Sustained efficacy and reduced hypoglycemia during one year of treatment with vildagliptin added to insulin in patients with type 2 diabetes mellitus

Impact of concomitant oral glucose-lowering medications on the success of basal insulin titration in insulin-naïve patients with type 2 diabetes: a systematic analysis

Basal insulin treatment for type 2 diabetes is usually initiated on a background of oral glucose-lowering medications (OGLM). We wanted to examine the influence of various OGLMs on fasting plasma glucose (FPG) and hemoglobin A_1c (HbA_1c) values achieved after titration. A PubMed literature search retrieved 42 publications (clinical trials introducing basal insulin in 17 433 insulin-naïve patients with type 2 diabetes on a defined background of OGLM) and reporting FPG, HbA_1c, target achievement, hypoglycemic events, and insulin doses. 60 individual study arms were grouped by OGLM (combinations) allowed during the titration process: (a) metformin only; (b) sulfonylureas only; (c) metformin and sulfonylureas; or (d) metformin and dipeptidyl peptidase-4 (DPP-4) inhibitors. For all OGLM categories, weighted means and SD were calculated for baseline and end-of-treatment FPG, HbA_1c, target achievement, incidence of hypoglycemic events, and insulin doses. Primary end point was a difference in FPG after titration between OGLM categories. Statistics: analysis of variance and post hoc comparisons. Sulfonylureas, alone or in combination with metformin, impair the titration of basal insulin (insulin doses 30%-40% lower, more hypoglycemic episodes), thus leading to poorer final glycemic control (p<0.05 for FPG and HbA_1c after titration). Conversely, adding a DPP-4 inhibitor to metformin is superior to metformin alone (p<0.05 for FPG and HbA_1c achieved) in patients with type 2 diabetes initiating basal insulin therapy. In conclusion, OGLM are a major determinant of the success of basal insulin therapy. Sulfonylureas impair, while DPP-4 inhibitors (added to metformin) may facilitate the achievement of ambitious fasting glucose targets. PROSPERO registration number CRD42019134821.

Impact of the Fasting Plasma Glucose Titration Target on the Success of Basal Insulin Titration in Insulin-Naïve Patients with Type 2 Diabetes: A Systematic Analysis

BACKGROUND/AIM

We aimed to examine beneficial and adverse outcomes of basal insulin titration performed with different fasting plasma glucose (FPG) titration targets (TT).

METHODS

A PubMed literature search retrieved 43 reported prospective clinical trials introducing basal insulin in 17643 insulin-naïve patients with type 2 diabetes reporting fasting plasma glucose (FPG), HbA_1c, target achievement, hypoglycemic events, and insulin doses. 61 individual study arms were grouped by fasting plasma glucose titration target (TT; 1: ≤5.0 mmol/l/90 mg/dl; 2: 5.01-5.6 mmol/l/90-100 mg/dl; and 3: ≥5.61 mmol/l/101 mg/dl). Weighted means and their standard deviations were calculated for baseline and end-of-treatment FPG (primary endpoint), HbA_1c, target achievement, hypoglycemic events, insulin doses, and body weight gain and compared over a duration of 31 ± 10 weeks.

RESULTS

Achieved FPG and HbA_1c at the end of the study were significantly lower (by up to 0.8 mmol/l or 0.23%, respectively) with more ambitious TTs (p < 0.0001), leading to better HbA_1c target achievement with more ambitious TTs (by up to 14.6% for HbA_1c ≤ 6.5%), without increasing the risk for hypoglycemic episodes.

CONCLUSIONS

Aiming for a lower FPG TT improves glycemic control without increasing the risk for hypoglycemia.

Optimal Type 2 Diabetes Mellitus Management and Active Ageing

Type two diabetes mellitus (T2DM) represents a chronic condition with increasing prevalence worldwide among the older population. The T2DM condition increases the risk of micro and macrovascular complications as well as the risk of geriatric syndromes such as falls, fractures and cognitive impairment. The management of T2DM in the older population represents a challenge for the clinician, and a Comprehensive Geriatric Assessment should always be prioritized, in order to tailor the glycated hemoglobin target according to functional and cognitive status comorbidities, life expectancy and type of therapy. According to the most recent guidelines, older adults with T2DM should be categorized into three groups: healthy patients with good functional status, patients with complications and reduced functionality and patients at the end of life; for each group the target for glycemic control is different, also according to the type of treatment drug. The therapeutic approach should always begin with lifestyle changes; after that, several lines of therapy are available, with different mechanisms of action and potential effects other than glucose level reduction. Particular interest is growing in sodium-glucose cotransporter-2 inhibitors, due to their effect on the cardiovascular system. In this review, we evaluate the therapeutic options available for the treatment of older diabetic patients, to ensure a correct treatment approach.

Safety and efficacy of vildagliptin: 52-week post-marketing surveillance of Japanese patients with type 2 diabetes in combination with other oral antidiabetics and insulin

Background: Vildagliptin is a dipeptidyl peptidase-4 inhibitor that reduces glycemia in patients with type 2 diabetes mellitus (T2DM). When approved in 2013, data on vildagliptin combined with >750 mg/day metformin in Japanese patients were limited. There is a need to confirm the safety and efficacy of vildagliptin in combination with oral antidiabetic drugs (OADs).Research design and methods: This 52-week post-marketing surveillance (PMS) observational study in Japanese T2DM patients evaluated the safety and efficacy of vildagliptin in combination with OADs including high-dose metformin or insulin but excluding combination with sulfonylureas alone.Results: During this survey of 3006 Japanese T2DM patients, 13.61% of patients experienced adverse events (AEs) and 2.20% reported a serious AE (SAE). The frequency of AEs/SAEs was similar when in combination with biguanides (12.93%/1.46%), metformin ≥1000 mg/day (12.92%/1.22%), metformin <1000 mg/day (12.62%/1.54%), thiazolidine derivatives (16.71%/2.86%), α-glucosidase inhibitors (13.18%/1.90%), rapid-acting insulin secretagogues  (glinides) (20.41%/5.71%), or insulin (15.87%/2.47%). The mean ± SD changes from baseline at endpoint in glycated hemoglobin and fasting blood glucose were -0.76 ± 1.27% and -23.3 ± 57.3 mg/dL, respectively, and these changes were consistent, regardless of concomitant OAD.Conclusions: Long-term vildagliptin combination therapy is safe and effective in Japanese T2DM patients in real-world settings.

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.

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

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

Effectiveness and safety of dipeptidyl peptidase 4 inhibitors in the management of type 2 diabetes in older adults: a systematic review and development of recommendations to reduce inappropriate prescribing

Background

Preventable drug-related hospital admissions can be associated with drugs used in diabetes and the benefits of strict diabetes control may not outweigh the risks, especially in older populations. The aim of this study was to look for evidence on risks and benefits of DPP-4 inhibitors in older adults and to use this evidence to develop recommendations for the electronic decision support tool of the PRIMA-eDS project.

Methods

Systematic review using a staged approach which searches for systematic reviews and meta-analyses first, then individual studies only if prior searches were inconclusive. The target population were older people (≥65 years old) with type 2 diabetes. We included studies reporting on the efficacy and/or safety of DPP-4 inhibitors for the management of type 2 diabetes. Studies were included irrespective of DPP-4 inhibitors prescribed as monotherapy or in combination with any other drug for the treatment of type 2 diabetes. The target intervention was DPP-4 inhibitors compared to placebo, no treatment, other drugs to treat type 2 diabetes or a non-pharmacological intervention.

Results

Thirty studies (reported in 33 publications) were included: 1 meta-analysis, 17 intervention studies and 12 observational studies. Sixteen studies were focused on older adults and 14 studies reported subgroup analyses in participants ≥65, ≥70, or ≥75 years. Comorbidities were reported by 26 studies and frailty or functional status by one study. There were conflicting findings regarding the effectiveness of DPP-4 inhibitors in older adults. In general, DPP-4 inhibitors showed similar or better safety than placebo and other antidiabetic drugs. However, these safety data are mainly based on short-term outcomes like hypoglycaemia in studies with HbA1c control levels recommended for younger people. One recommendation was developed advising clinicians to reconsider the use of DPP-4 inhibitors for the management of type 2 diabetes in older adults with HbA1c <8.5% because of scarce data on clinically relevant benefits of their use. Twenty-two of the included studies were funded by pharmaceutical companies and authored or co-authored by employees of the sponsor.

Conclusions

Other than the surrogate endpoint of improved glycaemic control, data on clinically relevant benefits of DPP-4 inhibitors in the treatment of type 2 diabetes mellitus in older adults is scarce. DPP-4 inhibitors might have a lower risk of hypoglycaemia compared to other antidiabetic drugs but data show conflicting findings for long-term benefits. Further studies are needed that evaluate the risks and benefits of DPP-4 inhibitors for the management of type 2 diabetes mellitus in older adults, using clinically relevant outcomes and including representative samples of older adults with information on their frailty status and comorbidities. Studies are also needed that are independent of pharmaceutical company involvement.

Electronic supplementary material

The online version of this article (doi:10.1186/s12877-017-0571-8) contains supplementary material, which is available to authorized users.

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

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Pattern of Onset and Risk Factors for Peripheral Oedema During Vildagliptin Use: Analysis from the Vildagliptin Prescription-Event Monitoring Study in England

INTRODUCTION

Clinical trials have identified peripheral oedema (PO) as an adverse event of vildagliptin (an oral anti-diabetic drug [OAD]). A post-marketing study (PMS) was conducted to advance the understanding of vildagliptin use and particular safety concerns identified within the risk-management plan. PMS objectives included comparing the hazards between vildagliptin monotherapy and combination therapy for selected a priori identified risks, including PO.

AIM

This study was a per-protocol supplementary analysis to investigate the pattern of onset and effect of vildagliptin combination therapy on PO risk.

METHODS

The PMS used an observational cohort design. OAD exposure, selected risk factors and outcome data were collected from general practitioners in England regarding vildagliptin users for the 6-month period after starting treatment. Data analysis comprised univariate case/non-case analysis, time-to-onset analysis and Cox proportional hazard models to estimate hazard ratios (HR) of PO adjusting for selected patients' baseline characteristics.

RESULTS

The study cohort included 4828 patients (median age 63 years; interquartile range [IQR] 54-71), 2692 of whom were male (55.8 %). The crude cumulative hazard of PO was 19.09 cases (95 % confidence interval [CI] 13.54-26.10) per 1000 person-years; 50 % of cases occurred during the first 34 days of treatment. A significantly faster time to PO onset was observed in patients prescribed concomitant sulfonylureas versus other treatment combinations (log rank test [LRT] p = 0.0365); in patients with a prior history of PO (LRT p < 0.001), arrhythmia (LRT p = 0.0003) or hypertension (LRT p = 0.0125); and in patients aged ≥60 years (LRT p = 0.0047). Similarly, the case/non-case univariate analysis indicated that patients with PO were older; had a higher prevalence of a history of either arrhythmia, hypertension or PO; and frequently used a sulfonylurea in combination. In the hazard function analysis, only sex and prior PO history had a profound effect on risk of PO after starting vildagliptin. Furthermore, effect modification was observed between sex and prior PO history; in male patients of average age (62 years), the HR was 12.84 (95 % CI 4.96-33.23); in females, it was 1.44 (95 % CI 0.32-6.40).

CONCLUSIONS

In this planned supplementary analysis, the findings suggest that PO occurred most frequently within 1 month after starting treatment with vildagliptin, and previous PO history and male sex in elderly patients were important predictors of this risk. The observation that concomitant use of a sulfonylurea may also increase PO risk early after starting treatment should be taken into consideration if prescribing OADs in combination with vildagliptin.

Improved glucose control with reduced hypoglycaemic risk when linagliptin is added to basal insulin in elderly patients with type 2 diabetes

AIM

To assess the efficacy, hypoglycaemia risk and other safety markers of linagliptin as an additional therapy in older patients (aged ≥70 years) inadequately controlled with basal insulin.

METHODS

A prespecified safety analysis from the linagliptin trials programme was carried out to explore the hypoglycaemia risk when linagliptin was added to background basal insulin therapy in elderly patients (≥70 years). To do this, two eligible, randomized, placebo-controlled, clinical trials (NCT00954447 and NCT01084005) of 24 and ≥52 weeks, respectively, were analysed.

RESULTS

A total of 247 elderly individuals [mean ± standard deviation (s.d.) age 74 ± 4 years, glycated haemoglobin (HbA1c) 8.2 ± 0.8%] on basal insulin (mean ± s.d. baseline dose 36 ± 25 IU/day) were identified. Alongside placebo-adjusted change in HbA1c with linagliptin of -0.77% [95% confidence interval (CI) -0.95 to 0.59; p < 0.0001] after 24 weeks, the hazard ratios (HRs) of both overall and confirmed hypoglycaemia [blood glucose ≤3.9 mmol/l (70 mg/dl)], were significantly lower with linagliptin than with placebo: HR 0.61 (95% CI 0.39-0.97) versus 0.59 (95% CI 0.37-0.94), respectively (both p < 0.05). Moreover, significantly less confirmed hypoglycaemia was present in linagliptin-treated patients with renal impairment [HR 0.45 (95% CI 0.27-0.76)], moderate hyperglycaemia [HbA1c 7.5 to <9.0%; HR 0.51 (95% CI 0.27-0.99)], lower fasting plasma glucose levels [<152 mg/dl; HR 0.49 (95% CI 0.28-0.86)] and those treated with higher insulin doses [insulin ≥35.6 IU/day; HR 0.46 (95% CI 0.23-0.91); p < 0.05 for all]. Severe hypoglycaemia was rare and the incidence was lower with linagliptin (0.8%) versus placebo (2.5%): HR 0.21 (95% CI 0.02-2.30).

CONCLUSIONS

Despite improvements in hyperglycaemia and no relevant on-trial insulin dose reductions, adding linagliptin to basal insulin appears to decrease hypoglycaemia risk. The biological basis of this phenomenon warrants further research but may involve counter-regulatory effects of incretin hormones.

DPP-4 inhibitors: pharmacological differences and their clinical implications

INTRODUCTION

Recently, incretin-based therapy was introduced for the treatment of type 2 diabetes (T2D). In particular, dipeptidyl peptidase-4 inhibitors (DPP-4i) (sitagliptin, vildagliptin, saxagliptin, linagliptin and alogliptin) play an increasing role in the management of T2D.

AREAS COVERED

An extensive literature search was performed to analyze the pharmacological characteristics of DPP-4i and their clinical implications.

EXPERT OPINION

DPP-4i present significant pharmacokinetic differences. They also differ in chemical structure, in the interaction with distinct subsites of the enzyme and in different levels of selectivity and potency of enzyme inhibition. Moreover, disparities in the effects on glycated hemoglobin, glucagon-like peptide-1 and glucagon levels and on glucose variability have been observed. However, indirect comparisons indicate that all DPP-4i have a similar safety and efficacy profiles. DPP-4i are preferred in overweight/obese and elderly patients because of the advantages of minimal or no influence on weight gain and low risk of hypoglycemia. For the same reasons, DPP-4i can be safely combined with insulin. However, currently cardiovascular outcomes related to DPP-4i are widely debated and the available evidence is controversial. Today, long-term studies are still in progress and upcoming results will allow us to better define the strengths and limits of this therapeutic class.

Efficacy of adding once-daily insulin glulisine in Japanese type 2 diabetes patients treated with insulin glargine and sitagliptin

BACKGROUND

Glucose fluctuation often remains to be corrected under basal-supported oral therapy. We investigated the efficacy of adding once-daily rapid-acting insulin in Japanese diabetes patients treated with basal-supported oral therapy.

SUBJECTS AND METHODS

In this 8-week, parallel-group, randomized, open-label trial, 62 Japanese adults with type 2 diabetes treated with insulin glargine and 50 mg of sitagliptin were randomized into the following two arms: the single-bolus group, in which once-daily insulin glulisine was initiated at a main meal at a fifth (i.e., 20%) the dose of insulin glargine, and the control group, in which the dose of sitagliptin was maximized to 100 mg. The primary end point was the change of glycemic fluctuation assessed with the M-value.

RESULTS

Baseline hemoglobin A1c levels, mean blood glucose profiles, and M-value were 7.2 ± 0.6%, 9.3 ± 1.7 mmol/L, and 21 ± 13 units, respectively. At the end of the study, the single-bolus group had a greater reduction of M-value than the control group (P=0.02); the difference was 6.5 units (95% confidence interval, 1.1-11.9 units). The single-bolus group also had a greater reduction of mean blood glucose levels (P=0.01). There were no significant differences in the incidence of hypoglycemia or the weight change between the two groups (P>0.05).

CONCLUSIONS

Adding once-daily insulin glulisine was more effective in controlling the glycemic fluctuation in Japanese type 2 diabetes patients treated with insulin glargine together with sitagliptin.

Patients with type 2 diabetes mellitus failing on oral agents and starting once daily insulin regimen; a small randomized study investigating effects of adding vildagliptin

Background

The addition of a DDP4-inhibitor to existing insulin therapy reduces HbA1c. However, no data exist about the addition of these agents at the beginning of insulin treatment in type 2 diabetes while this could especially be interesting because it is during this period that considerable residual beta cell function is still present. The benefit of such a strategy could be a lower insulin dose required for glycemic control. The hypothesis of our study was that adding a DPP4-inhibitor at the beginning of insulin treatment could lead to less exogenous insulin requirement, a reduction of hyperinsulinemia and side effects (hypoglycemia and weight gain), less glucose variability and improvement of insulin and glucagon dynamics during a mixed meal test.

Results

In this small clinical trial (trial registration NTR2022) 9 patients were randomized to receive vildagliptin and 6 to receive placebo in addition to start of once daily insulin treatment. Unfortunately, due to a difficult inclusion, the preset sample size of 40 patients could not be met. Median units of insulin at the end of the study was 47 U in the placebo group and 34 U in the vildagliptin group. Median glycemic variability (SD) at the end of study was 2.1 in the placebo group and 1.5 in the vildagliptin group. Median weight gain at the end of study was 3 kg in the placebo and 0.5 kg in the vildagliptin group. Occurrence of hypoglycemia was low in both groups. Insulin, C-peptide, glucose and glucagon levels were comparable during mixed meal tests.

Conclusions

This small randomized study did not have sufficient power to detect effects of the addition of vildagliptin to the start of once daily long-acting insulin. However in our opinion adding a DPP4-inhibitor, especially in this group remains a very interesting approach. This study could be used as a guidance for larger studies that are required to investigate the effects of this intervention on insulin requirements, glycemic variability, hypoglycemia and weight gain.

Electronic supplementary material

The online version of this article (doi:10.1186/1756-0500-7-579) contains supplementary material, which is available to authorized users.

Use of Vildagliptin in Management of Type 2 Diabetes: Effectiveness, Treatment Persistence and Safety from the 2-Year Real-Life VILDA Study

INTRODUCTION

There is an increasing interest for real-life data on drug use in many countries. Reimbursement authorities more and more request observational studies to assess the conditions of use of the products but also to improve knowledge about efficacy and safety in the real world and on a longer term than in clinical trials.

AIM

To evaluate the effectiveness, treatment persistence and tolerability of vildagliptin in clinical practice.

METHODS

This observational, 2-year prospective cohort study was conducted in France on request of the Health Authorities [Haute Autorite de Sante (HAS)]. Type 2 diabetic mellitus (T2DM) patients initiating vildagliptin (including the fixed combination vildagliptin-metformin) or treated for <6 months were recruited through a national representative sample of general practitioners (GPs) (n = 482) and diabetologists (n = 84) between March 2010 and December 2011. At inclusion and each follow-up visit at ~ 6, 12, 18 and 24 months, a questionnaire was completed by the physician collecting information on socio-demographic, clinical and biological data, treatments and adverse events.

RESULTS

1,700 patients were included: 60% were males, aged 63 ± 11 years, with diabetes duration 7 ± 6 years and body mass index (BMI) 30 ± 6 kg/m(2). 45% were obese, 70% treated for hypertension and 66% for dyslipidemia. 64% of the patients received vildagliptin in dual therapy with metformin. 82% of patients completed the 2-year follow-up. Glycosylated hemoglobin (HbA1c) decreased from a mean baseline of 7.8 ± 1.2% when vildagliptin was started, to 7.0 ± 1.1% at 6 months and remained stable thereafter over 2 years. Mean weight, glomerular filtration rate, liver enzymes, and lipid parameters were unchanged over the study period. Eight patients (0.5%), all concomitantly treated with insulin and/or sulphonylureas, reported one severe hypoglycemia and 47 (2.9%) patients reported 64 non-severe symptomatic hypoglycemia (59% occurred when patients were treated with insulin and/or sulphonylureas). At 6 months, 44.9% of vildagliptin-treated patients reached an HbA1c <7% without hypoglycemia and no weight gain, and this percentage increased to 49.7% at 24 months. Vildagliptin treatment maintenance at 2 years was 88.8% [95% CI (87.2%; 90.4%)], with 4% of patients discontinuing for adverse events.

CONCLUSIONS

In everyday conditions of care, vildagliptin efficacy was in line with existing data from randomized clinical trials, sustained over 2 years, with low discontinuation rate and low hypoglycemia risk.

Saxagliptin add-on therapy to insulin with or without metformin for type 2 diabetes mellitus: 52-week safety and efficacy

BACKGROUND

Achievement of glycemic control is an important objective in the management of type 2 diabetes mellitus (T2DM).

OBJECTIVE

The objective of this study was to evaluate the safety and efficacy of the dipeptidyl peptidase-4 inhibitor saxagliptin versus placebo as add-on therapy in patients with T2DM inadequately controlled with insulin alone or insulin plus metformin.

METHODS

This was a long-term (28-week) extension of a short-term (24-week), randomized, double-blind, parallel-group trial of saxagliptin 5 mg once daily versus placebo as add-on therapy to open-label insulin or insulin plus metformin therapy totaling 52 weeks of treatment. In contrast with the goal of maintaining a stable insulin dosage during the short-term phase, during the extension phase the insulin dosage was flexible and adjusted as deemed appropriate by the investigator. The study was conducted in a clinical practice setting, including family practice and hospital sites. Patients with T2DM aged 18-78 years with glycated hemoglobin (HbA1c) 7.5-11 % on a stable insulin regimen (30-150 U/day with or without metformin) for ≥8 weeks at screening were included in the study. Patients were stratified by metformin use and randomly assigned 2:1 to oral saxagliptin 5 mg (n = 304) or placebo (n = 151) once daily. All patients who completed the initial 24 weeks of treatment were eligible to participate in the 28-week extension, regardless of whether they had required rescue treatment. The main outcome measure was change in HbA1c from baseline to week 52.

RESULTS

In general, the outcomes achieved at week 24 were sustained to week 52. Adjusted mean change from baseline HbA1c at week 52 was greater with saxagliptin (-0.75 %) versus placebo (-0.38 %); the adjusted between-group difference was -0.37 % (95 % CI -0.55 to -0.19); between-group differences were similar in patients treated with metformin (-0.37 % [95 % CI -0.59 to -0.15]) and without metformin (-0.37 % [95 % CI -0.69 to -0.04]). At week 52, a greater proportion of patients receiving saxagliptin achieved HbA1c <7 % than those receiving placebo (21.3 vs. 8.7 %; between-group difference 12.6 % [95 % CI 6.1-19.1]). The increase from baseline in mean total daily insulin dose at week 52 was numerically smaller with saxagliptin (5.67 vs 6.67 U with placebo; difference, -1.01 U [95 % CI -3.24 to 1.22]). During the 52-week study period, the proportion of patients reporting ≥1 adverse event (AE) was 66.4 % with saxagliptin and 71.5 % with placebo, the majority being mild or moderate in intensity. The most common AEs (≥5 % with saxagliptin or placebo) were urinary tract infection, nasopharyngitis, upper respiratory tract infection, headache, influenza, and pain in extremity; the incidence of each AE was similar between treatment groups. In the saxagliptin and placebo groups, the incidence of reported hypoglycemia was 22.7 and 26.5 %, respectively; the incidence of confirmed hypoglycemia (fingerstick glucose ≤50 mg/dL [≤2.77 mmol/L] with characteristic symptoms) was 7.6 and 6.6 %, respectively. Adjusted mean change from baseline body weight was +0.8 kg with saxagliptin and +0.5 kg with placebo.

CONCLUSION

Saxagliptin 5 mg once daily as add-on to insulin, with or without concomitant metformin, produced a durable improvement in glycemic control and was well tolerated over 52 weeks of treatment.

Achieving glycaemic targets with basal insulin in T2DM by individualizing treatment

Insulin therapy is an effective method for reducing blood glucose levels in patients with type 2 diabetes mellitus (T2DM), and most patients with T2DM eventually require insulin replacement to attain and preserve satisfactory glycaemic control. All patients with T2DM should be considered as potential candidates for intensive insulin treatment; however, there are certain considerations regarding replacement therapy for different types of people and special populations, such as patients with multiple comorbidities, adolescents, pregnant women and the elderly. Lowering HbA1c levels in isolation without assessing the patient as a whole is becoming redundant. HbA1c targets should be individualized to the specific patient, and insulin treatment ought to be customized accordingly. There are several questions that need to be taken into account when considering adding insulin therapy to other oral antidiabetic agents, for example, for whom and when insulin therapy is indicated and which basal insulin should be utilized. Potential barriers exist related to patients, providers and health-care systems that can delay the start of insulin therapy, and every effort should be made to identify and address these obstacles.

Insulin plus incretin agent combination therapy in type 2 diabetes: a systematic review

BACKGROUND

Insulin and incretin agents (dipeptidyl peptidase-4 inhibitors [DPP4is] and glucagon-like peptide-1 receptor agonists [GLP1 RAs]) are second-line treatment options in patients with type 2 diabetes (T2D) not achieving glycemic targets with metformin. Combinations of insulin with incretin agents have been explored in randomized controlled trials (RCTs) and retrospective studies. However, the optimal approach is still elusive; numerous combination regimens can be envisioned, differing in composition and in order of addition.

SCOPE

A systematic survey was conducted of RCTs testing insulin/DPP4i or insulin/GLP1 RA regimens. PubMed and other online databases were queried using 'insulin' and the names of all incretin agents available in Canada, along with 'combination', 'concomitant', 'concurrent', and 'add-on'. Web of Science and clinicaltrials.gov were searched to identify unpublished trials.

FINDINGS

Fifteen placebo-controlled or active-comparator RCTs were identified, reporting outcomes for regimens combining insulins and incretin agents available in Canada. DPP4i add-on to insulin therapy (six trials) leads to modest A1c lowering, with weight neutrality. GLP1 RA and insulin combination therapy (GLP1 RA add-on, five trials; insulin add-on, two trials) is associated with significant A1c lowering, with beneficial effects on body weight. A single proof-of-concept trial compared GLP1 RA to DPP4i add-on to insulin, and only one RCT examined simultaneous introduction of an incretin agent with insulin. Adding an incretin agent to established basal insulin therapy may represent a useful alternative to insulin intensification with prandial or premixed insulin. Initial introduction of an incretin agent, with subsequent introduction of insulin, offers potential practical advantages. No study directly comparing order of addition has yet been reported.

CONCLUSIONS

Insulin/incretin combination therapy comprises a variety of efficacious, weight-sparing regimens and may be considered for many patients who do not achieve glycemic targets when treated with insulin or an incretin agent.

Effects of adding linagliptin to basal insulin regimen for inadequately controlled type 2 diabetes: a ≥52-week randomized, double-blind study

OBJECTIVE

To evaluate the efficacy and long-term safety of linagliptin added to basal insulins in type 2 diabetes inadequately controlled on basal insulin with or without oral agents.

RESEARCH DESIGN AND METHODS

A total of 1,261 patients (HbA1c ≥7.0% [53 mmol/mol] to ≤10.0% [86 mmol/mol]) on basal insulin alone or combined with metformin and/or pioglitazone were randomized (1:1) to double-blind treatment with linagliptin 5 mg once daily or placebo for ≥52 weeks. The basal insulin dose was kept unchanged for 24 weeks but could thereafter be titrated according to fasting plasma glucose levels at the investigators' discretion. The primary end point was the mean change in HbA1c from baseline to week 24. The safety analysis incorporated data up to a maximum of 110 weeks.

RESULTS

At week 24, HbA1c changed from a baseline of 8.3% (67 mmol/mol) by -0.6% (-6.6 mmol/mol) and by 0.1% (1.1 mmol/mol) with linagliptin and placebo, respectively (treatment difference -0.65% [95% CI -0.74 to -0.55] [-7.1 mmol/mol]; P < 0.0001). Despite the option to uptitrate basal insulin, it was adjusted only slightly upward (week 52, linagliptin 2.6 IU/day, placebo 4.2 IU/day; P < 0.003), resulting in no further HbA1c improvements. Frequencies of hypoglycemia (week 24, linagliptin 22.0%, placebo 23.2%; treatment end, linagliptin 31.4%, placebo 32.9%) and adverse events (linagliptin 78.4%, placebo 81.4%) were similar between groups. Mean body weight remained unchanged (week 52, linagliptin -0.30 kg, placebo -0.04 kg).

CONCLUSIONS

Linagliptin added to basal insulin therapy significantly improved glycemic control relative to placebo without increasing hypoglycemia or body weight.

Combination therapy with DPP-4 inhibitors and insulin in patients with type 2 diabetes mellitus: what is the evidence?

As type 2 diabetes mellitus (T2DM) progresses, most patients will require insulin replacement therapy. Whether oral antidiabetic drug (OAD) therapy should be retained when initiating insulin is still debated. While the rationale to keep metformin with insulin is strong (mostly as an insulin-sparing agent to limit weight gain), the evidence is less clear for other OADs. In particular, the question now comes up what the expected benefit could be of combining the newer agents, such as the dipeptidyl peptidase-4 (DPP-4) inhibitors with insulin. Additionally, when metformin is no longer a treatment option, as in the case of patients with severe renal impairment, insulin is often used as monotherapy, with little evidence of benefit in maintaining other OADs. In this specific situation, it is also of interest to evaluate the potential benefit of combined treatment with a DPP-4 inhibitor and insulin. Among the classic limitations of insulin therapy in patients with T2DM, hypoglycemia remains a major barrier to glycemic control, along with weight gain exacerbation. The oral DPP-4 inhibitors improve glycemic control by increasing the sensitivity of the islet cells to glucose, and thus are not associated with an increased risk for hypoglycemia and are weight neutral. In addition to the expected benefits associated with limiting insulin dose and regimen complexity, the specific advantages the DPP-4 inhibitor drug class on hypoglycemia and weight gain could justify combining DPP-4 inhibitors with insulin; additionally, a DPP-4 inhibitor may be of special value to decrease glycemic excursions that are not properly addressed by basal insulin therapy and metformin use, even after optimizing titration of the basal insulin. However, given the common original perception that treatment with DPP-4 inhibitors may be less beneficial with increasing disease progression because of the loss of β-cell function, the potential relevance of these agents in the setting of advanced T2DM treated with insulin was not necessarily anticipated. Promising data from studies on the use of these new agents in insulin-treated patients with T2DM have started to emerge. Our article provides a comprehensive overview of the currently available evidence from controlled randomized clinical trials and we discuss the potential role of DPP-4 inhibitors in the this setting. Further clinical experience will allow to fully assess the positioning of these agents in insulin-treated T2DM populations.

Profile of vildagliptin in type 2 diabetes: efficacy, safety, and patient acceptability

Vildagliptin is a selective and potent dipeptidyl peptidase-4 inhibitor that improves glycemic control by inhibiting the degradation of both endogenous glucagon-like peptide-1 and glucose-dependent insulinotropic peptide. This article is a comprehensive review of the safety and efficacy of vildagliptin in patients with type 2 diabetes. Clinical evidence has proven that it effectively decreases hemoglobin A_1c with a low risk of hypoglycemia and is weight neutral. The addition of vildagliptin to metformin improves glucose control and significantly reduces gastrointestinal adverse events, particularly in patients inadequately controlled with metformin monotherapy. Its long-term advantages include preservation of β-cell function, reduction in total cholesterol, decrease in fasting lipolysis in adipose tissue, and triglyceride storage in non-fat tissues. Vildagliptin is well tolerated with a low incidence of AEs, and it does not increase the risk of cardiovascular/cerebrovascular (CCV) events. It can be taken before or after meals, and has little drug interaction, thus it will be well accepted.

Effects of vildagliptin (Galvus®) therapy in patients with type 2 diabetes mellitus after heart transplantation

Background

Type 2 Diabetes mellitus (T2DM) is a common comorbidity in patients after heart transplantation (HTx) and is associated with adverse long-term outcomes.

Methods

The retrospective study reported here analyzed the effects of vildagliptin therapy in stable patients post-HTx with T2DM and compared these with control patients for matched-pairs analysis. A total of 30 stable patients post-HTx with T2DM were included in the study. Fifteen patients (mean age 58.6 ± 6.0 years, mean time post-HTx 4.9 ± 5.3 years, twelve male and three female) were included in the vildagliptin group (VG) and 15 patients were included in the control group (CG) (mean age 61.2 ± 8.3 years, mean time post-HTx 7.2 ± 6.6 years, all male).

Results

Mean glycated hemoglobin (HbA_1c) in the VG was 7.4% ± 0.7% before versus 6.8% ± 0.8% after 8 months of vildagliptin therapy (P = 0.002 vs baseline). In the CG, HbA_1c was 7.0% ± 0.7% versus 7.3% ± 1.2% at follow-up (P = 0.21). Additionally, there was a significant reduction in mean blood glucose in the VG, from 165.0 ± 18.8 mg/dL to 147.9 ± 22.7 mg/dL (P = 0.002 vs baseline), whereas mean blood glucose increased slightly in the CG from 154.7 ± 19.7 mg/dL to 162.6 ± 35.0 mg/dL (P = 0.21). No statistically significant changes in body weight (from 83.3 ± 10.8 kg to 82.0 ± 10.9 kg, P = 0.20), total cholesterol (1.5%, P = 0.68), or triglyceride levels (8.0%, P = 0.65) were seen in the VG. No significant changes in immunosuppressive drug levels or dosages were observed in either group.

Conclusion

Vildagliptin therapy significantly reduced HbA_1c and mean blood glucose levels in post-HTx patients in this study with T2DM and did not have any negative effects on lipid profile or body weight. Thus, vildagliptin therapy presented an interesting therapeutic approach for this selected patient cohort.

Improved glycaemic control with vildagliptin added to insulin, with or without metformin, in patients with type 2 diabetes mellitus

AIM

The aim of this study is to assess the efficacy and safety of vildagliptin 50 mg bid as add-on therapy to insulin in type 2 diabetes mellitus (T2DM).

METHODS

This is a multicentre, double-blind, placebo-controlled, parallel group, clinical trial in T2DM patients inadequately controlled by stable insulin therapy, with or without metformin. Patients received treatment with vildagliptin 50 mg bid or placebo for 24 weeks.

RESULTS

In all, 449 patients were randomized to vildagliptin (n = 228) or placebo (n = 221). After 24 weeks, the difference in adjusted mean change in haemoglobin A1c (HbA1c) between vildagliptin and placebo was -0.7 ± 0.1% (p < 0.001) in the overall study population, -0.6 ± 0.1% (p < 0.001) in the subgroup also receiving metformin and -0.8 ± 0.2% (p < 0.001) in the subgroup without metformin. Vildagliptin therapy was well tolerated and had a similarly low incidence of hypoglycaemia compared with placebo (8.4 vs. 7.2%, p = 0.66) in spite of improved glycaemic control, and was not associated with weight gain. (+0.1 vs. -0.4 kg).

CONCLUSIONS

Vildagliptin 50 mg bid added to insulin significantly reduced HbA1c in patients with T2DM inadequately controlled by insulin, with or without metformin. Vildagliptin was well tolerated, with a safety profile similar to placebo. These results were achieved without weight gain or an increase in hypoglycaemia incidence or severity in spite of improved glycaemic control.

Clinical evidence and mechanistic basis for vildagliptin's effect in combination with insulin

Due to the progressive nature of type 2 diabetes, many patients need insulin as add-on to oral antidiabetic drugs (OADs) in order to maintain adequate glycemic control. Insulin therapy primarily targets elevated fasting glycemia but is less effective to reduce postprandial hyperglycemia. In addition, the risk of hypoglycemia limits its effectiveness and there is a concern of weight gain. These drawbacks may be overcome by combining insulin with incretin-based therapies as these increase glucose sensitivity of both the α- and β-cells, resulting in improved postprandial glycemia without the hypoglycemia and weight gain associated with increasing the dose of insulin. The dipeptidyl peptidase-IV (DPP-4) inhibitor vildagliptin has also been shown to protect from hypoglycemia by enhancing glucagon counterregulation. The effectiveness of combining vildagliptin with insulin was demonstrated in three different studies in which vildagliptin decreased A1C levels when added to insulin therapy without increasing hypoglycemia. This was established with and without concomitant metformin therapy. Furthermore, the effectiveness of vildagliptin appears to be greater when insulin is used as a basal regimen as opposed to being used to reduce postprandial hyperglycemia, since improvement in insulin secretion likely plays a minor role when relatively high doses of insulin are administered before meals. This article reviews the clinical experience with the combination of vildagliptin and insulin and discusses the mechanistic basis for the beneficial effects of the combination. The data support the use of vildagliptin in combination with insulin in general and, in line with emerging clinical practice, suggest that treating patients with vildagliptin, metformin, and basal insulin could be an attractive therapeutic option.

Predictive clinical parameters and glycemic efficacy of vildagliptin treatment in korean subjects with type 2 diabetes

BACKGROUND

The aims of this study are to investigate the glycemic efficacy and predictive parameters of vildagliptin therapy in Korean subjects with type 2 diabetes.

METHODS

In this retrospective study, we retrieved data for subjects who were on twice-daily 50 mg vildagliptin for at least 6 months, and classified the subjects into five treatment groups. In three of the groups, we added vildagliptin to their existing medication regimen; in the other two groups, we replaced one of their existing medications with vildagliptin. We then analyzed the changes in glucose parameters and clinical characteristics.

RESULTS

Ultimately, 327 subjects were analyzed in this study. Vildagliptin significantly improved hemoglobin A1c (HbA1c) levels over 6 months. The changes in HbA1c levels (ΔHbA1c) at month 6 were -2.24% (P=0.000), -0.77% (P=0.000), -0.80% (P=0.001), -0.61% (P=0.000), and -0.34% (P=0.025) for groups 1, 2, 3, 4, and 5, respectively, with significance. We also found significant decrements in fasting plasma glucose levels in groups 1, 2, 3, and 4 (P<0.05). Of the variables, initial HbA1c levels (P=0.032) and history of sulfonylurea use (P=0.026) were independently associated with responsiveness to vildagliptin treatment.

CONCLUSION

Vildagliptin was effective when it was used in subjects with poor glycemic control. It controlled fasting plasma glucose levels as well as sulfonylurea treatment in Korean type 2 diabetic subjects.

One-year safety, tolerability and efficacy of vildagliptin in patients with type 2 diabetes and moderate or severe renal impairment

AIM

Assess long-term safety and efficacy of the dipeptidlyl peptidase-4 (DPP-4) inhibitor vildagliptin in 369 patients with type 2 diabetes mellitus (T2DM) and moderate or severe renal impairment (RI).

METHODS

Double-blind, randomized, parallel-group, 52-week clinical trial comparing safety and efficacy of vildagliptin (50 mg qd, n = 216) and placebo (n = 153) added to ongoing stable antihyperglycaemic treatment, in patients with T2DM and moderate or severe (glomerular filtration rate [GFR] ≥ 30 to <50 ml/min/1.73 m(2) and < 30 ml/min/1.73 m(2) ) RI.

RESULTS

The study population comprised 122 and 89 patients with moderate RI and 94 and 64 patients with severe RI randomized to vildagliptin and placebo, respectively, with the majority of patients receiving background insulin therapy (72% and 82% for moderate and severe RI, respectively). After 1 year, the between-treatment difference in adjusted mean change in A1C was -0.4 ± 0.2% (p = 0.005) in moderate RI (baseline = 7.8%) and -0.7 ± 0.2% (p < 0.0001) in severe RI (baseline = 7.6%). In patients with moderate RI, similar proportions of patients experienced any adverse event (AE) (84 vs. 85%), any serious adverse event (SAE) (21 vs. 19%), any AE leading to discontinuation (5% vs. 6%) and death (1% vs. 0%) with vildagliptin and placebo, respectively. This was also true for patients with severe RI: AEs (85% vs. 88%), SAEs (25% vs. 25%), AEs leading to discontinuation (10% vs. 6%) and death (3% vs. 2%).

CONCLUSIONS

In patients with T2DM and moderate or severe RI, vildagliptin added to ongoing antidiabetic therapy had a safety profile similar to placebo during 1-year observation. Furthermore, relative to placebo, a clinically significant decrease in A1C was maintained throughout 1-year treatment with vildagliptin.

Incretin-based therapy in combination with basal insulin: a promising tactic for the treatment of type 2 diabetes

Incretin therapies such as dipeptidyl peptidase-4 inhibitors (DPP-4Is) and GLP-1 receptor agonists (GLP-1RAs) have become well-established treatments for type 2 diabetes. Both drug classes reduce blood glucose through physiological pathways mediated by the GLP-1 receptor, resulting in glucose-dependent enhancement of residual insulin secretion and inhibition of glucagon secretion. In addition, the GLP-1RAs reduce gastrointestinal motility and appear to have appetite-suppressing actions and, so, are often able to produce clinically useful weight loss. The glucose-dependency of their glucagon-inhibiting and insulin-enhancing effects, together with their weight-sparing properties, make the incretin therapies a logical proposition for use in combination with exogenous basal insulin therapy. This combination offers the prospect of an additive or synergistic glucose-lowering effect without a greatly elevated risk of hypoglycaemia compared with insulin monotherapy, and any insulin-associated weight gain might also be mitigated. Furthermore, the incretin therapies can be combined with metformin, which is usually continued when basal insulin is introduced in type 2 diabetes. Although the combination of incretin and insulin therapy is currently not addressed in internationally recognized treatment guidelines, several clinical studies have assessed its use. The data, summarized in this review, are encouraging and show that glycaemic control is improved and weight gain is limited or reversed (especially with the combined use of GLP-1RAs and basal insulin), and that the use of an incretin therapy can also greatly reduce insulin dose requirements. The addition of basal insulin to established incretin therapy is straightforward, but insulin dose adjustment (though not discontinuation) is usually necessary if the sequence is reversed.

Glimepiride: evidence-based facts, trends, and observations (GIFTS). [corrected]

Type 2 diabetes mellitus is characterized by insulin resistance and progressive β cell failure; therefore, β cell secretagogues are useful for achieving sufficient glycemic control. Glimepiride is a second-generation sulfonylurea that stimulates pancreatic β cells to release insulin. Additionally, is has been shown to work via several extra pancreatic mechanisms. It is administered as monotherapy in patients with type 2 diabetes mellitus in whom glycemic control is not achieved by dietary and lifestyle modifications. It can also be combined with other antihyperglycemic agents, including metformin and insulin, in patients who are not adequately controlled by sulfonylureas alone. The effective dosage range is 1 to 8 mg/day; however, there is no significant difference between 4 and 8 mg/day, but it should be used with caution in the elderly and in patients with renal or hepatic disease. In clinical studies, glimepiride was generally associated with lower risk of hypoglycemia and less weight gain compared to other sulfonylureas. Glimepiride use may be safer in patients with cardiovascular disease because of its lack of detrimental effects on ischemic preconditioning. It is effective in reducing fasting plasma glucose, post-prandial glucose, and glycosylated hemoglobin levels and is a useful, cost-effective treatment option for managing type 2 diabetes mellitus.

The incretin hormones: from scientific discovery to practical therapeutics

The incretins are gut hormones secreted in response to nutrient/carbohydrate ingestion and act on the pancreatic beta cell to amplify glucose-stimulated insulin secretion. Incretin hormone-based treatments for patients with type 2 diabetes represent a major advance in diabetes therapeutics. The ability of the incretin agents (glucagon-like peptide 1 [GLP-1] agonists and dipeptidyl peptidase IV [DPP-4] inhibitors) to improve glycaemia with a low associated risk of hypoglycaemia, together with beneficial/neutral effects on body weight, offers a significant advantage for both patients and treating clinicians. In this edition of 'Then and Now,' it is useful to look back 25 years and reflect upon the developments in this field since Nauck and colleagues published two seminal papers. In 1986 they first documented a reduced incretin effect in patients with type 2 diabetes (Diabetologia 29:46-52), and then in 1993 they demonstrated that, in patients with poorly controlled type 2 diabetes, a single exogenous infusion of an incretin (GLP-1) increased insulin levels in a glucose-dependent manner and normalised fasting hyperglycaemia (Diabetologia 36:741-744). In the ensuing 26 years, progress in the field of incretin hormones has resulted in a greater understanding of the relative roles of GLP-1 and glucose-dependent insulinotropic polypeptide secretion and activity in the pathogenesis of type 2 diabetes and the important recognition that native GLP-1 is quickly degraded by the ubiquitous protease DPP-4. This has led to the development of GLP-1 agonists that are resistant to degradation by DPP-4 and of selective inhibitors of DPP-4 activity as therapeutic agents. GLP-1 agonists (exenatide and liraglutide) and DPP-4 inhibitors (sitagliptin, vildagliptin, saxagliptin and linagliptin) currently represent effective treatment options for patients with type 2 diabetes. Several additional agents are in the pipeline, including longer acting DPP-4-resistant GLP-1 agonists. More exciting, however, is the increasing recognition that the incretin agents have numerous extra-glycaemic effects that could translate into potential cardiovascular and other benefits.

Shadow of diabetes over cardiovascular disease: comparative quantification of population-attributable all-cause and cardiovascular mortality

BACKGROUND

We contrasted impacts on all-cause and cardiovascular disease (CVD) mortality of diabetes vs. CVD.

METHODS

Among participants the Tehran lipid and glucose study aged ≥ 30 years (n = 9752), we selected those who participated in the follow-up study until 20 March 2009 (n = 8795). Complete data on covariate were available for 8, 469 participants, contributing to a 67935 person-year follow up. In the analysis of outcomes (all-cause and CVD mortality), diabetes and CVD were assessed using Cox proportional hazard regression model adjusting for established CVD risk factors. We used population attributable hazard fraction (PAHF) and rate advancement period (RAP) that expresses how much sooner a given mortality rate is reached among exposed than among unexposed individuals.

RESULTS

Ten percent of the participants self-reported to have pervious CVD, and diabetes was ascertained in 17% of participants at baseline examination. During a median follow-up of 9 years 386 participants died of which 184 were due to CVD. All-cause and CVD mortality rate (95% CIs) were 5.5 (5.0-6.1) and 2.6 (2.3-3.0) per 1000 person-year, respectively. The PAHF of all-cause mortality for diabetes 9.2 (7.3-11.1) was greater than the one for CVD 3.5 (1.1-5.5). RAP estimates for all-cause mortality associated with diabetes ranged from 7.4 to 8.6 years whereas the RAP estimates for all-cause mortality associated with CVD ranged from 3.1 to 4.3 years. The PAHF of CVD mortality for diabetes 9.4 (6.8-12.0) was greater than the one for CVD 4.5 (1.8-7.0). RAP estimates for CVD mortality associated with diabetes ranged from 8.2 to 9.8 years whereas the RAP estimates for CVD mortality associated with CVD ranged from 4.7 to 6.7 years.

CONCLUSIONS

We demonstrated that diabetes, which was shown to be keeping pace with prevalent CVD in terms of conferring excess risk of incident CVD, is currently causing more deaths in the population than does CVD.

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 and preservation of pancreatic islet-cell function: a critical appraisal of the evidence

Type 2 diabetes mellitus (T2DM) develops as a consequence of progressive β-cell dysfunction in the presence of insulin resistance. None of the currently-available T2DM therapies is able to change the course of the disease by halting the relentless decline in pancreatic islet cell function. Recently, dipeptidyl peptidase (DPP)-4 inhibitors, or incretin enhancers, have been introduced in the treatment of T2DM. This class of glucose-lowering agents enhances endogenous glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) levels by blocking the incretin-degrading enzyme DPP-4. DPP-4 inhibitors may restore the deranged islet-cell balance in T2DM, by stimulating meal-related insulin secretion and by decreasing postprandial glucagon levels. Moreover, in rodent studies, DPP-4 inhibitors demonstrated beneficial effects on (functional) β-cell mass and pancreatic insulin content. Studies in humans with T2DM have indicated improvement of islet-cell function, both in the fasted state and under postprandial conditions and these beneficial effects were sustained in studies with a duration up to 2 years. However, there is at present no evidence in humans to suggest that DPP-4 inhibitors have durable effects on β-cell function after cessation of therapy. Long-term, large-sized trials using an active blood glucose lowering comparator followed by a sufficiently long washout period after discontinuation of the study drug are needed to assess whether DPP-4 inhibitors may durably preserve pancreatic islet-cell function in patients with T2DM.

Comparison of vildagliptin-metformin and glimepiride-metformin treatments in type 2 diabetic patients

BACKGROUND

The present study investigated the efficacy and safety of vildagliptin-metformin treatment compared to those of glimepiride-metformin treatment for type 2 diabetes.

METHODS

In a randomized, open-label, comparative study, 106 patients with type 2 diabetes were enrolled. The primary endpoint was a reduction in HbA1c from baseline and secondary endpoints included fasting plasma glucose (FPG) or 2-hour postprandial glucose (2h-PPG) reduction from baseline, as well as HbA1c responder rate and HbA1c reduction according to baseline HbA1c category.

RESULTS

Comparable HbA1c reduction was observed with a mean±standard deviation change from baseline to the 32-week endpoint of -0.94±1.15% in the vildagliptin group and -1.00±1.32% in the glimepiride group. A similar reduction in 2h-PPG (vildagliptin group 3.53±4.11 mmol/L vs. the glimepiride group 3.72±4.17 mmol/L) was demonstrated, and the decrements in FPG (vildagliptin group 1.54±2.41 mmol/L vs. glimepiride group 2.16±2.51 mmol/L) were not different between groups. The proportion of patients who achieved an HbA1c less than 7% at week 32 was 50.1% in the vildagliptin group and 56.0% in the glimepiride group. An average body weight gain of 2.53±1.21 kg in the glimepiride group was observed in contrast with the 0.23±0.69 kg weight gain noted in the vildagliptin group. A 10-fold lower incidence of hypoglycemia was demonstrated in the vildagliptin group, in addition to an absence of severe hypoglycemia.

CONCLUSION

Vildagliptin-metformin treatment provided blood glucose control efficacy comparable to that of glimepiride-metformin treatment and resulted in better adverse event profiles with lower risks of hypoglycemia and weight gain.

Mechanisms of action of the dipeptidyl peptidase-4 inhibitor vildagliptin in humans

Inhibition of dipeptidyl peptidase-4 (DPP-4) by vildagliptin prevents degradation of glucagon-like peptide-1 (GLP-1) and reduces glycaemia in patients with type 2 diabetes mellitus, with low risk for hypoglycaemia and no weight gain. Vildagliptin binds covalently to the catalytic site of DPP-4, eliciting prolonged enzyme inhibition. This raises intact GLP-1 levels, both after meal ingestion and in the fasting state. Vildagliptin has been shown to stimulate insulin secretion and inhibit glucagon secretion in a glucose-dependent manner. At hypoglycaemic levels, the counterregulatory glucagon response is enhanced relative to baseline by vildagliptin. Vildagliptin also inhibits hepatic glucose production, mainly through changes in islet hormone secretion, and improves insulin sensitivity, as determined with a variety of methods. These effects underlie the improved glycaemia with low risk for hypoglycaemia. Vildagliptin also suppresses postprandial triglyceride (TG)-rich lipoprotein levels after ingestion of a fat-rich meal and reduces fasting lipolysis, suggesting inhibition of fat absorption and reduced TG stores in non-fat tissues. The large body of knowledge on vildagliptin regarding enzyme binding, incretin and islet hormone secretion and glucose and lipid metabolism is summarized, with discussion of the integrated mechanisms and comparison with other DPP-4 inhibitors and GLP-1 receptor activators, where appropriate.

Emerging role of insulin with incretin therapies for management of type 2 diabetes

Type 2 diabetes mellitus (T2DM) is a progressive disease warranting intensification of treatment, as beta-cell function declines over time. Current treatment algorithms recommend metformin as the first-line agent, while advocating the addition of either basal-bolus or premixed insulin as the final level of intervention. Incretin therapy, including incretin mimetics or enhancers, are the latest group of drugs available for treatment of T2DM. These agents act through the incretin axis, are currently recommended as add-on agents either as second-or third-line treatment, without concurrent use of insulin. Given the novel role of incretin therapy in terms of reducing postprandial hyperglycemia, and favorable effects on weight with reduced incidence of hypoglycemia, we explore alternative options for incretin therapy in T2DM management. Furthermore, as some evidence alludes to incretins potentially increasing betacell mass and altering disease progression, we propose introducing these agents earlier in the treatment algorithm. In addition, we suggest the concurrent use of incretins with insulin, given the favorable effects especially in relation to weight gain.

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.

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.

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.

Hormonal and metabolic effects of morning or evening dosing of the dipeptidyl peptidase IV inhibitor vildagliptin in patients with type 2 diabetes

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

Vildagliptin is an orally active, potent inhibitor of dipeptidyl peptidase IV and was developed for the treatment of type 2 diabetes. In clinical trials, once or twice daily dosing with vildagliptin (up to 100 mg day(-1)) has been shown to reduce endogenous glucose production and fasting plasma glucose in patients with type 2 diabetes. The comparative efficacy of vildagliptin under a morning vs. evening dosing regimen has not previously been determined.

WHAT THIS STUDY ADDS

Once daily dosing with vildagliptin 100 mg for 28 days improved glycaemic control in patients with type 2 diabetes independent of whether vildagliptin was administered in the morning or evening. Morning or evening dosing with vildagliptin had similar effects on 24 h glycaemic control and plasma concentrations of the hormones insulin, glucagon and glucagon-like peptide 1.

AIM

This randomized, double-blind, crossover study compared post-prandial hormonal and metabolic effects of vildagliptin, (an oral, potent, selective inhibitor of dipeptidyl peptidase IV [DPP-4]) administered morning or evening in patients with type 2 diabetes.

METHODS

Forty-eight patients were randomized to once daily vildagliptin 100 mg administered before breakfast or before dinner for 28 days then crossed over to the other dosing regimen. Blood was sampled frequently after each dose at baseline (day -1) and on days 28 and 56 to assess pharmacodynamic parameters.

RESULTS

Vildagliptin inhibited DPP-4 activity (>80% for 15.5 h post-dose), and increased active glucagon-like peptide-1 compared with placebo. Both regimens reduced total glucose exposure compared with placebo (area under the 0-24 h effect-time curve [AUE(0,24 h)]: morning -467 mg dl(-1) h, P= 0.014; evening -574 mg dl(-1) h, P= 0.003) with no difference between regimens (P= 0.430). Reductions in daytime glucose exposure (AUE(0,10.5 h)) were similar between regimens. Reduction in night-time exposure (AUE(10.5,24 h) was greater with evening than morning dosing (-336 vs.-218 mg dl(-1) h, P= 0.192). Only evening dosing significantly reduced fasting plasma glucose (-13 mg dl(-1), P= 0.032) compared with placebo. Insulin exposure was greater with evening dosing (evening 407 microU ml(-1) h; morning 354 microU ml(-1) h, P= 0.050).

CONCLUSIONS

Both morning and evening dosing of once daily vildagliptin 100 mg significantly reduced post-prandial glucose in patients with type 2 diabetes; only evening dosing significantly decreased fasting plasma glucose. Although evening dosing with vildagliptin 100 mg tended to decrease night-time glucose exposure more than morning dosing, both regimens were equally effective in reducing 24 h mean glucose exposure (AUE(0,24 h)) in patients with type 2 diabetes.

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.

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).

GLP-1 agonists and dipeptidyl-peptidase IV inhibitors

Novel therapeutic options for type 2 diabetes based on the action of the incretin hormone glucagon-like peptide-1 (GLP-1) were introduced in 2005. Incretin-based therapies consist of two classes: (1) the injectable GLP-1 receptor agonists solely acting on the GLP-1 receptor and (2) dipeptidyl-peptidase inhibitors (DPP-4 inhibitors) as oral medications raising endogenous GLP-1 and other hormone levels by inhibiting the degrading enzyme DPP-4. In type 2 diabetes therapy, incretin-based therapies are attractive and more commonly used due to their action and safety profile. Stimulation of insulin secretion and inhibition of glucagon secretion by the above-mentioned agents occur in a glucose-dependent manner. Therefore, incretin-based therapies have no intrinsic risk for hypoglycemias. GLP-1 receptor agonists allow weight loss; DPP-4 inhibitors are weight neutral. This review gives an overview on the mechanism of action and the substances and clinical data available.

Secretion of glucagon-like peptide-1 (GLP-1) in type 2 diabetes: what is up, what is down?

The incretin hormones gastric inhibitory polypeptide and especially glucagon-like peptide (GLP) have an important physiological function in augmenting postprandial insulin secretion. Since GLP-1 may play a role in the pathophysiology and treatment of type 2 diabetes, assessment of meal-related GLP-1 secretory responses in type 2 diabetic patients vs healthy individuals is of great interest. A common view states that GLP-1 secretion in patients with type 2 diabetes is deficient and that this applies to a lesser degree in individuals with impaired glucose tolerance. Such a deficiency is the rationale for replacing endogenous incretins with GLP-1 receptor agonists or re-normalising active GLP-1 concentrations with dipeptidyl peptidase-4 inhibitors. This review summarises the literature on this topic, including a meta-analysis of published studies on GLP-1 secretion in individuals with and without diabetes after oral glucose and mixed meals. Our analysis does not support the contention of a generalised defect in nutrient-related GLP-1 secretory responses in type 2 diabetes patients. Rather, factors are identified that may determine individual incretin secretory responses and explain some of the variations in published findings of group differences in GLP-1 responses to nutrient intake.