Interim analysis of the effects of exenatide treatment on A1C, weight and cardiovascular risk factors over 82 weeks in 314 overweight patients with type 2 diabetes

Annual Prize Lecture 2024: Endogenous physiological mechanisms as basis for the treatment of obesity and type 2 diabetes

In 1964, it was proven that postprandial insulin secretion is largely regulated by gut hormones and, in 1973, it was proposed that a gut hormone would also regulate appetite and food intake. Several gut hormones were tested for metabolic actions with disappointing results until the discovery of the proglucagon derivative, glucagon-like peptide-1 (GLP-1). This peptide from the distal intestine has preserved activity on insulin secretion in people with type 2 diabetes and turned out to regulate both secretion and motility in the gastrointestinal tract and importantly, appetite and food intake, thus functioning as an efficient 'ileal brake' hormone. However, the natural hormone acts predominantly via sensory afferent systems and is extremely rapidly removed from the circulation by enzymatic degradation and renal elimination, and increasing the doses merely results in nausea and vomiting. Lipidation of analogs turned out to provide both stability and limit renal elimination, and very slow up-titration of dosing improves tolerance. Indeed, the most recent agonists may near-normalize glycaemic control in type 2 diabetes, may cause weight losses of up to 25% of body weight, and significantly reduce cardiovascular risk, effects that resemble those of bariatric surgery. Thus, a solution to one of the most serious health problems of modern civilization, the increased morbidity and mortality of the metabolic syndrome, may be addressed by mobilization of one of the body's own regulatory mechanisms.

Semaglutide treatment of hypothalamic obesity - a real-life data study

PURPOSE

Patients with tumors involving the hypothalamic region are at high risk of developing morbid obesity due to disturbances in the appetite regulative nuclei in hypothalamus. We evaluated the effect of the Glucagon-like peptide 1 (GLP-1) analogue semaglutide in patients with hypothalamic obesity.

METHODS

We recorded weight changes from real-time data before and after treatment with semaglutide in patients with hypothalamic obesity from our outpatient clinic at the Department of Endocrinology at Rigshospitalet, from September 2020 to November 2023.

RESULTS

A total of 26 patients were included in this study (15 females, median age at initiation of semaglutide was 52 (range 18-65) years). Body mass index (BMI) at initial diagnosis was median 25 (range 20-38) kg/m2 while BMI at initiation of semaglutide was median 38 (range 28-58) kg/m2. All but one patient lost weight during semaglutide treatment with a mean weight loss of 13.4 kg (95% CI 10.3-16.5 kg, p = < 0.001) after 12 months corresponding to a loss in BMI of 4.4 kg/m2 (95% CI 3.4-5.4 kg/m2, p = < 0.001) with a median dosage of semaglutide of 1.6 (range 0.5-2.5) mg. Fifteen patients (58%) lost more than 10% and two patients (8%) lost more than 20% of initial body weight, respectively.

CONCLUSION

Treatment with semaglutide shows promising results in reducing body weight in patients with acquired hypothalamic obesity. Whether the weight reduction remains stable after long time follow-up needs further investigation.

Bone Fragility in Diabetes and its Management: A Narrative Review

Bone fragility is a serious yet under-recognised complication of diabetes mellitus (DM) that is associated with significant morbidity and mortality. Multiple complex pathophysiological mechanisms mediating bone fragility amongst DM patients have been proposed and identified. Fracture risk in both type 1 diabetes (T1D) and type 2 diabetes (T2D) continues to be understated and underestimated by conventional risk assessment tools, posing an additional challenge to the identification of at-risk patients who may benefit from earlier intervention or preventive strategies. Over the years, an increasing body of evidence has demonstrated the efficacy of osteo-pharmacological agents in managing skeletal fragility in DM. This review seeks to elaborate on the risk of bone fragility in DM, the underlying pathogenesis and skeletal alterations, the approach to fracture risk assessment in DM, management strategies and therapeutic options.

Variants in PPARD-GLP1R are related to diabetic kidney disease in Chinese Han patients with type 2 diabetes mellitus

Genetic susceptibility is an important pathogenic mechanism in diabetic kidney disease (DKD). Our previous studies have identified that PPARδ and GLP-1R are located in a pathway that is closely related to DKD. We aimed to explore the impacts of variants in PPARD-GLP1R on the susceptibility to DKD in Chinese Han patients with type 2 diabetes mellitus (T2DM). A total of 600 T2DM patients (300 with DKD and 300 without DKD) and 200 healthy control subjects were enrolled to identify PPARD (rs2016520, rs2267668 and rs3777744) and GLP1R (rs3765467, rs1042044 and rs9296291) genotype. The SNaPshot method was used to identify variants in PPARD-GLP1R. We performed correlation analysis between variants in PPARD-GLP1R and the susceptibility to DKD. We observed that GLP1R rs3765467 (G > A) was associated with DKD (OR = 3.145, 95 % CI = 2.128-6.021, P = 0.035). None of the other SNPs were associated with DKD. Regarding DKD related traits, rs3765467 was associated with UACR levels and TC, significant differences were observed among patients with different genotypes of rs2016520 in terms of BMI and TG, and patients with the rs3777744 risk G allele had noticeably higher PPG and HbA1c levels (P < 0.05). Moreover, the results showed the interactions between PPARD rs3777744 and GLP1R rs3765467 in the occurrence of DKD (OR = 4.572, P = 0.029). The results of this study indicate the potential relationship between variants in PPARD-GLP1R and the susceptibility to DKD in Chinese Han patients with T2DM.

Towards Optimal Cardiovascular Health: A Comprehensive Review of Preventive Strategies

Heart disease remains a prominent global health concern, with cardiovascular disease (CVD) standing as a leading cause of death worldwide. Preventing heart disease not only decreases the risk of premature death but also mitigates complications like heart attacks, strokes, and arrhythmias, thereby enhancing overall health and quality of life. The economic burden of heart disease treatment highlights the importance of implementing preventive measures, such as lifestyle changes and early interventions, which can alleviate healthcare costs. These strategies, targeting risk factors like hypertension (HTN), diabetes mellitus (DM), dyslipidemia, and obesity, not only prevent heart disease but also reduce the risk of other health issues. Herein, this review covers various preventive measures, including dietary interventions, exercise, controlling HTN, DM, cholesterol, and weight, smoking cessation, and pharmacological interventions. By critically analyzing the guidelines and leveraging robust data alongside variations in recommendations, this review aims to elucidate effective primary prevention strategies for CVD.

PEGylated exenatide injection (PB-119) improves beta-cell function and insulin resistance in treatment-naïve type 2 diabetes mellitus patients

Objective: PB-119, a PEGylated exenatide injection, is a once-weekly glucagon-like peptide-1 receptor agonist. In the present study, we aimed to evaluate the effects of PB-119 on insulin resistance and beta-cell function in Chinese patients with type 2 diabetes mellitus (T2DM) to uncover its antidiabetic characteristics. Methods: A total of 36 Chinese T2DM patients were randomized to receive 25 μg and 50 μg PB-119 once weekly and exenatide (5-10 μg injected under the skin 2 times a day adjusted by the doctor) for 12 weeks. Oral mixed meal tolerance tests were conducted before the study and on Day 79. The data were fitted to estimate beta-cell function and insulin sensitivity parameters using the SAAM II package integrating the oral minimal model (OMM), which was compared with Homeostatic Model Assessment (HOMA) analysis results. Results: Exenatide or PB-119 treatment, compared with their baseline, was associated with higher beta-cell function parameters (φb, φs and φtot), disposition index, insulin secretion rates, and a lower glucose area under the curve. High-dose PB-119 also has a higher insulin resistance parameter (SI) than the baseline, but HOMA-IR did not. For the homeostatic model assessment parameters, HOMA-IR showed no statistically significant changes within or between treatments. Only high-dose PB-119 improved HOMA-β after 12 weeks of treatment. Conclusion: After 12 weeks of treatment, PB-119 decreased glycemic levels by improving beta-cell function and insulin resistance.

Differences in weight loss and safety between the glucagon-like peptide-1 receptor agonists: A non-randomized multicenter study from the titration phase

INTRODUCTION

Obesity increases the risk of type 2 diabetes mellitus and cardiovascular disease (CVD). Weight loss (≥5 %) reduces the risk of CVD. Glucagon-like peptide-1 receptor agonists (GLP1 RA) have shown clinically weight loss.

OBJECTIVES

1) To assess differences in the efficacy of weight loss and HbA1c; 2) to evaluate the safety and adherence during the titration phase.

METHODS

It is a multicenter, prospective, and observational study on GLP1 RA naïve patients. The primary end point was the weight loss (≥5 %). Changes in weight, BMI and HbA1c were also calculated as co-primary endpoints. Secondary endpoints were safety, adherence, and tolerance.

RESULTS

Among 94 subjects, 42.4 % received dulaglutide, 29,3 % subcutaneous semaglutide, 22,8 % oral semaglutide. 45 % female and the mean age was 62. Baseline characteristics were body weight 99.3 kg, BMI 36.7 kg/m² and Hba1c 8.2 %. Oral semaglutide achieved the highest reduction: 61.1 % of patients achieving ≥ 5 %, subcutaneous semaglutide 45.8 % and dulaglutide 40.6 %. GLP1 RA significantly reduced body weight (-4.95 kg, p < 0.001) and BMI (-1.86 kg/m², p < 0.001), without significant differences between groups. Gastrointestinal disorders were the most frequently reported events (74.5 %). 62 % of patients on dulaglutide, 25 % on oral semaglutide and 22 % on subcutaneous semaglutide.

CONCLUSIONS

Oral semaglutide achieved the highest proportion of patients that lost ≥ 5 %. GLP1 RA significantly reduced BMI and HbA1c. Most of the reported adverse events were gastrointestinal disorders and they were reported in a major frequency in the dulaglutide group. Oral semaglutide would be a reasonable switch in case of future shortages.

FALCON systematically interrogates free fatty acid biology and identifies a novel mediator of lipotoxicity

Cellular exposure to free fatty acids (FFA) is implicated in the pathogenesis of obesity-associated diseases. However, studies to date have assumed that a few select FFAs are representative of broad structural categories, and there are no scalable approaches to comprehensively assess the biological processes induced by exposure to diverse FFAs circulating in human plasma. Furthermore, assessing how these FFA- mediated processes interact with genetic risk for disease remains elusive. Here we report the design and implementation of FALCON (Fatty Acid Library for Comprehensive ONtologies) as an unbiased, scalable and multimodal interrogation of 61 structurally diverse FFAs. We identified a subset of lipotoxic monounsaturated fatty acids (MUFAs) with a distinct lipidomic profile associated with decreased membrane fluidity. Furthermore, we developed a new approach to prioritize genes that reflect the combined effects of exposure to harmful FFAs and genetic risk for type 2 diabetes (T2D). Importantly, we found that c-MAF inducing protein (CMIP) protects cells from exposure to FFAs by modulating Akt signaling and we validated the role of CMIP in human pancreatic beta cells. In sum, FALCON empowers the study of fundamental FFA biology and offers an integrative approach to identify much needed targets for diverse diseases associated with disordered FFA metabolism.

Highlights

FALCON (Fatty Acid Library for Comprehensive ONtologies) enables multimodal profiling of 61 free fatty acids (FFAs) to reveal 5 FFA clusters with distinct biological effectsFALCON is applicable to many and diverse cell typesA subset of monounsaturated FAs (MUFAs) equally or more toxic than canonical lipotoxic saturated FAs (SFAs) leads to decreased membrane fluidityNew approach prioritizes genes that represent the combined effects of environmental (FFA) exposure and genetic risk for diseaseC-Maf inducing protein (CMIP) is identified as a suppressor of FFA-induced lipotoxicity via Akt-mediated signaling.

Glucagon-like Peptide-1 Receptor Agonists in the Management of Type 2 Diabetes Mellitus and Obesity: The Impact of Pharmacological Properties and Genetic Factors

Glucagon-like peptide-1 (GLP-1) receptor agonists are a new class of antihyperglycemic drugs that enhance appropriate pancreatic β-cell secretion, pancreatic α-cell (glucagon) suppression, decrease liver glucose production, increase satiety through their action on the central nervous system, slow gastric emptying time, and increase insulin action on peripheral tissue. They are effective in the management of type 2 diabetes mellitus and have a favorable effect on weight loss. Their cardiovascular and renal safety has been extensively investigated and confirmed in many clinical trials. Recently, evidence has shown that in addition to the existing approaches for the treatment of obesity, semaglutide in higher doses promotes weight loss and can be used as a drug to treat obesity. However, some T2DM and obese patients do not achieve a desired therapeutic effect of GLP-1 receptor agonists. This could be due to the multifactorial etiologies of T2DM and obesity, but genetic variability in the GLP-1 receptor or signaling pathways also needs to be considered in non-responders to GLP-1 receptor agonists. This review focuses on the pharmacological, clinical, and genetic factors that may influence the response to GLP-1 receptor agonists in the treatment of type 2 diabetes mellitus and obesity.

Perirenalfat thickness is associated with bone turnover markers and bone mineral density in postmenopausal women with type 2 diabetes mellitus

OBJECTIVES

Emerging evidence demonstrated that perirenal fat may modulate bone metabolism through several pathological pathways. This study was aimed to assess the associations between perirenal fat thickness (PrFT) and bone turnover markers (BTMs) and bone mineral density (BMD) in postmenopausal women with type 2 diabetes mellitus (T2DM) and further explore the correlation between PrFT and osteoporosis.

METHODS

In this cross-sectional study, a total of 626 participants with complete data were enrolled in this study. Demographic and anthropometric information was collected. Biochemical parameters and BTMs were determined. PrFT and BMD were measured by computed tomography and dual-energy x-ray absorptiometry, respectively. Correlation analysis and regression models were used to assess the associations between PrFT and BTMs and BMD. The multiple binomial logistic regression model was used to estimate the independent variables of PrFT for osteoporosis.

RESULTS

Overall, the prevalence of osteoporosis was 38.7%. PrFT was negatively correlated with β-cross-linked C-telopeptide of type I collagen (β-CTX) (r = -0.216,< 0.001), L1-L4 BMD (r = -0.351, < 0.001), and T-score (r = -0.396, < 0.001). PrFT also remained significantly correlated with β-CTX (β = -0.291, P< 0.001), L1-L4 BMD (β = -0.109, P= 0.027), and L1-L4 T-score (β = -0.149, P= 0.001) after adjustment for other confounding factors. Furthermore, PrFT was also independently associated with osteoporosis after adjustment for other confounding factors; the OR (95% CI) was 1.13 (1.04-1.23). PrFT also seems to have a relatively good identifying value for osteoporosis. The area under the curve (AUC) value of PrFT in identifying osteoporosis was 0.766 (95% CI: 0.705-0.826, P < 0.001). The optimal cutoff value of PrFT was 15.2 mm (sensitivity: 72.5%, specificity: 79.8%).

CONCLUSIONS

PrFT was significantly associated with β-CTX, BMD, and osteoporosis. These findings indicate that perirenal fat may play an important role in bone metabolism.

CLINICAL TRIAL REGISTRATION

http://www.chictr.org.cn/, identifier (ChiCTR2100052032).

Real-world weight change, adherence, and discontinuation among patients with type 2 diabetes initiating glucagon-like peptide-1 receptor agonists in the UK

INTRODUCTION

Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are a type 2 diabetes mellitus (T2DM) treatment with demonstrated weight loss benefits in clinical trials. However, the extent to which real-world patients with T2DM achieve clinically meaningful weight loss (≥5%) has not been well characterized. Analysis of real-world data suggests adherence to injectable GLP-1 RAs is suboptimal and discontinuation following the first year of therapy is poorly characterized.

RESEARCH DESIGN AND METHODS

A retrospective cohort study among patients with T2DM initiating injectable GLP-1 RA therapy was conducted using the Clinical Practice Research Datalink that includes primary care medical records for 13 million patients in the UK. This study assessed weight change, adherence (proportion of days covered (PDC) ≥80%), and discontinuation (≥90-day gap between prescriptions) at 12 and 24 months during the study period spanning January 2009-December 2017.

RESULTS

Among 589 patients initiating a GLP-1 RA, 56.4% were female and the median age was 54 years (IQR (46, 61)). The median body mass index was 41.2 kg/m² (IQR (35.8, 46.4)). Among patients with weight measures available (n=341 at 12 months; n=232 at 24 months), 33.4% and 43.5% achieved weight loss ≥5% of baseline weight at 12 and 24 months, respectively. At 12 and 24 months, 64.5% and 59.2% were adherent, and 45.2% and 64.7% discontinued, respectively.

CONCLUSIONS

A minority of patients initiating GLP-1 RAs achieved ≥5% weight loss, suggesting the real-world benefit of these agents on weight loss may be lower than that observed in clinical trials. Patients on GLP-1 RAs may benefit from additional support to improve long-term adherence.

Weight-centric pharmacological management of type 2 diabetes mellitus - An essential component of cardiovascular disease prevention

Obesity and overweight are contributing factors for diseases such as type 2 diabetes mellitus (T2DM), hypertension, hyperlipidemia, and ultimately, cardiovascular (CV) disease. Obesity is imposing an increasing health burden in rich and poor nations, with almost 30% of people globally now either obese or overweight - a staggering 2.1 billion. The link between obesity and T2DM is widely held to involve two adverse effects: obesity-induced insulin resistance and β-cell failure. This "unified field theory" raises questions about whether defects favoring progressive weight gain and metabolic impairment also contribute to β-cell decompensation. The concept of weight-centric management of T2DM is considered justified because of the strong negative impact of obesity on the effects of treatment of diabetes. Two pharmacotherapy options are considered: drugs developed primarily for blood glucose control that also exert a favorable effect on body weight and drugs developed primarily to induce weight loss that also have a favorable effect on glycemia. Treating hunger counter-regulatory mechanisms will have an additional effect on glucose control in T2DM. This narrative review addresses advances in pharmacotherapy for the management of obesity and obesity-related co-morbidities, with a focus on T2DM. It is also important to identify the correct balance between weight-centric and glucose-centric management of T2DM.

Comparison of awareness of diabetes mellitus type II with treatment's outcome in term of direct cost in a hospital in Saudi Arabia

BACKGROUND

Saudi Arabia is among the top 10 countries with the highest prevalence of diabetes. Cost of prevention and the indirect cost must be calculated to increase the awareness of society and to emphasize disease prevention and limit further complications.

AIM

To understand the importance of awareness and the impact on the expenditure of diabetes mellitus and treatments outcomes.

METHODS

A prospective descriptive and comparative survey was carried out among patients with diabetes mellitus in Saudi Arabia.

RESULTS

One hundred and one participants were included in the study of which 40% were female and one third were above the age of 50. The mean of the first HbA1c reading was 6.95, and the median was 7. The mean of the second reading of HbA1c was 7.26, and the median was 7. The mean body mass index was 32.1, and the median was 30.9. The average yearly cost of the medication was 995.14 SR. Comparing participants who think that a healthy low-sugar diet can affect blood sugar with those who do not, showed a statistically significant difference when cost was considered (P value = 0.03). Also, when comparing the group of participants who know when to take their oral hyperglycemic medicine and their yearly direct cost and those who do not know when to take it, by using independent sample T test, showed significant statistical difference (P value = 0.046).

CONCLUSION

It is essential for the governments to invest in ways to prevent and help in the early detection of such an expensive disease by performing national screening and education programs. Many pharmaco-economic studies can be done to help the decision-maker in our hospitals think about strategies to help the patient to be physically fit by offering gymnasium or places to walk or contract.

Combined Amylin/GLP-1 pharmacotherapy to promote and sustain long-lasting weight loss

A growing appreciation of the overlapping neuroendocrine mechanisms controlling energy balance has highlighted combination therapies as a promising strategy to enhance sustained weight loss. Here, we investigated whether amylin- and glucagon-like-peptide-1 (GLP-1)-based combination therapies produce greater food intake- and body weight-suppressive effects compared to monotherapies in both lean and diet-induced obese (DIO) rats. In chow-maintained rats, systemic amylin and GLP-1 combine to reduce meal size. Furthermore, the amylin and GLP-1 analogs salmon calcitonin (sCT) and liraglutide produce synergistic-like reductions in 24 hours energy intake and body weight. The administration of sCT with liraglutide also led to a significant enhancement in cFos-activation in the dorsal-vagal-complex (DVC) compared to mono-therapy, suggesting an activation of distinct, yet overlapping neural substrates in this critical energy balance hub. In DIO animals, long-term daily administration of this combination therapy, specifically in a stepwise manner, results in reduced energy intake and greater body weight loss over time when compared to chronic mono- and combined-treated groups, without affecting GLP-1 receptor, preproglucagon or amylin-receptor gene expression in the DVC.

Phloretin Suppresses Bone Morphogenetic Protein-2-Induced Osteoblastogenesis and Mineralization via Inhibition of Phosphatidylinositol 3-kinases/Akt Pathway

Phloretin has pleiotropic effects, including glucose transporter (GLUT) inhibition. We previously showed that phloretin promoted adipogenesis of bone marrow stromal cell (BMSC) line ST2 independently of GLUT1 inhibition. This study investigated the effect of phloretin on osteoblastogenesis of ST2 cells and osteoblastic MC3T3-E1 cells. Treatment with 10 to 100 µM phloretin suppressed mineralization and expression of osteoblast differentiation markers, such as alkaline phosphatase (ALP), osteocalcin (OCN), type 1 collagen, runt-related transcription factor 2 (Runx2), and osterix (Osx), while increased adipogenic markers, peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer-binding protein α (C/EBPα), fatty acid-binding protein 4, and adiponectin. Phloretin also inhibited mineralization and decreased osteoblast differentiation markers of MC3T3-E1 cells. Phloretin suppressed phosphorylation of Akt in ST2 cells. In addition, treatment with a phosphatidylinositol 3-kinase (PI3K)/Akt inhibitor, LY294002, suppressed the mineralization and the expression of osteoblast differentiation markers other than ALP. GLUT1 silencing by siRNA did not affect mineralization, although it decreased the expression of OCN and increased the expression of ALP, Runx2, and Osx. The effects of GLUT1 silencing on osteoblast differentiation markers and mineralization were inconsistent with those of phloretin. Taken together, these findings suggest that phloretin suppressed osteoblastogenesis of ST2 and MC3T3-E1 cells by inhibiting the PI3K/Akt pathway, suggesting that the effects of phloretin may not be associated with glucose uptake inhibition.

Regulation of Memory Function by Feeding-Relevant Biological Systems: Following the Breadcrumbs to the Hippocampus

The hippocampus (HPC) controls fundamental learning and memory processes, including memory for visuospatial navigation (spatial memory) and flexible memory for facts and autobiographical events (declarative memory). Emerging evidence reveals that hippocampal-dependent memory function is regulated by various peripheral biological systems that are traditionally known for their roles in appetite and body weight regulation. Here, we argue that these effects are consistent with a framework that it is evolutionarily advantageous to encode and recall critical features surrounding feeding behavior, including the spatial location of a food source, social factors, post-absorptive processing, and other episodic elements of a meal. We review evidence that gut-to-brain communication from the vagus nerve and from feeding-relevant endocrine systems, including ghrelin, insulin, leptin, and glucagon-like peptide-1 (GLP-1), promote hippocampal-dependent spatial and declarative memory via neurotrophic and neurogenic mechanisms. The collective literature reviewed herein supports a model in which various stages of feeding behavior and hippocampal-dependent memory function are closely linked.

Glucagon-like peptide-1 receptor action in the vasculature

Glucagon-like peptide-1 receptor (GLP-1R) agonists augment insulin secretion and are thus used clinically to improve glycemia in subjects with type 2 diabetes (T2D). As recent data reveal marked improvements in cardiovascular outcomes in T2D subjects treated with the GLP-1R agonists liraglutide and semaglutide in the LEADER and SUSTAIN-6 clinical trials respectively, there is growing interest in delineating the mechanism(s) of action for GLP-1R agonist-induced cardioprotection. Of importance, negligible GLP-1R expression in ventricular cardiac myocytes suggests that cardiac-independent actions of GLP-1R agonists may account for the reduced death rates from cardiovascular causes in T2D subjects enrolled in the LEADER trial. Conversely, vascular smooth muscle cells (VSMCs) appear to express the canonical GLP-1R, and GLP-1/GLP-1R agonists exhibit a number of salutary actions on the vascular endothelium that could potentially contribute to GLP-1R agonists directly improving cardiovascular outcomes in subjects with T2D. We review herein the described actions of GLP-1/GLP-1R agonists on the vascular endothelium, which include antiproliferative actions on VSMCs and endothelial cells, reductions in oxidative stress, and increases in nitric oxide generation. GLP-1 also increases microvascular recruitment and microvascular blood flow. Taken together, such actions may explain the antihypertensive and/or antiatherosclerotic actions attributed to GLP-1/GLP-1R agonists in preclinical and clinical studies. Nonetheless, further mechanistic studies are still necessary to determine the relative importance of such actions in accounting for reductions in macrovascular cardiovascular disease in human subjects with T2D treated with GLP-1R agonists.

Is there a Chance to Promote Arteriogenesis by DPP4 Inhibitors Even in Type 2 Diabetes? A Critical Review

Cardiovascular diseases (CVD) are still the prevailing cause of death not only in industrialized countries, but even worldwide. Type 2 diabetes mellitus (type 2 DM) and hyperlipidemia, a metabolic disorder that is often associated with diabetes, are major risk factors for developing CVD. Recently, clinical trials proved the safety of gliptins in treating patients with type 2 DM. Gliptins are dipeptidyl-peptidase 4 (DPP4/CD26) inhibitors, which stabilize glucagon-like peptide-1 (GLP-1), thereby increasing the bioavailability of insulin. Moreover, blocking DPP4 results in increased levels of stromal cell derived factor 1 (SDF-1). SDF-1 has been shown in pre-clinical animal studies to improve heart function and survival after myocardial infarction, and to promote arteriogenesis, the growth of natural bypasses, compensating for the function of an occluded artery. Clinical trials, however, failed to demonstrate a superiority of gliptins compared to placebo treated type 2 DM patients in terms of cardiovascular (CV) outcomes. This review highlights the function of DPP4 inhibitors in type 2 DM, and in treating cardiovascular diseases, with special emphasis on arteriogenesis. It critically addresses the potency of currently available gliptins and gives rise to hope by pointing out the most relevant questions that need to be resolved.

Exposure-response analysis for evaluation of semaglutide dose levels in type 2 diabetes

AIMS

To evaluate dose levels for semaglutide, a glucagon-like peptide-1 analogue approved for the treatment of type 2 diabetes, by examining the effects of demographic factors on efficacy and safety in an exposure-response analysis.

METHODS

We analysed data from 1552 adults from four randomized phase III trials of 30 to 56 weeks' duration, investigating once-weekly semaglutide doses 0.5 and 1.0 mg. Exposure-response relationships were investigated using graphical and model-based techniques to assess the two dose levels and subgroups with the highest and lowest exposure and response.

RESULTS

The population had the following demographic characteristics: baseline mean age between 53.2 and 58.4 years, glycated haemoglobin (HbA1c) between 64 and 67 mmol/mol (8.0% and 8.3%), body weight between 71.3 and 96.2 kg, and diabetes duration between 4.2 and 8.9 years. Exposure-response analysis showed a clear HbA1c and weight reduction across exposures after 30 weeks, irrespective of baseline values. The exposure-response for HbA1c was influenced by baseline HbA1c, and body weight exposure-response was influenced by sex, with limited impact of other factors. Analyses for relevant subgroups of baseline body weight, baseline HbA1c and sex indicated clinically relevant additional benefits with regard to HbA1c and weight with 1.0 vs 0.5 mg semaglutide. The proportion of participants reporting gastrointestinal (GI) side effects increased with increasing exposure, but was counteracted by tolerance development.

CONCLUSIONS

The analysis showed that all subgroups obtained a clinically relevant benefit with semaglutide 0.5 mg and an additional benefit with semaglutide 1.0 mg. The increase in GI side effects with higher exposure was mitigated by gradually increasing the dose.

Cardiovascular Effects of Different GLP-1 Receptor Agonists in Patients with Type 2 Diabetes

PURPOSE OF REVIEW

Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have positive effects on weight loss, blood pressure, hyperlipidemia, and glycemic control. They exhibit a broad range of effects on the cardiovascular system that are independent of changes in blood glucose. Cardiovascular outcome trials have demonstrated safety of GLP-1 RAs but results for cardiovascular efficacy were varied. The aim of the present review is the assessment of the effects of GLP-1 RAs on cardiovascular risk factors, and major cardiovascular events.

RECENT FINDINGS

Use of GLP-1 RAs was associated with relative risk reduction in cardiovascular mortality and all-cause mortality with no significant differences for the incidence of severe hypoglycemia, pancreatitis, pancreatic cancer, or medullary thyroid cancer when compared to placebo. Although there are differences between individual medications with respect to their effects on cardiovascular events, GLP-1 RAs offer a favorable risk-benefit profile. The present review confirms the cardiovascular safety and efficacy vs placebo of GLP-1 RAs in patients with type 2 diabetes at moderate-to-high atherosclerotic cardiovascular risk without significant side effects. Although professional guidelines recommend metformin as the sole first-line agent, GLP-1 RAs can be used as first-line therapy in individuals with type 2 diabetes who either are intolerant to metformin or have high cardiovascular risk factors.

Exenatide has a pronounced effect on energy intake but not energy expenditure in non-diabetic subjects with obesity: A randomized, double-blind, placebo-controlled trial

AIMS

Exenatide is a glucagon-like peptide 1 (GLP-1) mimetic which induces weight loss predominantly, it is presumed, via decreased food intake. However, circulating GLP-1 is also a determinant of energy expenditure. We sought to quantify the effect of exenatide on energy expenditure (EE) and energy intake.

MATERIALS AND METHODS

In this single-center, randomized double-blind placebo controlled trial, we randomized 80 healthy, non-diabetic volunteers with obesity (46 women, age: 34.4 ± 8.7 y, body fat by DXA: 44.2 ± 7.8%) to subcutaneous exenatide 10 μg twice daily or placebo. Subjects were admitted to our clinical research unit for measurement of 24 h-EE in a whole-room indirect calorimeter and ad libitum food intake using an automated vending machine paradigm before and after randomization. Furthermore, energy expenditure and ad libitum food intake measures were repeated at 24-week after readmission for 7-day inpatient stay. Body weight was obtained weekly for up to 5 weeks and was recorded at each monthly follow up visit up to 24 weeks.

RESULTS

Prior to randomization, participants over ate during the 3-day vending machine period in the whole study group (114.6 ± 35.2%), expressed as percentage of weight maintaining energy needs (WMEN) with those who were eventually randomized to exenatide overeating more (121.6 ± 37.7%) compared to placebo group (107.6 ± 31.5%). In the exenatide group, ad libitum absolute energy intake decreased by 1016.1 ± 724.5 kcal/day (95% CI: -1250.9 to -781.2) versus a 245.1 ± 710.5 kcal/day (95% CI: -475.4 to -14.7) decrease in placebo (Δ = -624.8 Kcal/day, p < 0.0001) whereas the reduction in ad libitum caloric intake relative to WMEN was a more modest 366.8 ± 752.1 kcal/day (95% CI: -614.0 to -119.6) decrease compared to 8.0 ± 860.1 kcal/day (95% CI: -286.8 to 270.8) reduction in placebo (Δ = -382.3 Kcal/day, p = 0.03). The decrease was uniform across all macronutrients groups. No differences in 24hEE or substrate oxidation rates were found. In the exenatide group, body weight decreased more over the 5 weeks (β = -0.039 kg/week, p = 0.02) and was lower compared to placebo at the end of fifth week (-1.48 ± 0.77 kg; 95% CI: -3.02 to 0.05, p = 0.06). At the 24-week follow up, there was no difference in energy intake between exenatide group and placebo group and the treatment group decreased 24-h EE more compared to placebo (β = -160.6 Kcal/day, 95% CI: -307.6 to 13.6, p = 0.03) compared to their pre-randomization measurement. However, this reduction was not present after adjustment for changes in FM and FFM (β = -87 kcal/day, p = 0.14). No difference was observed in body weight (Δ = -1.72 kg, 95% CI: -5.77 to 2.30, p = 0.39) in exenatide versus placebo over 24 weeks.

CONCLUSION

Compared with placebo, exenatide decreased early ad libitum energy intake but did not change 24 h-EE. However, the reduction was more modest in relative versus absolute terms (i.e. below that needed for WMEN). Thus, although rate of weight change was greater in the exenatide treated subjects at 5 weeks, the absolute difference in weight was not significant. These findings indicate that although exenatide reduces food intake, it may be more beneficial in blunting overeating and thus may serve to more prevent weight regain following initial weight loss.

After the LEADER trial and SUSTAIN-6, how do we explain the cardiovascular benefits of some GLP-1 receptor agonists?

Recent cardiovascular outcome trials - the LEADER with liragutide and SUSTAIN-6 with semaglutide - have shown significant reductions of major cardiovascular (CV) events with these glucagon-like peptide (GLP)-1 receptor agonists. Progressive separation of the treatment and placebo curves, starting clearly between 12 and 18 months of the trial period, and significant reductions in the risk of myocardial infarction and stroke, indicate that the beneficial CV effects observed with GLP-1 receptor agonists could be due to an antiatherogenic effect. So far, the reasons for such an effect of GLP-1 receptor agonists have not been entirely clear, although several hypotheses may be proposed. As the reductions in glycated haemoglobin and systolic blood pressure (SBP) in these trials were modest, and both trials lasted only a short period of time, reductions in hyperglycaemia and SBP are unlikely to be involved in the beneficial CV effects of GLP-1 receptor agonists. On the other hand, their effect on lipids and, in particular, the dramatic decrease in postprandial hypertriglyceridaemia may explain their beneficial CV actions. Reduction of body weight, including a significant decrease in visceral fat in patients using GLP-1 receptor agonists, may also have beneficial CV effects by reducing chronic proatherogenic inflammation. In addition, there are in-vitro data showing a direct anti-inflammatory effect with these agents that could also be involved in their beneficial CV effects. Moreover, studies in humans have shown significant beneficial effects on ischaemic myocardium after a very short treatment period, suggesting a direct effect of GLP-1 receptor agonists on myocardium, although the precise mechanism remains unclear. Finally, as a reduction in insulin resistance has been associated with a decrease in CV risk, it cannot be ruled out that the lowering of insulin resistance induced by GLP-1 receptor agonists might also be involved in their beneficial CV actions.

Treatment satisfaction with ITCA 650, a novel drug-device delivering continuous exenatide, versus twice-daily injections of exenatide in type 2 diabetics using metformin

AIMS

To evaluate treatment satisfaction in patients with type 2 diabetes (T2D) not adequately controlled by metformin, randomized to ITCA 650 (continuous exenatide in osmotic mini-pump) vs twice-daily exenatide injections (Ex-BID).

MATERIALS AND METHODS

The Diabetes Medication Satisfaction Tool (DM-SAT) was administered and assessments were made at baseline, Week 8 and Week 20 during a 24-week open-label phase 2 trial. In Stage I (Weeks 1-12), 155 patients, comprising the ITT population, were randomized to 3 groups: ITCA 650 20 μg/day, ITCA 650 40 μg/day and Ex-BID 10 μg BID. In Stage II (Weeks 13-24), ITCA 650 groups were re-randomized to either remain on the Stage I dose or receive a higher dose. Patients treated with Ex-BID were randomized to 40 or 60 μg/day ITCA 650.

RESULTS

Patients using ITCA 650 reported significant increases in overall treatment satisfaction by Week 8 vs those using Ex-BID (P < .01), despite similar clinical efficacy and overall rates of nausea. During Stage II, further improvement in HbA1c and weight were seen after 3-fold dose escalation of ITCA 650 and treatment satisfaction was maintained. When patients using Ex-BID were switched to ITCA 650, treatment satisfaction increased and reached levels similar to those initially treated with ITCA 650. Neither GI side effects of nausea and/or vomiting, nor the procedure to sub-dermally place ITCA 650, significantly impacted treatment satisfaction scores.

CONCLUSION

ITCA 650 added to metformin for patients with T2D, and for those who switched to ITCA 650 from Ex-BID, meaningfully improved glucose control and significantly increased overall treatment satisfaction.

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.

Pharmacotherapy of type 2 diabetes: An update

Type 2 diabetes (T2DM) is a leading cause of morbidity and mortality worldwide and a major economic burden. The prevalence of T2DM is rising, suggesting more effective prevention and treatment strategies are necessary. The aim of this narrative review is to summarize the pharmacologic treatment options available for patients with T2DM. Each therapeutic class is presented in detail, outlining medication effects, side effects, glycemic control, effect on weight, indications and contraindications, and use in selected populations (heart failure, renal insufficiency, obesity and the elderly). We also present representative cost for each antidiabetic category. Then, we provide an individualized guide for initiation and intensification of treatment and discuss the considerations and rationale for an individualized glycemic goal.

Pharmacokinetic drug evaluation of exenatide for the treatment of type 2 diabetes

INTRODUCTION

Glucagon-like peptide-1 (GLP-1) receptor analogs are a group of therapeutic agents which mimic endogenous GLP-1, exerting their effect by the stimulation of the GLP-1 receptor with a wide distribution. Its activation increases insulin releasing dependent on blood glucose levels, suppression of glucagon secretion and a reduction of hepatic glucose output. It delays gastric emptying and increases satiety. Exenatide is the synthetic version of exendin-4, a natural peptide with similar properties to human GLP-1. There are two pharmaceutical forms, for subcutaneous injection: twice daily and once weekly. Clinical practice guidelines recommend them because of a high efficacy reducing hyperglycemia, low risk of hypoglycemia and a significative weight loss effect. Gastrointestinal adverse events are the most common beside injection site-related. Their cost is the main limitation to use. Areas covered: We review the recent literature investigating the pharmacokinetics and pharmacodynamics and efficacy-safety studies of exenatide twice daily and once weekly in type 2 diabetes Expert opinion: GLP-1 receptor analogs are now positioned as an effective and safe drug for the treatment of type 2 diabetes. Exenatide significally reduces HbA1c and fasting plasma glucose. Additionally, it produces moderate weight loss and decreases blood pressure. One weekly formulation may improve compliance while cost is still a limitation. EXSCEL trial has shown that, despite cardiovascular safety, exenatide do not exhibits cardiovascular benefits.

Combination SGLT2 inhibitor and GLP-1 receptor agonist therapy: a complementary approach to the treatment of type 2 diabetes

Among persons with type 2 diabetes (t2d), the development of glucose intolerance involves dysfunction in several organs and tissues, including the muscle, liver, pancreas, kidney, gastrointestinal tract, adipose tissue, and brain. individuals with t2d typically have a number of comorbidities, including hypertension, hyperlipidemia, and being overweight or obese, and are, consequently, at high cardiovascular risk. guidelines recommend a comprehensive care strategy that includes treatment of diabetes-related complications and comorbidities beyond those related to hyperglycemia. use of glucose-lowering therapies with complementary activities that address multiple facets of the disease may improve long-term outcomes for patients with t2d. two recent drug classes developed for use in t2d, glucagon-like peptide-1 receptor agonists (glp-1ras) and sodium glucose cotransporter 2 (sglt2) inhibitors, have been shown in clinical trials to have beneficial effects on glycemic control, body weight, cardiovascular risk factors, and (for liraglutide, semaglutide, and empagliflozin) cardiovascular outcomes, while having an acceptable safety profile. between them, these drug classes directly or indirectly affect many of the organs and tissues involved in the pathogenesis of t2d, and their beneficial effects on glycemic- and cardiovascular-related parameters are likely to be complementary and potentially additive. in the largest clinical trial of a glp-1ra and an sglt2 inhibitor in combination (duration-8), patients with t2d (n = 685) who received exenatide plus dapagliflozin added to their treatment regimen for 28 weeks had significantly greater reductions from baseline in glycated hemoglobin, body weight, and systolic blood pressure compared with patients who received either drug as monotherapy. this review summarizes the complementary aspects of these drug classes and presents the available data among patients receiving dual therapy with a glp-1ra and an sglt2 inhibitor.

Effects of exendin-4 and selenium on the expression of GLP-1R, IRS-1, and preproinsulin in the pancreas of diabetic rats

The mechanisms by which exendin-4 and selenium exert their antidiabetic actions are still unclear. Here, we investigated the effects of exendin-4 or selenium administration on the expression of glucagon-like peptide-1 receptor (GLP-1R), insulin receptor substrate-1 (IRS-1), and preproinsulin in the pancreas of diabetic rats. Diabetes was induced by streptozotocin administration. Diabetic rats were injected intraperitoneally with 0.03 μg exendin-4/kg body weight/daily or treated with 5 ppm selenium in drinking water for a period of 4 weeks. GLP-1R and IRS-1 levels were decreased while the level of preproinsulin messenger RNA (mRNA) was increased in the pancreas of diabetic untreated rats, as compared to that in control rats. Treatment of diabetic rats with exendin-4 increased protein and mRNA levels of GLP-1R, and IRS-1, and the mRNA level of preproinsulin in the pancreas, as compared to their levels in diabetic untreated rats. Selenium treatment of diabetic rats increased the pancreatic mRNA levels of GLP-1R, IRS-1, and preproinsulin. Exendin-4 or selenium treatment of diabetic rats also increased the numbers of pancreatic islets and GLP-1R molecules in the pancreas. Therefore, exendin-4 and selenium may exert their antidiabetic effects by increasing GLP-1R, IRS-1, and preproinsulin expression in the pancreas and by increasing the number of pancreatic islets.

Endogenous Glucagon-like Peptide-1 Receptor Signaling in the Nucleus Tractus Solitarius is Required for Food Intake Control

Alhough the glucagon-like peptide-1 (GLP-1) system is critical to energy balance control and is a target for obesity pharmacotherapies, the receptor-population-mediating effects of endogenous GLP-1 signaling are not fully understood. To address this, we developed a novel adeno-associated virus (AAV-GLP-1R) that utilizes short hairpin RNA to chronically knock down GLP-1 receptors (GLP-1R) in rats. As pharmacological studies highlight the hindbrain nucleus tractus solitarius (NTS) as a brain region important for GLP-1R-mediated effects on energy balance, AAV-GLP-1R was injected into the NTS to examine the role of endogenous NTS GLP-1R signaling in energy balance control. Chow intake and meal size were significantly increased following chronic NTS GLP-1R knockdown. In addition, NTS GLP-1R knockdown significantly increased self-administration of palatable food under both fixed and progressive ratio schedules of reinforcement. Collectively, these data demonstrate that endogenous NTS GLP-1R signaling is required for the control of food intake and motivation to feed, and provide a new strategy to investigate the importance of distinct GLP-1R populations in the control of a variety of functions.

Mechanisms of diabetes mellitus-induced bone fragility

The risk of fragility fractures is increased in patients with either type 1 diabetes mellitus (T1DM) or type 2 diabetes mellitus (T2DM). Although BMD is decreased in T1DM, BMD in T2DM is often normal or even slightly elevated compared with an age-matched control population. However, in both T1DM and T2DM, bone turnover is decreased and the bone material properties and microstructure of bone are altered; the latter particularly so when microvascular complications are present. The pathophysiological mechanisms underlying bone fragility in diabetes mellitus are complex, and include hyperglycaemia, oxidative stress and the accumulation of advanced glycation endproducts that compromise collagen properties, increase marrow adiposity, release inflammatory factors and adipokines from visceral fat, and potentially alter the function of osteocytes. Additional factors including treatment-induced hypoglycaemia, certain antidiabetic medications with a direct effect on bone and mineral metabolism (such as thiazolidinediones), as well as an increased propensity for falls, all contribute to the increased fracture risk in patients with diabetes mellitus.

Effects of obesity treatments on bone mineral density, bone turnover and fracture risk in adults with overweight or obesity

BACKGROUND

New evidence suggests that obesity is deleterious for bone health, and obesity treatments could potentially exacerbate this.

MATERIALS AND METHODS

This narrative review, largely based on recent systematic reviews and meta-analyses, synthesizes the effects on bone of bariatric surgery, weight loss pharmaceuticals and dietary restriction.

RESULTS AND CONCLUSIONS

All three obesity treatments result in statistically significant reductions in hip bone mineral density (BMD) and increases in bone turnover relative to pre-treatment values, with the reductions in hip BMD being strongest for bariatric surgery, notably Roux-en Y gastric bypass (RYGB, 8%-11% of pre-surgical values) and weakest for dietary restriction (1%-1.5% of pre-treatment values). Weight loss pharmaceuticals (orlistat or the glucagon-like peptide-1 receptor agonist, liraglutide) induced no greater changes from pre-treatment values than control, despite greater weight loss. There is suggestive evidence that liraglutide may increase bone mineral content (BMC) - but not BMD - and reduce fracture risk, but more research is required to clarify this. All three obesity treatments have variable effects on spine BMD, probably due to greater measurement error at this site in obesity, suggesting that future research in this field could focus on hip rather than spine BMD. Various mechanisms have been proposed for BMD loss with obesity treatments, notably reduced nutritional intake/absorption and insufficient exercise, and these are potential avenues for protection against bone loss. However, a pressing outstanding question is whether this BMD reduction contributes to increased fracture risk, as has been observed after RYGB, and whether any such increase in fracture risk outweighs the risks of staying obese (unlikely).

Long-term management of type 2 diabetes with glucagon-like peptide-1 receptor agonists

Continuously reducing excess blood glucose is a primary goal for the management of type 2 diabetes (T2D). Most patients with T2D require glucose-lowering medications to achieve and maintain adequate glycemic control; however, treatment failure may occur, limiting treatment options. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are an emerging therapeutic class that can be prescribed for patients instead of basal insulin after the failure of oral therapies. Recent studies have focused on the durability and tolerability of long-term GLP-1RA therapy. This review summarizes the key efficacy and safety findings from prospective phase 3 clinical studies of at least 76 weeks' duration for the GLP-1RAs currently approved in the United States and the European Union (albiglutide, dulaglutide, exenatide twice daily [BID], exenatide once weekly [QW], liraglutide, and lixisenatide). Currently, most of the long-term data are from uncontrolled extension studies, and continuous patient benefit has been observed for up to 3 years with multiple GLP-1RAs. Four-year comparative data demonstrated a longer time to treatment failure for exenatide BID than for sulfonylurea, and 3-year comparative extension data demonstrated greater glycated hemoglobin (HbA1c) reductions and weight loss with exenatide QW than with insulin glargine. Currently, the longest extension study for a GLP-1RA is the DURATION-1 study of exenatide QW, with >7 years of clinical data available. Data from DURATION-1 demonstrated that continuous HbA1c reductions and weight loss were observed for the patients continuing on the treatment, with no unexpected adverse events. Taken together, these data support GLP-1RAs as a long-term noninsulin treatment option after the failure of oral therapies.

Pharmacologic Treatment Options for Obesity: Current and Potential Medications

Pharmacotherapy has a role in obesity management when combined with diet, physical activity, and behavior modification. Currently available therapies are safe when used appropriately. New treatments with novel mechanisms of action are likely to be available in the future.

Pleiotropic effects of insulin and GLP-1 receptor agonists: Potential benefits of the association

The combination of basal insulin and glucagon-like peptide-1 receptor agonists (GLP-1RAs) is an emerging option for patients with type 2 diabetes (T2D). GLP-1RAs have been shown to improve glycaemic control with a low risk of hypoglycaemia and to promote body weight loss. However, GLP-1 receptors (GLP-1Rs) are widely expressed in extrapancreatic tissues and could sustain pleiotropic actions of GLP-1RAs beyond glycaemic control. The underlying molecular mechanisms maintaining these extrapancreatic actions of GLP-1 are complex, and involve GLP-1R signalling in both the brain and several peripheral tissues. The present review focuses specifically on the role of GLP-1RAs in the cardiovascular system and liver. Preclinical data in rodents and pilot studies in humans suggest that GLP-1RAs may have potential beneficial effects on heart function, blood pressure, postprandial lipaemia, liver steatosis and non-alcoholic steatohepatitis (NASH). Long-term studies are now warranted to determine the safety and clinical relevance of the association between insulin and GLP-1RAs in T2D.

The Use of Exenatide in Managing Markers of Cardiovascular Risk in Patients with Type 2 Diabetes: A Systematic Review

Objective: This review examines the use of exenatide twice daily in managing changes in markers of cardiovascular risk in patients with type 2 diabetes. Background: Type 2 diabetes is a progressive metabolic disorder, which results from defects in insulin secretion and/or insulin action leading to chronic hyperglycaemia and associated cardiovascular complications. Despite the use of diet, exercise, oral antihyperglycaemic agents and insulin, the progressive nature of the condition means that the levels of the preventive and treatment measures would have to be increased and/or new therapies have to be developed in order to address the long term impact of type 2 diabetes. The advent of exenatide, a glucagon-like peptide-1 receptor agonist provides a useful basis for managing type 2 diabetes and related cardiovascular complications without the side effects of regular diabetes therapies. However, exenatide twice daily is often used in combination with other therapies, although the mechanism of exenatide in managing diabetes and and associated cardiovascular risks and complications remain complex and still evolving. Method: A range of databases including EBSCOhost online research database were used to access articles based on PICO (Population, Interventions, Comparative Interventions, Outcomes) framework and Boolean operators. Results: Eleven randomised controlled studies which met the inclusion criteria were selected for this review. Nine of the eleven studies showed significant decrease in body weight among participants in the exenatide group compared with placebo or control group while the other two studies did not report statistically significant differences in body weight. In adition, all the studies showed statistically significant decrease in glycated haemoglobin (HbA1c) in the exenatide group compared to controls except in one study. In the present review, the seven studies, which looked at the effect of exenatide twice daily on lipid profile, did not find any significant difference between the exenatide group and the control group except for High density lipoprotein-cholesterol in two of the studies. However, statistically significant decrease was observed between exenatide group and controls with respect to blood pressure (systolic and/or diastolic) in these studies. Discussion: It would appear that exenatide is more effective in reducing body weight in patients with type 2 diabetes when used in combination with metformin than when used alone or in combination with thiazolidinedione. The findings of this review would suggest that exenatide twice daily may be useful in managing cardiovascular risks and complications by reducing body weight, HbA1c and blood pressure.

Current cardiovascular outcomes trials in type 2 diabetes: Perspectives and insight

AIMS

The increased risk of cardiovascular disease in patients with type 2 diabetes has been known for many years. However, until recently the cardiovascular (CV) impact of glucose lowering strategies has been inadequately understood. Major clinical trials have now investigated the impact of intensification of glycemic control upon CV outcomes, as well as the CV effects of glucose management with newer antihyperglycemic agents.

DATA SYNTHESIS

Key findings from recently completed CV outcomes trials of dipeptidyl peptidase-4 (DPP4) inhibitors, GLP-1 receptor agonists, and sodium-glucose cotransporter 2 (SGLT2) inhibitors completed thus far are reviewed and summarized.

CONCLUSIONS

Multiple trials designed to meet regulatory requirements for CV safety of antihyperglycemic medications have been initiated. The results of several completed CV outcomes trials clarify the risks and benefits associated with newer medications used to manage hyperglycemia in patients with type 2 diabetes, particularly in individuals at high CV risk. Important differences have been noted with respect to heart failure outcomes within the DPP4 inhibitor class, and thus far one agent in the SGLT2 inhibitor class has been found to significantly reduce rates of important CV outcomes. Robust safety related information from trials designed to assess the CV effects of diabetes therapies will permit the incorporation of outcomes-based evidence into the formulation of diabetes care guidelines.

Cardiometabolic Effects of Glucagon-Like Peptide-1 Agonists

Cardiovascular disease is the leading cause of death among adults in the USA. Both type 1 (T1DM) and type 2 diabetes mellitus (T2DM) are known risk factors for cardiovascular disease. Despite the development of numerous effective anti-glycemic therapies, we have been unable to completely mitigate cardiovascular risk with glucose lowering alone, and prevention of cardiovascular disease in patients with diabetes is primarily achieved with the use of medications that address other risk factors such as anti-hypertensives or statins. Glucagon-like peptide-1 (GLP-1) is a key hormone in the pathophysiology of diabetes. GLP-1 agonists have been recently approved for the treatment of T2DM as well as for chronic weight management. In this review, we aim to explore the effects of GLP-1 agonists on cardiovascular health with a focus on cardiometabolic variables and cardiac function.

SGLT2 inhibitors or GLP-1 receptor agonists as second-line therapy in type 2 diabetes: patient selection and perspectives

Controversy exists regarding the selection of second-line therapy for patients with type 2 diabetes mellitus (T2DM) who are unable to achieve glycemic control with metformin therapy alone. Newer pharmacologic treatments for T2DM include glucagon-like peptide-1 receptor agonists and sodium–glucose cotransporter 2 inhibitors. Both the classes of medication are efficacious, exhibit positive effects on weight, and are associated with minimal risk of hypoglycemia. The purpose of this review is to compare the clinical trial and real-world effectiveness data of glucagon-like peptide-1 receptor agonists versus sodium–glucose cotransporter 2 inhibitors related to A1c reduction, weight loss, cost-effectiveness, cardiovascular outcomes, and safety in patients with T2DM. This review summarizes comparative evidence for providers who are determining which of the two classes may be the most appropriate for a specific patient.

Exenatide exerts direct protective effects on endothelial cells through the AMPK/Akt/eNOS pathway in a GLP-1 receptor-dependent manner

Glucagon-like peptide-1 (GLP-1) may have direct favorable effects on cardiovascular system. The aim of this study was to investigate the effects of the GLP-1 analog exenatide on improving coronary endothelial function in patients with type 2 diabetes and to investigate the underlying mechanisms. The newly diagnosed type 2 diabetic subjects were enrolled and given either lifestyle intervention or lifestyle intervention plus exenatide treatment. After 12-wk treatment, coronary flow velocity reserve (CFVR), an important indicator of coronary endothelial function, was improved significantly, and serum levels of soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) were remarkably decreased in the exenatide treatment group compared with the baseline and the control group. Notably, CFVR was correlated inversely with hemoglobin A1c (Hb A1c) and positively with high-density lipoprotein cholesterol (HDL-C). In human umbilical vein endothelial cells, exendin-4 (a form of exenatide) significantly increased NO production, endothelial NO synthase (eNOS) phosphorylation, and GTP cyclohydrolase 1 (GTPCH1) level in a dose-dependent manner. The GLP-1 receptor (GLP-1R) antagonist exendin (9-39) or GLP-1R siRNA, adenylyl cyclase inhibitor SQ-22536, AMPK inhibitor compound C, and PI3K inhibitor LY-294002 abolished the effects of exendin-4. Furthermore, exendin-4 reversed homocysteine-induced endothelial dysfunction by decreasing sICAM-1 and reactive oxygen species (ROS) levels and upregulating NO production and eNOS phosphorylation. Likewise, exendin (9-39) diminished the protective effects of exendin-4 on the homocysteine-induced endothelial dysfunction. In conclusion, exenatide significantly improves coronary endothelial function in patients with newly diagnosed type 2 diabetes. The effect may be mediated through activation of AMPK/PI3K-Akt/eNOS pathway via a GLP-1R/cAMP-dependent mechanism.

A 52-week pilot study of the effects of exenatide on body weight in patients with hypothalamic obesity

OBJECTIVE

Hypothalamic obesity (HO) is a common complication of hypothalamic tumors, and effective therapies are lacking. The objective of this pilot study was to investigate changes in body weight before and during treatment with exenatide.

METHODS

This was a prospective, open-label, 52-week pilot study of exenatide (10 mcg b.i.d.) in adults with HO. Ten patients enrolled, and eight completed the study. Study measures included indirect calorimetry, body composition, buffet meals, diet recall, actigraphy, and hormone assays.

RESULTS

Participants had obesity with a baseline weight of 137.2 ± 37.6 kg. Exenatide therapy was well tolerated. Change in weight with exenatide therapy was not significant (-1.4 ± 4.3 kg [95% CI -4.9 to 2.2], P = 0.40), but six out of eight completers lost weight (-6.2 to -0.2 kg). Participants reported significantly lower intake on food recall during treatment compared with baseline (7837.8 ± 2796.6 vs. 6258.4 ± 1970.7 kJ [95% CI -2915.8 to -242.6], P = 0.027), but there was no change in intake during buffet meals.

CONCLUSIONS

Significant weight loss was not observed in patients with HO treated with exenatide, but 75% of completers had stable or decreasing weight. Further studies are needed to evaluate weight loss efficacy in patients with HO.

Cardiovascular Effects of Glucagon-Like Peptide-1 Receptor Agonists

Glucagon-like peptide-1 (GLP-1) is a member of the proglucagon incretin family, and GLP-1 receptor agonists (RAs) have been introduced as a new class of antidiabetic medications in the past decade. The benefits of GLP-1 RAs are derived from their pleiotropic effects, which include glucose-dependent insulin secretion, suppressed glucagon secretion, and reduced appetite. Moreover, GLP-1 RAs also exert beneficial roles on multiple organ systems in which the GLP-1 receptors exist, including the cardiovascular system. Cardiovascular effects of GLP-1 RAs have been of great interest since the burden from cardiovascular diseases (CVD) has been unbearably increasing in a diabetic population worldwide, despite strict glycemic control and advanced therapeutic techniques to treat CVD. Preclinical studies have already demonstrated the beneficial effects of GLP-1 on myocardium and vascular endothelium, and many clinical studies evaluating changes in surrogate markers of CVD have suggested potential benefits from the use of GLP-1 RAs. Data from numerous clinical trials primarily evaluating the antihyperglycemic effects of multiple GLP-1 RAs have also revealed that changes in most CVD risk markers reported as secondary outcomes have been in favor of GLP-1 RAs treatment. However, to date, there is only one randomized clinical trial of GLP-1 RAs (the ELIXA study) evaluating major cardiovascular events as their primary outcomes, and in this study, a neutral cardiovascular effect of lixisenatide was observed in high-risk diabetic subjects. Therefore, the results of ongoing CVD outcome trials with the use of GLP-1 RAs should be awaited to elucidate the translation of benefits previously seen in CVD risk marker studies into large clinical trials with primary cardiovascular outcomes.

Safety and Tolerability of Glucagon-Like Peptide-1 Receptor Agonists Utilizing Data from the Exenatide Clinical Trial Development Program

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) have demonstrated benefits for patients with type 2 diabetes including A1C reduction and weight loss with minimal risk of hypoglycemia. This article provides an evidence-based update of safety and tolerability considerations for the clinical use of GLP-1RAs as a class, with a specific detailed review of data from the exenatide clinical trial development program, which has the longest history and availability of safety and tolerability data as the first-approved GLP-1RA. Specific areas covered include comparative risk of hypoglycemia, as well as pancreatic, thyroid, and cardiovascular safety data; clinical guidance regarding current safety and tolerability data is also reviewed.

Comparison of exenatide with biphasic insulin aspart 30 on glucose variability in type 2 diabetes: study protocol for a randomized controlled trial

Background

Apart from the mean level of glycemic control, the extent of glucose excursions is another important issue to consider in type 2 diabetes mellitus (T2DM) management. Studies have showed that fluctuations of glucose seem to have more deleterious effects than sustained hyperglycemia in the development of diabetic complications as acute glucose swings activate the oxidative stress. However, until now, no randomized controlled trials have been conducted with the primary aim to evaluate glycemic fluctuation in the comparison between twice-daily exenatide and other treatment paradigms (for example, biphasic insulin aspart 30).

Methods/design

This multicenter, open-label, randomized, parallel trial includes a 1-week screening period and a 16-week treatment period. After the screening period, 150 patients with confirmed type 2 diabetes who are treated with stable, maximum-tolerated doses of metformin will be randomly assigned to one of two groups for antihyperglycemic therapies: exenatide and biphasic insulin aspart 30. The treatment with exenatide will be initiated at a low dose of 5 μg twice a day for 4 weeks and then titrated up to a standard dose of 10 ug twice a day until the completion of the study. The adjustment of insulin dose is instructed to achieve an optimal balance between glycemic control and the risk of hypoglycemia as dictated by clinical practice. The primary outcome is the absolute change of mean amplitude of glycemic excursion from baseline to week 16, which is calculated based on a real-time continuous glucose monitoring system (CGMS).

Discussion

This is the first randomized controlled trial using a CGMS to evaluate glycemic fluctuation between twice-daily exenatide and insulin aspart 30, which will provide beneficial evidence of exenatide usage in patients with T2DM.

Trial registration number

NCT02449603. Date of registration: 11 May 2015.

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.

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.

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.

Empagliflozin as add-on to metformin plus sulphonylurea in patients with type 2 diabetes

This study investigated the long-term efficacy and safety of empagliflozin as add-on to metformin plus sulphonylurea in patients with type 2 diabetes mellitus (T2DM). Of 666 patients treated with empagliflozin 10 mg, empagliflozin 25 mg or placebo once daily for 24 weeks, 472 patients (70.9%) were treated in a double-blind extension trial for ≥52 weeks. Pre-specified exploratory endpoints included changes from baseline in HbA(1c), weight and blood pressure at week 76. At week 76, adjusted mean differences versus placebo in change from baseline in HbA(1c) were -0.7% (-8 mmol/mol) with empagliflozin 10 mg or 25 mg (both p<0.001), in weight were -1.8 kg and -1.6 kg with empagliflozin 10 mg and 25 mg, respectively (both p<0.001), and in systolic blood pressure (SBP) were -2.2 mmHg with empagliflozin 10 mg (p=0.021) and -2.1 mmHg with empagliflozin 25 mg (p=0.029). Sensitivity analyses provided consistent results for HbA1c and weight, but showed no significant difference between empagliflozin and placebo in change from baseline in SBP. Adverse events (AEs) were reported in 81.7%, 82.0% and 81.3% of patients on empagliflozin 10 mg, 25 mg and placebo, respectively. Confirmed hypoglycaemic AEs (glucose ≤3.9 mmol/l and/or requiring assistance) were reported in 23.7%, 19.4% and 15.6% of patients on empagliflozin 10 mg, 25 mg and placebo, respectively; one patient each on empagliflozin 10mg and placebo required assistance. In conclusion, empagliflozin as add-on to metformin plus sulphonylurea for 76 weeks was well tolerated and led to sustained reductions in HbA1c and weight versus placebo. CLINICALTRIALS.GOV: NCT01289990.