A clinical review of GLP-1 receptor agonists: efficacy and safety in diabetes and beyond

Exenatide exhibits anti-inflammatory properties and modulates endothelial response to tumor necrosis factor α-mediated activation

INTRODUCTION

Cardiovascular disease is the main cause of mortality and morbidity in the industrialized world. Incretin-mimetic compounds such as exenatide are currently used in the treatment of type 2 diabetes.

AIMS

We investigated the effects of incretin drugs on apoptosis, adhesion molecule expression, and concentration of extracellular matrix (ECM) metalloproteinases under inflammatory conditions within the context of atherosclerotic plaque formation of both human coronary artery endothelial cells (hCAECs) and human aortic endothelial cells (hAoECs). TNF-α-stimulated hCAEC and hAoEC were treated with exenatide (1 and 10 nmol/L) and GLP-1 (10 and 100 nmol/L) then evaluated for caspase 3/7 activity and assayed for protein levels of adhesion molecules sICAM-1, sVCAM-1, and P-selectin. Concentrations of matrix metalloproteinases (MMPs) MMP-1, MMP-2, MMP-9, and their inhibitors-tissue inhibitor of metalloproteinases (TIMPs), TIMP-1, TIMP-2 were also measured to evaluate the effects on extracellular matrix turnover within an inflammatory environment. Intracellular signaling pathways were evaluated via transfection of endothelial cells with a GFP vector under the NF-κB promoter.

RESULTS

Our experimental data suggest that GLP-1 receptor (GLP-1R) agonists downregulate activation of NF-κB and adhesion molecules ICAM and VCAM, but not P-selectin, in both endothelial cell lines. Exendin-4 and GLP-1 modulate the expression of MMPs and TIMPs, with statistically significant effects observed at high concentrations of both incretins. Expressive modulation may be mediated by NF-κB as observed by activation of the vector when stimulated under inflammatory conditions.

CONCLUSION

These findings indicate that GLP-1 analogs have anti-inflammatory properties in endothelial cells that may play an important role in preventing atherosclerosis.

GLP-1 Receptor Agonists and Cardiovascular Disease in Patients with Type 2 Diabetes

Diabetes mellitus is a chronic disease prevalence of which is high and continually growing. Cardiovascular disease continues to be the leading cause of death in patients with T2DM. The prevention of cardiovascular complications and the cardiovascular safety of treatments should be a primary objective when selecting treatment. Among all the drugs available, the compounds known as glucagon-like peptide-1 receptor agonists (GLP-1 RAs) appear to be not just innocuous in terms of CVD but indeed to be beneficial. GLP-1 RA actions not only translate on an improvement of well-known cardiovascular risk factors such as glycaemic control, dyslipidaemia, weight, or arterial hypertension but also might show benefits on endothelial function, coronary ischaemia, and heart failure. On the other hand, recent clinical trials aimed at studying cardiovascular episodes have been conducted with GLP-1 RAs. Only liraglutide and semaglutide have shown superiority in cardiovascular benefit compared with placebo. Although many of the mechanisms by which liraglutide and semaglutide produce a cardiovascular benefit are still unknown it would be desirable for these benefits to be incorporated into the therapeutic algorithms routinely used in clinical practice. The purpose of this review is to explore GLP-1 RA actions not only in cardiovascular risk factors (glucose, weight, and hypertension) but also the possible effects on established cardiovascular disease.

A real-world, observational study of weekly exenatide added to basal insulin in patients with type 2 diabetes mellitus (NCT02895672)

AIM

This is a pre-post observational study from an endocrinology ambulatory care practice which assessed the effectiveness and safety following the addition of a glucagon-like peptide-1 (GLP-1) agonist, weekly exenatide (Bydureon), to basal insulin therapy in patients with type 2 diabetes mellitus (T2DM). Liraglutide plus basal insulin served as a comparison group.

MATERIALS AND METHODS

A data collection form was utilized to collect study-related information. The primary study outcome was change in HbA1c from baseline to 12 months after GLP-1 receptor agonist therapy was added to basal insulin therapy. Secondary outcomes were change in weight, percentage of patients achieving an HbA1c of <7% (53 mmol/mol) or ≤6.5% (48 mmol/mol) and changes in blood pressure and lipid parameters. Safety was assessed by a collection of reported adverse events.

RESULTS

One-hundred and fifty patients met inclusion criteria (seventy-five per treatment arm). After 1 year of therapy, HbA1c decreased by 0.7% in the entire cohort (once-weekly exenatide: -0.7%; once-daily liraglutide: -0.8%; no significant between-group difference). More subjects in the weekly exenatide arm achieved an HbA1c < 7% (53 mmol/mol) (P = .03), but a comparable number achieved an HbA1c ≤ 6.5% (48 mmol/mol). Although significantly more patients achieved an HbA1c < 7% (53 mmol/mol) in the once-weekly exenatide arm, the baseline HbA1c was lower (7.9%) than the liraglutide arm (8.4%). No significant differences were observed between groups for other secondary outcomes. A similar number of subjects discontinued therapy, mainly due to gastrointestinal-ill effects, and hypoglycaemia incidence did not increase compared with the previous year.

CONCLUSION

The addition of once-weekly exenatide to basal insulin was associated with appreciable reductions in HbA1c and weight without an increase in hypoglycaemia.

Feasibility, Adherence and Efficacy of Liraglutide Treatment in a Sample of Individuals With Mood Disorders and Obesity

Background: Liraglutide is a once-daily injectable medication approved for the treatment of obesity. Hereby we report the feasibility, adherence and efficacy of liraglutide treatment in a sample of individuals with mood disorders and obesity. Methods and Sample: Twenty-nine patients with Bipolar or Major Depressive Disorder received liraglutide once daily subcutaneously at a dose gradually titrated from 0.6 to 3 mg. All patients were obese and had previously failed multiple healthy lifestyle interventions, including exercise and diet programs. Patients' weight was recorded before liraglutide treatment (T0) and then 1 (T1), 3 (T3), and 6 months (T6) following T0. Results: Mean baseline (T0) weight was 110.54 Kg (±24.95). Compared to baseline, the percentage of weight loss was 3.37% at T1, 7.85% at T3, and 10.20% at T6. Thirty-one percent (n = 9) of patients had no side effects, 34.48% (n = 10) had one, 24.14% (n = 7) had two, and 10.34% (n = 3) had three side effects. All 29 subjects were still on liraglutide at T1; 79.31 and 48.28% were on liraglutide at T3 and T6. No significant relationship was found between liraglutide dose and likelihood to continue the medication. No patient showed a worsening of the psychiatric condition due to liraglutide treatment. Acceptability and satisfaction with treatment were good for the 48% that completed the study. Conclusions: Liraglutide treatment was efficacious, accepted and tolerated by ~50% of our sample, followed up for a period of 180 days. Larger, longer, controlled, prospective studies are warranted.

Antiobesity and emetic effects of a short-length peptide YY analog and its PEGylated and alkylated derivatives

Neuropeptide Y2 receptor (Y2R) agonism is an important anorectic signal and a target of antiobesity drug discovery. Recently, we synthesized a short-length Y2R agonist, PYY-1119 (4-imidazolecarbonyl-[d-Hyp²⁴,Iva²⁵,Pya(4)²⁶,Cha^27,36,γMeLeu²⁸,Lys³⁰,Aib³¹]PYY(23-36), 1) as an antiobesity drug candidate. Compound 1 induced marked body weight loss in diet-induced obese (DIO) mice; however, 1 also induced severe vomiting in dogs at a lower dose than the minimum effective dose administered to DIO mice. The rapid absorption of 1 after subcutaneous administration caused the severe vomiting. Polyethylene glycol (PEG)- and alkyl-modified derivatives of 1 were synthesized to develop Y2R agonists with improved pharmacokinetic profiles, i.e., lower maximum plasma concentration (C_max) and longer time at maximum concentration (T_max). Compounds 5 and 10, modified with 20 kDa PEG at the N-terminus and eicosanedioic acid at the Lys³⁰ side chain of 1, respectively, showed high Y2R binding affinity and induced significant body weight reduction upon once-daily administration to DIO mice. Compounds 5 and 10, with their relatively low C_max and long T_max, partially attenuated emesis in dogs compared with 1. These results indicate that optimization of pharmacokinetic properties of Y2R agonists is an effective strategy to alleviate emesis induced by Y2R agonism.

Calcium-dependent ultrasound stimulation of secretory events from pancreatic beta cells

BACKGROUND

Our previous studies have indicated that ultrasound can stimulate the release of insulin from pancreatic beta cells, providing a potential novel treatment for type 2 diabetes. The purpose of this study was to explore the temporal dynamics and Ca2+-dependency of ultrasound-stimulated secretory events from dopamine-loaded pancreatic beta cells in an in vitro setup.

METHODS

Carbon fiber amperometry was used to detect secretion from INS-1832/13 beta cells in real time. The levels of released insulin were also measured in response to ultrasound treatment using insulin-specific ELISA kit. Beta cells were exposed to continuous wave 800 kHz ultrasound at intensities of 0.1 W/cm2, 0.5 W/cm2 and 1 W/cm2 for several seconds. Cell viability tests were done with trypan blue dye exclusion test and MTT analysis.

RESULTS

Carbon fiber amperometry experiments showed that application of 800 kHz ultrasound at intensities of 0.5 and 1 W/cm2 was capable of stimulating secretory events for durations lasting as long as the duration of the stimulus. Furthermore, the amplitude of the detected peaks was reduced by 64% (p < 0.01) when extracellular Ca2+ was chelated with 10 mM EGTA in cells exposed to ultrasound intensity of 0.5 W/cm2. Measurements of released insulin in response to ultrasound stimulation showed complete inhibition of insulin secretion by chelating extracellular Ca2+ with 10 mM EGTA (p < 0.01). Viability studies showed that 800 kHz, 0.5 W/cm2 ultrasound did not cause any significant effects on viability and metabolic activity in cells exposed to ultrasound as compared to sham-treated cells.

CONCLUSIONS

Our results demonstrated that application of ultrasound was capable of stimulating the release of insulin from pancreatic beta cells in a safe, controlled and Ca2+-dependent manner.

iGlarLixi, a titratable once-daily fixed-ratio combination of basal insulin and lixisenatide for intensifying type 2 diabetes management for patients inadequately controlled on basal insulin with or without oral agents

BACKGROUND

Achieving and maintaining glycemic control is important for people with type 2 diabetes (T2D), to reduce disease-related complications and mortality; however, about half of US patients fail to meet glycemic targets. iGlarLixi, a titratable fixed-ratio combination of insulin glargine 100 U/mL (iGlar) and lixisenatide for once-daily administration, was recently approved by the US Food and Drug Administration for use in adults with T2D inadequately controlled on basal insulin (<60 U daily) or lixisenatide. iGlar and lixisenatide have complementary mechanisms of action, primarily targeting fasting plasma glucose and postprandial plasma glucose, respectively. In the US, iGlarLixi is available in a 3:1 ratio of iGlar and lixisenatide, respectively, across the dosage range of 15-60 U of iGlar and 5-20 µg of lixisenatide.

METHODS

This study identified phase 3 trials which assessed the efficacy and safety of iGlarLixi. Relevant trials were LixiLan-O, which compared iGlarLixi with iGlar or lixisenatide alone in insulin-naïve patients, and LixiLan-L, which compared iGlarLixi with iGlar alone in insulin-experienced patients.

RESULTS

Patients on iGlarLixi experienced greater A1C reduction and were more likely to achieve A1C <7.0% than its comparators. iGlarLixi mitigated the weight gain associated with iGlar without increasing hypoglycemia risk, and resulted in a lower frequency of gastrointestinal adverse events compared with lixisenatide.

CONCLUSIONS

iGlarLixi provides a new approach to therapy intensification in patients with T2D. iGlarLixi showed greater A1C efficacy compared with either iGlar or lixisenatide, mitigating iGlar-associated weight gain, without increasing hypoglycemia risk, and reducing the gastrointestinal side-effects seen with lixisenatide.

Postprandial hyperglycemia and postprandial hypertriglyceridemia in type 2 diabetes

Postprandial glucose level is an independent risk factor for cardiovascular disease that exerts effects greater than glucose levels at fasting state, whereas increase in serum triglyceride level, under both fasting and postprandial conditions, contributes to the development of arteriosclerosis. Insulin resistance is a prevailing cause of abnormalities in postabsorptive excursion of blood glucose and postprandial lipid profile. Excess fat deposition renders a vicious cycle of hyperglycemia and hypertriglyceridemia in the postprandial state, and both of which are contributors to atherosclerotic change of vessels especially in patients with type 2 diabetes mellitus. Several therapeutic approaches for ameliorating each of these abnormalities have been attempted, including various antidiabetic agents or new compounds targeting lipid metabolism.

Evaluating the short-term cost-effectiveness of liraglutide versus lixisenatide in patients with type 2 diabetes in the United States

AIMS

Bringing patients with type 2 diabetes to recommended glycated hemoglobin (HbA1c) treatment targets can reduce the risk of developing diabetes-related complications. The aim of the present analysis was to evaluate the short-term cost-effectiveness of once-daily liraglutide 1.8 mg vs once-daily lixisenatide 20 μg as an add-on to metformin for treatment of type 2 diabetes in the US by assessing the cost per patient achieving HbA1c-focused and composite treatment targets.

MATERIALS AND METHODS

Percentages of patients achieving recommended targets were obtained from the LIRA-LIXI trial, which compared the efficacy and safety of once-daily liraglutide 1.8 mg and once-daily lixisenatide 20 μg as an add-on to metformin in patients with type 2 diabetes failing to achieve glycemic control with metformin. Annual costs were estimated from a healthcare payer perspective. An economic model was developed to evaluate the annual cost per patient achieving target (cost of control) with liraglutide 1.8 mg vs lixisenatide 20 μg for five end-points.

RESULTS

Annual treatment costs were higher with liraglutide 1.8 mg than lixisenatide 20 μg, but this was offset by greater clinical efficacy, and the cost of control was lower with liraglutide 1.8 mg than lixisenatide 20 μg for all five end-points. The annual cost of control was USD 3,850, USD 11,404, USD 3,807, USD 4,299, and USD 6,901 lower for liraglutide 1.8 mg than lixisenatide 20 μg for targets of HbA1c < 7.0%, HbA1c ≤ 6.5%, HbA1c < 7.0% and no weight gain, HbA1c < 7.0% with no weight gain and no confirmed hypoglycemia, and HbA1c < 7.0% with no weight gain and systolic blood pressure <140 mmHg, respectively.

CONCLUSIONS

Once-daily liraglutide 1.8 mg was associated with greater clinical efficacy than once-daily lixisenatide 20 μg, which resulted in a lower annual cost of control for HbA1c-focused and composite treatment targets.

Exenatide modulates tumor-endothelial cell interactions in human ovarian cancer cells

Diabetes and cancer are prevalent diseases whose incidence is increasing globally. Diabetic women have a moderate risk increase in ovarian cancer, suggested to be due to an interaction between these two disorders. Furthermore, patients manifesting both diseases have associated worse prognosis, reduced survival and shorter relapse-free survival. According to current recommendations, incretin drugs such as Exenatide, a synthetic analog of Exendin-4, and Liraglutide are used as therapy for the type 2 diabetes (T2D). We studied the effects of GLP-1 and Exendin-4 on migration, apoptosis and metalloproteinase production in two human ovarian cancer cells (SKOV-3 and CAOV-3). Exendin-4 inhibited migration and promoted apoptosis through caspase 3/7 activation. Exendin-4 also modulated the expression of key metalloproteinases (MMP-2 and MMP-9) and their inhibitors (TIMP-1 and TIMP-2). Vascular endothelial cells, which contribute to the formation and progression of metastasis, were also analyzed. TNF-α-stimulated endothelial cells from iliac artery after Exendin-4 treatment showed reduced production of adhesion molecules (ICAM-1 and VCAM-1). Additionally, incretin treatment inhibited activation of apoptosis in TNF-α-stimulated endothelial cells. In the same experiment, MMPs (MMP-1 and MMP-9), which are relevant for tumor development, were also reduced. Our study demonstrated that incretin drugs may reduce cancer cell proliferation and dissemination potential, hence limiting the risk of metastasis in epithelial ovarian cancer.

Exenatide modulates metalloproteinase expression in human cardiac smooth muscle cells via the inhibition of Akt signaling pathway

BACKGROUND

Incretin analogue drugs, a FDA-approved treatment in diabetes, has been tested for its therapeutic properties as modulators of atherosclerosis. We investigated the effects of incretin drugs on the modulation of gene expression and protein levels of matrix metalloproteinases (MMPs) as well as their inhibitors - tissue inhibitors of metalloproteinases (TIMPs) in coronary artery smooth muscle cells (hCASMC) in the context of atherosclerotic plaque formation and inflammation.

METHODS

TNFα-stimulated hCASMC were treated with Glucagon-like Peptide 1 (GLP-1) (10nM and 100nM) and Exendin-4 (1nM and 10nM). Messenger RNA (mRNA) levels and protein concentrations of MMP-1, MMP-2, MMP-9 and TIMP-1, TIMP-2 were measured and the effects on extracellular matrix turnover under TNFα-mediated microenvironment were evaluated. Intracellular signaling pathways were also examined.

RESULTS

Our experiments reveal that GLP-1 receptor agonists downregulate the expression of MMP-1, MMP-2, MMP-9 in hCASMC under TNFα mediated inflammatory conditions. Signaling pathway analysis show that GLP-1 receptor agonists induced inhibition of AKT-Thr308 phosphorylation, PRAS40 and S6 proteins but not AKT-Ser473.

CONCLUSIONS

These findings indicate that GLP-1 receptor agonists modulate the expression of MMPs through inhibition of AKT-Thr308 phosphorylation in hCASMC. These results suggest a possible role of incretin analogue drugs in therapy of coronary atherosclerosis.

Protective effects of the GLP-1 mimetic exendin-4 in Parkinson's disease

There is increasing interest in the potential role of glucagon-like peptide-1 (GLP-1) receptor agonists as neuroprotective treatments in neurodegenerative diseases including Parkinson's disease following the publication of the results of the Exenatide-PD trial. Of the current GLP-1 receptor agonists already licensed to treat Type 2 diabetes several including exenatide, liraglutide and lixisenatide are the subject of ongoing clinical trials in PD. The underlying rationale for using drugs licensed and effective for T2DM in PD patients therefore needs to be scrutinized, and the results obtained to date critically reviewed. We review the relationship between insulin resistance and Parkinson's disease, the implications on pathogenesis and the efforts to reposition GLP-1 agonists as potential treatments for Parkinson's disease and give an overview of the pre-clinical and clinical data supporting the use of exenatide in Parkinson's disease with a discussion regarding possible mechanisms of action. This article is part of the Special Issue entitled 'Metabolic Impairment as Risk Factors for Neurodegenerative Disorders.'

The EP3 Receptor/Gz Signaling Axis as a Therapeutic Target for Diabetes and Cardiovascular Disease

Cardiovascular disease is a common co-morbidity found with obesity-linked type 2 diabetes. Current pharmaceuticals for these two diseases treat each of them separately. Yet, diabetes and cardiovascular disease share molecular signaling pathways that are increasingly being understood to contribute to disease pathophysiology, particularly in pre-clinical models. This review will focus on one such signaling pathway: that mediated by the G protein-coupled receptor, Prostaglandin E2 Receptor 3 (EP3), and its associated G protein in the insulin-secreting beta-cell and potentially the platelet, Gz. The EP3/Gz signaling axis may hold promise as a dual target for type 2 diabetes and cardiovascular disease.

Monoacylglycerol signalling and ABHD6 in health and disease

Lipid metabolism dysregulation underlies chronic pathologies such as obesity, diabetes and cancer. Besides their role in structure and energy storage, lipids are also important signalling molecules regulating multiple biological functions. Thus, understanding the precise lipid metabolism enzymatic steps that are altered in some pathological conditions is helpful for designing better treatment strategies. Several monoacylglycerol (MAG) species are only recently being recognized as signalling lipid molecules in different tissues. Recent studies indicated the importance of the ubiquitously expressed serine hydrolase α/β-hydrolase domain 6 (ABHD6), which is a MAG hydrolase, in regulating signalling competent MAG in both central and peripheral tissues. The central and peripheral function of the endocannabinoid 2-arachidonoylglycerol, which is a 2-MAG, and its breakdown by both ABHD6 and classical MAG lipase has been well documented. ABHD6 and its substrate MAG appear to be involved in the regulation of various physiological and pathological processes including insulin secretion, adipose browning, food intake, neurotransmission, autoimmune disorders, neurological and metabolic diseases as well as cancer. Diverse cellular targets such as mammalian unc13-1 (Munc13-1), PPARs, GPR119 and CB1/2 receptors, for MAG-mediated signalling processes have been proposed in different cell types. The purpose of this review is to provide a comprehensive summary of the current state of knowledge regarding ABHD6/MAG signalling and its possible therapeutic implications.

Effect of an Intensive Lifestyle Intervention on Glycemic Control in Patients With Type 2 Diabetes: A Randomized Clinical Trial

Importance

It is unclear whether a lifestyle intervention can maintain glycemic control in patients with type 2 diabetes.

Objective

To test whether an intensive lifestyle intervention results in equivalent glycemic control compared with standard care and, secondarily, leads to a reduction in glucose-lowering medication in participants with type 2 diabetes.

Design, Setting, and Participants

Randomized, assessor-blinded, single-center study within Region Zealand and the Capital Region of Denmark (April 2015-August 2016). Ninety-eight adult participants with non-insulin-dependent type 2 diabetes who were diagnosed for less than 10 years were included. Participants were randomly assigned (2:1; stratified by sex) to the lifestyle group (n = 64) or the standard care group (n = 34).

Interventions

All participants received standard care with individual counseling and standardized, blinded, target-driven medical therapy. Additionally, the lifestyle intervention included 5 to 6 weekly aerobic training sessions (duration 30-60 minutes), of which 2 to 3 sessions were combined with resistance training. The lifestyle participants received dietary plans aiming for a body mass index of 25 or less. Participants were followed up for 12 months.

Main Outcomes and Measures

Primary outcome was change in hemoglobin A1c (HbA1c) from baseline to 12-month follow-up, and equivalence was prespecified by a CI margin of ±0.4% based on the intention-to-treat population. Superiority analysis was performed on the secondary outcome reductions in glucose-lowering medication.

Results

Among 98 randomized participants (mean age, 54.6 years [SD, 8.9]; women, 47 [48%]; mean baseline HbA1c, 6.7%), 93 participants completed the trial. From baseline to 12-month follow-up, the mean HbA1c level changed from 6.65% to 6.34% in the lifestyle group and from 6.74% to 6.66% in the standard care group (mean between-group difference in change of -0.26% [95% CI, -0.52% to -0.01%]), not meeting the criteria for equivalence (P = .15). Reduction in glucose-lowering medications occurred in 47 participants (73.5%) in the lifestyle group and 9 participants (26.4%) in the standard care group (difference, 47.1 percentage points [95% CI, 28.6-65.3]). There were 32 adverse events (most commonly musculoskeletal pain or discomfort and mild hypoglycemia) in the lifestyle group and 5 in the standard care group.

Conclusions and Relevance

Among adults with type 2 diabetes diagnosed for less than 10 years, a lifestyle intervention compared with standard care resulted in a change in glycemic control that did not reach the criterion for equivalence, but was in a direction consistent with benefit. Further research is needed to assess superiority, as well as generalizability and durability of findings.

Trial Registration

clinicaltrials.gov Identifier: NCT02417012.

Lixisenatide, a Once-Daily Prandial Glucagon-Like Peptide-1 Receptor Agonist for the Treatment of Adults with Type 2 Diabetes

Lixisenatide, a short-acting glucagon-like peptide-1 receptor agonist (GLP-1 RA), has been available in Europe since 2013 and was recently approved in the United States for the treatment of type 2 diabetes (T2D) as an adjunct to diet and exercise. The objective of this systematic review is to describe the pharmacology, pharmacokinetics, safety, and efficacy of lixisenatide in patients with T2D. We conducted a search of the EMBASE database, limited to human studies with abstracts available in English. Published conference abstracts, limited to the American Diabetes Association (ADA) and the European Association for the Study of Diabetes meetings in 2015, as well as abstracts presented at the ADA meeting in 2016, were also screened. The abstracts retrieved were assessed for relevance; review articles and meta-analyses focusing on GLP-1 RAs as a class were excluded. Lixisenatide induced mean reductions of 0.46-0.99% in glycated hemoglobin A_1c (Hb_A1c ), 55.86-143.43 mg/dl in 2-hour postprandial glucose (PPG) levels, and 56.58-127.75 mg/dl in mealtime glucose level variations. Changes in fasting plasma glucose (FPG) levels and weight ranged from -21.98 to +5.41 mg/dl and from -2.96 to +0.3 kg, respectively, in patients with T2D enrolled in the GetGoal clinical program (a program of clinical trials that established the efficacy and safety profile of lixisenatide 20 μg once/day across patients with T2D with differing background therapies). Lixisenatide was well tolerated, demonstrating rates of symptomatic hypoglycemia of 0.8-42.9% and a very low rate of severe hypoglycemia (< 1.5%) as well as no increased risk of cardiovascular events. The most common adverse events were gastrointestinal in nature, mainly transient nausea and vomiting of mild-to-moderate severity. Lixisenatide effectively lowers Hb_A1c levels in patients with T2D through a mechanism of action complementary to that of agents that mainly target FPG, with the additional benefit of weight loss. Its once-daily administration schedule and effect on PPG levels make it an attractive option as add-on treatment to basal insulin therapy or oral antidiabetic agents.

Dietary capsaicin and its anti-obesity potency: from mechanism to clinical implications

Obesity is a growing public health problem, which has now been considered as a pandemic non-communicable disease. However, the efficacy of several approaches for weight loss is limited and variable. Thus, alternative anti-obesity treatments are urgently warranted, which should be effective, safe, and widely available. Active compounds isolated from herbs are similar with the practice of Traditional Chinese Medicine, which has a holistic approach that can target to several organs and tissues in the whole body. Capsaicin, a major active compound from chili peppers, has been clearly demonstrated for its numerous beneficial roles in health. In this review, we will focus on the less highlighted aspect, in particular how dietary chili peppers and capsaicin consumption reduce body weight and its potential mechanisms of its anti-obesity effects. With the widespread pandemic of overweight and obesity, the development of more strategies for the treatment of obesity is urgent. Therefore, a better understanding of the role and mechanism of dietary capsaicin consumption and metabolic health can provide critical implications for the early prevention and treatment of obesity.

Evaluation of the long-term cost-effectiveness of liraglutide vs lixisenatide for treatment of type 2 diabetes mellitus in the UK setting

AIMS

To compare the cost-effectiveness of 2 glucagon-like peptide-1 (GLP-1) receptor agonists, liraglutide 1.8 mg and lixisenatide 20 µg, in the UK setting based on the LIRA-LIXI trial (NCT01973231).

MATERIALS AND METHODS

Projections of costs (in 2015 pounds sterling [£]) and clinical outcomes were made over patient lifetimes using the IMS CORE Diabetes Model (IMS Health, Basel, Switzerland). The baseline cohort and treatment effects applied after initiation of GLP-1 receptor agonists were taken from the LIRA-LIXI trial. Future costs and clinical benefits were discounted at 3.5% annually.

RESULTS

Liraglutide 1.8 mg was associated with improved discounted quality-adjusted life expectancy (8.87 vs 8.76 quality-adjusted life years [QALYs]) vs lixisenatide 20 µg. A greater reduction in glycated haemoglobin with liraglutide 1.8 mg led to fewer diabetes-related complications and delayed their time of onset. Liraglutide 1.8 mg was associated with increased total costs (£37 153 vs £36 174), driven by higher acquisition costs, but this was partially offset by savings from diabetes-related complications avoided (£26 969 vs £27 912). Liraglutide 1.8 mg was associated with an incremental cost-effectiveness ratio of £8901 per QALY gained vs lixisenatide 20 µg.

CONCLUSIONS

Long-term projections suggest that treatment of patients with type 2 diabetes with liraglutide 1.8 mg is likely to be considered highly cost-effective compared with lixisenatide 20 µg treatment in the UK setting.

Treatment Strategy for Type 2 Diabetes with Obesity: Focus on Glucagon-like Peptide-1 Receptor Agonists

PURPOSE

The progressive nature of type 2 diabetes mellitus (T2DM) calls for step-wise intensification of therapy for maintaining normal glycemic levels and lowering cardiovascular (CV) risk. Because obesity is a prominent risk factor and comorbidity of T2DM, it further elevates the CV risk in T2DM. Therefore, it is vital to manage weight, obesity, and glycemic parameters for effective T2DM management. Few oral antidiabetic drugs (sulfonylureas and thiazolidinediones) and insulin are not suitable for obese patients with T2DM because these drugs cause weight gain. The present review discusses the place of glucagon-like peptide-1 receptor agonists (GLP-1RAs) in the treatment of obese patients with T2DM and the significance of these drugs in the prevention of future CV risk in patients with T2DM.

METHODS

A literature search of PubMed and EMBASE was conducted by using the search terms T2DM, GLP-1RAs, obesity, and cardiovascular complication. Randomized controlled trials measuring the effect of GLP-1RAs versus that of placebo on CV outcomes were included in the review.

FINDINGS

GLP-1RAs have emerged as a therapeutic alternative; these drugs exert their actions by providing glycemic control, improving insulin resistance and ö̇-cell function, and reducing weight. The risk of hypoglycemia with GLP-1RAs is minimal; however, GLP-1RAs are associated with gastrointestinal adverse events and raise concerns regarding pancreatitis. Combining GLP-1RAs with insulin analogues results in higher efficacy, a lowered insulin dose, and reduced insulin-related hypoglycemia and weight gain. Longer acting GLP-1RAs are also associated with improvement in medication adherence. Improvement in CV risk factors such as blood pressure and lipid profile further increases their usability for improving CV outcomes.

IMPLICATIONS

Overall, the properties of GLP-1RAs make them suitable for combination with oral antidiabetic drugs in the early stages of T2DM and with insulins in the later stages for optimizing comprehensive management of the disease.

Targeting endothelial metaflammation to counteract diabesity cardiovascular risk: Current and perspective therapeutic options

The association of obesity and diabetes, termed "diabesity", defines a combination of primarily metabolic disorders with insulin resistance as the underlying common pathophysiology. Cardiovascular disorders associated with diabesity represent the leading cause of morbidity and mortality in the Western world. This makes diabesity, with its rising impacts on both health and economics, one of the most challenging biomedical and social threats of present century. The emerging comprehension of the genes whose alteration confers inter-individual differences on risk factors for diabetes or obesity, together with the potential role of genetically determined variants on mechanisms controlling responsiveness, effectiveness and safety of anti-diabetic therapy underlines the need of additional knowledge on molecular mechanisms involved in the pathophysiology of diabesity. Endothelial cell dysfunction, resulting from the unbalanced production of endothelial-derived vascular mediators, is known to be present at the earliest stages of insulin resistance and obesity, and may precede the clinical diagnosis of diabetes by several years. Once considered as a mere consequence of metabolic abnormalities, it is now clear that endothelial dysfunctional activity may play a pivotal role in the progression of diabesity. In the vicious circle where vascular defects and metabolic disturbances worsen and reinforce each other, a low-grade, chronic, and 'cold' inflammation (metaflammation) has been suggested to serve as the pathophysiological link that binds endothelial and metabolic dysfunctions. In this paradigm, it is important to consider how traditional antidiabetic treatments (specifically addressing metabolic dysregulation) may directly impact on inflammatory processes or cardiovascular function. Indeed, not all drugs currently available to treat diabetes possess the same anti-inflammatory potential, or target endothelial cell function equally. Perspective strategies pointing at reducing metaflammation or directly addressing endothelial dysfunction may disclose beneficial consequences on metabolic regulation. This review focuses on existing and potential new approaches ameliorating endothelial dysfunction and vascular inflammation in the context of diabesity.

Liraglutide Versus Lixisenatide: Long-Term Cost-Effectiveness of GLP-1 Receptor Agonist Therapy for the Treatment of Type 2 Diabetes in Spain

INTRODUCTION

Glucagon-like peptide-1 (GLP-1) receptor agonists are used successfully in the treatment of patients with type 2 diabetes as they are associated with low hypoglycemia rates, weight loss and improved glycemic control. This study compared, in the Spanish setting, the cost-effectiveness of liraglutide 1.8 mg versus lixisenatide 20 μg, both GLP-1 receptor agonists, for patients with type 2 diabetes who had not achieved glycemic control targets on metformin monotherapy.

METHODS

The IMS CORE Diabetes Model was used to project clinical outcomes and costs, expressed in 2015 Euros, over patient lifetimes. Baseline cohort data and treatment effects were taken from the 26-week, open-label LIRA-LIXI™ trial (NCT01973231). Treatment and management costs of diabetes-related complications were retrieved from published sources and databases. Future benefits and costs were discounted by 3% annually. Sensitivity analyses were conducted.

RESULTS

Compared with lixisenatide 20 μg, liraglutide 1.8 mg was associated with higher life expectancy (14.42 vs. 14.29 years), higher quality-adjusted life expectancy [9.40 versus 9.26 quality-adjusted life years (QALYs)] and a reduced incidence of diabetes-related complications. Higher acquisition costs resulted in higher total costs for liraglutide 1.8 mg (EUR 42,689) than for lixisenatide 20 μg (EUR 42,143), but these were partly offset by reduced costs of treating diabetes-related complications (EUR 29,613 vs. EUR 30,636). Projected clinical outcomes and costs resulted in an incremental cost-effectiveness ratio of EUR 4113 per QALY gained for liraglutide 1.8 mg versus lixisenatide 20 μg.

CONCLUSIONS

Long-term projections in the Spanish setting suggest that liraglutide 1.8 mg is likely to be cost-effective compared with lixisenatide 20 μg in type 2 diabetes patients who have not achieved glycemic control targets on metformin monotherapy. Liraglutide 1.8 mg presents a clinically and economically attractive treatment option in the Spanish setting.

Anti-obesogenic and antidiabetic effects of plants and mushrooms

Obesity is reaching global epidemic proportions as a result of factors such as high-calorie diets and lack of physical exercise. Obesity is now considered to be a medical condition, which not only contributes to the risk of developing type 2 diabetes mellitus, cardiovascular disease and cancer, but also negatively affects longevity and quality of life. To combat this epidemic, anti-obesogenic approaches are required that are safe, widely available and inexpensive. Several plants and mushrooms that are consumed in traditional Chinese medicine or as nutraceuticals contain antioxidants, fibre and other phytochemicals, and have anti-obesogenic and antidiabetic effects through the modulation of diverse cellular and physiological pathways. These effects include appetite reduction, modulation of lipid absorption and metabolism, enhancement of insulin sensitivity, thermogenesis and changes in the gut microbiota. In this Review, we describe the molecular mechanisms that underlie the anti-obesogenic and antidiabetic effects of these plants and mushrooms, and propose that combining these food items with existing anti-obesogenic approaches might help to reduce obesity and its complications.

Glucagon-like peptide-1 and glucagon-like peptide-1 receptor agonists in the treatment of type 2 diabetes

The prevalence of type 2 diabetes (T2D) is increasing worldwide. Patients with T2D suffer from various diabetes-related complications. Since there are many patients with T2D that cannot be controlled by previously developed drugs, it has been necessary to develop new drugs, one of which is a glucagon-like peptide-1 (GLP-1) based therapy. GLP-1 has been shown to ameliorate diabetes-related conditions by augmenting pancreatic β-cell insulin secretion and having the low risk of causing hypoglycemia. Because of a very short half-life of GLP-1, many researches have been focused on the development of GLP-1 receptor (GLP-1R) agonists with long half-lives such as exenatide and dulaglutide. Now GLP-1R agonists have a variety of dosing-cycle forms to meet the needs of various patients. In this article, we review the physiological features of GLP-1, the effects of GLP-1 on T2D, the features of several GLP-1R agonists, and the therapeutic effect on T2D.

Treatment Outcomes and Tolerability Following Initiation of GLP-1 Receptor Agonists Among Type 2 Diabetes Patients in Primary Care Practices in Germany

BACKGROUND

The aim was to investigate real-world treatment outcomes and tolerability of GLP-1 receptor agonist (GLP-1RA) therapy in patients with type 2 diabetes in Germany.

METHODS

Patients from 323 primary care practices who started any GLP-1RA therapy (89 Byetta, 108 Bydureon, 347 Victoza patients) between January 1, 2011, and December 31, 2013 (index date) were analyzed retrospectively (Disease Analyzer database, Germany). Changes from baseline in HbA1c, weight, and hypoglycemia were evaluated in 3 follow-up periods of 0-6, 7-12, and 13-18 months.

RESULTS

A total of 544 diabetes patients (mean age: 57.9 years; men: 54%) were eligible for the study. Mean (SD) HbA1c (%) decreased from 8.3 (1.4) at baseline to 7.4 (1.2) in 6 months, 7.6 (1.3) in 7-12 months and 7.6 (1.4) in 13-18 months, respectively ( P < .001 for all), while the proportion of patients with HbA1c <7% increased from 15% at baseline to 38%, 36% and 35% in the corresponding periods ( P < .0001 for all). Multivariate-adjusted beta coefficients corresponding to changes in HbA1c (%) from baseline were -.52, -.44, and -.44, respectively, in the follow-up periods for baseline HbA1c (%) ( P < .0001 for all). The prevalence of hypoglycemia at baseline was 0.7%; this did not change significantly after treatment.

CONCLUSIONS

In clinical practice, GLP-1RA treatment was associated with improved glycemic control without increased hypoglycemia for up to 18 months. The higher the baseline HbA1c, the greater the HbA1c reduction recorded.

Evaluating the Long-Term Cost-Effectiveness of Daily Administered GLP-1 Receptor Agonists for the Treatment of Type 2 Diabetes in the United Kingdom

INTRODUCTION

The glucagon-like peptide-1 (GLP-1) receptor agonist class has grown in the last decade, with several agents available in the UK. However there is currently a paucity of evidence regarding the relative cost-effectiveness of liraglutide 1.2 mg versus other daily administered GLP-1 receptor agonists, due to a lack of head-to-head trial data. Therefore the present analysis was performed, using results from a network meta-analysis (NMA), to compare the cost-effectiveness of three currently available daily administered GLP-1 receptor agonists for treatment of diabetes in the UK setting.

METHODS

A validated and published diabetes model was used to make long-term projections of clinical outcomes and direct costs (2015 GBP) for patients receiving liraglutide 1.2 mg once-daily, exenatide 10 μg twice daily and lixisenatide 20 μg once-daily. Treatment effects were taken from an NMA evaluating the efficacy of GLP-1 receptor agonists and were applied in a cohort based on the Liraglutide Effect and Action in Diabetes 6 (LEAD-6) trial. Costs and utilities were based on published sources.

RESULTS

Liraglutide 1.2 mg was associated with improved quality-adjusted life expectancy versus exenatide [9.19 versus 9.17 quality-adjusted life years (QALYs)] and lixisenatide (9.19 versus 9.12 QALYs). Improvements were driven by benefits in glycemic control, leading to a reduced incidence of diabetes-related complications. Liraglutide 1.2 mg was associated with reduced costs versus exenatide (GBP 36,394 versus GBP 36,547) and lixisenatide (GBP 36,394 versus GBP 36,496), with cost savings as a result of complications avoided entirely offsetting increased acquisition costs. Based on the projected outcomes, liraglutide was found to be dominant over both exenatide and lixisenatide.

CONCLUSION

Liraglutide 1.2 mg is likely to be considered cost-effective versus alternative daily administered GLP-1 receptor agonists for treatment of type 2 diabetes in the UK.

Reasons for discontinuation of GLP1 receptor agonists: data from a real-world cross-sectional survey of physicians and their patients with type 2 diabetes

AIM

Nonadherence to glucagon-like peptide-1 receptor agonists (GLP1 RAs) is relatively common among patients with type 2 diabetes mellitus (T2DM). This study sought to identify reasons why patients discontinue GLP1 RAs.

MATERIALS AND METHODS

Retrospective data from the Adelphi Diabetes Disease Specific Programme were used. Physicians managing patients with T2DM were surveyed via face-to-face interviews, and patients treated for T2DM were surveyed via self-completed questionnaires. Patient data were stratified by current versus prior GLP1 RA use.

RESULTS

Physicians (n=443) most frequently reported inadequate blood glucose control (45.6%), nausea/vomiting (43.8%), and gastrointestinal (GI) side effects (36.8%) as reasons for GLP1 RA discontinuation. Patients (n=194) reported the GI-related issues "Made me feel sick" (64.4%) and "Made me throw up" (45.4%) as their top reasons for discontinuation. The most common problems reported (excluding cost) for those currently using GLP1 RAs were "Prefer oral medication over injections" (patients 56%, physicians 32.6%), "Made me feel sick" (patients 38.1%, physicians 16.3%), and "Did not help lose weight" (patients 25.4%, physicians 18%). The most bothersome problems for patients globally (frequency reporting very/extremely bothersome) (excluding cost) were "Difficult to plan meals around" (55.6%), "Made me throw up" (51.6%), and "Caused weight gain" (50%).

CONCLUSION

Both patients and physicians reported GI-related issues as a prominent factor, but disparities between patient experiences and physician perceptions were revealed, suggesting gaps in physician-patient communication. Understanding patients' expectations of GLP1 RAs and physicians' patient-management practices may help increase GLP1 RA adherence and thereby potentially enhance diabetes care.

Medical Management of Diabesity: Do We Have Realistic Targets?

PURPOSE OF REVIEW

The global prevalence of "diabesity"-diabetes related to obesity-is increasing steadily over the past few decades because of the obesity epidemic. Although bariatric surgery is an effective treatment option for patients with diabesity, its limited availability, invasiveness, relatively high costs and the potential for surgical and postsurgical complications restrict its widespread use. Therefore, medical management is the only option for a majority of patients with diabesity. Diabetes control with several anti-diabetic agents, including insulin, causes weight gain with probability of worsening diabesity. Rational use of anti-diabetic medications with weight loss potential in varying combinations may help to address this key issue for long-term management of diabesity. There is no consensus on such an approach from different professional bodies like American Diabetes Association, European Association for Study of Diabetes, or International Diabetes Federation. We attempt to discuss the key issues and realistic targets for diabesity management in this paper.

RECENT FINDINGS

Rational use of anti-diabetic combinations can mitigate worsening of diabesity to some extent while managing patients. Retrospective studies showed that combination therapy with glucagon-like peptide-1 (GLP-1) receptor agonists and sodium glucose co-transporter 2 (SGLT-2) inhibitors, when administered along with other anti-diabetic medications, offer the best therapeutic benefit in the medical management of diabesity. Different combinations of other anti-diabetic drugs with minimum weight gain potential were also found useful. Because of insufficient evidence based on prospective randomised controlled trials (RCTs), future research should focus on evolving the appropriate rational drug combinations for the medical management of diabesity.

Glucagon-like peptide 1 in the pathophysiology and pharmacotherapy of clinical obesity

Though the pathophysiology of clinical obesity is undoubtedly multifaceted, several lines of clinical evidence implicate an important functional role for glucagon-like peptide 1 (GLP-1) signalling. Clinical studies assessing GLP-1 responses in normal weight and obese subjects suggest that weight gain may induce functional deficits in GLP-1 signalling that facilitates maintenance of the obesity phenotype. In addition, genetic studies implicate a possible role for altered GLP-1 signalling as a risk factor towards the development of obesity. As reductions in functional GLP-1 signalling seem to play a role in clinical obesity, the pharmacological replenishment seems a promising target for the medical management of obesity in clinical practice. GLP-1 analogue liraglutide at a high dose (3 mg/d) has shown promising results in achieving and maintaining greater weight loss in obese individuals compared to placebo control, and currently licensed anti-obesity medications. Generally well tolerated, provided that longer-term data in clinical practice supports the currently available evidence of superior short- and long-term weight loss efficacy, GLP-1 analogues provide promise towards achieving the successful, sustainable medical management of obesity that remains as yet, an unmet clinical need.

Nutritional modulation of endogenous glucagon-like peptide-1 secretion: a review

BACKGROUND

The positive influences of glucagon-like peptide-1 (GLP-1) on blood glucose homeostasis, appetite sensations, and food intake provide a strong rationale for its therapeutic potential in the nutritional management of obesity and type 2 diabetes.

AIM

To summarize GLP-1 physiology and the nutritional modulation of its secretion in the context of obesity and type 2 diabetes management.

FINDINGS

GLP-1 is mainly synthesized and secreted by enteroendocrine L-cells of the gastrointestinal tract. Its secretion is partly mediated by the direct nutrient sensing by G-protein coupled receptors which specifically bind to monosaccharides, peptides and amino-acids, monounsaturated and polyunsaturated fatty acids as well as to short chain fatty acids. Foods rich in these nutrients, such as high-fiber grain products, nuts, avocados and eggs also seem to influence GLP-1 secretion and may thus promote associated beneficial outcomes in healthy individuals as well as individuals with type 2 diabetes or with other metabolic disturbances.

CONCLUSION

The stimulation of endogenous GLP-1 secretion by manipulating the composition of the diet may be a relevant strategy for obesity and type 2 diabetes management. A better understanding of the dose-dependent effects as well as the synergistic effects of nutrients and whole foods is needed in order to develop recommendations to appropriately modify the diet to enhance GLP-1 beneficial effects.

Lixisenatide Improves Glycemic Control in Asian Type 2 Diabetic Patients Inadequately Controlled With Oral Antidiabetic Drugs: An Individual Patient Data Meta-Analysis

INTRODUCTION

Lixisenatide is a novel GLP-1 receptor agonist for the treatment of type 2 diabetes mellitus (T2DM). Its efficacy and safety have been assessed in a series of phase 3 studies included in the GetGoal program. In these studies, lixisenatide was found to be superior to placebo in glycemic control. The aim of this meta-analysis was to assess the safety and efficacy of lixisenatide as an adjunct therapy in Asian patients with T2DM in adequately controlled with oral antidiabetic drugs (OADs).

METHODS

We performed a meta-analysis from five lixisenatide phase 3 studies. In each of these multiethnic studies, patients with T2DM inadequately controlled (glycated hemoglobin, HbA1c ≥7%) with established OADs were randomized to lixisenatide or placebo for 24 weeks, with a balanced distribution of Asian patients in these two arms (503 and 338 patients in the intent-to-treat population, respectively).

RESULTS

Lixisenatide was superior to placebo in reducing HbA1c (weighted, total mean difference -0.57%; P = 0.002). More patients treated with lixisenatide versus placebo achieved HbA1c targets of ≤7% (49.1% vs. 28.4%, P = 0.003). Lixisenatide was superior to placebo in lowering 2-h postprandial glucose (PPG) (weighted, total mean difference -5.50 mmol/l, P = 0.0005). More patients treated with lixisenatide versus placebo achieved 2-h PPG targets of ≤7.8 mmol/l (39.2% vs. 2.2%, P < 0.0001). More patients treated with lixisenatide versus placebo achieved both an HbA1c target of ≤7% and a 2-h PPG target of ≤10 mmol/l (34.8% vs. 2.69%, P < 0.00001). The body weight of the lixisenatide group tended to decrease. Lixisenatide was generally well tolerated.

CONCLUSION

Lixisenatide as an adjunct therapy can significantly improve the glycemic control of Asian patients with type 2 DM who do not meet targets for glycemic control with an established OAD regimen.

FUNDING

Sanofi (China) Investment Co., Ltd., Shanghai, China.

Glucagon-like peptide-2 treatment improves glucose dysmetabolism in mice fed a high-fat diet

Previous studies suggested that endogenous glucagon-like peptide 2 (GLP-2) is dispensable for the regulation of glucose homeostasis under normal conditions, while it can play a beneficial role in obesity conditions. The purpose of the present study was to investigate whether chronic treatment with Gly²-GLP-2, a stable analogue of GLP-2, can have an impact on glycaemic and lipid control in mice fed a high-fat diet (HFD), an animal model of human obesity and insulin resistance. HFD mice were treated once a day with Gly²-GLP-2 for 4 weeks. Body weight, food intake, fasting glucose, intraperitoneal glucose tolerance, insulin-induced glucose clearance, glucose-stimulated insulin secretion, β-cell mass, plasma lipid metabolic profile, and lipid deposition in the liver were examined. In untreated HFD mice, fasting glucose levels, glucose tolerance, glucose-stimulated plasma insulin and sensibility to exogenous insulin were deteriorating with time and β-cell mass increased. In Gly²-GLP-2-treated mice, we found significant increase in glucose tolerance and exogenous insulin sensitivity, reduction in glucose-stimulated plasma insulin and in the increase in β-cell mass in comparison with pair-aged HFD untreated animals. The chronic treatment with the peptide was not associated with remarkable improvements of dyslipidemia and it did not prevent liver fat accumulation and the presence of microvesicular steatosis. In conclusion, the results of the present study suggest, for the first time, that Gly²-GLP-2 may produce glucose metabolic benefits in mice with diet-induced obesity. The mechanisms underlying the beneficial impact of GLP-2 on glucose metabolism remain to be established.

Oral delivery of diabetes peptides - Comparing standard formulations incorporating functional excipients and nanotechnologies in the translational context

While some orally delivered diabetes peptides are moving to late development with standard formulations incorporating functional excipients, the demonstration of the value of nanotechnology in clinic is still at an early stage. The goal of this review is to compare these two drug delivery approaches from a physico-chemical and a biopharmaceutical standpoint in an attempt to define how nanotechnology-based products can be differentiated from standard oral dosage forms for oral bioavailability of diabetes peptides. Points to consider in a translational approach are outlined to seize the opportunities offered by a better understanding of both the intestinal barrier and of nano-carriers designed for oral delivery.

[Lixisenatide in patients with type 2 diabetes and obesity: Beyond glycaemic control]

Objetivo

Evaluar la tolerancia a lixisenatida y sus efectos sobre el peso y el control metabólico de pacientes con diabetes tipo 2 y obesidad.

Diseño

Estudio prospectivo.

Emplazamiento

Consultas de atención especializada de Endocrinología y Nutrición en Almería, Granada y Málaga.

Participantes

Pacientes con diabetes tipo 2 y obesidad.

Intervenciones

Respuesta y tolerancia al tratamiento con lixisenatida.

Mediciones principales

Se analizaron datos clínicos y analíticos con medidas de cambio intrasujeto antes-después del tratamiento.

Resultados

Evaluamos 104 pacientes (51% mujeres) con diabetes tipo 2 y obesidad (Almería 18,3%; Granada 40,4%; Málaga 41,3%). Edad media 58,4 ± 10,5 años y duración media de diabetes 11,2 ± 6,7 años. El tiempo medio desde la visita basal a la revisión tras inicio de tratamiento con lixisenatida fue de 3,8 ± 1,6 meses. Encontramos mejoría significativa del peso (p < 0,001), índice de masa corporal (p < 0,001), circunferencia de cintura (p = 0,002), presión arterial sistólica (p < 0,001) y diastólica (p = 0,001), glucemia en ayunas (p < 0,001), HbA1c (p = 0,022), colesterol total (p < 0,001), colesterol LDL (p = 0,046) y triglicéridos (p = 0,020). No se observó alteración de cifras de amilasa en relación con el tratamiento con lixisenatida, y el 7,9% no lo toleraron.

Conclusiones

Lixisenatida consigue: 1) mejoría significativa de parámetros antropométricos y control glucémico (glucemia basal y HbA1c); 2) descenso significativo de la presión arterial y del perfil lipídico, y 3) seguridad y buena tolerancia en la mayoría de los pacientes. Además, encontramos una significativa intensificación del tratamiento antihipertensivo e hipolipemiante.

Investigational glucagon-like peptide-1 agonists for the treatment of obesity

INTRODUCTION

Obesity is a worldwide problem predisposing to type 2 diabetes mellitus (T2DM), hypertension, cardiovascular disease, cancer and other comorbidities. Lifestyle modification is the first line intervention but adjunctive pharmacotherapy is often required. The GLP-1 receptor agonists (GLP-1RAs) were developed primarily for T2DM and they also reduce body weight. Liraglutide was approved for the treatment of obesity and other GLP-1RAs are likely to be suitable for this indication.

AREAS COVERED

This review describes the GLP-1RAs that have been approved for the treatment of T2DM as potential candidates for the treatment of obesity and the new agents currently under development which may have advantages in patient adherence.

EXPERT OPINION

The GLP-1RAs offer a welcome addition to obesity pharmacotherapy. They appear to be free of serious adverse effects although uncertainty remains about possible risks of pancreatitis and neoplasms. However, they have frequent gastrointestinal side effects, particularly nausea, which limits their tolerability. Cardiovascular outcome studies in T2DM support their use and this is likely to increase in both T2DM and obesity. Other GLP-1RAs which can be given by subcutaneous injection once weekly or less frequently or by oral administration would have advantages especially if nausea is less frequent than with liraglutide.

DPP-4 inhibitors in diabetic complications: role of DPP-4 beyond glucose control

Dipeptidyl peptidase-4 (DPP-4) inhibitors (gliptins) are an emerging class of antidiabetic drugs that constitutes approximately fifty percent of the market share of the oral hypoglycemic drugs. Its mechanism of action for lowering blood glucose is essentially via inhibition of the rapid degradation of incretin hormones, such as glucagon-like peptide (GLP)-1 and gastric inhibitory polypeptide (GIP), thus the plasma concentration of GLP-1 increases, which promotes insulin secretion from the pancreatic β cells and suppresses glucagon secretion from the α cells. In addition to the direct actions on the pancreas, GLP-1 exhibits diverse actions on different tissues through its action on GLP-1 receptor, which is expressed ubiquitously. Moreover, DPP-4 has multiple substrates besides GLP-1 and GIP, including cytokines, chemokines, neuropeptides, and growth factors, which are involved in many pathophysiological conditions. Recently, it was suggested that DPP-4 is a new adipokine secreted from the adipose tissue, which plays an important role in the regulation of the endocrine function in obesity-associated type 2 diabetes. Consequently, DPP-4 inhibitors have been reported to exhibit cytoprotective functions against various diabetic complications affecting the liver, heart, kidneys, retina, and neurons. This review outlines the current understanding of the effect of DPP-4 inhibitors on the complications associated with type 2 diabetes, such as liver steatosis and inflammation, dysfunction of the adipose tissue and pancreas, cardiovascular diseases, nephropathy, and neuropathy in preclinical and clinical studies.

Exenatide Treatment Alone Improves β-Cell Function in a Canine Model of Pre-Diabetes

Background

Exenatide’s effects on glucose metabolism have been studied extensively in diabetes but not in pre-diabetes.

Objective

We examined the chronic effects of exenatide alone on glucose metabolism in pre-diabetic canines.

Design and Methods

After 10 weeks of high-fat diet (HFD), adult dogs received one injection of streptozotocin (STZ, 18.5 mg/kg). After induction of pre-diabetes, while maintained on HFD, animals were randomized to receive either exenatide (n = 7) or placebo (n = 7) for 12 weeks. β-Cell function was calculated from the intravenous glucose tolerance test (IVGTT, expressed as the acute insulin response, AIR_G), the oral glucose tolerance test (OGTT, insulinogenic index) and the graded-hyperglycemic clamp (clamp insulinogenic index). Whole-body insulin sensitivity was assessed by the IVGTT. At the end of the study, pancreatic islets were isolated to assess β-cell function in vitro.

Results

OGTT: STZ caused an increase in glycemia at 120 min by 22.0% (interquartile range, IQR, 31.5%) (P = 0.011). IVGTT: This protocol also showed a reduction in glucose tolerance by 48.8% (IQR, 36.9%) (P = 0.002). AIR_G decreased by 54.0% (IQR, 40.7%) (P = 0.010), leading to mild fasting hyperglycemia (P = 0.039). Exenatide, compared with placebo, decreased body weight (P<0.001) without altering food intake, fasting glycemia, insulinemia, glycated hemoglobin A1c, or glucose tolerance. Exenatide, compared with placebo, increased both OGTT- (P = 0.040) and clamp-based insulinogenic indexes (P = 0.016), improved insulin secretion in vitro (P = 0.041), but had no noticeable effect on insulin sensitivity (P = 0.405).

Conclusions

In pre-diabetic canines, 12-week exenatide treatment improved β-cell function but not glucose tolerance or insulin sensitivity. These findings demonstrate partial beneficial metabolic effects of exenatide alone on an animal model of pre-diabetes.

Pharmacologic Therapy of Type 2 Diabetes

Type 2 diabetes (T2DM) is a common condition. Treatment of diabetes and related complications can be complex. In addition to lifestyle changes, medications play an important role in controlling patients' blood glucose levels and preventing complications. From an individual and societal standpoint, it is also an expensive disease. Medical spending attributed to diabetes per individual is significant. With appropriate therapy, patients can lead full, healthy lives with the disease, so making informed decisions regarding pharmacotherapy for T2DM is clearly of great importance.

GLP-1 receptor agonist as treatment for cancer as well as diabetes: beyond blood glucose control

Recent studies indicate that cancer is a new complication of diabetes. In Japan, cancer is the most critical cause of death in patients with type 2 diabetes. Areas covered: Unlike diabetic angiopathies, diabetes does not accelerate the onset and progression of cancer, even though diabetes and cancer exhibit very similar pathophysiological features including obesity, insulin resistance, chronic inflammation, oxidative stress, and decreased adipokine imbalance. Agonists to glucagon-like peptide-1 (GLP-1) receptor are a newly identified therapy for type 2 diabetes. These drugs exert their effects by enhancing glucose-induced insulin secretion and inhibiting appetite. However, the relationship between GLP-1 receptor agonists and cancer is controversial. Expert commentary: GLP-1 receptor agonist may possess anti-cancer effect in several kind of cancers.

Structurally Enabled Discovery of Adenosine A2A Receptor Antagonists

Over the past decade there has been a revolution in the field of G protein-coupled receptor (GPCR) structural biology. Many years of innovative research from different areas have come together to fuel this significant change in the fortunes of this field, which for many years was characterized by the paucity of high-resolution structures. The determination to succeed has been in part due to the recognized importance of these proteins as drug targets, and although the pharmaceutical industry has been focusing on these receptors, it can be justifiably argued and demonstrated that many of the approved and commercially successful GPCR drugs can be significantly improved to increase efficacy and/or reduce undesired side effects. In addition, many validated targets in this class remain to be drugged. It is widely recognized that application of structure-based drug design approaches can help medicinal chemists a long way toward discovering better drugs. The achievement of structural biologists in providing high-resolution insight is beginning to transform drug discovery efforts, and there are a number of GPCR drugs that have been discovered by use of structural information that are in clinical development. This review aims to highlight the key developments that have brought success to GPCR structure resolution efforts and exemplify the practical application of structural information for the discovery of adenosine A_2A receptor antagonists that have potential to treat multiple conditions.

Limiting glucocorticoid secretion increases the anorexigenic property of Exendin-4

Objective

Glucagon-like peptide-1 (GLP-1) analogs are attractive options for the treatment of type II diabetes and obesity because of their incretin and anorexigenic effects. Peripheral administration of the GLP-1R agonist Exendin-4 (Ex-4) also increases glucocorticoid secretion in rodents and humans, but whether the released glucocorticoids interact with Ex-4's anorexigenic effect remains unclear.

Methods

To test this, we used two experimental approaches that suppress corticosterone secretion and then assessed Ex-4 effects on eating in adult male rats. First, we combined acute and chronic low dose dexamethasone treatment with Ex-4. Second, we ablated hindbrain catecholamine neurons projecting to the hypothalamus with anti-dopamine-β-hydroxylase-saporin (DSAP) to block Ex-4-induced corticosterone secretion.

Results

Combining dexamethasone and Ex-4 produced a larger acute anorexigenic effect than Ex-4 alone. Likewise, chronic dexamethasone and Ex-4 co-treatment produced a synergistic effect on eating and greater body weight loss in diet-induced obese rats than Ex-4 alone. DSAP lesions not only blunted Ex-4's ability to increase corticosterone secretion, but potentiated the anorexigenic effect of Ex-4, indicating that Ex-4-dependent corticosterone secretion opposes Ex-4's actions. Consistent with the enhancement of Ex-4's anorexigenic effect, DSAP lesion altered Ex-4-dependent changes in neuropeptide Y, preproglucagon, and corticotropin releasing hormone gene expression involved in glucocorticoid feedback.

Conclusions

Our findings demonstrate that limiting glucocorticoid secretion and actions with low dose dexamethasone or DSAP lesion increases Ex-4's ability to reduce food intake and body weight. Novel glucocorticoid receptor based mechanisms, therefore, may help enhance GLP-1-based obesity therapies.

•

Blocking HPA axis by low dose dexamethasone increased the anorexigenic property of Ex-4.

•

Dexamethasone/Ex-4 co-treatment reduced food intake and body weight in diet-induced obese rats more than Ex-4 alone.

•

A brain lesion model identified a potential central interaction between glucocorticoids and GLP-1 in food intake control.

Combination therapy of SGLT2 inhibitors with incretin-based therapies for the treatment of type 2 diabetes mellitus: Effects and mechanisms of action

Type 2 diabetes mellitus (T2DM) is a growing health problem worldwide; its pathogenesis is multifactorial and its progressive nature often necessitates a combination therapy with multiple antihyperglycemic agents. Sodium glucose cotransporter 2 (SGLT2) inhibitors and the incretin-based therapies - dipeptidyl peptidase 4(DPP-4) inhibitors and glucagon-like peptide 1 (GLP-1) receptor agonists - were introduced for the treatment of T2DM within the last decade. Evidence of the beneficial effects of these antihyperglycemic agents on micro- and macrovascular complications have started to emerge, which will become important in individualizing different combinations of antihyperglycemic agents to different patient populations. We review here the mechanisms of action, glycemic and cardiovascular effects of SGLT2 inhibitors and incretin-based therapies and their combination in the treatment of T2DM.

Exenatide inhibits fatty acid induced hepatocyte steatosis and inflammation through activating AMPK

AIM: To detect the effect of glucagon-like peptide-1 (GLP-1) agonist exenatide (EXE) on fat deposition in liver cells and explore the underlying mechanism.

METHODS: A HepG2 cell deposition model was induced with palmitic acid (PA). After cells were incubated with different doses of EXE (25-100 nmoL/L) and PA (500 μmoL/L) for 24 h, fatty deposition was assessed by oil red O staining and the level of intracellular triglyceride (TG). Real-time quantitative PCR (qRT-PCR) was used to detect the expression of lipid metabolism related genes, including fatty acid synthase (FAS), tumor necrosis factor α (TNF-α), and interleukin 6 (IL-6). The expression of p-AMPK and AMPK protein was tested by Western blot. An AMPK inhibitor was used to explore the role of AMPK in fat deposition and inflammation.

RESULTS: Compared with the control group, PA significantly elevated TG and oil red O content, as well as the expression of FAS in HepG2 cells (P < 0.05). EXE significantly inhibited PA induced elevation of TG and oil red O content, as well as FAS gene expression in a dose dependent manner (P < 0.05). The expression of TNF-α and IL-6 significantly increased in the PA treated group (P < 0.05). EXE significantly inhibited the expression of TNF-α and IL-6 in PA treated HepG2 cells (P < 0.05). Co-treatment with AMPK inhibitor significantly reduced the effect of EXE on AMPK, and reduced the inhibitory effect of EXE on fatty deposition and PA induced FAS activation (P < 0.05). AMPK inhibitor significantly diminished the inhibitory effect of EXE on TNF-α and IL-6 activation induced by PA (P < 0.05).

CONCLUSION: EXE reduces fatty acid induced fatty deposition and inflammatory response in liver cells through activation of AMPK.

An Update on the Effect of Incretin-Based Therapies on β-Cell Function and Mass

Type 2 diabetes mellitus (T2DM) is a multifactorial disease with a complex and progressive pathogenesis. The two primary mechanisms of T2DM pathogenesis are pancreatic β-cell dysfunction and insulin resistance. Pancreatic β-cell dysfunction is recognized to be a prerequisite for the development of T2DM. Therapeutic modalities that improve β-cell function are considered critical to T2DM management; however, blood glucose control remains a challenge for many patients due to suboptimal treatment efficacy and the progressive nature of T2DM. Incretin-based therapies are now the most frequently prescribed antidiabetic drugs in Korea. Incretin-based therapies are a favorable class of drugs due to their ability to reduce blood glucose by targeting the incretin hormone system and, most notably, their potential to improve pancreatic β-cell function. This review outlines the current understanding of the incretin hormone system in T2DM and summarizes recent updates on the effect of incretin-based therapies on β-cell function and β-cell mass in animals and humans.

Elastin-like polypeptides in drug delivery

The use of recombinant elastin-like materials, or elastin-like recombinamers (ELRs), in drug-delivery applications is reviewed in this work. Although ELRs were initially used in similar ways to other, more conventional kinds of polymeric carriers, their unique properties soon gave rise to systems of unparalleled functionality and efficiency, with the stimuli responsiveness of ELRs and their ability to self-assemble readily allowing the creation of advanced systems. However, their recombinant nature is likely the most important factor that has driven the current breakthrough properties of ELR-based delivery systems. Recombinant technology allows an unprecedented degree of complexity in macromolecular design and synthesis. In addition, recombinant materials easily incorporate any functional domain present in natural proteins. Therefore, ELR-based delivery systems can exhibit complex interactions with both their drug load and the tissues and cells towards which this load is directed. Selected examples, ranging from highly functional nanocarriers to macrodepots, will be presented.