (Vilda) as an add-on to metformin in type 2 diabetes mellitus (T2DM) patients with normal renal function (GFR >80mL/min/1.73m(2)) and mild renal impairment (GFR: >50 to ≤80mL/min/1.73m(2)).

METHODS

Adverse events (AE) from this 12-week, randomized, open-label study comparing Vilda 100mg and thiazolidinediones (TZD) as an add-on therapy in patients with T2DM inadequately controlled (HbA(1c): 7-10%) on a stable dose of metformin (≥1000mg/day) were analyzed.

RESULTS

Of 2627 randomized patients, 1278 in the Vilda and 635 in the TZD groups had normal renal function; 463 in the Vilda and 230 in the TZD groups had mild renal impairment. Higher incidence of headache and rash was noted in both Vilda groups, whereas those with mild renal impairment receiving TZD experienced a higher incidence of peripheral edema and URI. Fewer patients in the Vilda group discontinued the study due to AEs compared to TZD group. Serious AEs were greater in TZD groups (normal: 2.4%; mild renal impairment: 3.0%) compared to Vilda groups (normal: 1.6%; mild renal impairment: 2.4%).

CONCLUSION

The safety profile of Vilda or TZD as an add-on to metformin was similar in patients with mild renal impairment and normal renal function.

DPP-4 inhibitors: what may be the clinical differentiators?

Attenuation of the prandial incretin effect, mediated by glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP), contributes to hyperglycemia in type 2 diabetes mellitus (T2DM). Since the launch of sitagliptin in 2006, a compelling body of evidence has accumulated showing that dipeptidyl peptidase-4 (DPP-4) inhibitors, which augment endogenous GLP-1 and GIP levels, represent an important advance in the management of T2DM. Currently, three DPP-4 inhibitors - sitagliptin, vildagliptin and saxagliptin - have been approved in various countries worldwide. Several other DPP-4 inhibitors, including linagliptin and alogliptin, are currently in clinical development. As understanding of, and experience with, the growing number of DPP-4 inhibitors broadens, increasing evidence suggests that the class may offer advantages over other antidiabetic drugs in particular patient populations. The expanding evidence base also suggests that certain differences between DPP-4 inhibitors may prove to be clinically significant. This therapeutic diversity should help clinicians tailor treatment to the individual patient, thereby increasing the proportion that safely attain target HbA(1c) levels, and reducing morbidity and mortality. This review offers an overview of DPP-4 inhibitors in T2DM and suggests some characteristics that may provide clinically relevant differentiators within this class.

Vildagliptin add-on to metformin produces similar efficacy and reduced hypoglycaemic risk compared with glimepiride, with no weight gain: results from a 2-year study

AIM

To show that vildagliptin added to metformin is non-inferior to glimepiride in reducing HbA1c levels from baseline over 2 years.

METHODS

A randomized, double-blind, active-comparator study of patients with type 2 diabetes mellitus inadequately controlled (HbA1c 6.5-8.5%) by metformin monotherapy. Patients received vildagliptin (50 mg twice daily) or glimepiride (up to 6 mg/day) added to metformin.

RESULTS

In all, 3118 patients were randomized (vildagliptin, n = 1562; glimepiride, n = 1556). From similar baseline values (7.3%), after 2 years adjusted mean (s.e.) change in HbA1c was comparable between vildagliptin and glimepiride treatment: -0.1% (0.0%) and -0.1% (0.0%), respectively. The primary objective of non-inferiority was met. A similar proportion of patients reached HbA1c <7% (36.9 and 38.3%, respectively), but with vildagliptin more patients reached this target without hypoglycaemia (36.0% vs. 28.8%; p = 0.004). The initial response (IR) was sustained for a mean (s.d.) of 309 (244) days with vildagliptin versus 270 (223) days for glimepiride (p < 0.001) (IR = nadir HbA1c where change from baseline > or =0.5% or HbA1c < or =6.5% within the first six months of treatment. After IR was detected, sustained response = time between nadir and an increase of >0.3% above IR). Independent of disease duration, age was a predictor of effect sustainability. Fewer patients experienced hypoglycaemia with vildagliptin (2.3% vs. 18.2% with glimepiride) with a 14-fold difference in the number of hypoglycaemic events (59 vs. 838). Vildagliptin had a beneficial effect on body weight [mean (s.e.) change from baseline -0.3 (0.1) kg; between-group difference -1.5 kg; p < 0.001]. Overall, both treatments were well tolerated and displayed similar safety profiles.

CONCLUSIONS

Vildagliptin add-on has similar efficacy to glimepiride after 2 years' treatment, with markedly reduced hypoglycaemia risk and no weight gain.

Role of vildagliptin in managing type 2 diabetes mellitus in the elderly

BACKGROUND

The prevalence of type 2 diabetes (T2DM) increases with age. Older patients have an increased likelihood for T2DM-related morbidity and mortality. The objective of this review is to provide an overview of the challenges in managing T2DM in the elderly, with an emphasis on prevention of hypoglycaemia and the role of the DPP-4 inhibitor vildagliptin in this patient population.

METHODS

A search of PubMed was conducted (from 2003 to 2010) to identify English-language articles relevant to the management of elderly patients with T2DM, with an emphasis on vildagliptin treatment. A limitation of this review is that it does not provide an overview of the entire class of dipeptidyl-peptidase-4 (DPP-4) inhibitors.

FINDINGS

Management of T2DM in elderly patients is complicated by numerous factors, including a high prevalence of cardiovascular risk factors and other comorbidities and a high frequency of polypharmacy issues. Hypoglycaemia may pose the greatest barrier to optimal glycaemic control in elderly patients, who are less likely to recognise and respond to hypoglycaemic episodes, leading to increased frequency and severity of events. Data on the DPP-4 inhibitor vildagliptin indicate that reductions in A1C in elderly patients are at least as good as those observed in younger patients and are achieved with minimal risk of hypoglycaemia. T2DM in older individuals is associated with relative hyperglucagonaemia and elevated postprandial glucose (PPG). Vildagliptin treatment appears to address both these defects. Vildagliptin improves the ability of alpha- and beta-cells to respond appropriately to changes in plasma glucose levels. This, in the face of high glucose levels, results in reduced inappropriate glucagon secretion and PPG excursions. In the face of low glucose, however, the protective glucagon response is well-preserved. These factors help explain the efficacy and minimal risk of hypoglycaemia observed with vildagliptin in elderly patients.

CONCLUSION

The elderly population with T2DM poses unique treatment challenges and have not been particularly well-represented in clinical trials, highlighting the need for additional studies to better define appropriate glucose targets and to ascertain the best strategies for achieving and maintaining appropriate glycaemic levels. Because vildagliptin does not expose patients to hypoglycaemic risk, it seems particularly suited to oral therapy of T2DM in the elderly.

An assessment of adverse effects of vildagliptin versus comparators on the liver, the pancreas, the immune system, the skin and in patients with impaired renal function from a large pooled database of Phase II and III clinical trials

AIM

To assess the safety of vildagliptin versus all comparators (ACs) with regard to organs, systems or tissues of particular interest in type 2 diabetes (T2DM) and areas of potential concern with dipeptidyl peptidase-IV (DPP-4) inhibitors.

METHODS

Data were pooled from 38 studies where vildagliptin was given for > or =12 to > 104 weeks in patients with T2DM. Absolute and exposure-adjusted incidence rates and Peto odds ratios (ORs) versus ACs with corresponding 95% confidence intervals (CI) were calculated.

RESULTS

There were > 7000 subject-years of exposure (SYE) to vildagliptin 50 mg bid and > 6500 SYE to ACs. For mild hepatic enzyme elevations with and without elevated bilirubin levels, the ORs for vildagliptin 50 mg bid were 1.24 (95% CI: [0.80, 1.93]) and 1.19 (95% CI: [0.29, 4.90]), respectively. The exposure-adjusted incidences of markedly elevated hepatic enzymes and for enzyme elevations with bilirubin > or = 2x ULN with vildagliptin 50 mg bid were < or = those in the ACs group. For hepatic and pancreatitis-related AEs, the ORs for vildagliptin 50 mg bid were 0.87 (95% CI: [0.64, 1.19]) and 0.70 (95% CI: [0.26, 1.88]), respectively, and for any AE in the infections and infestations SOC, this was 1.04 (95% CI: [0.96, 1.13]). The incidences of skin-related AEs were low and the risk with vildagliptin 50 mg bid was not significantly different from ACs [(OR = 1.10 (95% CI: [0.80, 1.51])].

CONCLUSIONS

The present meta-analyses indicate that vildagliptin was not associated with increased risk of hepatic events or hepatic enzyme elevations indicative of drug-induced liver injury, pancreatitis, infections or skin-related toxicity.

Assessing the cardio-cerebrovascular safety of vildagliptin: meta-analysis of adjudicated events from a large Phase III type 2 diabetes population

AIM

To assess the cardiovascular and cerebrovascular (CCV) safety of the dipeptidyl peptidase-IV inhibitor vildagliptin.

METHODS

Data were pooled from 25 Phase III studies of vildagliptin, used either as monotherapy or combination therapy, with durations of 12 weeks to > or = 2 years. The safety of vildagliptin [50 mg qd (N = 1393) or 50 mg bid (N = 6116)] was assessed relative to a pool of all comparators [both placebo and active comparators (N = 6061)]. CCV events were adjudicated in a prospective, blinded fashion by an independent CCV adjudication committee. Meta-analysis of confirmed CCV events was performed with Mantel-Haenszel risk ratios (RRs); categories included in the composite endpoint were acute coronary syndrome, transient ischaemic attack (with imaging evidence of infarction), stroke and CCV death. Subgroup analyses by age (< and > or = 65 years), gender and cardiovascular (CV) risk status [high CV risk status defined as a previous history of events in the Standard MedDRA Queries of ischaemic heart disease, cardiac failure, ischaemic cerebrovascular conditions and/or embolic/thrombotic events, arterial) were also carried out. In addition, unadjusted and exposure-adjusted incidences are presented for both the composite endpoint and its components.

RESULTS

Relative to all comparators, the RRs for the composite endpoint were < 1 for both vildagliptin 50 mg qd [RR = 0.88; 95% CI (0.37, 2.11)] and vildagliptin 50 mg bid [RR = 0.84; 95% CI (0.62, 1.14)]. The results were consistent across subgroups defined by age, gender and CV risk status, including the higher CV risk subgroups of elderly patients [RR for vildagliptin 50 mg bid vs. all comparators = 1.04; 95% CI (0.62, 1.73)], males [RR = 0.87; 95% CI (0.60, 1.24)] or patients with a high CV risk status [RR = 0.78; 95% CI (0.51, 1.19)]. The exposure-adjusted incidences of each component of the composite endpoint for vildagliptin 50 mg bid were also lower than or similar to those of all comparators.

CONCLUSIONS

In a large meta-analysis, vildagliptin was not associated with an increased risk of adjudicated CCV events relative to all comparators in the broad population of type 2 diabetes including patients at increased risk of CCV events.

Risk of fatal and nonfatal lactic acidosis with metformin use in type 2 diabetes mellitus

BACKGROUND

Metformin is an oral anti-hyperglycemic agent that has been shown to reduce total mortality compared to other anti-hyperglycemic agents, in the treatment of type 2 diabetes mellitus. Metformin, however, is thought to increase the risk of lactic acidosis, and has been considered to be contraindicated in many chronic hypoxemic conditions that may be associated with lactic acidosis, such as cardiovascular, renal, hepatic and pulmonary disease, and advancing age.

OBJECTIVES

To assess the incidence of fatal and nonfatal lactic acidosis, and to evaluate blood lactate levels, for those on metformin treatment compared to placebo or non-metformin therapies.

SEARCH STRATEGY

A comprehensive search was performed of electronic databases to identify studies of metformin treatment. The search was augmented by scanning references of identified articles, and by contacting principal investigators.

SELECTION CRITERIA

Prospective trials and observational cohort studies in patients with type 2 diabetes of least one month duration were included if they evaluated metformin, alone or in combination with other treatments, compared to placebo or any other glucose-lowering therapy.

DATA COLLECTION AND ANALYSIS

The incidence of fatal and nonfatal lactic acidosis was recorded as cases per patient-years, for metformin treatment and for non-metformin treatments. The upper limit for the true incidence of cases was calculated using Poisson statistics. In a second analysis lactate levels were measured as a net change from baseline or as mean treatment values (basal and stimulated by food or exercise) for treatment and comparison groups. The pooled results were recorded as a weighted mean difference (WMD) in mmol/L, using the fixed-effect model for continuous data.

MAIN RESULTS

Pooled data from 347 comparative trials and cohort studies revealed no cases of fatal or nonfatal lactic acidosis in 70,490 patient-years of metformin use or in 55,451 patients-years in the non-metformin group. Using Poisson statistics the upper limit for the true incidence of lactic acidosis per 100,000 patient-years was 4.3 cases in the metformin group and 5.4 cases in the non-metformin group. There was no difference in lactate levels, either as mean treatment levels or as a net change from baseline, for metformin compared to non-metformin therapies.

AUTHORS' CONCLUSIONS

There is no evidence from prospective comparative trials or from observational cohort studies that metformin is associated with an increased risk of lactic acidosis, or with increased levels of lactate, compared to other anti-hyperglycemic treatments.

Vildagliptin in clinical practice: a review of literature

Vildagliptin is the second member of the DPP-IV inhibitor class of drugs licensed for the treatment of type 2 diabetes mellitus (T2DM). The novel action of these drugs has promoted a new outlook in the pathobiology of T2DM. This review undertakes to examine the clinical studies published to date, with the aim of evaluating the position of vildagliptin among the drugs that are now available to treat this common dysmetabolic state.

Risk of fatal and nonfatal lactic acidosis with metformin use in type 2 diabetes mellitus

BACKGROUND

Metformin is an oral anti-hyperglycemic agent that has been shown to reduce total mortality compared to other anti-hyperglycemic agents, in the treatment of type 2 diabetes mellitus. Metformin, however, is thought to increase the risk of lactic acidosis, and has been considered to be contraindicated in many chronic hypoxemic conditions that may be associated with lactic acidosis, such as cardiovascular, renal, hepatic and pulmonary disease, and advancing age.

OBJECTIVES

To assess the incidence of fatal and nonfatal lactic acidosis, and to evaluate blood lactate levels, for those on metformin treatment compared to placebo or non-metformin therapies.

SEARCH STRATEGY

A comprehensive search was performed of electronic databases to identify studies of metformin treatment. The search was augmented by scanning references of identified articles, and by contacting principal investigators.

SELECTION CRITERIA

Prospective trials and observational cohort studies in patients with type 2 diabetes of least one month duration were included if they evaluated metformin, alone or in combination with other treatments, compared to placebo or any other glucose-lowering therapy.

DATA COLLECTION AND ANALYSIS

The incidence of fatal and nonfatal lactic acidosis was recorded as cases per patient-years, for metformin treatment and for non-metformin treatments. The upper limit for the true incidence of cases was calculated using Poisson statistics. In a second analysis lactate levels were measured as a net change from baseline or as mean treatment values (basal and stimulated by food or exercise) for treatment and comparison groups. The pooled results were recorded as a weighted mean difference (WMD) in mmol/L, using the fixed-effect model for continuous data.

MAIN RESULTS

Pooled data from 347 comparative trials and cohort studies revealed no cases of fatal or nonfatal lactic acidosis in 70,490 patient-years of metformin use or in 55,451 patients-years in the non-metformin group. Using Poisson statistics the upper limit for the true incidence of lactic acidosis per 100,000 patient-years was 4.3 cases in the metformin group and 5.4 cases in the non-metformin group. There was no difference in lactate levels, either as mean treatment levels or as a net change from baseline, for metformin compared to non-metformin therapies.

AUTHORS' CONCLUSIONS

There is no evidence from prospective comparative trials or from observational cohort studies that metformin is associated with an increased risk of lactic acidosis, or with increased levels of lactate, compared to other anti-hyperglycemic treatments.

DPP-4 inhibitors in clinical practice

Type 2 diabetes is a very common worldwide disorder, with major consequences for patients, society, and health care services. Good glycemic control is an important aspect of diabetes management because it has a significant impact on diabetes-related microvascular and possibly macrovascular complications. Based on our understanding of the pathogenesis of diabetes, multiple pharmacological interventions have been developed in the past 60 years. Although effective, none have had a lasting effect on glycemic control because of the progressive nature of type 2 diabetes requiring combination therapies and insulin treatment. In addition, several pharmacologic interventions have undesirable side effects, including hypoglycemia and weight gain. Drugs targeting the incretin pathway are the latest addition to the available antidiabetes agents. Incretin-based therapy is either delivered orally (dipeptidyl peptidase-4 [DPP-4]) inhibitors or injected subcutaneously (glucagon-like peptide-1 [GLP-1] mimetics and analogues). Dipeptidyl peptidase-4 inhibitors are effective either as a single or combination therapy in lowering glycated hemoglobin, fasting and postprandial glucose levels, with a low incidence of hypoglycemia and no weight gain. There are 3 DPP-4 inhibitors currently available (sitagliptin, saxagliptin, and vildagliptin), with more expected to be available in the future. In this article, we review the scientific background for incretin-based therapy and the available evidence regarding the role and efficacy of DPP-4 inhibitors in the treatment of patients with type 2 diabetes.