Effects of exenatide (exendin-4) on glycemic control over 30 weeks in sulfonylurea-treated patients with type 2 diabetes

A systematic review of the safety of incretin-based therapies in type 2 diabetes

INTRODUCTION

Large randomized clinical trials have demonstrated that incretin-based therapies provide effective glycemic control in type 2 diabetes. Long-term safety assessments are ongoing.

METHODS

This systematic review of incretin-based therapy safety is based on 112 randomized clinical trials of duration ≥26 weeks published between January 2000 and February 2015 in patients with type 2 diabetes.

RESULTS

As expected, hypoglycemia rates were lower with dipeptidyl peptidase-4 inhibitors (DPP-4is) and glucagon-like peptide-1 receptor agonists (GLP-1 RAs) versus other oral antidiabetic drugs and insulin. The most common adverse events were infection and infestation (DPP-4is) and gastrointestinal (GLP-1 RAs). Pancreatitis cases were rare across all studies and, in the SAVOR-TIMI and EXAMINE trials, pancreatitis rates were similar in DPP-4i- and placebo-treated patients. No thyroid tumors were reported, and increased risk of cardiovascular events was not associated with DPP-4is in SAVOR-TIMI and EXAMINE, albeit over a short follow-up period.

CONCLUSIONS

Overall, incretin-based therapies were well tolerated; however, their long-term safety profile should continue to be periodically assessed.

Role of gastrointestinal hormones in feeding behavior and obesity treatment

Food intake regulation is generally evaluated by many aspects consisting of complex mechanisms, including homeostatic regulatory mechanism, which is based on negative feedback, and hedonic regulatory mechanism, which is driven by a reward system. One important aspect of food intake regulation is the peripheral hormones that are secreted from the gastrointestinal tract. These hormones are secreted from enteroendocrine cells as feedback to nutrient and energy intake, and will communicate with the brain directly or via the vagus nerve. Gastrointestinal hormones are very crucial in maintaining a steady body weight, despite variations in nutrient intake and energy expenditure. In this review, we provide an overview of the regulation of feeding behavior by gut hormones, and its role in obesity treatments.

Treatment potential of the GLP-1 receptor agonists in type 2 diabetes mellitus: a review

Over the last decade, the discovery of glucagon-like peptide 1 receptor agonists (GLP-1 RAs) has increased the treatment options for patients with type 2 diabetes mellitus (T2DM). GLP-1 RAs mimic the effects of native GLP-1, which increases insulin secretion, inhibits glucagon secretion, increases satiety and slows gastric emptying. This review evaluates the phase III trials for all approved GLP-1 RAs and reports that all GLP-1 RAs decrease HbA1c, fasting plasma glucose, and lead to a reduction in body weight in the majority of trials. The most common adverse events are nausea and other gastrointestinal discomfort, while hypoglycaemia is rarely reported when GLP-1 RAs not are combined with sulfonylurea or insulin. Treatment options in the near future will include co-formulations of basal insulin and a GLP-1 RA.

The value of short- and long-acting glucagon-like peptide-1 agonists in the management of type 2 diabetes mellitus: experience with exenatide

BACKGROUND

Only about half of patients with type 2 diabetes treated with antihyperglycemic drugs achieve glycemic control (HbA1c <7%), most commonly due to poor treatment adherence. Glucagon-like peptide-1 (GLP-1) receptor agonists act on multiple targets involved in glucose homeostasis and have a low risk of causing hypoglycemia. While GLP-1 receptor (GLP-1R) agonists share the same mechanism of action, clinical profiles of individual agents differ, particularly between short- and long-acting agents. In this article, recent findings regarding the pharmacology of GLP-1 agonists are reviewed, and the clinical effects of short- versus long-acting agents are compared.

DATA SOURCES

Relevant articles were identified through a search of PubMed using the keywords glucagon-like peptide-1, GLP-1, glucagon-like peptide-1 receptor agonist, GLP-1R agonist, and exenatide for publications up to 22 May 2015. Supporting data were obtained from additional searches for albiglutide, dulaglutide, liraglutide and lixisenatide as well as from the bibliographies of key articles.

FINDINGS

Short-acting GLP-1R agonists produce greater reductions in postprandial glucose levels by slowing gastric emptying, whereas long-acting GLP-1R agonists produce greater reductions in fasting blood glucose by stimulating insulin secretion from the pancreas. These characteristics can be exploited to provide individualized treatment to patients. A large body of evidence supports the benefits of short- and long-acting exenatide as add-on therapy in patients with inadequate glycemic control despite maximum tolerated doses of metformin and/or sulfonylurea. Exenatide is generally well tolerated and no new safety concerns were identified during long-term follow-up of up to 5 years. A limitation of this review of short-and long-acting GLP-1 receptor agonists is that it focuses on exenatide rather than all the drugs in this class. However, the focus on a single molecule helps to avoid any confusion that may be introduced as a result of differences in molecular structure and size.

CONCLUSIONS

Short-acting GLP-1R agonists including exenatide are well suited to patients with type 2 diabetes with exaggerated postprandial glucose excursions and for co-administration with basal insulin therapy. Long-acting GLP-1R agonists including once weekly exenatide offer greater convenience and are well suited to patients who require specific control of fasting hyperglycemia.

Hindbrain GLP-1 receptor mediation of cisplatin-induced anorexia and nausea

While chemotherapy-induced nausea and vomiting are clinically controlled in the acute (<24 h) phase following treatment, the anorexia, nausea, fatigue, and other illness-type behaviors during the delayed phase (>24 h) of chemotherapy are largely uncontrolled. As the hindbrain glucagon-like peptide-1 (GLP-1) system contributes to energy balance and mediates aversive and stressful stimuli, here we examine the hypothesis that hindbrain GLP-1 signaling mediates aspects of chemotherapy-induced nausea and reductions in feeding behavior in rats. Specifically, hindbrain GLP-1 receptor (GLP-1R) blockade, via 4th intracerebroventricular (ICV) exendin-(9-39) injections, attenuates the anorexia, body weight reduction, and pica (nausea-induced ingestion of kaolin clay) elicited by cisplatin chemotherapy during the delayed phase (48 h) of chemotherapy-induced nausea. Additionally, the present data provide evidence that the central GLP-1-producing preproglucagon neurons in the nucleus tractus solitarius (NTS) of the caudal brainstem are activated by cisplatin during the delayed phase of chemotherapy-induced nausea, as cisplatin led to a significant increase in c-Fos immunoreactivity in NTS GLP-1-immunoreactive neurons. These data support a growing body of literature suggesting that the central GLP-1 system may be a potential pharmaceutical target for adjunct anti-emetics used to treat the delayed-phase of nausea and emesis, anorexia, and body weight loss that accompany chemotherapy treatments.

Adherence to NICE guidance on glucagon-like peptide-1 receptor agonists among patients with type 2 diabetes mellitus: an evaluation using the Clinical Practice Research Datalink

AIMS

To assess adherence to the UK's National Institute for Health and Care Excellence (NICE) guidelines for initiating and continuing glucagon-like peptide-1 (GLP-1) receptor agonists in patients with type 2 diabetes (T2DM).

RESEARCH DESIGN AND METHODS

A retrospective cohort study of 7133 primary care patients ≥40 years with a first prescription for a GLP-1 receptor agonist following publication of NICE guideline/guidance. Patient characteristics and levels of clinical monitoring were assessed using descriptive analyses.

MAIN OUTCOME MEASURES

Main outcomes were the proportion of patients initiating GLP-1 receptor agonists as part of NICE-recommended dual- or triple-therapy regimens; the proportions meeting NICE triple therapy initiation criteria (glycosylated hemoglobin [HbA1c] ≥7.5% and body mass index [BMI] ≥35 kg/m(2)) and the proportions continuing GLP-1 receptor agonist at 6 months according to NICE recommendations.

RESULTS

Mean age at initiating GLP-1 receptor agonists was 58.2 years (SD 9.4), BMI 38.4 kg/m(2) (SD 6.8) and HbA1c 9.2% (SD 3.2%). Overall, only 25% of patients initiated GLP-1 receptor agonists as part of a NICE-recommended regimen. Of patients initiated on a recommended triple-therapy regimen, 50% (646/1284) fulfilled both NICE HbA1c and BMI initiation criteria. Approximately 18% (32/174) of patients continuing NICE-recommended dual therapy at 6 months achieved a 1% reduction in HbA1c and 6.4% (33/515) continuing with NICE-recommended triple therapy achieved NICE's target reductions for both HbA1c and body weight. About 8% of patients continuing exenatide as triple therapy (N = 243) achieved both targets.

CONCLUSIONS

Adherence to NICE guidance for initiating and continuing GLP-1 receptor agonists is low. However, lack of data on ethnicity (for assessing NICE's BMI criteria) and on contraindications and/or hypersensitivity to other diabetes medication in the treatment pathway have limited our ability to fully assess adherence to GLP-1 prescribing. Further research is warranted to better understand general practitioners' prescribing decisions given the cost of prescribing GLP-1 receptor agonists.

Chemical Conjugation of Evans Blue Derivative: A Strategy to Develop Long-Acting Therapeutics through Albumin Binding

The efficacy of therapeutic drugs is highly dependent on their optimal in vivo pharmacokinetics. Albumin conjugation is considered to be one of the most effective means of protracting the short lifespan of peptides and proteins. In this study, we proposed a novel platform for developing long lasting therapeutics by conjugating a small molecular albumin binding moiety, truncated Evans blue, to either peptides or proteins. Using the anti-diabetic peptide drug Exendin-4 as a model peptide, we synthesized a new long-acting Exendin-4 derivative (denoted as Abextide). Through complexation with albumin in situ, the biological half-life of Abextide was significantly extended. The hypoglycemic effect of Abextide was also improved remarkably over Exendin-4. Thus, Abextide has considerable potential to treat type 2 diabetes. This strategy as a general technology platform can be applied to other small molecules and biologics for the development of long-acting therapeutic drugs.

Liraglutide Versus Exenatide Once Weekly: Persistence, Adherence, and Early Discontinuation

PURPOSE

This study examines real-world, evidence-based comparisons of persistence and adherence to daily versus weekly glucagon-like peptide 1 (GLP-1) receptor agonists for the treatment of type 2 diabetes (T2D).

METHODS

This retrospective observational study used U.S. insurance claims data to compare persistence and adherence to GLP-1 receptor agonists in patients with T2D initiating once weekly (QW) exenatide or daily liraglutide over a 6-month follow-up period. Eligible patients had ≥2 diagnoses of T2D, were 18 years of age or older, initiated a new prescription of either the index drug between February 1, 2012 (market availability launch date of exenatide QW) and March 31, 2013, and had ≥6 months continuous eligibility in the pre- and postindex periods. A 1:1 propensity score match was used to account for selection bias. Outcome measures included persistence as measured by the percentage of patients who continued to take the index drug over an index period of 182 days with an allowable gap of 60 days and adherence as measured by the proportion of days covered (PDC). The percentage of patients achieving PDC ≥0.8 and ≥0.9 was also calculated.

FINDINGS

There were no significant differences between baseline characteristics after propensity score matching. Each matched cohort included 12,306 patients. The overall persistence observed with liraglutide was 66% compared with 63% for exenatide QW. The mean (SD) PDC adherence during the 6-month follow-up period was 0.694 (0.309) for the exenatide QW cohort and 0.689 (0.286) for the liraglutide cohort. The PDC threshold of ≥0.8 during the 6-month follow-up period was met by 6309 (51%) and 5820 (47%) patients in the exenatide QW and liraglutide cohorts, respectively. For the exenatide QW cohort, 76% of patients treated previously with BID exenatide continued treatment in the 6-month follow-up period compared with 59% who were not previously treated with exenatide BID. For the liraglutide cohort, 77% of previous exenatide BID patients continued treatment versus 63% of patients who were not previously treated with exenatide BID.

IMPLICATIONS

These results reveal slight differences in persistence and adherence rates in patients receiving exenatide QW versus patients receiving liraglutide daily that vary by outcome and previous incretin-based therapy used. Differences may be due to dosing device differences for exenatide QW and liraglutide, which, in the case of liraglutide, allows the opportunity for daily self-titration dosing. Implications of these findings for clinical practice are that persistence is determined by the broader context of treatment and medications being used and should be considered when prescribing GLP-1 receptor agonists.

Characterization of Patients with Type 2 Diabetes according to Body Mass Index: Korea National Health and Nutrition Examination Survey from 2007 to 2011

BACKGROUND

The present study aimed to investigate the clinical characteristics of type 2 diabetes mellitus (T2DM) in Korean adults according to body mass index (BMI) and to analyze the association with cardiovascular disease (CVD).

METHODS

We conducted a cross-sectional study of data from the Korea National Health and Nutrition Examination Survey from 2007 to 2011. A total of 3,370 patients with T2DM were divided into categories according to BMI. We conducted a comparison of the T2DM patient population composition by BMI category between different countries. We investigated the prevalence of awareness, treatment, and target control of T2DM according to BMI.

RESULTS

Patients with T2DM had a higher BMI, and were more likely to have a history of CVD than healthy controls. For Korean adults with T2DM, 8% had BMI ≥30 kg/m². By contrast, the population of patients with T2DM and BMI ≥30 kg/m² was 72% in patients in the USA and 56% in the UK. The rate of recognition, treatment, and control has worsened in parallel with increasing BMI. Even in patients with BMI 25 to 29.9 kg/m², the prevalence of CVD or high risk factors for CVD was significantly higher than in patients with BMI 18.5 to 22.9 kg/m² (odds ratio, 2.07).

CONCLUSION

Korean patients with T2DM had lower BMI than those in Western countries. Higher BMI was associated with lower awareness, treatment, and control of diabetes, and a positive association was observed between CVD or high risk factors for CVD and BMI, even for patients who were overweight but not obese.

Exendin-4 promotes extracellular-superoxide dismutase expression in A549 cells through DNA demethylation

Exendin-4 is an agonist of the glucagon-like peptide 1 receptor (GLP-1R) and is used in the treatment of type 2 diabetes. Since human GLP-1R has been identified in various cells besides pancreatic cells, exendin-4 is expected to exert extrapancreatic actions. It has also been suggested to affect gene expression through epigenetic regulation, such as DNA methylation and/or histone modifications. Furthermore, the expression of extracellular-superoxide dismutase (EC-SOD), a major SOD isozyme that is crucially involved in redox homeostasis, is regulated by epigenetic factors. In the present study, we demonstrated that exendin-4 induced the demethylation of DNA in A549 cells, which, in turn, affected the expression of EC-SOD. Our results showed that the treatment with exendin-4 up-regulated the expression of EC-SOD through GLP-1R and demethylated some methyl-CpG sites (methylated cytosine at 5'-CG-3') in the EC-SOD gene. Moreover, the treatment with exendin-4 inactivated DNA methyltransferases (DNMTs), but did not change their expression levels. In conclusion, the results of the present study demonstrated for the first time that exendin-4 regulated the expression of EC-SOD by reducing the activity of DNMTs and demethylation of DNA within the EC-SOD promoter region in A549 cells.

Dapagliflozin combination therapy in type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is a progressive disease, and most patients ultimately require two or more antidiabetes drugs in addition to lifestyle changes to achieve and maintain glycemic control. Current consensus statements and guidelines recommend metformin as first-line pharmacotherapy for the treatment of T2DM in most patients. When glycemic control cannot be maintained with metformin alone, the sequential, stepwise addition of other agents is recommended. Agents such as thiazolidinediones or sulfonylureas have typically been added to metformin therapy. Although effective in reducing glycated hemoglobin, these drugs are often associated with adverse effects, most notably weight gain, and in the case of sulfonylureas, hypoglycemia. Sodium-glucose cotransporter 2 inhibitors, such as dapagliflozin, are the newest class of antidiabetes drugs approved for the treatment of T2DM. Dapagliflozin effectively improves glycemic control by increasing the renal excretion of excess glucose. In clinical trials, dapagliflozin has been well tolerated and has additional benefits of weight loss, low risk of hypoglycemia and reduction in blood pressure. This review discusses the clinical evidence and rationale for the use of dapagliflozin as add-on therapy in T2DM. The results suggest that dapagliflozin add-on therapy is a promising new treatment option for a wide range of patients with T2DM. Results from an ongoing cardiovascular outcomes trial are needed to establish the long-term safety of dapagliflozin.

Ghrelin regulates GLP-1 production through mTOR signaling in L cells

Glucagon-like peptide (GLP-1), an intestinal incretin produced in L-cells and released in response to meal intake, functions to promote insulin secretion and to decrease plasma glucose. Ghrelin is an orexigenic hormone critical for glucose homeostasis. The molecular mechanism by which ghrelin alters GLP-1 production remains largely unknown. Here we showed that ghrelin attenuates GLP-1 production through mTOR signaling. In GHSR1a null mice, ileal mTOR signaling, proglucagon and circulating GLP-1 were significantly increased. Antagonism of the GHSR1a by D-Lys-3-GHRP-6 increased GLP-1 synthesis and release in STC-1 cells. Treatment of STC-1 cells with ghrelin decreased the production of GLP-1. This effect was associated with a significant inhibition of mTOR signaling. Overexpression of ghrelin inhibited proglucagon promoter activity and GLP-1 production. Inhibition of mTOR activity by mTOR siRNA blocked D-Lys-3-GHRP-6 induced GLP-1 production in STC-1 cells. Our results suggest that mTOR signaling mediates the inhibitory effect of ghrelin on GLP-1 production.

GLP-1 Receptor Agonists: Practical Considerations for Clinical Practice

PURPOSE

Type 2 diabetes (T2D) imparts an increased risk of adverse health outcomes in patients unable to achieve glycemic control. Patient education and individualization of treatment are important for effective management of T2D. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are a class of injectable glucose-lowering agents that lower A1C with added benefits of weight loss and improved cardiovascular risk markers. This review discusses the role of GLP-1RAs currently approved in the United States (exenatide, liraglutide, albiglutide, dulaglutide) for T2D management and characterizes the efficacy and safety profiles of individual GLP-1RAs.

CONCLUSIONS

GLP-1RAs are recommended as a preferred add-on agent to existing metformin monotherapy, as first-line therapy if metformin is contraindicated or poorly tolerated, and for use in combination with other oral glucose-lowering agents or basal insulin. Shorter-acting GLP-1RAs (exenatide and liraglutide) offer improved coverage of postprandial hyperglycemia, while longer-acting GLP-1RA formulations (exenatide extended-release, dulaglutide, and albiglutide) further improve fasting plasma glucose, which can result in additional A1C lowering. Reductions in body weight and blood pressure appear similar among individual agents, and small increases in heart rate are of unknown clinical relevance. Gastrointestinal adverse events abate over time with continued treatment and are less frequent with longer-acting GLP-1RAs. Hypoglycemia incidence is low but increased when GLP-1RAs are used with insulin secretagogues or insulin. GLP-1RAs target multiple pathophysiologic mechanisms in patients with T2D and improve glycemic control, although there are some differences within this drug class that may be relevant in clinical practice. Therefore, selection of the most appropriate treatment for individual patients is important.

Optimal glycaemic control in elderly people with type 2 diabetes: what does the evidence say?

The global prevalence of type 2 diabetes mellitus (T2DM) is rising in an ageing population through a combination of lifestyle changes and greater longevity. However, by excluding participants aged over 70 years, most major interventional trials on which current diabetes therapeutic guidelines are based have failed to provide specific evidence to support the prescribed management of diabetes in elderly people. While diabetes per se has a significant impact on the elderly person, the side effects of medications, particularly hypoglycaemia, prevent optimisation of diabetes treatment. Hypoglycaemia is associated with significant morbidity, to which elderly people are often more vulnerable because of factors such as the effects of ageing, progressive renal impairment, frailty, polypharmacy and cognitive decline. T2DM is associated with accelerated cognitive decline in some individuals, and recurrent severe hypoglycaemia has been implicated as a potential contributory factor. Although the evidence for selection of appropriate glycaemic targets in elderly patients is sparse, it is now acknowledged that prevention of hypoglycaemia must influence individualisation of treatment goals in this vulnerable group. This should also be reflected by the choice of anti-diabetes agents that are initiated when diet and lifestyle advice is ineffective. Recently developed international guidelines, which have specifically addressed the management of diabetes in elderly people, highlight the importance of a pragmatic management approach rather than attempting to achieve a generic glycated haemoglobin goal and are summarised in this article.

Comparison Review of Short-Acting and Long-Acting Glucagon-like Peptide-1 Receptor Agonists

Glucagon-like peptide-1 (GLP-1) receptor agonists (GLP-1 RAs) are useful tools for treating type 2 diabetes mellitus. In their recent position statement, the American Diabetes Association and European Association for the Study of Diabetes recommend GLP1-RAs as add-on to metformin when therapeutic goals are not achieved with monotherapy, particularly for patients who wish to avoid weight gain or hypoglycemia. GLP1-RAs differ substantially in their duration of action, frequency of administration and clinical profile. Members of this class approved for clinical use include exenatide twice-daily, exenatide once-weekly, liraglutide and lixisenatide once-daily. Recently, two new once-weekly GLP1-RAs have been approved: dulaglutide and albiglutide. This article summarizes properties of short- and long-acting GLP-1 analogs, and provides useful information to help choose the most appropriate compound for individual patients.

Effects of three injectable antidiabetic agents on glycaemic control, weight change and drop-out in type 2 diabetes suboptimally controlled with metformin and/or a sulfonylurea: A network meta-analysis

AIMS

The objective of this review was to assess glucagon-like peptide-1 receptor agonists (GLP-1 RAs), basal insulin, and premixed insulin among participants with type 2 diabetes inadequately controlled with metformin and/or a sulfonylurea.

METHODS

We searched PubMed, EmBase, and the Cochrane Library to identify eligible randomized controlled trials (RCTs) for a network meta-analysis.

RESULTS

A total of 17 RCTs involving 5874 adult individuals were included. Compared with placebo, all three therapies showed a significant effect on achieving target glycated hemoglobin (HbA1c) (GLP-1 RAs: 31.7%, 95% CI, 24.7-38.6%; premixed insulin: 31.1%, 95% CI, 20.4-41.8%; basal insulin: 26.0%, 95% CI, 16.4-35.7%). However, there was no significant difference between the three therapies. A similar result was found in HbA1c reduction. The use of GLP-1 RAs resulted in significant body weight loss (-3.73 kg, 95% CI, -4.52 to -2.95 kg vs. basal insulin and -5.27 kg, 95% CI, -6.17 to -4.36 kg vs. premixed insulin) but there was a higher drop-out rate of participants. Premixed insulin seemed associated with more severe hypoglycemic episodes.

CONCLUSIONS

The three injectables had similar impact on glycemic control but other differentiating features relevant to the management of type 2 diabetes with GLP-1 RAs having the most favorable profile.

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.

Exenatide twice daily: a review of its use in the management of patients with type 2 diabetes mellitus

Exenatide, administered subcutaneously twice daily (Byetta(®)), is a synthetic version of the natural peptide exendin-4, which is a glucagon-like peptide-1 (GLP-1) receptor agonist (incretin mimetic). Exenatide binds to the GLP-1 receptor with the same affinity as GLP-1, but has a much longer half-life, since it is not degraded by the enzyme dipeptidyl peptidase-4. Exenatide twice daily enhances glucose-dependent insulin secretion, suppresses inappropriately elevated glucagon secretion, slows gastric emptying and reduces caloric intake. In well-designed clinical trials, adjunctive subcutaneous exenatide 5 or 10 μg twice daily for 16-52 weeks significantly and dose-dependently improved glycaemic control and reduced mean body weight compared with placebo in patients with type 2 diabetes inadequately controlled with oral antihyperglycaemic drugs (OADs) and/or basal insulin. The improvements in glycaemic control and reductions in body weight were stably maintained during long-term therapy (up to 3.5 years). The efficacy of adjunctive exenatide twice daily was generally similar to that of basal, prandial or biphasic insulin, sulfonylureas, rosiglitazone and lixisenatide, and less than that of liraglutide, taspoglutide or exenatide once weekly with respect to reductions in glycated haemoglobin. Exenatide twice daily was generally well tolerated; mild to moderate nausea and vomiting, which decreased with time on therapy, were the most common adverse events. In patients not receiving concomitant sulfonylureas or insulin, the incidence of hypoglycaemia was low; when it did occur, it was generally mild in severity. Thus, adjunctive exenatide twice daily is a valuable option in the treatment of type 2 diabetes inadequately controlled with OADs and/or basal insulin.

Recent Trends in Therapeutic Approaches for Diabetes Management: A Comprehensive Update

Diabetes highlights a growing epidemic imposing serious social economic crisis to the countries around the globe. Despite scientific breakthroughs, better healthcare facilities, and improved literacy rate, the disease continues to burden several sections, especially middle and low income countries. The present trends indicate the rise in premature death, posing a major threat to global development. Scientific and technological advances have witnessed the development of newer generation of drugs like sulphonylureas, biguanides, alpha glucosidase inhibitors, and thiazolidinediones with significant efficacy in reducing hyperglycemia. Recent approaches in drug discovery have contributed to the development of new class of therapeutics like Incretin mimetics, Amylin analogues, GIP analogs, Peroxisome proliferator activated receptors, and dipeptidyl peptidase-4 inhibitor as targets for potential drugs in diabetes treatment. Subsequently, the identification and clinical investigation of bioactive substances from plants have revolutionized the research on drug discovery and lead identification for diabetes management. With a focus on the emerging trends, the review article explores the current statistical prevalence of the disease, discussing the benefits and limitations of the commercially available drugs. Additionally, the critical areas in clinical diabetology are discussed, with respect to prospects of statins, nanotechnology, and stem cell technology as next generation therapeutics and why the herbal formulations are consistently popular choice for diabetes medication and management.

Cardiovascular Risk in Diabetes Mellitus: Complication of the Disease or of Antihyperglycemic Medications

Cardiovascular disease is the principal complication and the leading cause of death for patients with diabetes (DM). The efficacy of antihyperglycemic treatments on cardiovascular disease risk remains uncertain. Cardiovascular risk factors are affected by antihyperglycemic medications, as are many intermediate markers of cardiovascular disease. Here we summarize the evidence assessing the cardiovascular effects of antihyperglycemic medications with regard to risk factors, intermediate markers of disease, and clinical outcomes.

Gut Peptides Are Novel Regulators of Intestinal Lipoprotein Secretion: Experimental and Pharmacological Manipulation of Lipoprotein Metabolism

Individuals with metabolic syndrome and frank type 2 diabetes are at increased risk of atherosclerotic cardiovascular disease, partially due to the presence of lipid and lipoprotein abnormalities. In these conditions, the liver and intestine overproduce lipoprotein particles, exacerbating the hyperlipidemia of fasting and postprandial states. Incretin-based, antidiabetes therapies (i.e., glucagon-like peptide [GLP]-1 receptor agonists and dipeptidyl peptidase-4 inhibitors) have proven efficacy for the treatment of hyperglycemia. Evidence is accumulating that these agents also improve fasting and postprandial lipemia, the latter more significantly than the former. In contrast, the gut-derived peptide GLP-2, cosecreted from intestinal L cells with GLP-1, has recently been demonstrated to enhance intestinal lipoprotein release. Understanding the roles of these emerging regulators of intestinal lipoprotein secretion may offer new insights into the regulation of intestinal lipoprotein assembly and secretion and provide new opportunities for devising novel strategies to attenuate hyperlipidemia, with the potential for cardiovascular disease reduction.

The Effect of Glucagon-Like Peptide 1 Receptor Agonists on Weight Loss in Type 2 Diabetes: A Systematic Review and Mixed Treatment Comparison Meta-Analysis

AIMS

To determine the effects of glucagon-like peptide-1 receptor agonists compared with placebo and other anti-diabetic agents on weight loss in overweight or obese patients with type 2 diabetes mellitus.

METHODS

Electronic searches were conducted for randomised controlled trials that compared a glucagon-like peptide-1 receptor agonist therapy at a clinically relevant dose with a comparator treatment (other type 2 diabetes treatment or placebo) in adults with type 2 diabetes and a mean body mass index ≥ 25 kg/m2. Pair-wise meta-analyses and mixed treatment comparisons were conducted to examine the difference in weight change at six months between the glucagon-like peptide-1 receptor agonists and each comparator.

RESULTS

In the mixed treatment comparison (27 trials), the glucagon-like peptide-1 receptor agonists were the most successful in terms of weight loss; exenatide 2 mg/week: -1.62 kg (95% CrI: -2.95 kg, -0.30 kg), exenatide 20 μg: -1.37 kg (95% CI: -222 kg, -0.52 kg), liraglutide 1.2 mg: -1.01 kg (95%CrI: -2.41 kg, 0.38 kg) and liraglutide 1.8 mg: -1.51 kg (95% CI: -2.67 kg, -0.37 kg) compared with placebo. There were no differences between the GLP-1 receptor agonists in terms of weight loss.

CONCLUSIONS

This review provides evidence that glucagon-like peptide-1 receptor agonist therapies are associated with weight loss in overweight or obese patients with type 2 diabetes with no difference in weight loss seen between the different types of GLP-1 receptor agonists assessed.

Review on the effect of glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors for the treatment of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a common liver disease and it represents the hepatic manifestation of metabolic syndrome, which includes type 2 diabetes mellitus (T2DM), dyslipidemia, central obesity and hypertension. Glucagon-like peptide-1 (GLP-1) analogues and dipeptidyl peptidase-4 (DPP-4) inhibitors were widely used to treat T2DM. These agents improve glycemic control, promote weight loss and improve lipid metabolism. Recent studies have demonstrated that the GLP-1 receptor (GLP-1R) is present and functional in human and rat hepatocytes. In this review, we present data from animal researches and human clinical studies that showed GLP-1 analogues and DPP-4 inhibitors can decrease hepatic triglyceride (TG) content and improve hepatic steatosis, although some effects could be a result of improvements in metabolic parameters. Multiple hepatocyte signal transduction pathways and mRNA from key enzymes in fatty acid metabolism appear to be activated by GLP-1 and its analogues. Thus, the data support the need for more rigorous prospective clinical trials to further investigate the potential of incretin therapies to treat patients with NAFLD.

Glucagon-like polypeptide agonists in type 2 diabetes mellitus: efficacy and tolerability, a balance

Glucagon-like polypeptide (GLP-1) receptor agonist treatment has multiple effects on glucose metabolism, supports the β cell, and promotes weight loss. There are now five GLP-1 agonists in clinical use with more in development. GLP-1 treatment typically can induce a lowering of hemoglobin A1c (HbA1c) of 0.5-1.5% over time with weight loss of 2-5%. In some individuals, a progressive loss of weight occurs. There is evidence that GLP-1 therapy opposes the loss of β cells which is a feature of type 2 diabetes. The chief downside of GLP-1 treatment is the gastrointestinal motility disturbance which is one of the modes of action of the hormone; significant nausea, vomiting, and diarrhea may lead to discontinuation of treatment. Although daily injection of GLP-1 agents is successful, the development of extended release preparations allows for injection once weekly, and perhaps much longer in the future. The indication for GLP-1 use is diabetes, but now, liraglutide has been approved for primary treatment of obesity. When oral agents fail to control glucose levels in type 2 diabetes, there is a choice between long-acting insulin and GLP-1 agonists as additional treatments. The lowering of HbA1c by either modality is equivalent in most studies. Patients lose weight with GLP-1 treatment and gain weight on insulin. There is a lower incidence of hypoglycemia with GLP-1 therapy but a much higher incidence of gastrointestinal complaints. Insulin dosing is flexible while GLP-1 agents have historically been administered at fixed dosages. Now, the use of combined long-acting insulin and GLP-1 agonists is promising a major therapeutic change. Combined therapy takes advantage of the benefits of both insulin and GLP-1 agents. Furthermore, direct admixture of both in the same syringe will permit flexible dosing, improvement of glucose levels, and reduction of both hypoglycemia and gastrointestinal side effects.

Clinical use of dipeptidyl peptidase-4 and sodium-glucose cotransporter 2 inhibitors in combination therapy for type 2 diabetes mellitus

OBJECTIVE

To review the efficacy, safety, and tolerability of combination treatment regimens including a dipeptidyl peptidase-4 (DPP-4) inhibitor and/or sodium-glucose cotransporter 2 (SGLT2) inhibitor for type 2 diabetes mellitus (T2DM).

METHODS

Clinical trials of combination therapies including a DPP-4 and/or SGLT2 inhibitor were identified through a PubMed database search. To be included, studies had to have a primary end point of change from baseline to ≥24 weeks in glycated hemoglobin, include ≥1 other oral antidiabetic drug (OAD), and have randomized more than 200 patients. Results were limited to medications approved by the US Food and Drug Administration at the time of the search (March 2015).

RESULTS

A total of 1534 articles for the DPP-4 inhibitor class and 434 articles for the SGLT2 inhibitor class were retrieved from PubMed. Of these, 33 articles from the DPP-4 inhibitor class and 24 articles from the SGLT2 inhibitor class were included for review. In each study, the addition of a DPP-4 or SGLT2 inhibitor as a second or third agent resulted in improved glycemic control versus comparator arms. Reductions in weight or lack of weight gain were consistently observed, as were low rates of hypoglycemic events, particularly when the combination regimen also included metformin. Overall, the pattern of adverse events observed in combination treatment groups was consistent with the known effects of the individual agents.

CONCLUSION

Combination treatment with a DPP-4 and/or SGLT2 inhibitor is an efficacious option for patients with T2DM starting pharmacological therapy, or for patients who have received treatment but require additional glycemic control. Study findings indicate that the underlying mechanisms of action of DPP-4 inhibitors and SGLT2 inhibitors complement a variety of OADs.

Implications of incretin-based therapies on cardiovascular disease

BACKGROUND

Incretin-based therapies offer another treatment option for patients with type 2 diabetes. Agents that provide glycaemic control in addition to attenuating cardiovascular disease (CVD) risk factors are important for diabetes management. This review will focus on the off-target effects of incretin-based therapies on CVD risk factors [body weight, blood pressure (BP), lipid profile and albuminuria], major adverse cardiovascular events (MACE), heart failure (HF) and beta-cell preservation.

METHODS

A literature search was conducted to identify English-language publications for incretin-based therapies evaluating the following off-target end-points: body weight, BP, lipid profile, albuminuria, MACE, HF and beta-cell function. Randomised controlled trials (RCTs) were prioritised as the primary source of information.

RESULTS

Overall, incretin-based therapies have shown beneficial effects on CVD risk factors, and glucagon-like peptide 1 (GLP-1) receptor agonists appear to have a more pronounced effect compared with dipeptidyl peptidase-4 inhibitors. RCTs are being conducted to determine if these positive effects on CVD risk factors translate to a reduction in MACE. To date, these studies have not shown an increase in MACE. A signal of increased hospitalisations for HF was observed with saxagliptin, warranting continued evaluation and vigilance in high-risk patients. In addition, incretin-based therapies have shown positive effects on measures of beta-cell function supporting their durability in the management of diabetes.

CONCLUSIONS

Incretin-based therapies are an important treatment option for patients with type 2 diabetes, offering beneficial effects on CVD risk factors without increasing MACE.

A model of mild hypoglycemia

OBJECTIVE

To investigate the impact associated with mild hypoglycemia among patients with type 2 diabetes (T2DM) in the United States and to identify risk factors among different subpopulations.

METHODS

We performed a literature search to gather available data allowing estimation of rates of mild hypoglycemia. Because risk factors are interdependent, risk factors included in the model were based on those reported within multivariate analyses or judged to be biologically plausible by the medical community. Based on literature search results, we built a mathematical model predicting the rates of mild hypoglycemia in individual patients as a function of the patient's antidiabetic medications, hemoglobin A1c levels, duration of diabetes, kidney function, and body mass index.

RESULTS

We estimated an overall average rate of mild hypoglycemia among US patients with T2DM of 2.2 ± 0.8 events per person per year. Patients taking oral antidiabetic medications only had an average rate of 1.9 ± 0.8 events per person per year. The average rate for all patients taking insulin, including those combining it with other antidiabetic medications, was 4.9 ± 2.0 events per person per year. Mild hypoglycemia rates increased with age, with 80-year-old patients experiencing 1.5 times the risk of 40-year-old patients. Based on published values for direct and indirect medical costs for mild hypoglycemia events, we determined that the economic impact in the US of mild hypoglycemic events is approximately $900 million per year, roughly equal to that of severe hypoglycemic events. One of the key limitations to our model is that it applies to the US population under standard medical care and not to clinical trials and does not include certain known risk factors such as rigorous exercise.

CONCLUSIONS

Understanding the benefit versus risk of glycemic control and hypoglycemia is fundamental to the successful management of patients with T2DM. Our validated hypoglycemia model is an important step in addressing this issue and may be helpful to researchers, clinicians, and payers to determine the patients who are at the highest risk for hypoglycemia, whether a patient is experiencing events at 'higher-than-expected' rates, and the corresponding economic burden.

Glucagon-like peptide 1 receptor agonists and cardiovascular risk in type 2 diabetes: a clinical perspective

Diabetes is associated with the development of premature atherosclerotic disease, including coronary heart disease and acute coronary syndromes. A late consequence of this process is the development of chronic heart failure, which contributes to the increased cardiovascular (CV) morbidity and mortality associated with diabetes. Reduction of cholesterol with statins and intensive blood pressure control significantly reduce vascular events in people with diabetes. Intensive treatment of glycaemia reduces microvascular complications, especially retinopathy and nephropathy, but has only a modest effect in reducing macrovascular complications. Attention has therefore focused on individual antidiabetic drugs or drug classes to determine if these have effects in reducing CV events beyond the reduction of blood glucose. Glucagon-like peptide 1 (GLP-1) receptor agonists are a class of injected therapies that enhance the incretin effect, increasing insulin release from the pancreas and reducing glucagon production. They also have a central effect, increasing satiety, and in routine clinical use are associated with reductions in body weight. Another possibly beneficial effect of these drugs is a slight but significant reduction in systolic blood pressure. Data from cohort studies have indicated no increase in CV events with GLP-1 receptor agonists, and perhaps some reductions in CV events. The safety and possible CV benefit of these drugs is now being tested in large, multicentre, randomized, placebo-controlled trials.

Effects of vildagliptin versus sitagliptin, on cardiac function, heart rate variability and mitochondrial function in obese insulin-resistant rats

BACKGROUND AND PURPOSE

Long-term high-fat diet (HFD) consumption has been shown to cause insulin resistance, which is characterized by hyperinsulinaemia with metabolic inflexibility. Insulin resistance is associated with cardiac sympathovagal imbalance, cardiac dysfunction and cardiac mitochondrial dysfunction. Dipeptidyl peptidase-4 (DPP-4) inhibitors, vildagliptin and sitagliptin, are oral anti-diabetic drugs often prescribed in patients with cardiovascular disease. Therefore, in this study, we sought to determine the effects of vildagliptin and sitagliptin in a murine model of insulin resistance.

EXPERIMENTAL APPROACH

Male Wistar rats weighing 180-200 g, were fed either a normal diet (20% energy from fat) or a HFD (59% energy from fat) for 12 weeks. These rats were then divided into three subgroups to receive vildagliptin (3 mg·kg(-1)·day(-1)), sitagliptin (30 mg·kg(-1)·day(-1)) or vehicle for another 21 days. Metabolic parameters, oxidative stress, heart rate variability (HRV), cardiac function and cardiac mitochondrial function were determined.

KEY RESULTS

Rats that received HFD developed insulin resistance characterized by increased body weight, plasma insulin, total cholesterol and oxidative stress levels along with a decreased high-density lipoprotein (HDL) level. Moreover, cardiac dysfunction, depressed HRV, cardiac mitochondrial dysfunction and cardiac mitochondrial morphology changes were observed in HFD rats. Both vildagliptin and sitagliptin decreased plasma insulin, total cholesterol and oxidative stress as well as increased HDL level. Furthermore, vildagliptin and sitagliptin attenuated cardiac dysfunction, prevented cardiac mitochondrial dysfunction and completely restored HRV.

CONCLUSIONS AND IMPLICATIONS

Both vildagliptin and sitagliptin share similar efficacy in cardioprotection in obese insulin-resistant rats.

Pharmacologic Treatment of Type 2 Diabetes

Objective: To review the oral and injectable pharmacologic treatment options for type 2 diabetes. Data Sources: A literature search was conducted using PubMed electronic database for studies published in English between 1993 and September 2014. Search terms included diabetes mellitus, type 2 diabetes, and the individual name for each antidiabetic medication reviewed. In addition, manual searches were performed for cross-references from publications. Package inserts, United States Food and Drug Administration (FDA) Web site, Institute for Safe Medication Practices Web site, American Diabetes Association Web site and scientific session poster presentations, and individual drug company Web pages were also reviewed. Study Selection and Data Extraction: This review focused on information elucidated over the past 10 years to assist prescribers in choosing optimal therapy based on individual patient characteristics. Studies leading to the approval of or raising safety concerns for the antidiabetic medications reviewed in this article were included. Data Synthesis: In the past 10 years, there have been 4 novel oral antidiabetic medication classes and 10 new injectable agents and insulin products approved by the FDA for the treatment of type 2 diabetes as well as new information regarding the safety and use of several older antidiabetic medication classes. The distinctions were reviewed for each individual agent, and a comparison was completed if there was more than one agent in a particular therapeutic class. Using current information available, select investigational agents in phase III trials or with a pending new drug application were highlighted. Conclusion: There are now 9 distinct oral pharmacologic classes and a variety of insulin and noninsulin injectable medications available for the treatment of type 2 diabetes. Metformin remains the first-line treatment option for most patients. When considering options for alternative or additional treatment, prescribers must weigh the benefits and risks using individual patient characteristics.

Combination Therapy When Metformin Is Not an Option for Type 2 Diabetes

Objective: Consensus on combination options for patients with type 2 diabetes mellitus (T2DM) unable to use metformin is lacking. This review summarizes data describing–non-metformin based combination therapy. Data Sources: PubMed searches (January 1990 to August 2014) were conducted with terms for newer drug therapies alone and with the term combination; filters were applied for Clinical Trial, Meta Analysis, and English language. Study Selection and Data Extraction: Results were reviewed for multicenter, randomized controlled trials of non-metformin–based combination therapy conducted in the past 5 years and specific to the US or multinational populations. Data Synthesis: Although multiple injectable and oral agents have been studied in combination with metformin for management of T2DM, data are more limited for combinations without metformin. Combinations of incretins (injectable glucagon-like peptide-1 receptor agonists or oral dipeptidyl peptidase-4 [DPP-4] inhibitors) with a sulfonylurea, thiazolidinedione, or insulin are well studied and provide greater glucose-lowering efficacy than monotherapy. Incretins are associated with a low risk of hypoglycemia when used as monotherapy; the dosage of sulfonylurea or insulin should be reduced when used in combination. Newer studies are investigating the combined use of an oral sodium-glucose cotransporter 2 inhibitor and a DPP-4 inhibitor. In a recent study, reductions in glycated hemoglobin (A1C) of 1.1% to 1.2% and reduced weight with no additive risk of hypoglycemia were observed. Conclusions: Selecting the most appropriate combination therapy for patients with T2DM requires balancing clinical benefits with the risks, such as weight gain and hypoglycemia. Treatment approaches should be individualized for vulnerable patient populations for whom metformin is not appropriate.

Cost-Effectiveness Analysis of Incretin Therapy for Type 2 Diabetes in Spain: 1.8 mg Liraglutide Versus Sitagliptin

OBJECTIVES

Metformin is the first-line therapy for most patients with type 2 diabetes, but the majority require treatment intensification at some stage due to the progressive nature of the disease. The 1860-LIRA-DPP-4 trial showed that liraglutide exhibited greater improvements compared with sitagliptin in glycated hemoglobin and body mass index in patients with type 2 diabetes inadequately controlled on metformin monotherapy. As a follow-up to a previously published cost-effectiveness analysis of 1.2 mg liraglutide versus sitagliptin in Spain, the aim of this analysis was to compare long-term projections of the clinical and cost implications associated with 1.8 mg liraglutide and sitagliptin.

METHODS

For the modeling analysis, 52-week treatment effect data (as opposed to 26-week data in the previous analysis) were taken from the 1860-LIRA-DPP-4 trial, for adults with type 2 diabetes receiving 1.8 mg liraglutide or 100 mg sitagliptin daily in addition to metformin. Long-term (patient lifetime) projections of clinical outcomes and direct costs (2012 EUR) were made using a published and validated model of type 2 diabetes, with modeling assumptions as per the 1.2 mg liraglutide analysis.

RESULTS

Liraglutide was associated with increased life expectancy (14.24 versus 13.87 years) and quality-adjusted life expectancy [9.24 versus 8.84 quality-adjusted life years (QALYs)] over sitagliptin. Improved clinical outcomes were attributable to the improvement in glycemic control, leading to a reduced incidence of diabetes-related complications, including renal disease, cardiovascular disease, ophthalmic and diabetic foot complications. Liraglutide was associated with increased direct costs (EUR 56,628 versus EUR 52,450), driven by increased pharmacy costs. Based on these estimates, liraglutide was associated with an incremental cost-effectiveness ratio of EUR 10,436 per QALY gained versus sitagliptin.

CONCLUSIONS

A previous analysis has suggested that 1.2 mg liraglutide is cost-effective from a healthcare payer perspective in Spain, and the present analysis suggests that the 1.8 mg dose is also likely to be cost-effective.

Adverse Effects of GLP-1 Receptor Agonists

Glucagon-like peptide-1 (GLP-1) receptor agonists are a class of injective anti-diabetic drugs that improve glycemic control and many other atherosclerosis-related parameters in patients with type 2 diabetes (T2D). However, the use of this relatively new class of drugs may be associated with certain adverse effects. Concerns have been expressed regarding the effects of these drugs on pancreatic and thyroid tissue, since animal studies and analyses of drug databases indicate an association of GLP-1 receptor agonists with pancreatitis, pancreatic cancer, and thyroid cancer. However, several meta-analyses failed to confirm a cause-effect relation between GLP-1 receptor agonists and the development of these adverse effects. One benefit of GLP-1 receptor agonists is that they do not cause hypoglycemia when combined with metformin or thiazolidinediones, but the dose of concomitant sulphonylurea or insulin may have to be decreased to reduce the risk of hypoglycemic episodes. On the other hand, several case reports have linked the use of these drugs, mainly exenatide, with the occurrence of acute kidney injury, primarily through hemodynamic derangement due to nausea, vomiting, and diarrhea. The most common symptoms associated with the use of GLP-1 receptor agonists are gastrointestinal symptoms, mainly nausea. Other common adverse effects include injection site reactions, headache, and nasopharyngitis, but these effects do not usually result in discontinuation of the drug. Current evidence shows that GLP-1 receptor agonists have no negative effects on the cardiovascular risk of patients with T2D. Thus, GLP-1 receptor agonists appear to have a favorable safety profile, but ongoing trials will further assess their cardiovascular effects. The aim of this review is to analyze critically the available data regarding adverse events of GLP-1 receptor agonists in different anatomic systems published in Pubmed and Scopus. Whenever possible, certain differences between GLP-1 receptor agonists are described. The review also provides the reader with structured data that compare the rates of the most common adverse effects for each of the various GLP-1 receptor agonists.

Efficacy and tolerability of glucagon-like peptide-1 receptor agonists in patients with type 2 diabetes mellitus

Glucagon-like peptide-1 (GLP-1) has been evaluated for use in the treatment of type 2 diabetes mellitus (T2DM) due to its role in glucose regulation. Four GLP-1 receptor agonists (RAs) are currently indicated for T2DM in the USA. Exenatide and liraglutide are short-acting and require twice-daily and daily dosing, respectively. Two longer acting agents, exenatide long-acting release (LAR) and albiglutide, were formulated to allow for once-weekly dosing. All four GLP-1 RAs have demonstrated reductions in hemoglobin A1c, fasting blood glucose, and body weight both as monotherapy and in combination with first- and second-line diabetes agents including metformin, sulfonylureas, thiazolidinediones, and insulin. Greater glycemic control was seen with liraglutide compared with the other GLP-1 treatment options; however, the two long-acting agents were superior to exenatide twice daily. All agents were well tolerated with most adverse events being mild or moderate in nature. The most common adverse event was transient nausea which typically resolved 4-8 weeks after treatment initiation. Long-acting agents had lower rates of nausea but an increased incidence of injection site reactions. Trials have suggested GLP-1 RAs may improve cardiovascular risk factors including blood pressure, lipid parameters and inflammatory markers. Future trials are needed to confirm the clinical outcomes of these agents. Overall, GLP-1 RAs will provide benefit for patients with T2DM intolerable to or not reaching glycemic goals with first-line agents, especially in patients in need of weight loss.

Safety and efficacy of dulaglutide, a once weekly GLP-1 receptor agonist, for the management of type 2 diabetes

BACKGROUND

Type 2 diabetes (T2D) is an increasingly common endocrine disorder that is characterized by chronic hyperglycemia and tissue compartment abnormalities, including macrovascular and microvascular complications. More than 90% of patients with T2D will be diagnosed and treated in the primary care setting. One of the relatively recent additions to the increasing array of approved antidiabetic medications is the glucagon-like peptide-1 receptor agonist class. Mechanisms of action for glucagon-like peptide-1 receptor agonists include: 1) stimulation of insulin secretion through β-cells, though only when glucose levels are elevated (hence, minimizing risk for hypoglycemia); 2) blunting of glucagon secretion; 3) increased satiety; and 4) decreased rate of release of gastric contents into the small intestine, thereby reducing glycemic load. Recent T2D treatment guidelines encourage individualization of therapy. Many patients still do not achieve optimal glycemic control. Therefore, other treatment options are important.

METHODS

A literature search was performed using PubMed and MEDSCAPE to retrieve abstracts and articles pertinent to topics discussed in this review. Original research articles, reviews, and clinical trial manuscripts were identified based on relevance. Only English language articles were considered. Results In 3 phase 3 registration trials in patients with T2D, once-weekly dulaglutide demonstrated superior efficacy at the primary endpoint to metformin as monotherapy, to sitagliptin as add-on to metformin, and to exenatide twice daily as add-on to metformin and pioglitazone. The safety profile of dulaglutide in these trials is similar to currently available glucagon-like peptide-1 receptor agonists, characterized predominantly by gastrointestinal symptoms (ie, nausea, vomiting, and diarrhea). Based on these results, once-weekly dulaglutide should be a relevant additional treatment option for the management of T2D.

Dulaglutide: an evidence-based review of its potential in the treatment of type 2 diabetes

Introduction

As the prevalence of type 2 diabetes mellitus (T2DM) is anticipated to continue to rise worldwide, so too are the treatment options also continuing to expand. Current guidelines recommend individualized treatment plans which allow for provider choice and diversity of pharmacotherapeutic regimens. The glucagon-like peptide-1 receptor agonist (GLP-1 RA) class is rapidly expanding, with dulaglutide (Trulicity™) as a once-weekly agent recently approved.

Aims

This article examines the evidence currently available on the efficacy and safety of dulaglutide for use in T2DM.

Evidence review

Dulaglutide has been shown to have similar efficacy and safety to other newer GLP-1 RAs, and better glycemic control than placebo. It lowers glycated hemoglobin (A_1c), fasting and postprandial glucose levels, and promotes weight loss when used as first-, second-, or third-line therapy. It has also been shown to improve β-cell function and provide cardiovascular benefits, such as lower blood pressure and improved lipid levels. Dulaglutide also has a low risk for hypoglycemia and a similar adverse effect profile to other GLP-1 RAs in the class, with transient gastrointestinal problems and potential risk for pancreatitis.

Place in therapy

While long-term data on safety and efficacy are forthcoming, dulaglutide is positioned to be placed at the same level as other GLP-1 RAs in the class: as second-line therapy in addition to diet and exercise in those patients who cannot achieve glycemic control on monotherapy metformin. It may also be useful as first-line therapy instead of metformin.

Conclusion

Dulaglutide is a once-weekly GLP-1 RA approved for the treatment of T2DM that has shown similar efficacy to other agents in this class.

Clinical implications of canagliflozin treatment in patients with type 2 diabetes

IN BRIEF Sodium glucose cotransporter 2 (SGLT2) inhibitors are a new class of antihyperglycemic agents that lower blood glucose levels in patients with type 2 diabetes. SGLT2 inhibitors have an insulin-independent mechanism of action, acting to inhibit the reabsorption of glucose in the kidney, which leads to increases in urinary glucose excretion in individuals with elevated blood glucose levels. This article provides an overview of the role of the kidney in type 2 diabetes, describes the rationale for renal SGLT2 as a new target for glycemic control, and focuses on the clinical implications of incorporating the SGLT2 inhibitor canagliflozin into type 2 diabetes treatment regimens based on data from phase 3 studies.

Incretin-based therapies

Incretin-based therapies are steadily gaining clinical popularity, with many more products in the developmental pipeline. Current treatment recommendations incorporate GLP-1 RAs and DPP-4 inhibitors as important agents for consideration in the treatment of T2DM owing to their low hypoglycemia risk, ability to address postprandial hyperglycemia (DPP-4 inhibitors and short-acting GLP-1 RAs), and potential for weight reduction (GLP-1 RAs). These properties may likewise prove advantageous in older adults in whom hypoglycemia is particularly undesirable, although older adults may be more prone to the nausea and vomiting associated with GLP-1 RA therapy. Other safety issues for incretin-based therapies, such as pancreatitis, C-cell hyperplasia, and renal failure, should be considered when choosing an appropriate patient to receive such therapies. Ongoing CV outcome studies will further inform the health care community regarding the CV safety of incretin-based therapies. The availability of both short-acting and long-acting GLP-1 RAs currently allows practitioners to consider individualized blood glucose trends and therapeutic needs when choosing an optimal agent.

Gastrointestinal adverse events of glucagon-like peptide-1 receptor agonists in patients with type 2 diabetes: a systematic review and network meta-analysis

INTRODUCTION

Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are a new class of drugs used in the treatment of type 2 diabetes mellitus (T2DM). Gastrointestinal (GI) adverse events (AEs) are the most frequently reported treatment-related AEs for GLP-1 RAs. We aim to evaluate the effect of GLP-1 RAs on the incidence of GI AEs of T2DM.

MATERIALS AND METHODS

The overview of the GI events of GLP-1 RAs has been performed on relevant publications through the literature search, such as MEDLINE, EMBASE, Cochrane Library, and ClinicalTrials.gov The manufacturer was contacted regarding unpublished data. We analyzed direct and indirect comparisons of different treatments using Bayesian network meta-analysis.

RESULTS

Taspoglutide 30 mg once weekly (TAS30QW) and lixisenatide 30 μg twice daily (LIX30BID) were ranked the top two drugs in terms of GI AEs versus placebo. The odds ratios of nausea and vomiting for TAS30QW were 11.8 (95% confidence interval [CI], 2.89, 46.9) and 51.7 (95% CI, 7.07, 415), respectively, and that of diarrhea was 4.93 (95% CI, 1.75, 14.7) for LIX30BID.

CONCLUSIONS

Our study found all GLP-1 RA dose regimens significantly increased the incidence of GI AEs, compared with placebo or conventional treatment. The occurrence of GI AEs was different with diverse dose regimens of GLP-1 RAs. TAS30QW had the maximum probability to occur nausea and vomiting, whereas LIX30BID had the maximum probability to cause development of diarrhea versus other treatments.