Exenatide in obese or overweight patients without diabetes: A systematic review and meta-analyses of randomized controlled trials

Glucagon-like peptide-1 receptor agonists: a review from a cardiovascular perspective

Introduction

Glucagon-like peptide-1 receptor agonists (GLP-1 RA) are novel agents with proven cardiovascular (CV) benefits. GLP-1 RAs have been used for diabetes and found to improve CV outcomes in diabetic and nondiabetic patients. They are authorized for treating obesity. Our narrative review discussed the CV benefits of GLP-1 RAs in terms of controlling CV risk factors and improving CV outcomes in diabetic and nondiabetic patients regardless of their CV history, and the CV perspectives related to their use in clinical practice.

Areas covered

Literature was searched with no limits on date or language, using various combinations of keywords. Data on the CV benefits of GLP-1 RAs and their use in clinical practice were summarized.

Results

Several studies have discussed the CV beneficial effects of GLP-1 RAs in terms of reducing blood pressure, lipid levels, body weight, risk for arrhythmias, reducing the risk of major adverse CV events, and hospital admission for heart failure.

Conclusion

The cardioprotective effects and low risk of hypoglycemia of GLP-1 RAs make them preferred agents in any multidisciplinary approach aiming to reduce CV disease burden and improve prognosis. Cardiologists are encouraged to strongly consider the CV benefits of GLP-1 RAs in their risk-reduction strategies.

Semaglutide as a GLP-1 Agonist: A Breakthrough in Obesity Treatment

This review addresses the role of semaglutide (SMG), a GLP-1 receptor agonist, in the treatment of obesity and its related comorbidities. Originally developed for type 2 diabetes (DM2), SMG has shown significant efficacy in weight reduction, with superior results compared to other treatments in the same class. Its effects include appetite suppression, increased satiety, and improvements in cardiovascular, renal, and metabolic parameters. Studies such as SUSTAIN, PIONEER, and STEP highlight its superiority compared to other GLP-1 receptor agonists and anti-obesity drugs. The oral formulation showed promising initial results, with higher doses (50 mg) showing weight losses comparable to those of subcutaneous administration. Despite its benefits, there are challenges, such as weight regain after cessation of treatment, gastrointestinal adverse effects, and variability of response. Future studies should explore strategies to mitigate these effects, identify predictive factors of efficacy, and expand therapeutic indications to other conditions related to obesity and insulin resistance. The constant innovation in this class of drugs reinforces the potential of SMG to transform treatment protocols for chronic weight-related diseases.

Drug release profile of a novel exenatide long-term drug delivery system (OKV-119) administered to cats

Beneficial weight-loss properties of glucagon-like peptide-1 receptor agonists (GLP-1RA) in obese people, with corresponding improvements in cardiometabolic risk factors, are well established. OKV-119 is an investigational drug delivery system that is being developed for the long-term delivery of the GLP-1RA exenatide to feline patients. The purpose of this study was to evaluate the drug release characteristics of subcutaneous OKV-119 implants configured to release exenatide for 84 days. Following a 7-day acclimation period, five purpose-bred cats were implanted with OKV-119 protypes and observed for a 112-day study period. Food intake, weekly plasma exenatide concentrations and body weight were measured. Exenatide plasma concentrations were detected at the first measured timepoint (Day 7) and maintained above baseline for over 84 Days. Over the first 28 days, reduced caloric intake and a reduction in body weight were observed in four of five cats. In these cats, a body weight reduction of at least 5% was maintained throughout the 112-day study period. This study demonstrates that a single OKV-119 implant can deliver the GLP-1RA exenatide for a months long duration. Results suggest that exposure to exenatide plasma concentrations ranging from 1.5 ng/ml to 4 ng/ml are sufficient for inducing weight loss in cats.

Exenatide for obesity in children and adolescents: Systematic review and meta-analysis

Objectives: There is no curative treatment for childhood obesity. We aim to synthesize published Randomized Controlled Trials (RCTs) evidence on the efficacy of exenatide in obese children and adolescents. Methods: We conducted a comprehensive search and analysis of relevant studies in popular databases such as PubMed, Web of Science, Embase, and Cochrane Library. Our focus was on RCTs that examined the effectiveness of exenatide for treating obesity in children. We primarily assessed changes in body weight, body mass index (BMI), fasting plasma glucose (FPG), or HbA1c levels. Additionally, we considered any adverse events reported during the treatment period, with particular attention to hypoglycemia. To evaluate the quality of RCTs included in our study, we employed the Cochrane bias assessment tool. Results: Five studies met the inclusion criteria. A group of 100 children were assigned to receive treatment with exenatide. Compared with controls, exenatide therapy reduced body weight and BMI by -0.6% (95% CI -0.93, -0.27), -1.11% (95% CI -1.91, -0.31), respectively. Undesirable consequences encompass gastrointestinal symptoms, with the majority of instances being characterized by mild severity. Conclusion: Exenatide demonstrates efficacy in the treatment of pediatric and adolescent obesity. Systematic Review Registration: PROSPERO https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=413706.

A Comprehensive Review on Weight Loss Associated with Anti-Diabetic Medications

Obesity is a complex metabolic condition that can have a negative impact on one's health and even result in mortality. The management of obesity has been addressed in a number of ways, including lifestyle changes, medication using appetite suppressants and thermogenics, and bariatric surgery for individuals who are severely obese. Liraglutide and semaglutide are two of the five Food and Drug Administration (FDA)-approved anti-obesity drugs that are FDA-approved agents for the treatment of type 2 diabetes mellitus (T2DM) patients. In order to highlight the positive effects of these drugs as anti-obesity treatments, we analyzed the weight loss effects of T2DM agents that have demonstrated weight loss effects in this study by evaluating clinical studies that were published for each agent. Many clinical studies have revealed that some antihyperglycemic medications can help people lose weight, while others either cause weight gain or neutral results. Acarbose has mild weight loss effects and metformin and sodium-dependent glucose cotransporter proteins-2 (SGLT-2) inhibitors have modest weight loss effects; however, some glucagon-like peptide-1 (GLP-1) receptor agonists had the greatest impact on weight loss. Dipeptidyl peptidase 4 (DPP-4) inhibitors showed a neutral or mild weight loss effect. To sum up, some of the GLP-1 agonist drugs show promise as weight-loss treatments.

Efficacy and safety of semaglutide on weight loss in obese or overweight patients without diabetes: A systematic review and meta-analysis of randomized controlled trials

Objectives: This study aims to explore the weight loss effect and safety of semaglutide as a conventional anti-obesity drug systematically in obese or overweight patients without diabetes.

Methods: The randomized controlled trials (RCTs) of semaglutide in obese or overweight patients without diabetes were retrieved from PubMed, Cochrane Library, EMBASE, and ClinicalTrials.gov from database inception until 2 May 2022. Data extraction and quality assessment of studies meeting the inclusion criteria were performed, and statistical analysis was conducted by Review Manager 5.3 and Stata 14.

Results: Eight studies involving 4,567 patients were enrolled in the meta-analysis. Compared with placebo, semaglutide induced a significant body weight loss (MD: −10.09%; 95% CI: −11.84 to −8.33; p ˂ 0.00001), elicited a larger reduction in body mass index (MD: −3.71 kg/m²; 95% CI: −4.33 to −3.09; p ˂ 0.00001) and waist circumference (MD: −8.28 cm; 95% CI: −9.51 to −7.04; p ˂ 0.00001), achieved weight loss of more than 5, 10, 15, and 20% with a higher proportion of participants. Semaglutide exhibited a positive effect on blood pressure, C-reactive protein, and lipid profiles, expressed more adverse effects than placebo, mainly gastrointestinal reactions. The results were stable and reliable with dose-dependence.

Conclusion: Semaglutide indicated a significant weight loss with an acceptable safety for obese or overweight patients without diabetes.

The Antiobesity Effect and Safety of GLP-1 Receptor Agonist in Overweight/Obese Patients Without Diabetes: A Systematic Review and Meta-Analysis

Aim To determine the antiobesity effect and safety of glucagon-like peptide-1 receptor agonist (GLP-1RA) including liraglutide, exenatide and semaglutide treatment in overweight/obese patients without diabetes. The random-effect model was used to pool data extracted from included literatures. The weighted mean difference (WMD), odds ratio and 95% confidence interval (CI) were used to present the meta-analysis results (PROSPERO registration number: CRD 42020173199). The sources of intertrial heterogeneity, bias and the robustness of results were evaluated by subgroup analysis, sensitivity analysis and regression analysis, respectively. A total of 24 RCTs were recruited in the present analysis which included 5867 patients. The results showed that the treatment of overweight/obese patients without diabetes with GLP-1RAs including liraglutide, exenatide and semaglutide significantly achieved greater weight loss than placebo [WMD=-5.39, 95% CI (-6.82, -3.96)] and metformin [WMD=-5.46, 95% CI (-5.87, -5.05)]. The subgroup analysis showed that semaglutide displayed the most obvious antiobesity effect in terms of weight loss, the reduction of body mass index (BMI) and waist circumference (WC). However, GLP-1RAs treatments had more gastrointestinal adverse events (such as nausea and vomiting) than placebo and Met. The subgroup analysis also represented that semaglutide displayed the lowest risk of gastrointestinal adverse events among three kinds of GLP-1RAs. Our meta-analysis demonstrated that GLP-1RA had a superior antiobesity effect than placebo/Met in overweight/obese patients without diabetes in terms of body weight, BMI, and WC, especially for semaglutide, which had more obvious antiobesity effect and lower GI adverse events than liraglutide and exenatide.

Short-term combined treatment with exenatide and metformin for overweight/obese women with polycystic ovary syndrome

Background:

Obesity and insulin resistance (IR) are common features of polycystic ovary syndrome (PCOS). Metformin (MET) increases insulin sensitivity, but it is associated with unsatisfactory weight loss. The glucagon-like peptide-1 receptor agonist exenatide has been shown to reduce weight and IR in patients with diabetes. This study aimed to explore the therapeutic effects of exenatide once-weekly (QW) combined with MET on body weight, as well as metabolic and endocrinological parameters in overweight/obese women with PCOS.

Methods:

Fifty overweight/obese women with PCOS diagnosed via the Rotterdam criteria were randomized to one of two treatment groups: MET (500 mg three times a day [TID]) or combination treatment (COM) (MET 500 mg TID, exenatide 2 mg QW) for 12 weeks. The primary outcomes were anthropometric changes associated with obesity, and the secondary outcomes included changes in reproductive hormone levels, glucose and lipid metabolism, and C-reactive protein.

Results:

Forty (80%) patients completed the study. COM therapy was superior to MET monotherapy in reducing weight (P = 0.045), body mass index (BMI) (P = 0.041), and waist circumference (P = 0.023). Patients in the COM group on an average lost 3.8 ± 2.4 kg compared with 2.1 ± 3.0 kg in the MET group. In the COM group, BMI and waist circumference decreased by 1.4 ± 0.87 kg/m² and 4.63 ± 4.42 cm compared with 0.77 ± 1.17 kg/m² and 1.72 ± 3.07 cm in the MET group, respectively. Moreover, levels of fasting glucose, oral glucose tolerance test (OGTT) 2-h glucose, and OGTT 2-h insulin were significantly lower with COM therapy than with MET (P < 0.050). Mild and moderate gastrointestinal reactions were the most common adverse events in both groups.

Conclusions:

COM therapy was more effective than MET alone in reducing body weight, BMI, and waist circumference, and improving insulin sensitivity in overweight/obese women with PCOS, with acceptable short-term side effects.

Trial registration:

ClinicalTrials.gov, NCT04029272. https://clinicaltrials.gov/ct2/show/NCT04029272

GLP-1 agonists for obesity and type 2 diabetes in children: Systematic review and meta-analysis

Pharmacological options for management of obesity and type 2 diabetes mellitus (T2DM) in children are limited. We aimed to synthesize published randomized controlled trial (RCT) evidence on the efficacy of glucagon-like peptide-1 (GLP-1) agonists in T2DM, pre-diabetes, and obesity in children aged <18 years. Inclusion criteria were RCTs of any GLP-1 agonist, solely or in conjunction with other drugs, for the treatment of obesity, pre-diabetes, and/or T2DM in children aged <18 years old. Nine studies met the inclusion criteria (two for T2DM, one for pre-diabetes, and six for obesity without diabetes). In total, 286 children were allocated to GLP-1 agonist therapy. Compared with controls, GLP-1 agonist therapy reduced HbA1c by -0.30% (95% confidence interval [CI] -0.57, -0.04) with a larger effect in children with (pre-)diabetes (-0.72%; 95% CI -1.17, -0.28; three studies) than in children with obesity (-0.08%; 95% CI -0.13, -0.02; four studies). Conversely, GLP-1 agonist therapy reduced body weight more in children with obesity (-2.74 kg; 95% CI -3.77, -1.70; six studies) than in children with T2DM (-0.97 kg; 95% CI -2.01, 0.08; two studies). Adverse effects included gastrointestinal symptoms and minor hypoglycemic episodes, but not severe hypoglycemia. GLP-1 agonists are efficacious in treating children with obesity and/or T2DM. Effect sizes are comparable with those reported in adults.

Safety, Tolerability, and Proof-Of-Concept Study of OKV-119, a Novel Exenatide Long-Term Drug Delivery System, in Healthy Cats

Background: Glucagon-like peptide-1 (GLP-1) is an incretin hormone that plays an important role in glucose homeostasis and food intake. In people, GLP-1 receptor agonists (GLP-1RAs) are commonly used for the treatment of type 2 diabetes mellitus (DM) and obesity; however, non-adherence to injectable medications is common. OKV-119 is an investigational drug delivery system intended for subdermal implantation and delivery of the GLP-1RA exenatide for up to 6 months.

Hypothesis/Objectives: Develop protocols for the subcutaneous (SC) insertion and removal of OKV-119 and to evaluate its tolerability, in vivo drug-releasing characteristics, and weight-loss effects in cats.

Animals: Two cadaveric and 19 purpose-bred cats.

Methods: In cadavers, OKV-119 insertion protocol and imaging were performed at three SC locations. The safety and tolerability of OKV-119 implants were assessed in a small (n = 4 cats) 62-day study. Weekly plasma exenatide concentrations and body weight were measured in a 42-day proof-of-concept study designed to evaluate OKV-119 prototypes implanted in cats (n = 15).

Results: In anesthetized cats, the duration of insertion and removal procedures was 1–2 min. OKV-119 was easily identified on radiographs, and well-tolerated without any apparent implant site reactions. Following implantation, exanatide plasma concentrations were observed for up to 35 days. Plasma exenatide concentrations were correlated to weight loss.

Conclusion and clinical importance: Our findings suggest that OKV-119 could be easily inserted and removed during a routine clinic visit and can be used to safely and effectively deliver exenatide. Future studies of OKV-119, configured to release exenatide for a longer extended months-long duration, are warranted to determine whether the combination of metabolic improvements and beneficial weight-loss, coupled with minimal impact on pet-owner's lifestyle, lead to improved outcomes for obese cats and feline DM patients.

The Fight Against Obesity Escalates: New Drugs on the Horizon and Metabolic Implications

PURPOSE OF REVIEW

There is currently a steep rise in the global prevalence of obesity. Pharmaceutical therapy is a valuable component of conservative obesity therapy. Herein, medications currently in the phase of preclinical or clinical testing are reviewed, along with an overview of the mechanisms that regulate energy intake and expenditure. In addition, the current and potential future directions of obesity drug therapy are discussed.

RECENT FINDINGS

Although the current arsenal of obesity pharmacotherapy is limited, a considerable number of agents that exert their actions through a variety of pharmacodynamic targets and mechanisms are in the pipeline. This expansion shapes a potential near future of obesity conservative management, characterized by tailored combined therapeutic regimens, targeting not only weight loss but also improved overall health outcomes. The progress regarding the elucidation of the mechanisms which regulate the bodily energy equilibrium has led to medications which mimic hormonal adaptations that follow bariatric surgery, in the quest for a "Medical bypass." These, combined with agents which could increase energy expenditure, point to a brilliant future in the conservative treatment of obesity.

Twelve weeks of exenatide treatment increases [18F]fluorodeoxyglucose uptake by brown adipose tissue without affecting oxidative resting energy expenditure in nondiabetic males

AIMS/HYPOTHESIS

Brown adipose tissue (BAT) improves energy metabolism by combusting glucose and lipids into heat. Agonism of the glucagon-like peptide-1 receptor (GLP-1R) within the central nervous system activates BAT in mice. Moreover, in patients with type 2 diabetes, GLP-1R agonism lowers body weight and improves glucose and lipid levels, possibly involving BAT activation. Interestingly, people from South Asian descent are prone to develop cardiometabolic disease. We studied the effect of GLP-1R agonism on BAT in humans, specifically in South Asians and Europids without obesity or type 2 diabetes.

METHODS

Twelve Dutch South Asian and 12 age- and BMI-matched Europid nondiabetic men received 12 weeks extended-release exenatide (Bydureon) in this single-arm prospective study. Before and after treatment, BAT was visualized by a cold-induced [¹⁸F]FDG-PET/CT scan and a thermoneutral MRI scan, and resting energy expenditure (REE), substrate oxidation, body composition and fasting plasma glucose and serum lipids were determined. Appetite was rated using a visual analogue scale.

RESULTS

Since the effect of exenatide on metabolic parameters did not evidently differ between ethnicities, data of all participants were pooled. Exenatide decreased body weight (-1.5 ± 0.4 kg, p < 0.01), without affecting REE or substrate oxidation, and transiently decreased appetite ratings during the first weeks. Exenatide also lowered triglycerides (-15%, p < 0.05) and total cholesterol (-5%, p < 0.05), and tended to lower glucose levels. Notably, exenatide increased BAT metabolic volume (+28%, p < 0.05) and mean standardized uptake value (+11%, p < 0.05) ([¹⁸F]FDG-PET/CT), without affecting supraclavicular adipose tissue fat fraction (MRI).

CONCLUSIONS/INTERPRETATION

We show for the first time that GLP-1R agonism increases [¹⁸F]FDG uptake by BAT in South Asian and Europid men without obesity or type 2 diabetes.

TRIAL REGISTRY

Clinicaltrials.gov NCT03002675.

Pharmacotherapy of obesity: Available medications and drugs under investigation

Obesity is a chronic disease with a continuously rising prevalence that currently affects more than half a billion people worldwide. Energy balance and appetite are highly regulated via central and peripheral mechanisms, and weight loss triggers a homeostatic response leading to weight regain. Lifestyle and behavioral modifications are the cornerstones of obesity management; however, they often fail to achieve or sustain long-term weight loss. Pharmacotherapy added onto lifestyle modifications results in an additional, albeit limited, weight reduction. Regardless, this weight reduction of 5-10% conveys multiple cardiovascular and metabolic benefits. In this review, evidence on the food and drug administration (FDA)-approved medications, i.e., orlistat, lorcaserin, phentermine/topiramate, liraglutide and naltrexone/bupropion, is summarized. Furthermore, anti-obesity agents in the pipeline for potential future therapeutic use are presented.

Comparative Study of In Situ Loaded Antibody and PEG-Fab NIPAAM Gels

Hydrogels can potentially prolong the release of a therapeutic protein, especially to treat blinding conditions. One challenge is to ensure that the protein and hydrogel are intimately mixed by better protein entanglement within the hydrogel. N-isopropylacrylamide (NIPAAM) gels are optimized with poly(ethylene glycol) diacrylate (PEDGA) crosslinker in the presence of either bevacizumab or PEG conjugated ranibizumab (PEG₁₀ -Fab_rani ). The release profiles of the hydrogels are evaluated using an outflow model of the eye, which is previously validated for human clearance of proteins. Release kinetics of in situ loaded bevacizumab-NIPAAM gels displays a prolonged bimodal release profile in phosphate buffered saline compared to bevacizumab loaded into a preformed NIPAAM gel. Bevacizumab release in simulated vitreous from in situ loaded gels is similar to bevacizumab control indicating that diffusion through the vitreous rather than from the gel is rate limiting. Ranibizumab is site-specifically PEGylated by disulfide rebridging conjugation. Prolonged and continuous release is observed with the in situ loaded PEG₁₀ -Fab_rani -NIPAAM gels compared to PEG₁₀ -Fab_rani injection (control). Compared to an unmodified protein, there is better mixing due to PEG entanglement and compatibility of PEG₁₀ -Fab_rani within the NIPAAM-PEDGA hydrogel. These encouraging results suggest that the extended release of PEGylated proteins in the vitreous can be achieved using injectable hydrogels.

Efficacy and safety of glucagon-like peptide-1 receptor agonists in non-alcoholic fatty liver disease: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

New drugs are urgently needed for the treatment of non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH). The aim of this meta-analysis was to evaluate the efficacy and safety of glucagon-like peptide-1 receptor agonists (GLP-1RAs) in NAFLD/NASH.

METHODS

We searched the MEDLINE, Embase, and Cochrane Library Central to identify randomized controlled trials (RCTs) and observational studies that compared GLP-1RAs with a control treatment or baseline values with respect to efficacy and safety in patients with NAFLD/NASH. Mean differences (MDs) with 95% confidence intervals (CIs) and odds ratios (ORs) were pooled using a random-effect model.

RESULTS

Six studies were eligible and included. Among the 329 NAFLD/NASH patients included in these studies, 277 patients had type 2 diabetes (T2D). GLP-1RA treatment produced significant reductions relative to baseline in liver histology scores for steatosis (MD, 0.80; 95% CI, 0.49 to 1.11), lobular inflammation (MD, 0.22; 95% CI, 0.00 to 0.45), hepatocellular ballooning (MD, 0.41; 95% CI, 0.15 to 0.67) and fibrosis (MD, 0.35; 95% CI, 0.00 to 0.70). Compared with placebo and positive agents, GLP-1RAs significantly reduced gamma-glutamyl transpeptidase (GGT) levels (MD, 13.8 U/L; 95% CI, 7.4 to 20.3; P<0.001). The reported major adverse events associated with GLP-1RA treatment included mild to moderate gastrointestinal discomfort that resolved within a few weeks.

CONCLUSIONS

Our study suggests that in NASH patients, particularly patients with diabetes, GLP-1RAs may improve liver histology and reduce aminotransferase levels from baseline. Benefits of GLP-1RAs are considered to outweigh the risks in NAFLD/NASH patients with or without diabetes.

Blood pressure control in type 2 diabetic patients

Diabetes mellitus (DM) and essential hypertension are common conditions that are frequently present together. Both are considered risk factors for cardiovascular disease and microvascular complications and therefore treatment of both conditions is essential. Many papers were published on blood pressure (BP) targets in diabetic patients, including several works published in the last 2 years. As a result, guidelines differ in their recommendations on BP targets in diabetic patients. The method by which to control hypertension, whether pharmacological or non-pharmacological, is also a matter of debate and has been extensively studied in the literature. In recent years, new medications were introduced for the treatment of DM, some of which also affect BP and the clinician treating hypertensive and diabetic patients should be familiar with these medications and their effect on BP. In this manuscript, we discuss the evidence supporting different BP targets in diabetics and review the various guidelines on this topic. In addition, we discuss the various options available for the treatment of hypertension in diabetics and the recommendations for a specific treatment over the other. Finally we briefly discuss the new diabetic drug classes and their influence on BP.