Weight Loss Outcomes Among Early High Responders to Exenatide Treatment: A Randomized, Placebo Controlled Study in Overweight and Obese Women

Intranasal delivery of glucagon-like peptide-1 to the brain for obesity treatment: opportunities and challenges

INTRODUCTION

Glucagon-like peptide-1 receptor agonists (GLP-1 RAs), approved by the US FDA for obesity treatment, are typically administered subcutaneously, an invasive method leading to suboptimal patient adherence and peripheral side effects. Additionally, this route requires the drug to cross the restrictive blood-brain barrier (BBB), limiting its safety and effectiveness in weight management and cognitive addiction disorders. Delivering the drug intranasally could overcome these drawbacks.

AREAS COVERED

This review summarizes GLP-1 RAs used as anti-obesity agents, focusing on the intranasal route as a potential pathway to deliver these biomolecules to the brain. It also discusses strategies to overcome challenges associated with nasal delivery.

EXPERT OPINION

Nose-to-brain (N2B) pathways can address limitations of the subcutaneous route for GLP-1 RAs. However, peptide delivery to the brain is challenging due to nasal physiological barriers and the drug's physicochemical properties. Innovative approaches, such as cell permeation enhancers, mucoadhesive systems, and nanocarriers in nasal formulations, along with efficient drug delivery devices, show promising preclinical results. Despite this, successful preclinical data does not guarantee clinical effectiveness, highlighting the need for comprehensive clinical investigations to optimize formulations and fully utilize the nose-to-brain interface for peptide delivery.

Efficacy and safety of GLP-1RAs for people with obesity: A systematic review based on RCT and Bayesian network meta-analysis

BACKGROUND

GLP-1 receptor agonists (GLP-1RAs) reduce glucagon and glycogen secretion, inhibit appetite and slow gastric empties and have recently been approved to treat obesity.

OBJECTIVE

To explore the safety and efficacy of GLP-1RAs in the treatment of obesity and clarify the optimal GLP-1RAs treatment regimen.

METHODS

PubMed, Embase, Web of Science, and Cochrane Library databases were searched for English randomized controlled trials (RCTs) on GLP-1RAs in the treatment and management of obesity published before July 18, 2023. Literature screening and data extraction were performed independently by three researchers. Bayesian random effect model was used to compare the effects of interventions. Continuous variables were expressed as mean difference with 95% CI, and dichotomous variables were reported as RR with 95% CI.

RESULTS

A total of 29 studies with 10,333 participants were included in the present study. The combination of cagrilintide and semaglutide (short for cagrANDsema) was an optimal strategy for weight loss and glycosylated hemoglobin (HbA1c) reduction. Compared to placebo, cagrANDsema reduced weight by - 14.13 kg (95% CI: -16.49, -11.73) and HbA1c by - 0.33% (95% CI: -0.41, -0.25). Moreover, this study indicated that orforglipron and semaglutide also had relatively good effects on weight loss. Meta-regression results indicated that higher dose levels might have better effects on weight loss.

CONCLUSIONS

CagrANDsema exerts the best effect for weight loss. In terms of current dose levels, a higher dose gets better weight-loss effects without increasing the risk of adverse events.

A model-based approach to predict individual weight loss with semaglutide in people with overweight or obesity

AIMS

To determine the relationship between exposure and weight-loss trajectories for the glucagon-like peptide-1 analogue semaglutide for weight management.

MATERIALS AND METHODS

Data from one 52-week, phase 2, dose-ranging trial (once-daily subcutaneous semaglutide 0.05-0.4 mg) and two 68-week phase 3 trials (once-weekly subcutaneous semaglutide 2.4 mg) for weight management in people with overweight or obesity with or without type 2 diabetes were used to develop a population pharmacokinetic (PK) model describing semaglutide exposure. An exposure-response model describing weight change was then developed using baseline demographics, glycated haemoglobin and PK data during treatment. The ability of the exposure-response model to predict 1-year weight loss based on weight data collected at baseline and after up to 28 weeks of treatment, was assessed using three independent phase 3 trials.

RESULTS

Based on population PK, exposure levels over time consistently explained the weight-loss trajectories across trials and dosing regimens. The exposure-response model had high precision and limited bias for predicting body weight loss at 1 year in independent datasets, with increased precision when data from later time points were included in the prediction.

CONCLUSION

An exposure-response model has been established that quantitatively describes the relationship between systemic semaglutide exposure and weight loss and predicts weight-loss trajectories for people with overweight or obesity who are receiving semaglutide doses up to 2.4 mg once weekly.

Metabolite profiles of diabetes mellitus and response to intervention in anti-hyperglycemic drugs

Type 2 diabetes mellitus (T2DM) has become a major health problem, threatening the quality of life of nearly 500 million patients worldwide. As a typical multifactorial metabolic disease, T2DM involves the changes and interactions of various metabolic pathways such as carbohydrates, amino acid, and lipids. It has been suggested that metabolites are not only the endpoints of upstream biochemical processes, but also play a critical role as regulators of disease progression. For example, excess free fatty acids can lead to reduced glucose utilization in skeletal muscle and induce insulin resistance; metabolism disorder of branched-chain amino acids contributes to the accumulation of toxic metabolic intermediates, and promotes the dysfunction of β-cell mitochondria, stress signal transduction, and apoptosis. In this paper, we discuss the role of metabolites in the pathogenesis of T2DM and their potential as biomarkers. Finally, we list the effects of anti-hyperglycemic drugs on serum/plasma metabolic profiles.

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 Obex® in overweight and obese subjects: a randomised, double-blind, placebo-controlled clinical trial

BACKGROUND

Obex® may be helpful in reducing body weight and fat. The current study was carried out to evaluate the efficacy and safety of Obex® in the treatment of overweight and obese subjects.

METHODS

A double-blind, randomised, controlled phase III clinical trial was conducted involving 160 overweight and obese subjects (BMI ≥ 25.0 and < 40 kg/m²) aged 20 to 60 years, who received Obex® (n = 80) and placebo (n = 80) plus non-pharmacological treatment (physical activity and nutritional counseling). One sachet of Obex® or placebo were administered before the two main meals each day for 6 months. In addition to anthropometric measurements and blood pressure, fasting plasma and 2 h glucose levels during the oral glucose tolerance test, lipid profile, insulin, liver enzymes, creatinine, and uric acid (UA) were determined, insulin resistance (HOMA-IR) beta-cell function (HOMA-β) were assessed and insulin sensitivity (IS) was calculated with three indirect indexes.

RESULTS

After 3 months of Obex®, 48.3% of the participants (28/58) achieved complete success in reducing both weight and waist circumference by greater than or equal to 5% from baseline, as opposed to 26.0% (13/50) of individuals receiving placebo (p = 0.022). Compared to baseline, at 6 months no differences were found between the groups concerning anthropometric and biochemical measurements, except for high-density lipoprotein cholesterol (HDL-c) levels, which were higher in subjects receiving Obex® compared to those receiving placebo (p = 0.030). After 6 months of treatment, both groups showed reduced cholesterol and triglyceride levels (p < 0.012) compared to baseline value. However, only those intake Obex® showed reduced insulin concentrations and HOMA-IR, improved IS (p < 0.05), and decreased creatinine and UA levels (p < 0.005).

CONCLUSIONS

The consumption of Obex® together with lifestyle changes increased HDL-c, contributed to a rapid reduction of weight and waist circumference, as well as improved insulin homeostasis, which did not occur in the placebo group, and appears to be safe as an adjunct at conventional obesity treatment.

TRIAL REGISTRATION

Clinical trial protocol was registered in the Cuban public registry of clinical trials under code RPCEC00000267 on 17/04/2018 and also registered in the international registry of clinical trials, ClinicalTrials.gov, under code: NCT03541005 on 30/05/2018.

Pharmacological Support for the Treatment of Obesity-Present and Future

Obesity is a growing civilization problem, associated with a number of negative health consequences affecting almost all tissues and organs. Currently, obesity treatment includes lifestyle modifications (including diet and exercise), pharmacologic therapies, and in some clinical situations, bariatric surgery. These treatments seem to be the most effective method supporting the treatment of obesity. However, they are many limitations to the options, both for the practitioners and patients. Often the comorbidities, cost, age of the patient, and even geographic locations may influence the choices. The pharmacotherapy of obesity is a fast-growing market. Currently, we have at our disposal drugs with various mechanisms of action (directly reducing the absorption of calories-orlistat, acting centrally-bupropion with naltrexone, phentermine with topiramate, or multidirectional-liraglutide, dulaglutide, semaglutide). The drugs whose weight-reducing effect is used in the course of the pharmacotherapy of other diseases (e.g., glucose-sodium cotransporter inhibitors, exenatide) are also worth mentioning. The obesity pharmacotherapy is focusing on novel therapeutic agents with improved safety and efficacy profiles. These trends also include an assessment of the usefulness of the weight-reducing properties of the drugs previously used for other diseases. The presented paper is an overview of the studies related to both drugs currently used in the pharmacotherapy of obesity and those undergoing clinical trials, taking into account the individual approach to the patient.

Predictors of weight loss in patients with obesity treated with a Very Low-Calorie Ketogenic Diet

Introduction

The Very Low-Calorie Ketogenic Diet (VLCKD) has emerged as a safe and effective intervention for the management of metabolic disease. Studies examining weight loss predictors are scarce and none has investigated such factors upon VLCKD treatment. Among the molecules involved in energy homeostasis and, more specifically, in metabolic changes induced by ketogenic diets, Fibroblast Growth Factor 21 (FGF21) is a hepatokine with physiology that is still unclear.

Methods

We evaluated the impact of a VLCKD on weight loss and metabolic parameters and assessed weight loss predictors, including FGF21. VLCKD is a severely restricted diet (<800 Kcal/die), characterized by a very low carbohydrate intake (<50 g/day), 1.2-1.5 g protein/kg of ideal body weight and 15-30 g of fat/day. We treated 34 patients with obesity with a VLCKD for 45 days. Anthropometric parameters, body composition, and blood and urine chemistry were measured before and after treatment.

Results

We found a significant improvement in body weight and composition and most metabolic parameters. Circulating FGF21 decreased significantly after the VLCKD [194.0 (137.6-284.6) to 167.8 (90.9-281.5) p < 0.001] and greater weight loss was predicted by lower baseline FGF21 (Beta = -0.410; p = 0.012), male sex (Beta = 0.472; p = 0.011), and central obesity (Beta = 0.481; p = 0.005).

Discussion

VLCKD is a safe and effective treatment for obesity and obesity related metabolic derangements. Men with central obesity and lower circulating FGF21 may benefit more than others in terms of weight loss obtained following this diet. Further studies investigating whether this is specific to this diet or to any caloric restriction are warranted.

Medicines for Obesity: Appraisal of Clinical Studies with Grading of Recommendations, Assessment, Development, and Evaluation Tool

We evaluated the quality of evidence from phase III/IV clinical trials of drugs against obesity using the principles of Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) tool. Our systematic review evaluates the quality of clinical evidence from existing clinical trials and not the pharmacological efficacy of anti-obesity therapies. A literature search using select keywords in separate was performed in PubMed and ClinicalTrials.gov databases for phase III/IV clinical trials during the last ten years. Our findings indicate that the quality of existing clinical evidence from anti-obesity trials generally ranges from low to moderate. Most trials suffered from publication bias. Less frequently, trials suffered from the risk of bias mainly due to lack of blindness in the treatment. Our work indicates that additional higher-quality clinical trials are needed to gain more confidence in the estimate of the effect of currently used anti-obesity medicines, to allow more informed clinical decisions, thus reducing the risk of implementing potentially ineffective or even harmful therapeutic strategies.

Exenatide regulates Th17/Treg balance via PI3K/Akt/FoxO1 pathway in db/db mice

BACKGROUND

The T helper 17 (Th17)/T regulatory (Treg) cell imbalance is involved in the course of obesity and type 2 diabetes mellitus (T2DM). In the current study, the exact role of glucagon-like peptide-1 receptor agonist (GLP-1RA) exenatide on regulating the Th17/Treg balance and the underlying molecular mechanisms are investigated in obese diabetic mice model.

METHODS

Metabolic parameters were monitored in db/db mice treated with/without exenatide during 8-week study period. The frequencies of Th17 and Treg cells from peripheral blood and pancreas in db/db mice were assessed. The phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/Forkhead box O1 (FoxO1) pathway in Th17 and Treg cells from the spleens of male C57BL/6J mice was detected by western blotting. In addition, the expression of glucagon-like peptide-1 receptor (GLP-1R) in peripheral blood mononuclear cells (PBMCs) of male C57BL/6J mice was analyzed.

RESULTS

Exenatide treatment improved β-cell function and insulitis in addition to glucose, insulin sensitivity and weight. Increased Th17 and decreased Treg cells in peripheral blood were present as diabetes progressed while exenatide corrected this imbalance. Progressive IL-17 + T cell infiltration of pancreatic islets was alleviated by exenatide intervention. In vitro study showed no significant difference in the level of GLP-1R expression in PBMCs between control and palmitate (PA) groups. In addition, PA could promote Th17 but suppress Treg differentiation along with down-regulating the phosphorylation of PI3K/Akt/FoxO1, which was reversed by exenatide intervention. FoxO1 inhibitor AS1842856 could abrogate all these effects of exenatide against lipid stress.

CONCLUSIONS

Exenatide could restore systemic Th17/Treg balance via regulating FoxO1 pathway with the progression of diabetes in db/db mice. The protection of pancreatic β-cell function may be partially mediated by inhibiting Th17 cell infiltration into pancreatic islets, and the resultant alleviation of islet inflammation.