GLP-1 physiology informs the pharmacotherapy of obesity

Survodutide for treatment of obesity: rationale and design of two randomized phase 3 clinical trials (SYNCHRONIZE™-1 and -2)

OBJECTIVE

The objective of this study was to describe the rationale and design of two multinational phase 3 clinical trials of survodutide, an investigational glucagon and glucagon-like peptide-1 receptor dual agonist for the treatment of obesity with or without type 2 diabetes (T2D; SYNCHRONIZE-1 and -2).

METHODS

In these ongoing double-blind trials, participants were randomized to once-weekly subcutaneous injections of survodutide or placebo added to lifestyle modification. Survodutide doses are uptitrated to 3.6 or 6.0 mg, and dose flexibility is permitted. Participants (n = 726) in SYNCHRONIZE-1 (NCT06066515) have a baseline BMI ≥ 30 kg/m2 or ≥27 kg/m2 with at least one obesity-related complication but without T2D; participants (n = 755) in SYNCHRONIZE-2 (NCT06066528) have a baseline BMI ≥ 27 kg/m2 and T2D. The primary endpoints are percentage change in body weight and proportion of participants achieving ≥5% body weight reduction from baseline to week 76. Secondary endpoints include change in systolic blood pressure and measures of glycemia. A SYNCHRONIZE-1 substudy is evaluating changes in body composition and liver fat content using magnetic resonance imaging.

CONCLUSIONS

These trials are designed to provide robust evaluation of the efficacy, safety, and tolerability of survodutide for the treatment of obesity in the presence or absence of T2D.

A Pragmatic Management Approach for Metabolic Dysfunction-Associated Steatosis and Steatohepatitis

Obesity and associated insulin resistance induce a chronic metaboinflammatory state that lead to injury and dysfunction of multiple organs resulting in a cluster of noncommunicable diseases such as type 2 diabetes mellitus, hypertension, cardiovascular disease, chronic kidney disease, and metabolic dysfunction-associated steatotic liver disease (MASLD). Metabolic dysfunction-associated steatohepatitis (MASH) is a histologically active form of MASLD and characterized by greater injury and inflammation and progresses to cirrhosis with greater certainty than steatosis alone. The progression to cirrhosis is characterized by increasing fibrosis. The goal of treatment of MASLD/MASH was to improve the metaboinflammatory state i.e., the root cause of the liver disease and to prevent fibrosis progression to cirrhosis whereas in those who already have cirrhosis need additional care to prevent portal hypertension-related outcomes. Fibrosis regression is thus a key objective of treatment. The recent approval of resmetirom for MASH with fibrosis and the use of glucagon-like peptide-1 receptor agonists for obesity and type 2 diabetes has increased awareness of these NCDs and resulted in the growing demand for liver assessment and care in obese individuals. Patients with MASLD also have multiple metabolic comorbidities which represent competing threats to life, and the care of the patient requires both assessment of the totality of the risk and a more holistic approach integrating the care of all of the threats to life. Here, we provide a pragmatic and easily implementable risk-based approach to the evaluation and management of MASLD.

Glucagon-Like Peptide-1 Agonists: A Practical Overview for Plastic and Reconstructive Surgeons

BACKGROUND

Glucagon-like peptide-1 (GLP-1) agonists, such as exenatide, liraglutide, dulaglutide, semaglutide, and tirzepatide, effectively manage type 2 diabetes by promoting insulin release, suppressing glucagon secretion, and enhancing glucose metabolism. They also aid weight reduction and cardiovascular health, potentially broadening their therapeutic scope. In plastic surgery, they hold promise for perioperative weight management and glycemic control, potentially impacting surgical outcomes.

METHODS

A comprehensive review was conducted to assess GLP-1 agonists' utilization in plastic surgery. We analyzed relevant studies, meta-analyses, and trials to evaluate their benefits and limitations across surgical contexts, focusing on weight reduction, glycemic control, cardiovascular risk factors, and potential complications.

RESULTS

Studies demonstrate GLP-1 agonists' versatility, spanning weight management, cardiovascular health, neurological disorders, and metabolic dysfunction-associated liver diseases. Comparative analyses highlight variations in glycemic control, weight loss, and cardiometabolic risk. Meta-analyses reveal significant reductions in hemoglobin A1C levels, especially with high-dose semaglutide (2 mg) and tirzepatide (15 mg). However, increased dosing may lead to gastrointestinal side effects and serious complications like pancreatitis and bowel obstruction. Notably, GLP-1 agonists' efficacy in weight reduction and glycemic control may impact perioperative management in plastic surgery, potentially expanding surgical candidacy for procedures like autologous flap-based breast reconstruction and influencing outcomes related to lymphedema. Concerns persist regarding venous thromboembolism and delayed gastric emptying, necessitating further investigation into bleeding and aspiration risk with anesthesia.

CONCLUSIONS

GLP-1 agonists offer advantages in perioperative weight management and glycemic control in plastic surgery patients. They may broaden surgical candidacy and mitigate lymphedema risk but require careful consideration of complications, particularly perioperative aspiration risk. Future research should focus on their specific impacts on surgical outcomes to optimize their integration into perioperative protocols effectively. Despite challenges, GLP-1 agonists promise to enhance surgical outcomes and patient care in plastic surgery.

Anti-Obesity Medication in the Management of Children and Adolescents With Obesity: Recent Developments and Research Gaps

BACKGROUND

Paediatric obesity is a global public health concern. While in most countries the incidence keeps rising, the need for effective and long-term management for children and adolescents living with this chronic, relapsing disease is pressing. Health behaviour and lifestyle treatment (HBLT) is recommended as first-line treatment.

METHODS

Narrative review.

RESULTS

A new generation of recently approved anti-obesity medications (AOM) now has the potential to fill the gap between limited effects on body mass index (BMI) by HBLT alone and large effects by metabolic and bariatric surgery in adolescents with obesity aged 12 years and older. While, for semaglutide and phentermine/topiramate, effectiveness is substantial with relevant, but mostly mild to moderate adverse events, there is a gap in evidence regarding long-term effects and safety, effects on outcomes beyond BMI reduction and data for certain groups of patients, such as children < 12 years and minority groups. When integrating AOM treatment into national healthcare systems it should be offered as part of a comprehensive patient-centred approach.

CONCLUSION

This article summarizes recent AOM developments, integration into paediatric obesity management, and identifies research gaps.

Incretin-based therapies for the management of cardiometabolic disease in the clinic: Past, present, and future

Among newer classes of drugs for type 2 diabetes mellitus (T2DM), glucagon-like peptide 1 receptor agonists (GLP-1 RAs) are incretin-based agents that lower both blood sugar levels and promote weight loss. They do so by activating pancreatic GLP-1 receptors (GLP-1R) to promote glucose-dependent insulin release and inhibit glucagon secretion. They also act on receptors in the brain and gastrointestinal tract to suppress appetite, slow gastric emptying, and delay glucose absorption. Phase 3 clinical trials have shown that GLP-1 RAs improve cardiovascular outcomes in the setting of T2DM or overweight/obesity in people who have, or are at high risk of having atherosclerotic cardiovascular disease. This is largely driven by reductions in ischemic events, although emerging evidence also supports benefits in other cardiovascular conditions, such as heart failure with preserved ejection fraction. The success of GLP-1 RAs has also seen the evolution of other incretin therapies. Tirzepatide has emerged as a dual glucose-dependent insulinotropic polypeptide (GIP)/GLP-1 RA, with more striking effects on glycemic control and weight reduction than those achieved by isolated GLP-1R agonism alone. This consists of lowering glycated hemoglobin levels by more than 2% and weight loss exceeding 15% from baseline. Here, we review the pharmacological properties of GLP-1 RAs and tirzepatide and discuss their clinical effectiveness for T2DM and overweight/obesity, including their ability to reduce adverse cardiovascular outcomes. We also delve into the mechanistic basis for these cardioprotective effects and consider the next steps in implementing existing and future incretin-based therapies for the broader management of cardiometabolic disease.

Glucagon-Like Peptide-1 Receptor Agonists Decrease Medical and Surgical Complications in Morbidly Obese Patients Undergoing Primary TKA

BACKGROUND

Weight optimization methods in morbidly obese patients with a body mass index (BMI) of ≥40 kg/m2 undergoing total knee arthroplasty (TKA) have shown mixed results. The purpose of this study was to evaluate the effect of perioperative use of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) in patients with a BMI of ≥40 kg/m2 undergoing primary TKA.

METHODS

Using an administrative claims database, patients with morbid obesity undergoing primary TKA were stratified into GLP-1 RA use for 3 months before and after the surgical procedure (treatment group) and GLP-1 RA non-use (control group), and were matched on the basis of patient age, gender, diagnosis of type-2 diabetes mellitus, and Charlson Comorbidity Index (CCI). In addition, these groups were compared with a contemporaneous cohort of patients undergoing TKA with a BMI of 35.0 to 39.9 kg/m2. Outcomes including infection, complications, revision, and readmission were compared between the matched cohorts.

RESULTS

There were significant decreases in the rates of 90-day periprosthetic joint infection (PJI) (1.0% compared with 1.8%; p = 0.037), any medical complications (10.6% compared with 12.7%; p = 0.033), pulmonary embolism (<0.4% compared with 0.6%; p = 0.050), and readmissions (5.3% compared with 8.9%; p < 0.001) in patients with a BMI of ≥40 kg/m2 who were taking GLP-1 RA versus the control group who were not. There were no differences in the 2-year rates of surgical complications (p > 0.05) between these groups. Compared with obese patients (BMI of 35.0 to 39.9 kg/m2), patients who had a BMI of ≥40 kg/m2 and were taking a GLP-1 RA did not have increased rates of infection or 90-day or 2-year complications (p > 0.05).

CONCLUSIONS

GLP-1 RA administration for at least 90 days prior to and after primary TKA in patients with a BMI of ≥40 kg/m2 was associated with reductions in the risks of 90-day PJI, any medical complications, and readmission. Additionally, the reduced complication rate that was achieved was similar to that of obese patients with a BMI of 35.0 to 39.9 kg/m2 undergoing TKA. Randomized clinical trials are needed to define the true effect of these agents on clinical outcomes following TKA.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Spotlight on the Mechanism of Action of Semaglutide

Initially intended to control blood glucose levels in patients with type 2 diabetes, semaglutide, a potent glucagon-like peptide 1 analogue, has been established as an effective weight loss treatment by controlling appetite. Integrating the latest clinical trials, semaglutide in patients with or without diabetes presents significant therapeutic efficacy in ameliorating cardiometabolic risk factors and physical functioning, independent of body weight reduction. Semaglutide may modulate adipose tissue browning, which enhances human metabolism and exhibits possible benefits in skeletal muscle degeneration, accelerated by obesity and ageing. This may be attributed to anti-inflammatory, mitochondrial biogenesis, antioxidant and autophagy-regulating effects. However, most of the supporting evidence on the mechanistic actions of semaglutide is preclinical, demonstrated in rodents and not actually confirmed in humans, therefore warranting caution in the interpretation. This article aims to explore potential innovative molecular mechanisms of semaglutide action in restoring the balance of several interlinking aspects of metabolism, pointing to distinct functions in inflammation and oxidative stress in insulin-sensitive musculoskeletal and adipose tissues. Moreover, possible applications in protection from infections and anti-aging properties are discussed. Semaglutide enhancement of the core molecular mechanisms involved in the progress of obesity and diabetes, although mostly preclinical, may provide a framework for future research applications in human diseases overall.

Diverting hepatic lipid fluxes with lifestyles revision and pharmacological interventions as a strategy to tackle steatotic liver disease (SLD) and hepatocellular carcinoma (HCC)

Steatotic liver disease (SLD) and Hepatocellular Carcinoma (HCC) are characterised by a substantial rewiring of lipid fluxes caused by systemic metabolic unbalances and/or disrupted intracellular metabolic pathways. SLD is a direct consequence of the interaction between genetic predisposition and a chronic positive energy balance affecting whole-body energy homeostasis and the function of metabolically-competent organs. In this review, we discuss how the impairment of the cross-talk between peripheral organs and the liver stalls glucose and lipid metabolism, leading to unbalances in hepatic lipid fluxes that promote hepatic fat accumulation. We also describe how prolonged metabolic stress builds up toxic lipid species in the liver, and how lipotoxicity and metabolic disturbances drive disease progression by promoting a chronic activation of wound healing, leading to fibrosis and HCC. Last, we provide a critical overview of current state of the art (pre-clinical and clinical evidence) regarding mechanisms of action and therapeutic efficacy of candidate SLD treatment options, and their potential to interfere with SLD/HCC pathophysiology by diverting lipids away from the liver therefore improving metabolic health.

Addressing the essentials of the recent guidelines for managing patients with metabolic dysfunction-associated steatotic liver disease

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the leading cause of end-stage liver disease and liver transplantation in the Western world, with an approximate prevalence of 30% worldwide which is continuously rising. It is characterized by intrahepatic fat deposition along with at least one cardiometabolic risk factor, such as diabetes mellitus, obesity, hypertriglyceridemia, and hypertension. MASLD consists of a spectrum of liver diseases ranging from simple liver steatosis to steatohepatitis, liver fibrosis, and cirrhosis. Recently, the European Association for the Study of the Liver (EASL), the European Association for the Study of Diabetes (EASD), and the European Association for the Study of Obesity (EASO) released the latest guidelines regarding the management of patients with MASLD. This article highlights the critical points of these guidelines and emphasizes problematic issues that need further evaluation.

Pre-immunization of diet-induced obese male mice with inactivated pathogens increases power in a liraglutide intervention study

Pre-immunization with inactivated antigens has been developed as an alternative to the use of 'dirty' mice, which in contrast to specific pathogen free (SPF) mice, harbour a range of pathogens. Within certain research areas, such mice are considered better models for humans than SPF mice, as they have an immune system that better mirrors human immunity. We inactivated murine adenovirus type 1 (FL), minute virus of mice, mouse hepatitis virus (A59), respirovirus muris (Sendai), Theiler's encephalomyelitis virus (GD7) and Mycoplasma pulmonis by ultraviolet irradiation. We show that pre-immunization with these inactivated pathogens combined with adjuvant prior to the dietary induction of obesity in C57BL/6NTac mice substantially reduced the group sizes needed for showing an effect of the GLP-1 receptor analogue, liraglutide. Nesting, open field and novel object behaviours of the mice were unaffected. We conclude that pre-immunization with inactivated pathogens may be a simple tool to increase power in this type of intervention study on the DIO mouse model.

Utilization of Glucagon-Like Peptide-1 Receptor Agonist at the Time of Total Hip Arthroplasty for Patients Who Have Morbid Obesity

BACKGROUND

Morbid obesity negatively affects outcomes after total hip arthroplasty (THA). The optimal strategy for weight loss before THA has not been identified. Recently, glucagon-like peptide-1 receptor agonists (GLP-1 RA) have become increasingly popular as an effective pharmacologic weight loss agent. The goal of this study was to evaluate the effect of perioperative GLP-1 RA use in patients who have morbid obesity undergoing primary THA on postoperative outcomes.

METHODS

Using an administrative claims database, patients who had morbid obesity (body mass index [BMI] ≥ 40.0) undergoing primary THA were identified. Patients who had morbid obesity and GLP-1 RA use for three months before and after surgery (treatment) were matched to patients who had morbid obesity without GLP-1 RA use (control) and to a comparison group of patients who had severe obesity (BMI = 35.0 to 39.9) in a 1:4:4 ratio, resulting in 771, 3,084, and 3,084 patients in the treatment, control, and severe obesity comparison group, respectively. Overall group differences in 90-day and 2-year postoperative outcomes were compared using univariable tests, followed by post hoc pairwise testing and P-value adjustment.

RESULTS

Patients who had morbid obesity on GLP-1 RA had a significantly lower rate of 90-day periprosthetic joint infection (PJI) (1.6 versus 3.2%; P = 0.03), readmission (6.9 versus 9.7%; P = 0.04), any medical complication (10.5 versus 14.1%; P = 0.03), and postoperative hematoma formation (0 versus 1.3%, P < 0.01) compared to controls. Patients who had morbid obesity on GLP-1 RA demonstrated lower rates of hematoma formation (0 versus 1.0%; P <0.01) compared to patients who had severe obesity (BMI = 35.0 to 39.9). There were no differences in 2-year surgical complications.

CONCLUSION

Perioperative use of GLP-1 RA in patients who had morbid obesity is associated with reduced risk of acute PJI and 90-day hospital readmission. The risk is reduced to a level comparable to obese patients who have a BMI < 40.0. Randomized controlled trials are necessary to determine the true effect and mechanism of action.

Pain persists in mice lacking both Substance P and CGRPα signaling

The neuropeptides Substance P and CGRPα have long been thought important for pain sensation. Both peptides and their receptors are expressed at high levels in pain-responsive neurons from the periphery to the brain making them attractive therapeutic targets. However, drugs targeting these pathways individually did not relieve pain in clinical trials. Since Substance P and CGRPα are extensively co-expressed we hypothesized that their simultaneous inhibition would be required for effective analgesia. We therefore generated Tac1 and Calca double knockout (DKO) mice and assessed their behavior using a wide range of pain-relevant assays. As expected, Substance P and CGRPα peptides were undetectable throughout the nervous system of DKO mice. To our surprise, these animals displayed largely intact responses to mechanical, thermal, chemical, and visceral pain stimuli, as well as itch. Moreover, chronic inflammatory pain and neurogenic inflammation were unaffected by loss of the two peptides. Finally, neuropathic pain evoked by nerve injury or chemotherapy treatment was also preserved in peptide-deficient mice. Thus, our results demonstrate that even in combination, Substance P and CGRPα are not required for the transmission of acute and chronic pain.

Male infertility and obesity

PURPOSE OF REVIEW

The increasing rate of obesity is having an adverse impact on male reproduction.

RECENT FINDINGS

The negative effect of reactive oxygen species on male reproductive tissues and the age of onset of obesity are new areas of research on male infertility.

SUMMARY

This review highlights how obesity impairs male reproduction through complex mechanisms, including metabolic syndrome, lipotoxicity, sexual dysfunction, hormonal and adipokine alterations as well as epigenetic changes, and how new management strategies may improve the reproductive health of men throughout life.

The effect of GLP-1R agonists on the medical triad of obesity, diabetes, and cancer

Glucagon-like peptide-1 receptor (GLP-1R) agonists have garnered significant attention for their therapeutic potential in addressing the interconnected health challenges of diabetes, obesity, and cancer. The role of GLP-1R in type 2 diabetes mellitus (T2DM) is highlighted, emphasizing its pivotal contribution to glucose homeostasis, promoting β-cell proliferation, and facilitating insulin release. GLP-1R agonists have effectively managed obesity by reducing hunger, moderating food intake, and regulating body weight. Beyond diabetes and obesity, GLP-1R agonists exhibit a multifaceted impact on cancer progression across various malignancies. The mechanisms underlying these effects involve the modulation of signaling pathways associated with cell growth, survival, and metabolism. However, the current literature reveals a lack of in vivo studies on specific GLP-1R agonists such as semaglutide, necessitating further research to elucidate its precise mechanisms and effects, particularly in cancer. While other GLP-1R agonists have shown promising outcomes in mitigating cancer progression, the association between some GLP-1R agonists and an increased risk of cancer remains a topic requiring more profound investigation. This calls for more extensive research to unravel the intricate relationships between the GLP-1R agonist and different cancers, providing valuable insights for clinicians and researchers alike.

Treatment of Hypothalamic Obesity With GLP-1 Analogs

Introduction

Congenital and acquired damage to hypothalamic nuclei or neuronal circuits controlling satiety and energy expenditure results in hypothalamic obesity (HO). To date, successful weight loss and satiety has only been achieved in a limited number of affected patients across multiple drug trials. Glucagon-like peptide-1 (GLP-1) acts via central pathways that are independent from the hypothalamus to induce satiety. GLP-1 receptor agonists (GLP-1RAs) may provide an alternative approach to treating HO.

Methods

We performed a comprehensive search in Medline, Google Scholar, and clinical trials registries (ClinicalTrials.gov; clinicaltrialsregister.eur). This nonsystematic literature review was conducted to identify scientific papers published from January 2005 to February 2024 using the Pubmed and Embase databases. Key words used were GLP-1, GLP-1RA, hypothalamic obesity, suprasellar tumor, and craniopharyngioma.

Results

Our search identified 7 case studies, 5 case series, and 2 published clinical trials relating to the use of GLP-1RAs in HO. All case studies demonstrated weight loss and improved metabolic function. In contrast, results from case series were variable, with some showing no weight loss and others demonstrating moderate to significant weight loss and improved metabolic parameters. In the ECHO clinical trial, nearly half the subjects randomized to weekly exenatide showed reduced body mass index (BMI). Paradoxically, BMI reduction was greater in patients with more extensive hypothalamic injuries.

Conclusion

GLP-1RAs potentially offer a new approach to treating HO. There is a need to stratify patients who are more likely to respond. Further randomized controlled trials are required to determine their efficacy either in isolation or combined with other therapies.

Anorexigenic and anti-inflammatory signaling pathways of semaglutide via the microbiota-gut--brain axis in obese mice

Our study focused on a mouse model of obesity induced by a high-fat diet (HFD). We administered Semaglutide intraperitoneally (Ozempic ®-0.05 mg/Kg-translational dose) every seven days for six weeks. HFD-fed mice had higher blood glucose, lipid profile, and insulin resistance. Moreover, mice fed HFD showed high gut levels of TLR4, NF-kB, TNF-α, IL-1β, and nitrotyrosine and low levels of occludin, indicating intestinal inflammation and permeability, culminating in higher serum levels of IL-1β and LPS. Treatment with semaglutide counteracted the dyslipidemia and insulin resistance, reducing gut and serum inflammatory markers. Structural changes in gut microbiome were determined by 16S rRNA sequencing. Semaglutide reduced the relative abundance of Firmicutes and augmented that of Bacteroidetes. Meanwhile, semaglutide dramatically changed the overall composition and promoted the growth of acetate-producing bacteria (Bacteroides acidifaciens and Blautia coccoides), increasing hypothalamic acetate levels. Semaglutide intervention increased the number of hypothalamic GLP-1R+ neurons that mediate endogenous action on feeding and energy. In addition, semaglutide treatment reversed the hypothalamic neuroinflammation HDF-induced decreasing TLR4/MyD88/NF-κB signaling and JNK and AMPK levels, improving the hypothalamic insulin resistance. Also, semaglutide modulated the intestinal microbiota, promoting the growth of acetate-producing bacteria, inducing high levels of hypothalamic acetate, and increasing GPR43+ /POMC+ neurons. In the ARC, acetate activated the GPR43 and its downstream PI3K-Akt pathway, which activates POMC neurons by repressing the FoxO-1. Thus, among the multifactorial effectors of hypothalamic energy homeostasis, possibly higher levels of acetate derived from the intestinal microbiota contribute to reducing food intake.

Interplay of gut microbiota, glucagon-like peptide receptor agonists, and nutrition: New frontiers in metabolic dysfunction-associated steatotic liver disease therapy

The gut-liver axis plays a crucial role in the development and progression of metabolic dysfunction-associated steatotic liver disease (MASLD). Key metabolites, including lipopolysaccharides, short-chain fatty acids (SCFAs), bile acids, and beneficial gut bacteria such as Bifidobacterium and Lactobacillus, are pivotal in this process. Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) show promise in managing MASLD by promoting weight loss, enhancing insulin secretion, and improving liver health. They restore gut-liver axis functionality, and their effects are amplified through dietary modifications and gut microbiome-targeted therapies. Emerging research highlights the interplay between GLP-1 RAs and gut microbiota, indicating that the gut microbiome significantly influences therapeutic outcomes. Metabolites produced by gut bacteria, can stimulate glucagon-like peptide-1 (GLP-1) secretion, further improving metabolic health. Integrating dietary interventions with GLP-1 RA treatment may enhance liver health by modulating the gut microbiota-SCFAs-GLP-1 pathway. Future research is needed to understand personalized effects, with prebiotics and probiotics offering treatment avenues for MASLD.

Safety and Effectiveness of Naltrexone-Bupropion in Korean Adults with Obesity: Post-Marketing Surveillance Study

Purpose

To investigate the safety and effectiveness of naltrexone-bupropion in Korean adults with obesity.

Patients and methods

This was a prospective, observational multicenter study from April 29, 2016, to April 28, 2022. Individuals with obesity with a body mass index of ≥30 kg/m2 or ≥27 kg/m2 who had obesity-related comorbidities were included. The naltrexone-bupropion dose was gradually titrated weekly from 8/90 to 32/360 mg and maintained at the maximum tolerated dose. In total, 612 and 300 individuals were evaluated for safety and effectiveness, respectively.

Results

In total, 41.34% individuals reported drug-related adverse reactions, such as nausea (19.12%), headache (7.68%), and dizziness (5.23%). Older age and comorbidities were significantly associated with adverse events. At 12 weeks after reaching the maintenance dose, naltrexone-bupropion 32/360 mg resulted in the greatest weight reduction (-7.21%) compared with other doses, which persisted at week 24 (-7.69%). The naltrexone-bupropion 16/180 mg resulted in significant weight reduction, achieving -5.99% and -9.18% reductions at weeks 12 and 24, similar to that with naltrexone-bupropion 32/360 mg. Young age and no comorbidities were significantly associated >5% weight reduction.

Conclusion

Naltrexone-bupropion demonstrated marked stability and weight loss effectiveness, particularly in young individuals with obesity without comorbidities. Therefore, individualized treatment is necessary when prescribing naltrexone-bupropion.

Semaglutide promotes the transition of microglia from M1 to M2 type to reduce brain inflammation in APP/PS1/tau mice

A growing number of studies show that the diabetes drug Semaglutide is neuroprotective in Alzheimer's disease (AD) animal models, but its mode of action is not fully understood. In order to explore the mechanism of Semaglutide, 7-month-old APP/PS1/tau transgenic (3xTg) mice and wild-type (WT) mice were randomly divided into four groups: control group (WT + PBS), AD model group (3xTg + PBS), Semaglutide control group (WT + Semaglutide) and Semaglutide treatment group (3xTg + Semaglutide). Semaglutide (25 nmol/kg) or PBS was administered intraperitoneally once every two days for 30 days, followed by behavioral and molecular experiments. The results show that Semaglutide can improve working memory and spatial reference memory of 3xTg-AD mice, promote the release of anti-inflammatory factors and inhibit the production of pro-inflammatory factors in the cortex and hippocampus, and reduce Aβ deposition in the hippocampal CA1 region of 3xTg mice. Semaglutide can inhibit the apoptosis of BV2 cells induced by Aβ1-42 in a dose-dependent manner and promote the transformation of microglia from M1 to M2, thereby exerting anti-inflammatory and neuroprotective effects. Therefore, we speculate that Semaglutide shows an anti-inflammatory effect by promoting the transformation of microglia from M1 to M2 type in the brain of 3xTg mice, and thus exerts a neuroprotective effect.

Engineering Supramolecular Nanofiber Depots from a Glucagon-Like Peptide-1 Therapeutic

Diabetes and obesity have emerged as major global health concerns. Glucagon-like peptide-1 (GLP-1), a natural incretin hormone, stimulates insulin production and suppresses glucagon secretion to stabilize and reduce blood glucose levels and control appetite. The therapeutic use of GLP-1 receptor agonists (e.g., semaglutide) has transformed the standard of care in recent years for treating type 2 diabetes and reversing obesity. The native GLP-1 sequence has a very short half-life, and therapeutic advances have come from molecular engineering to alter the pharmacokinetic profile of synthetic GLP-1 receptor agonists to enable once-weekly administration, reduce the frequency of injection, and improve adherence. Efforts to further extend this profile would offer additional convenience or enable entirely different treatment modalities. Here, an injectable GLP-1 receptor agonist depot is engineered through integration of a prosthetic self-assembling peptide motif to enable supramolecular nanofiber formation and hydrogelation. This supramolecular GLP-1 receptor agonistic (PA-GLP1) offers sustained release in vitro for multiple weeks, supporting long-lasting therapy. Moreover, in a rat model of type 2 diabetes, a single injection of the supramolecular PA-GLP1 formulation achieved sustained serum concentrations for at least 40 days, with an overall reduction in blood glucose levels and reduced weight gain, comparing favorably to daily injections of semaglutide. The general and modular approach is also extensible to other next-generation peptide therapies. Accordingly, the formation of supramolecular nanofiber depots offers a more convenient and long-lasting therapeutic option to manage diabetes and treat metabolic disorders.

Unraveling the impaired incretin effect in obesity and type 2 diabetes: Key role of hyperglycemia-induced unscheduled glycolysis and glycolytic overload

Glucagon-like peptide-1 (GLP-1) agonists and GLP-1 and glucose-dependent insulinotropic polypeptide (GIP) co-agonists are major treatment options for subjects with obesity and patients with type 2 diabetes mellitus (T2DM). They counter without addressing the mechanistic cause of the impaired incretin effect associated with obesity and T2DM. Incretin effect impairment is characterized by decreased secretion of incretins from enteroendocrine cells and incretin resistance of pancreatic β-cells. It is linked to hyperglycemia. We present evidence that subversion of the gating of glucose entry into glycolysis, mainly by glucokinase (hexokinase-4), during persistent hyperglycemia in enteroendocrine cells, pancreatic β- and α-cells and appetite-regulating neurons contributes to the biochemical mechanism of the impaired incretin effect. Unscheduled glycolysis and glycolytic overload thereby produced decreases cell signalling of incretin secretion to glucose and other secretion stimuli and incretin receptor responses. This mechanism provides a guide for development of alternative therapies targeting recovery of the impaired incretin effect.

GLP-1 therapy increases visceral adipose tissue metabolic activity: lessons from a randomized controlled trial in obstructive sleep apnea

OBJECTIVE

Glucagon-like peptide-1 (GLP-1) analogues are currently the most widely used pharmacotherapies for weight loss. Their primary mechanism of action is attributed to reduction in energy intake. Data from murine studies also support an additional impact of those agents on energy homeostasis through upregulation of visceral adipose tissue (VAT) metabolic activity, but this remains uncertain in humans.

METHODS

Here, we present data from a proof-of-concept study on 30 individuals with obstructive sleep apnea and obesity who were randomized to a GLP-1 therapy-based weight loss regimen, continuous positive airway pressure, or a combination of both for 24 weeks. At baseline and study completion, 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography-computed tomography (PET-CT) was performed to evaluate VAT metabolic activity, expressed as VAT target to background ratio.

RESULTS

Treatment with GLP-1, but not with continuous positive airway pressure, was associated with a significant increase in VAT target to background ratio. There was a strong correlation between the increase in VAT metabolic activity and the degree of weight loss.

CONCLUSIONS

These data support the hypothesis that upregulation of VAT metabolic activity by GLP-1 contributes to its weight loss action in humans, and this subject warrants further detailed investigation.

Pharmacological Treatment of Obesity in Older Adults

Obesity is a complex health issue with growing prevalence worldwide. It is also becoming more prevalent in the population of older adults (i.e., 65 years of age and older), affecting frequency and severity as well as other comorbidities, quality of life and consequently, life expectancy. In this article we review currently available data on pharmacotherapy of obesity in the population of older adults and its role in obesity management. Even though there is growing evidence, in particular in the general population, of favourable efficacy and safety profiles of glucagon-like peptide-1 (GLP-1) receptor agonists liraglutide and semaglutide, and recently dual GLP-1 and glucose-dependent insulinotropic polypeptide (GIP) agonist tirzepatide, concise guidelines for older adults are not available to this day. We further discuss specific approaches to frequently represented phenotype of obesity in older adults, in particular sarcopenic obesity and rationale when to treat and how. In older adults with obesity there is a need for more drug trials focusing not only on weight loss, but also on geriatric endpoints including muscle mass preservation, bone quality and favourable fat distribution changes to get enough data for evidence-based recommendation on obesity treatment in this growing sub-population.

Efficacy and Safety of GLP-1 Medicines for Type 2 Diabetes and Obesity

The development of glucagon-like peptide 1 receptor agonists (GLP-1RA) for type 2 diabetes and obesity was followed by data establishing the cardiorenal benefits of GLP-1RA in select patient populations. In ongoing trials investigators are interrogating the efficacy of these agents for new indications, including metabolic liver disease, peripheral artery disease, Parkinson disease, and Alzheimer disease. The success of GLP-1-based medicines has spurred the development of new molecular entities and combinations with unique pharmacokinetic and pharmacodynamic profiles, exemplified by tirzepatide, a GIP-GLP-1 receptor coagonist. Simultaneously, investigational molecules such as maritide block the GIP and activate the GLP-1 receptor, whereas retatrutide and survodutide enable simultaneous activation of the glucagon and GLP-1 receptors. Here I highlight evidence establishing the efficacy of GLP-1-based medicines, while discussing data that inform safety, focusing on muscle strength, bone density and fractures, exercise capacity, gastrointestinal motility, retained gastric contents and anesthesia, pancreatic and biliary tract disorders, and the risk of cancer. Rapid progress in development of highly efficacious GLP-1 medicines, and anticipated differentiation of newer agents in subsets of metabolic disorders, will provide greater opportunities for use of personalized medicine approaches to improve the health of people living with cardiometabolic disorders.

Safety and efficacy of glucagon-like peptide-1 (GLP-1) receptor agonists in patients with weight regain or insufficient weight loss after metabolic bariatric surgery: A systematic review and meta-analysis

INTRODUCTION

Weight regain and insufficient weight loss are major challenges after metabolic bariatric surgery (MBS), affecting patients' comorbidities and quality of life. The current systematic review and meta-analysis aim to assess the efficacy and safety of GLP-1 receptor agonists (GLP-1 RA) in patients with weight regain or insufficient weight loss after MBS.

METHODS

A systematic search was conducted across PubMed, Embase, Scopus, and Web of Science databases to find the relevant studies.

RESULTS

A total of 19 articles were included. The highest doses of liraglutide and semaglutide were 3 mg per day and 1 mg once weekly, respectively, in the included studies. The mean differences in weight and body mass index after treatment were -7.02 kg or 3.07 kg/m2, -8.65 or -5.22 kg/m2, and -6.99 kg or -3.09 kg/m2 for treatment durations of ≤ 6 months, 6-12 months, and >12 months with liraglutide, respectively. Additionally, weekly semaglutide showed significantly greater weight loss compared to daily liraglutide, with a mean difference of 4.15 kg. Common complications included nausea (19.1%), constipation (8.6%), abdominal pain (3.7%), and vomiting (2.4%).

CONCLUSION

Using GLP-1 RA is a safe and effective treatment for weight regain and insufficient weight loss after MBS.

Endocrine Care for the Surgical Patient: Diabetes Mellitus, Thyroid and Adrenal Conditions

Patients with hyperglycemia, thyroid dysfunction, and adrenal insufficiency face increased perioperative risk, which may be mitigated by appropriate management. This review addresses preoperative glycemic control, makes evidence-based recommendations for the increasingly complex perioperative management of noninsulin diabetes medications, and provides guideline-supported strategies for the perioperative management of insulin, including suggested indications for continuous intravenous insulin. The authors propose a strategy for determining when surgery should be delayed in patients with thyroid dysfunction and present a matrix for managing perioperative stress dose corticosteroids based on the limited evidence available.

Effectiveness and Safety of GLP-1 Receptor Agonists in Patients with Type 1 Diabetes

Background: GLP-1 receptor agonists (GLP-1RA) are used in the management of type II diabetes mellitus or obesity, although its role in patients with type I diabetes mellitus (T1DM) has been debated. This study aimed to investigate the efficacy and safety of GLP-1RA in patients with T1DM using real-world data. Methods: This multicenter, retrospective study was conducted at three tertiary medical centers in Riyadh, Saudi Arabia. The study followed up patients (>16 years old) with T1DM treated with insulin followed by GLP-1RA add-on therapy. The efficacy outcomes included changes in HbA1c, body weight, and insulin requirements from baseline to each follow-up visit. The main safety outcomes assessed included hypoglycemic events and gastrointestinal (GI) adverse events. Results: The study included 144 patients with a mean age of 33.0 ± 10.1 years. Semaglutide was the most used GLP-1RA (63.9%) followed by liraglutide (34.0%). From baseline to 3-month follow-up, HbA1c (mean difference (MD) = -0.8%; p = 0.0053), weight (MD = -2.4 kg; p = 0.0253), and daily basal insulin dose (MD = -2.1 units; p = 0.0349) were significantly reduced. Likewise, HbA1c (MD = -0.5%; p = 0.0004), weight (MD = -3.6 kg; p < 0.0001), and daily basal insulin (MD = -2.4 units; p = 0.0282) were significantly reduced at the 4-6-month follow-up. The significant reductions in HbA1c, weight, and daily basal insulin levels were consistent for up to 18-month follow-up. Only one patient had a major hypoglycemic event, whereas 8.3% of the patients had GI adverse events. Conclusions: Overall, significant improvements in glycemic control, weight loss, and insulin requirements were observed with the use of GLP-1RA in patients with T1DM, with a limited number of GI adverse events.

Activation of Gs signaling in mouse enteroendocrine K cells greatly improves obesity- and diabetes-related metabolic deficits

Following a meal, glucagon-like peptide 1 (GLP1) and glucose-dependent insulinotropic polypeptide (GIP), the 2 major incretins promoting insulin release, are secreted from specialized enteroendocrine cells (L and K cells, respectively). Although GIP is the dominant incretin in humans, the detailed molecular mechanisms governing its release remain to be explored. GIP secretion is regulated by the activity of G protein-coupled receptors (GPCRs) expressed by K cells. GPCRs couple to 1 or more specific classes of heterotrimeric G proteins. In the present study, we focused on the potential metabolic roles of K cell Gs. First, we generated a mouse model that allowed us to selectively stimulate K cell Gs signaling. Second, we generated a mouse strain harboring an inactivating mutation of Gnas, the gene encoding the α-subunit of Gs, selectively in K cells. Metabolic phenotyping studies showed that acute or chronic stimulation of K cell Gs signaling greatly improved impaired glucose homeostasis in obese mice and in a mouse model of type 2 diabetes, due to enhanced GIP secretion. In contrast, K cell-specific Gnas-KO mice displayed markedly reduced plasma GIP levels. These data strongly suggest that strategies aimed at enhancing K cell Gs signaling may prove useful for the treatment of diabetes and related metabolic diseases.

Fibroblast growth factor 21: update on genetics and molecular biology

PURPOSE OF REVIEW

Since its discovery, most research on fibroblast growth factor 21 (FGF21) has focused on its antihyperglycemia properties. However, attention has recently shifted towards elucidating the ability of FGF21 to lower circulating lipid levels and ameliorate liver inflammation and steatosis. We here discuss the physiology of FGF21 and its role in lipid metabolism, with a focus on genetics, which has up until now not been fully appreciated.

RECENT FINDINGS

New developments have uncovered associations of common small-effect variants of the FGF21 gene, such as the single nucleotide polymorphisms rs2548957 and rs838133, with numerous physiological, biochemical and behavioural phenotypes linked to energy metabolism and liver function. In addition, rare loss-of-function variants of the cellular receptors for FGF21 have been recently associated with severe endocrine and metabolic phenotypes. These associations corroborate the findings from basic studies and preliminary clinical investigations into the therapeutic potential of FGF21 for the treatment of metabolic dysfunction-associated steatotic liver disease (MASLD) and hypertriglyceridemia. Furthermore, recent breakthrough research has begun to dissect mechanisms of a potential FGF21 brain-adipose axis. Such inter-organ communication would be comparable to that seen with other potent metabolic hormones. A deeper understanding of FGF21 could prove to be further beneficial for drug development.

SUMMARY

FGF21 is a potent regulator of lipid and energy homeostasis and its physiology is currently at the centre of investigative efforts to develop agents targeting hypertriglyceridemia and MASLD.

Bioengineered Nanomedicines Targeting the Intestinal Fc Receptor Achieve the Improved Glucoregulatory Effect of Semaglutide in a Type 2 Diabetic Mice Model

The oral administration of the glucagon-like peptide-1 analogue, semaglutide, remains a hurdle due to its limited bioavailability. Herein, neonatal Fc receptor (FcRn)-targeted nanoparticles (NPs) were designed to enhance the oral delivery of semaglutide. The nanocarriers were covalently linked to the FcRn-binding peptide FcBP or the affibody molecule ZFcRn that specifically binds to the human FcRn (hFcRn) in a pH-dependent manner. These FcRn-targeted ligands were selected over the endogenous ligands of the receptor (albumin and IgG) due to their smaller size and simpler structure, which could facilitate the transport of functionalized NPs through the tissues. The capacity of FcRn-targeted semaglutide-NPs in controlling the blood glucose levels was evaluated in an hFcRn transgenic mice model, where type 2 diabetes mellitus (T2DM) was induced via intraperitoneal injection of nicotinamide followed by streptozotocin. The encapsulation of semaglutide into FcRn-targeted NPs was translated in an improved glucoregulatory effect in T2DM-induced mice when compared to the oral free semaglutide or nontargeted NP groups, after daily oral administrations for 7 days. Notably, a similar glucose-lowering response was observed between both FcRn-targeted NPs and the subcutaneous semaglutide groups. An increase in insulin pancreatic content and a recovery in β cell mass were visualized in the mice treated with FcRn-targeted semaglutide-NPs. The biodistribution of fluorescently labeled NPs through the gastrointestinal tract demonstrated that the nanosystems targeting the hFcRn are retained longer in the ileum and colorectum, where the expression of FcRn is more prevalent, than nontargeted NPs. Therefore, FcRn-targeted nanocarriers proved to be an effective platform for improving the pharmacological effect of semaglutide in a T2DM-induced mice model.

Inflammatory Trajectory of Type 2 Diabetes: Novel Opportunities for Early and Late Treatment

Low-grade inflammation (LGI) represents a key driver of type 2 diabetes (T2D) and its associated cardiovascular diseases (CVDs). Indeed, inflammatory markers such as hs-CRP and IL-6 predict the development of T2D and its complications, suggesting that LGI already increases before T2D diagnosis and remains elevated even after treatment. Overnutrition, unhealthy diets, physical inactivity, obesity, and aging are all recognized triggers of LGI, promoting insulin resistance and sustaining the pathogenesis of T2D. Once developed, and even before frank appearance, people with T2D undergo a pathological metabolic remodeling, with an alteration of multiple CVD risk factors, i.e., glycemia, lipids, blood pressure, and renal function. In turn, such variables foster a range of inflammatory pathways and mechanisms, e.g., immune cell stimulation, the accrual of senescent cells, long-lasting epigenetic changes, and trained immunity, which are held to chronically fuel LGI at the systemic and tissue levels. Targeting of CVD risk factors partially ameliorates LGI. However, some long-lasting inflammatory pathways are unaffected by common therapies, and LGI burden is still increased in many T2D patients, a phenomenon possibly underlying the residual inflammatory risk (i.e., having hs-CRP > 2 mg/dL despite optimal LDL cholesterol control). On the other hand, selected disease-modifying drugs, e.g., GLP-1RA, seem to also act on the pathogenesis of T2D, curbing the inflammatory trajectory of the disease and possibly preventing it if introduced early. In addition, selected trials demonstrated the potential of canonical anti-inflammatory therapies in reducing the rate of CVDs in patients with this condition or at high risk for it, many of whom had T2D. Since colchicine, an inhibitor of immune cell activation, is now approved for the prevention of CVDs, it might be worth exploring a possible therapeutic paradigm to identify subjects with T2D and an increased LGI burden to treat them with this drug. Upcoming studies will reveal whether disease-modifying drugs reverse early T2D by suppressing sources of LGI and whether colchicine has a broad benefit in people with this condition.

Type 2 diabetes mellitus in adults: pathogenesis, prevention and therapy

Type 2 diabetes (T2D) is a disease characterized by heterogeneously progressive loss of islet β cell insulin secretion usually occurring after the presence of insulin resistance (IR) and it is one component of metabolic syndrome (MS), and we named it metabolic dysfunction syndrome (MDS). The pathogenesis of T2D is not fully understood, with IR and β cell dysfunction playing central roles in its pathophysiology. Dyslipidemia, hyperglycemia, along with other metabolic disorders, results in IR and/or islet β cell dysfunction via some shared pathways, such as inflammation, endoplasmic reticulum stress (ERS), oxidative stress, and ectopic lipid deposition. There is currently no cure for T2D, but it can be prevented or in remission by lifestyle intervention and/or some medication. If prevention fails, holistic and personalized management should be taken as soon as possible through timely detection and diagnosis, considering target organ protection, comorbidities, treatment goals, and other factors in reality. T2D is often accompanied by other components of MDS, such as preobesity/obesity, metabolic dysfunction associated steatotic liver disease, dyslipidemia, which usually occurs before it, and they are considered as the upstream diseases of T2D. It is more appropriate to call "diabetic complications" as "MDS-related target organ damage (TOD)", since their development involves not only hyperglycemia but also other metabolic disorders of MDS, promoting an up-to-date management philosophy. In this review, we aim to summarize the underlying mechanism, screening, diagnosis, prevention, and treatment of T2D, especially regarding the personalized selection of hypoglycemic agents and holistic management based on the concept of "MDS-related TOD".

Approach to the Treatment of Children and Adolescents with Obesity

Pediatric obesity continues to be an omnipresent disease; 1 in 5 children and adolescents have obesity in the United States. The comorbidities associated with youth-onset obesity tend to have a more severe disease progression in youth compared to their adult counterparts with the same obesity-related condition. A comorbidity of focus in this study is metabolism-associated steatotic liver disease (MASLD), which has rapidly evolved into the most common liver disease seen in the pediatric population. A direct association exists between the treatment of MASLD and the treatment of pediatric obesity. The current evidence supports that obesity treatment is safe and effective.

Pharmacotherapy of Weight-loss and Obesity with a Focus on GLP 1-Receptor Agonists

Obesity is a disease of epidemic proportions in the United States and contributes to morbidity and mortality for a large part of the population. In addition, the financial costs of this disease to society are high. Lifestyle modifications are key to prevention and treatment but adherence and long-term success have been challenging. Bariatric surgery has been available and pharmacologic approaches, first developed in the 1950s, continue to be an option; however, existing formulations have not provided optimal clinical efficacy and have had many concerning adverse effects. Over the last decade, glucagon-like peptide-1 (GLP-1) receptor agonists, a novel group of medications for the treatment of type 2 diabetes, were found to produce significant weight loss. Several formulations, at higher doses, received FDA approval for the treatment of obesity or those overweight with weight-related co-morbidities. More hormone-based therapies were and are being developed, some with dual or triple-receptor agonist activity. Their use, however, is not without questions and concerns as to long-term safety and efficacy, problems with cost and reimbursement, and how their use may intersect with public health efforts to manage the obesity epidemic. This review will focus on the GLP-1 receptor agonists currently used for weight loss and discuss their pharmacology, pertinent research findings establishing their benefits and risks, issues with prescribing these medications, and a perspective from a public health point of view.

Semaglutide as a promising treatment for hypothalamic obesity: a six-month case series on four females with craniopharyngioma

PURPOSE

Patients with hypothalamic pathology often develop hypothalamic obesity, causing severe metabolic alterations resulting in increased morbidity and mortality. Treatments for hypothalamic obesity have not proven very effective, although the glucagon-like peptide-1 receptor agonist semaglutide has been shown to have positive effects. We examined semaglutide's effect on weight loss in a sample of patients with hypothalamic obesity.

METHODS

Four female patients with hypothalamic obesity resulting from treatment of craniopharyngiomas were treated with semaglutide for six months. Whole Body Dual-energy x-ray absorptiometry scans were performed, and blood samples drawn at baseline and after six months. Semaglutide dosages were increased monthly along with tracking of body weight and eating behavior (Three Factor Eating Questionnaire, TFEQ-R18).

RESULTS

BMI was reduced in all cases, with an average of 7.9 BMI (range: 6.7 to 10.1) corresponding to a weight loss of 17.0% (range: 11.3-22.4%) or 20.2 kg (range 16.2 kg to 23.4 kg). We found a comparable reduction in total fat mass (17.2%, p = 0.006) and lean mass (16.0%, p = 0.05), whereas bone mass was unchanged (2.6%, p = 0.12). All cases reported an increase in energy levels, improved mobility and physical activity. Unfavorable eating behaviors were reduced after 1 month of treatment (emotional eating - 41 points, p = 0.02, uncontrolled eating - 23 points, p = 0.11). HbA1c and total cholesterol were significantly reduced (p = 0.014 for both).

CONCLUSION

Semaglutide is a promising and safe treatment option for HO, that improves eating behavior, reduces weight, and improves metabolic markers.

Understanding the role of the human gut microbiome in overweight and obesity

The gut microbiome may be related to the prevalence of overweight and obesity, but high interindividual variability of the human microbiome complicates our understanding. Obesity often occurs concomitantly with micronutrient deficiencies that impair energy metabolism. Microbiota composition is affected by diet. Host-microbiota interactions are bidirectional. We propose three pathways whereby these interactions may modulate the gut microbiome and obesity: (1) ingested compounds or derivatives affecting small intestinal transit, endogenous secretions, digestion, absorption, microbiome balance, and gut barrier function directly affect host metabolism; (2) substrate availability affecting colonic microbial composition and contact with the gut barrier; and (3) microbial end products affecting host metabolism. The quantity/concentration, duration, and/or frequency (circadian rhythm) of changes in these pathways can alter the gut microbiome, disrupt the gut barrier, alter host immunity, and increase the risk of and progression to overweight and obesity. Host-specific characteristics (e.g., genetic variations) may further affect individual sensitivity and/or resilience to diet- and microbiome-associated perturbations in the colonic environment. In this narrative review, the effects of selected interventions, including fecal microbiota transplantation, dietary calorie restriction, dietary fibers and prebiotics, probiotics and synbiotics, vitamins, minerals, and fatty acids, on the gut microbiome, body weight, and/or adiposity are summarized to help identify mechanisms of action and research opportunities.

Sitagliptin elevates plasma and CSF incretin levels following oral administration to nonhuman primates: relevance for neurodegenerative disorders

The endogenous incretins glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) possess neurotrophic, neuroprotective, and anti-neuroinflammatory actions. The dipeptidyl peptidase 4 (DPP-4) inhibitor sitagliptin reduces degradation of endogenous GLP-1 and GIP, and, thereby, extends the circulation of these protective peptides. The current nonhuman primate (NHP) study evaluates whether human translational sitagliptin doses can elevate systemic and central nervous system (CNS) levels of GLP-1/GIP in naive, non-lesioned NHPs, in line with our prior rodent studies that demonstrated sitagliptin efficacy in preclinical models of Parkinson's disease (PD). PD is an age-associated neurodegenerative disorder whose current treatment is inadequate. Repositioning of the well-tolerated and efficacious diabetes drug sitagliptin provides a rapid approach to add to the therapeutic armamentarium for PD. The pharmacokinetics and pharmacodynamics of 3 oral sitagliptin doses (5, 20, and 100 mg/kg), equivalent to the routine clinical dose, a tolerated higher clinical dose and a maximal dose in monkey, were evaluated. Peak plasma sitagliptin levels were aligned both with prior reports in humans administered equivalent doses and with those in rodents demonstrating reduction of PD associated neurodegeneration. Although CNS uptake of sitagliptin was low (cerebrospinal fluid (CSF)/plasma ratio 0.01), both plasma and CSF concentrations of GLP-1/GIP were elevated in line with efficacy in prior rodent PD studies. Additional cellular studies evaluating human SH-SY5Y and primary rat ventral mesencephalic cultures challenged with 6-hydroxydopamine, established cellular models of PD, demonstrated that joint treatment with GLP-1 + GIP mitigated cell death, particularly when combined with DPP-4 inhibition to maintain incretin levels. In conclusion, this study provides a supportive translational step towards the clinical evaluation of sitagliptin in PD and other neurodegenerative disorders for which aging, similarly, is the greatest risk factor.

GLP-1 receptor agonist-based therapies and cardiovascular risk: a review of mechanisms

Cardiovascular outcome trials (CVOTs) in people living with type 2 diabetes mellitus and obesity have confirmed the cardiovascular benefits of glucagon-like peptide 1 receptor agonists (GLP-1RAs), including reduced cardiovascular mortality, lower rates of myocardial infarction, and lower rates of stroke. The cardiovascular benefits observed following GLP-1RA treatment could be secondary to improvements in glycemia, blood pressure, postprandial lipidemia, and inflammation. Yet, the GLP-1R is also expressed in the heart and vasculature, suggesting that GLP-1R agonism may impact the cardiovascular system. The emergence of GLP-1RAs combined with glucose-dependent insulinotropic polypeptide and glucagon receptor agonists has shown promising results as new weight loss medications. Dual-agonist and tri-agonist therapies have demonstrated superior outcomes in weight loss, lowered blood sugar and lipid levels, restoration of tissue function, and enhancement of overall substrate metabolism compared to using GLP-1R agonists alone. However, the precise mechanisms underlying their cardiovascular benefits remain to be fully elucidated. This review aims to summarize the findings from CVOTs of GLP-1RAs, explore the latest data on dual and tri-agonist therapies, and delve into potential mechanisms contributing to their cardioprotective effects. It also addresses current gaps in understanding and areas for further research.

An acidic polysaccharide promoting GLP-1 secretion from Dendrobium huoshanense protocorm-like bodies: Structure validation and activity exploration

Glucagon-like peptide-1 (GLP-1) as a multifunctional hormone is secreted mainly from enteroendocrine L-cells, and enhancing its endogenous secretion has potential benefits of regulating glucose homeostasis and controlling body weight gain. In the present study, a novel polysaccharide (h-DHP) with high ability to enhance plasma GLP-1 level in mice was isolated from Dendrobium huoshanense protocorm-like bodies under the guidance of activity evaluation. Structural identification showed that h-DHP was an acidic polysaccharide with the molecular weight of 1.38 × 105 Da, and was composed of galactose, glucose, arabinose and glucuronic acid at a molar ratio of 15.7: 11.2: 4.5: 1.0 with a backbone consisting of →5)-α-L-Araf-(1→, →3)-α-D-Galp-(1→, →6)-α-D-Galp-(1→, →3,6)-α-D-Galp-(1→, →6)-β-D-Glcp-(1→ and →4,6)-β-D-Glcp-(1→ along with branches consisting of α-L-Araf-(1→, α-D-Galp-(1→, α-D-GlcAp-(1→, β-D-Glcp-(1→ and →4)-β-D-Glcp-(1→. Animal experiments with different administration routes demonstrated that h-DHP-enhanced plasma GLP-1 level was attributed to h-DHP-promoted GLP-1 secretion in the enteroendocrine L-cells, which was supported by h-DHP-enhanced extracellular GLP-1 level in STC-1 cells. Inhibition of adenylate cyclase and phospholipase C indicated that cAMP and cAMP-triggered intracellular Ca2+ increase participated in h-DHP-promoted GLP-1 secretion. These results suggested that h-DHP has the potential of enhancing endogenous GLP-1 level through h-DHP-promoted and cAMP-mediated GLP-1 secretion from enteroendocrine cells.

Fatty acids promote uncoupled respiration via the ATP/ADP carrier in white adipocytes

Adipocytes store energy as triglycerides, while mobilizing energy when needed via lipolysis. Triglyceride lipolysis releases fatty acids and glycerol into the circulation to fuel other tissues. However, a significant fraction of fatty acids released by lipolysis are retained within the white adipose tissue and handled by adipocytes. While some of these retained fatty acids are re-esterified in white adipocytes1-6, the a substantial amount undergo oxidative metabolism via a pathway regulated by the nongenomic effects of STAT37-10. Here we report that fatty acids promote uncoupled oxidative metabolism in white adipocytes via the ATP/ADP carrier, contributing to thermogenesis and cold tolerance in obese thermoneutral-adapted mice, independent of brown adipose tissue and muscle activity. Our results suggest that uncoupled respiration in white adipocytes significantly contributes to whole-body energy expenditure and could be a promising target for obesity treatment.

Directly targeting PRDM16 in thermogenic adipose tissue to treat obesity and its related metabolic diseases

Obesity is increasing globally and is closely associated with a range of metabolic disorders, including metabolic associated fatty liver disease, diabetes, and cardiovascular diseases. An effective strategy to combat obesity involves stimulating brown and beige adipocyte thermogenesis, which significantly enhances energy expenditure. Recent research has underscored the vital role of PRDM16 in the development and functionality of thermogenic adipocytes. Consequently, PRDM16 has been identified as a potential therapeutic target for obesity and its related metabolic disorders. This review comprehensively examines various studies that focus on combating obesity by directly targeting PRDM16 in adipose tissue.

Obesity in Adolescents: A Review

Importance

Obesity affects approximately 21% of US adolescents and is associated with insulin resistance, hypertension, dyslipidemia, sleep disorders, depression, and musculoskeletal problems. Obesity during adolescence has also been associated with an increased risk of mortality from cardiovascular disease and type 2 diabetes in adulthood.

Observations

Obesity in adolescents aged 12 to younger than 18 years is commonly defined as a body mass index (BMI) at the 95th or greater age- and sex-adjusted percentile. Comprehensive treatment in adolescents includes lifestyle modification therapy, pharmacotherapy, and metabolic and bariatric surgery. Lifestyle modification therapy, which includes dietary, physical activity, and behavioral counseling, is first-line treatment; as monotherapy, lifestyle modification requires more than 26 contact hours over 1 year to elicit approximately 3% mean BMI reduction. Newer antiobesity medications, such as liraglutide, semaglutide, and phentermine/topiramate, in combination with lifestyle modification therapy, can reduce mean BMI by approximately 5% to 17% at 1 year of treatment. Adverse effects vary, but severe adverse events from these newer antiobesity medications are rare. Surgery (Roux-en-Y gastric bypass and vertical sleeve gastrectomy) for severe adolescent obesity (BMI ≥120% of the 95th percentile) reduces mean BMI by approximately 30% at 1 year. Minor and major perioperative complications, such as reoperation and hospital readmission for dehydration, are experienced by approximately 15% and 8% of patients, respectively. Determining the long-term durability of all obesity treatments warrants future research.

Conclusions and Relevance

The prevalence of adolescent obesity is approximately 21% in the US. Treatment options for adolescents with obesity include lifestyle modification therapy, pharmacotherapy, and metabolic and bariatric surgery. Intensive lifestyle modification therapy reduces BMI by approximately 3% while pharmacotherapy added to lifestyle modification therapy can attain BMI reductions ranging from 5% to 17%. Surgery is the most effective intervention for adolescents with severe obesity and has been shown to achieve BMI reduction of approximately 30%.

IUPHAR review - Glucagon-like peptide-1 (GLP-1) and substance use disorders: An emerging pharmacotherapeutic target

Addiction is a chronic relapsing disease with high morbidity and mortality. Treatments for addiction include pharmacological and psychosocial interventions; however, currently available medications are limited in number and efficacy. The glucagon-like-peptide-1 (GLP-1) system is emerging as a potential novel pharmacotherapeutic target for alcohol and other substance use disorders (ASUDs). In this review, we summarize and discuss the wealth of available evidence from testing GLP-1 receptor (GLP-1R) agonist medications in preclinical models and humans with ASUDs, possible mechanisms underlying the impact of GLP-1R agonists on alcohol/substance use, gaps in knowledge, and future directions. Most of the research with GLP-1R agonists has been conducted in relation to alcohol use; psychostimulants, opioids, and nicotine have also been investigated. Preclinical evidence suggests that GLP-1R agonists reduce alcohol/substance use and other related outcomes. The main proposed mechanisms are related to reward processing, stress, and cognitive function, as well as broader mechanisms related to satiety, changes in gastric motility, and glucose homeostasis. More in-depth mechanistic studies are warranted. Clinical studies have been limited and their findings have been less conclusive; however, most support the safety and potential efficacy of GLP-1R agonists in ASUD treatment. Identifying preferred compounds, as well as possible subgroups who are most responsive to GLP-1R agonists are some of the key research questions to translate the promising preclinical data into clinical settings. Several clinical trials are underway to test GLP-1R agonists in people with ASUDs.

Advances in small-molecule insulin secretagogues for diabetes treatment

Diabetes, a metabolic disease caused by abnormally high levels of blood glucose, has a high prevalence rate worldwide and causes a series of complications, including coronary heart disease, stroke, peripheral vascular disease, end-stage renal disease, and retinopathy. Small-molecule compounds have been developed as drugs for the treatment of diabetes because of their oral advantages. Insulin secretagogues are a class of small-molecule drugs used to treat diabetes, and include sulfonylureas, non-sulfonylureas, glucagon-like peptide-1 receptor agonists, dipeptidyl peptidase 4 inhibitors, and other novel small-molecule insulin secretagogues. However, many small-molecule compounds cause different side effects, posing huge challenges to drug monotherapy and drug selection. Therefore, the use of different small-molecule drugs must be improved. This article reviews the mechanism, advantages, limitations, and potential risks of small-molecule insulin secretagogues to provide future research directions on small-molecule drugs for the treatment of diabetes.

EASL-EASD-EASO Clinical Practice Guidelines on the management of metabolic dysfunction-associated steatotic liver disease (MASLD)

Metabolic dysfunction-associated steatotic liver disease (MASLD), previously termed non-alcoholic fatty liver disease (NAFLD), is defined as steatotic liver disease (SLD) in the presence of one or more cardiometabolic risk factor(s) and the absence of harmful alcohol intake. The spectrum of MASLD includes steatosis, metabolic dysfunction-associated steatohepatitis (MASH, previously NASH), fibrosis, cirrhosis and MASH-related hepatocellular carcinoma (HCC). This joint EASL-EASD-EASO guideline provides an update on definitions, prevention, screening, diagnosis and treatment for MASLD. Case-finding strategies for MASLD with liver fibrosis, using non-invasive tests, should be applied in individuals with cardiometabolic risk factors, abnormal liver enzymes, and/or radiological signs of hepatic steatosis, particularly in the presence of type 2 diabetes (T2D) or obesity with additional metabolic risk factor(s). A stepwise approach using blood-based scores (such as FIB-4) and, sequentially, imaging techniques (such as transient elastography) is suitable to rule-out/in advanced fibrosis, which is predictive of liver-related outcomes. In adults with MASLD, lifestyle modification - including weight loss, dietary changes, physical exercise and discouraging alcohol consumption - as well as optimal management of comorbidities - including use of incretin-based therapies (e.g. semaglutide, tirzepatide) for T2D or obesity, if indicated - is advised. Bariatric surgery is also an option in individuals with MASLD and obesity. If locally approved and dependent on the label, adults with non-cirrhotic MASH and significant liver fibrosis (stage ≥2) should be considered for a MASH-targeted treatment with resmetirom, which demonstrated histological effectiveness on steatohepatitis and fibrosis with an acceptable safety and tolerability profile. No MASH-targeted pharmacotherapy can currently be recommended for the cirrhotic stage. Management of MASH-related cirrhosis includes adaptations of metabolic drugs, nutritional counselling, surveillance for portal hypertension and HCC, as well as liver transplantation in decompensated cirrhosis.

Bettie's travels: How pigs enable new connections between human health innovations and industrial agricultural pork production in Denmark

Drawing on ethnographic fieldwork, this paper unfolds the past and present uses of pigs that structured the emergence of a pig model of gut-hormone based appetite control, leading to the current scientific breakthrough in treatment of obesity. While the hyping of next generation medications for obesity and type 2 diabetes centers on the efficacy and profits attached to these drugs, I unfold how science embedded in this development had the in-vivo and in-vitro travels of Bettie-an obese Göttingen Minipig pig-at its heart. Tracing how she became embedded in a circuit of vitality connecting industrial agriculture and science on human health, I show how both are governed by a shared valuation of pigs' fat. Bettie's fat, however, was not to be eaten. Instead, Bettie was consumed in knowledge production. For pigs to enter this new trajectory, Bettie emerged as a promissory site for extraction of molecular information made possible by new visualization technologies and representational strategies that allowed for the coupling of human-pig physiology at the cellular level. While her travels were spurred by the hope of discovery of small molecules, Bettie allows us to grasp an important shift in science, as the insights derived from her work emphasized the importance of physiology and the environment for human obesity. In doing so, she served as a visceral model. On a larger scale, Bettie's entering science on human health reflects a recursive structure of knowledge in which the present problems with obesity and type 2 diabetes derive from the solutions to previous problems associated with alleviating hunger.

Intestinal Nogo-B reduces GLP1 levels by binding to proglucagon on the endoplasmic reticulum to inhibit PCSK1 cleavage

Glucagon-like peptide 1 (GLP1), which is mainly processed and cleaved from proglucagon in enteroendocrine cells (EECs) of the intestinal tract, acts on the GLP1 receptor in pancreatic cells to stimulate insulin secretion and to inhibit glucagon secretion. However, GLP1 processing is not fully understood. Here, we show that reticulon 4B (Nogo-B), an endoplasmic reticulum (ER)-resident protein, interacts with the major proglucagon fragment of proglucagon to retain proglucagon on the ER, thereby inhibiting PCSK1-mediated cleavage of proglucagon in the Golgi. Intestinal Nogo-B knockout in male type 2 diabetes mellitus (T2DM) mice increases GLP1 and insulin levels and decreases glucagon levels, thereby alleviating pancreatic injury and insulin resistance. Finally, we identify aberrantly elevated Nogo-B expression and inhibited proglucagon cleavage in EECs from diabetic patients. Our study reveals the subcellular regulatory processes involving Nogo-B during GLP1 production and suggests intestinal Nogo-B as a potential therapeutic target for T2DM.

Cardioprotective benefits of metabolic surgery and GLP-1 receptor agonist-based therapies

Individuals with excessive adipose tissue and type 2 diabetes mellitus (T2DM) face a heightened risk of cardiovascular morbidity and mortality. Metabolic surgery is an effective therapy for people with severe obesity to achieve significant weight loss. Additionally, metabolic surgery improves blood glucose levels and can lead to T2DM remission, reducing major adverse cardiovascular outcomes (MACE). Glucagon-like peptide 1 (GLP-1) receptor agonists (GLP-1RAs) are a class of medication that effectively reduce body weight and MACE in patients with T2DM. This review explores the potential mechanisms underlying the cardioprotective benefits of metabolic surgery and GLP-1RA-based therapies and discusses recent evidence and emerging therapies in this dynamic area of research.

Therapeutic Advances in Obesity: How Real-World Evidence Impacts Affordability Beyond Standard of Care

Obesity is currently considered a global epidemic, with rising prevalence worldwide and rather pessimistic projections. Based on its close interconnection with various co-morbidities, such as diabetes mellitus and cardiovascular disease, obesity is associated with significant increases in morbidity and mortality, while it also poses a substantial economic burden for national healthcare systems. Apparently, the majority of individuals classified as obese do not achieve adequate weight loss with the adoption of a healthy lifestyle intervention, including dietary modification and physical activity. Fortunately, during the last decade, a significant progress in pharmacotherapy of obesity has been observed, with the introduction of agents that have gained approval from regulatory authorities, namely semaglutide, liraglutide and tirzepatide, due to their impressive results in body weight reduction, alongside their beneficial, pleiotropic effects. The aim of the present review article is to discuss on evidence retrieved from real-world studies regarding the efficacy of those agents in obesity treatment, with emphasis on cost-effectiveness data, towards an effort to tackle efficiently the progression of obesity epidemic.

Disproportionality Analysis From World Health Organization Data on Semaglutide, Liraglutide, and Suicidality

Importance

Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have gained use primarily due to their weight-reduction effects, although a regulatory review was undertaken for potential suicidality concern.

Objectives

To evaluate potential signals for suicidal and self-injurious adverse drug reactions (ADRs) associated with the GLP-1 RAs semaglutide and liraglutide.

Design, Setting, and Participants

Disproportionality analysis through the case-control design using the World Health Organization (WHO) global database of suspected ADRs. Participants were clinical patients worldwide experiencing an ADR suspectedly attributable to semaglutide or liraglutide in the database from inception to August 30, 2023. Data were analyzed from September to December 2023.

Exposure

Treatment with semaglutide or liraglutide regardless of indication or treatment duration.

Main Outcomes and Measures

Reporting odds ratio (ROR) and the bayesian information component (IC) with 95% CIs were calculated as measures of disproportionate reporting of suicidal and self-injurious ADRs associated with semaglutide and liraglutide compared with all other medications. Sensitivity analyses were conducted including patients with coreported use of antidepressants and benzodiazepines and using dapagliflozin, metformin, and orlistat as comparators. A disproportionality signal was considered when the lower limits of the ROR and IC were above 1 and 0, respectively.

Results

A total of 107 (median [IQR] age 48 [40-56] years; 59 female patients [55%]) and 162 (median [IQR] age 47 [38-60] years; 100 female patients [61%]) cases of suicidal and/or self-injurious ADRs were reported between November 2000 and August 2023 with semaglutide and liraglutide, respectively. Significant disproportionality was detected only for semaglutide-associated suicidal ideation (ROR, 1.45; 95% CI, 1.18-1.77; IC, 0.53; 95% CI, 0.19-0.78), which remained significant in patients with coreported use of antidepressants (ROR, 4.45; 95% CI, 2.52-7.86; IC, 1.96; 95% CI, 0.98-2.63) and benzodiazepines (ROR, 4.07; 95% CI, 1.69-9.82; IC, 1.67; 95% CI, 0.11-2.65), when compared with dapagliflozin (ROR, 5.56; 95% CI, 3.23-9.60; IC, 0.70; 95% CI, 0.36-0.95), metformin (ROR, 3.86; 95% CI, 2.91-5.12; IC, 1.20; 95% CI, 0.94-1.53) and orlistat (ROR, 4.24; 95% CI, 2.69-6.69; IC, 0.70; 95% CI, 0.36-0.95).

Conclusions and Relevance

This study using the WHO database found a signal of semaglutide-associated suicidal ideation, which warrants urgent clarification.