GLP-1 Analog Modulates Appetite, Taste Preference, Gut Hormones, and Regional Body Fat Stores in Adults with Obesity

Exogenous oral application of PYY and exendin-4 impacts upon taste-related behavior and taste perception in wild-type mice

Several gut peptides have been implicated in feeding and body mass accumulation. Glucagon-like peptide 1 (GLP-1) and peptide tyrosine-tyrosine (PYY) have been shown to mediate satiety and reduce food intake. While systemic administration of such peptides has been explored as a therapy for metabolic disease, the effects of these hormones on taste signaling should also be considered given the importance of taste to feeding decisions and considering the fact that components of these signaling systems are expressed in cells of the peripheral gustatory system. We previously demonstrated that genetic disruption of PYY signaling in mice can impact on taste responsiveness and feeding and that viral expression of PYY in the salivary glands of PYY knockout mice can rescue responsiveness. The present work uses adeno-associated virus-mediated salivary gland treatment with both GLP-1 receptor agonist exendin-4 and/or PYY encoding vectors to explore the effect of stimulating these orally present signaling systems on taste-related behavioral responsiveness in male wild-type mice with intact peptide signaling systems. Results showed a significant effect of salivary gland treatment on responsiveness to multiple taste qualities. Data gathered from taste bud cells in vitro suggest that these peptides directly influence the responsiveness of these primary sensory cells. Collectively, these findings show that taste perception can be modulated by the exogenous application of satiety peptides in wild-type mice and suggest that the taste bud is a promising substrate for food intake modulation.

Heart failure and obesity: Translational approaches and therapeutic perspectives. A scientific statement of the Heart Failure Association of the ESC

Obesity and heart failure (HF) represent two growing pandemics. In the general population, obesity affects one in eight adults and is linked with an increased risk for HF. Obesity is even more common in patients with HF, where it complicates the diagnosis of HF and is linked with worse symptoms and impaired exercise capacity. Over the past few years, new evidence on the mechanisms linking obesity with HF has been reported, particularly in relation to HF with preserved ejection fraction. Novel therapies inducing weight loss appear to have favourable effects on health status and cardiovascular risk. Against the backdrop of this rapidly evolving evidence landscape, HF clinicians are increasingly required to tailor their preventive, diagnostic, and therapeutic approaches to HF in the presence of obesity. This scientific statement by the Heart Failure Association of the European Society of Cardiology provides an up-to-date summary on obesity in HF, covering key areas such as epidemiology, translational aspects, diagnostic challenges, therapeutic approaches, and trial design.

Characterization of the effect of naltrexone/bupropion on body composition

AIMS

Oral treatment extended-release naltrexone/bupropion (NB) leads to significant weight loss, but its effect on body composition remains unclear. We investigated changes in body composition with dual-energy x-ray absorptiometry after treatment with NB or placebo in a subgroup of participants from a randomized control phase 3 study (COR-I).

MATERIALS AND METHODS

Observed changes from baseline to week 52 were estimated for total, lean, and fat mass. Changes in body composition were evaluated using linear regression and adjusted for baseline covariates.

RESULTS

The analysis included 82 participants (placebo, n = 26; NB, n = 56) with comparable baseline characteristics (age, BMI, sex). The NB group experienced a significant -7.8% change of total mass (-12.9% change in fat mass and -4.1% in lean mass), compared with a -2.8% change of total mass (-4.8% change in fat mass and -1.4% in lean mass) in the placebo group. The adjusted changes in lean-to-fat mass ratio of 0.069 in the NB group and -0.056 in the placebo group were significantly different (p < 0.05).

CONCLUSIONS

NB-induced weight loss is associated with significant reductions in total percent fat mass, increase in total percent lean mass, and change in lean-to-fat mass ratio, in comparison to placebo. Larger studies are needed to further elucidate the clinical significance of these changes and impact of a potentially healthier metabolism.

Obesity: pathophysiology and therapeutic interventions

Over the past few decades, obesity has transitioned from a localized health concern to a pressing global public health crisis affecting over 650 million adults globally, as documented by WHO epidemiological surveys. As a chronic metabolic disorder characterized by pathological adipose tissue expansion, chronic inflammation, and neuroendocrine dysregulation that disrupts systemic homeostasis and impairs physiological functions, obesity is rarely an isolated condition; rather, it is frequently complicated by severe comorbidities that collectively elevate mortality risks. Despite advances in nutritional science and public health initiatives, sustained weight management success rates and prevention in obesity remain limited, underscoring its recognition as a multifactorial disease influenced by genetic, environmental, and behavioral determinants. Notably, the escalating prevalence of obesity and its earlier onset in younger populations have intensified the urgency to develop novel therapeutic agents that simultaneously ensure efficacy and safety. This review aims to elucidate the pathophysiological mechanisms underlying obesity, analyze its major complications-including type 2 diabetes mellitus (T2DM), cardiovascular diseases (CVD), non-alcoholic fatty liver disease (NAFLD), obesity-related respiratory disorders, obesity-related nephropathy (ORN), musculoskeletal impairments, malignancies, and psychological comorbidities-and critically evaluate current anti-obesity strategies. Particular emphasis is placed on emerging pharmacological interventions, exemplified by plant-derived natural compounds such as berberine (BBR), with a focus on their molecular mechanisms, clinical efficacy, and therapeutic advantages. By integrating mechanistic insights with clinical evidence, this review seeks to provide innovative perspectives for developing safe, accessible, and effective obesity treatments.

Efficacy of Simplifying Complex Insulin Regimen on Glycometabolic Parameters and Target Organ Damage in Type 2 Diabetes: A Retrospective Cohort Study

Background: Fixed-ratio combinations (FRCs) provide an alternative to intensified conservative insulin treatments (ICTs); however, therapy simplification in patients with high total daily insulin dose (TDD) or high HbA1c is a debated issue; additionally, its influence on target organ damage (TOD) is less known. Methods: Data were retrospectively collected from patients with Type 2 diabetes, including 58 patients who continued ICT and 104 patients who underwent therapy simplification between January 1, 2017, and January 1, 2023. Patient characteristics and therapy details are at baseline and 3, 6, 12, and 24 months after FRC initiation. Results: HbA1c significantly decreased in both groups (-0.9% [-1.6%, -0.5%] with ICT vs. -1.3% [-2.1%, -0.3%] with FRC), whereas body weight significantly decreased only after simplification (-1 kg [-4, 1] vs. -5 kg [-7, -2]). Diabetes duration was not associated with therapy efficacy. Significant HbA1c reduction and FRC dose elevation occurred earlier in patients with an initial HbA1c > 8.0% than in those with an initial HbA1c < 8.0%. FRC dose was significantly higher at 3 months in patients with a TDD of > 60 U/day than in those with lower TDD. Relative risk reduction with therapy simplification was 72.1%, 50.6%, 32.3%, and 59.7% for hypoglycemia, renal function decline, microalbuminuria, and macrovascular complications, respectively. Risk of retinopathy, neuropathy, and chronic kidney disease did not significantly change with FRCs. Discussion: FRCs are safe and as effective as ICT even in patients with high initial HbA1c, high TDD, or long diabetes duration. A protective role of FRCs in diabetic ASCVD has been proven, but their protective role in CKD was not observed. Conclusions: The significant improvements in glycemic and weight control, as well as in TODs, suggest that therapy simplification may represent a more favorable approach compared to the continuation of previous ICT even in patients characterized by high baseline TDD and HbA1c levels.

Hedonic eating is controlled by dopamine neurons that oppose GLP-1R satiety

Hedonic eating is defined as food consumption driven by palatability without physiological need. However, neural control of palatable food intake is poorly understood. We discovered that hedonic eating is controlled by a neural pathway from the peri-locus ceruleus to the ventral tegmental area (VTA). Using photometry-calibrated optogenetics, we found that VTA dopamine (VTADA) neurons encode palatability to bidirectionally regulate hedonic food consumption. VTADA neuron responsiveness was suppressed during food consumption by semaglutide, a glucagon-like peptide receptor 1 (GLP-1R) agonist used as an antiobesity drug. Mice recovered palatable food appetite and VTADA neuron activity during repeated semaglutide treatment, which was reversed by consumption-triggered VTADA neuron inhibition. Thus, hedonic food intake activates VTADA neurons, which sustain further consumption, a mechanism that opposes appetite reduction by semaglutide.

GLP-1 receptor agonists significantly impair taste function

Over 10% of the US population are prescribed glucagon-like peptide-1 receptor agonists (GLP-1 RAs) to combat obesity. Although they decrease cravings for foods, their influence on chemosensory function is unknown. We employed state-of-the-art quantitative taste and smell tests to address this issue. The 53-item Waterless Empirical Taste Test (WETT®) and the 40-item University of Pennsylvania Smell Identification Test (UPSIT®) were completed by 46 persons taking GLP-1 RAs and 46 controls matched on age, sex, smoking behavior, and COVID-19 infection histories. Data were analyzed using analyses of variance. The WETT® scores were significantly diminished in the GLP-1 RA group relative to controls [total means (95% CIs) = 28.61 (25.66,31.56) and 40.63 (38.35,42.91), p < 0.001, η2 = 0.37]. Eighty five percent of the GLP-1 subjects scored worse than their individually matched controls. All 5 WETT® subtest scores were similarly affected (ps < 0.001). Smell function, although slightly decreased on average, was not significantly impacted (p = 0.076). Women outperformed men on all tests. Remarkably, UPSIT® and WETT® scores were higher, i.e., better, in those reporting nausea, diarrhoea, and other GLP-1-related side effects. This study demonstrates, for the first time, that GLP-1 RAs alter the function of a major sensory system, significantly depressing the perception of all five basic taste qualities. The physiologic basis of this effect is unknown but may involve GLP-1 receptors in the brainstem and afferent taste pathways, as well as vagus nerve-related processes.

Precision medicine for obesity: current evidence and insights for personalization of obesity pharmacotherapy

Obesity is a chronic and complex disease associated with increased morbidity, mortality, and financial burden. It is expected that by 2030 one of two people in the United States will have obesity. The backbone for obesity management continues to be lifestyle interventions, consisting of calorie deficit diets and increased physical activity levels, however, these interventions are often insufficient to achieve sufficient and maintained weight loss. As a result, multiple patients require additional interventions such as antiobesity medications or bariatric interventions in order to achieve clinically significant weight loss and improvement or resolution of obesity-associated comorbidities. Despite the recent advances in the field of obesity pharmacotherapy that have resulted in never-before-seen weight loss outcomes, comorbidity improvement, and even reduction in cardiovascular mortality, there is still a significant interindividual variability in terms of response to antiobesity medications, with a subset of patients not achieving a clinically significant weight loss. Currently, the trial-and-error paradigm for the selection of antiobesity medications results in increased costs and risks for developing side effects, while also reduces engagement in weight management programs for patients with obesity. The implementation of a precision medicine framework to the selection of antiobesity medications might help reduce heterogeneity and optimize weight loss outcomes by identifying unique subsets of patients, or phenotypes, that have a better response to a specific intervention. The detailed study of energy balance regulation holds promise, as actionable behavioral and physiologic traits could help guide antiobesity medication selection based on previous mechanistic studies. Moreover, the rapid advances in genotyping, multi-omics, and big data analysis might hold the key to discover additional signatures or phenotypes that might respond better to a certain intervention and might permit the widespread adoption of a precision medicine approach for obesity management.

Changes in food preferences and ingestive behaviors after glucagon-like peptide-1 analog treatment: techniques and opportunities

BACKGROUND

Glucagon-like peptide-1 (GLP-1) analogs are approved for the treatment of obesity in adults and adolescents. Reports have emerged that the weight loss effect of these medications may be related to changes in food preferences and ingestive behaviors following the treatment. Understanding the mechanisms which impact ingestive behavior could expand opportunities to develop more refined and personalized treatment options for obesity.

METHODS

Recent studies investigating the relationship between GLP-1 analogs and ingestive behaviors were retrieved from PubMed using the search terms: "obesity," "food preference," "taste," "ingestive behavior," "weight loss medication," "anti-obesity medication," "GLP-1 analog," "tirzepatide," "liraglutide," "semaglutide." Measurement tools were studied to compare variables used to assess food intake behavior. The main outcomes from each study were analyzed to evaluate the current standing and future directions of appetitive, ingestive, and consummatory behaviors and their association with GLP-1 analogs.

RESULTS

Thus far, studies have primarily explored the weight loss phase and report decreased short-term appetite and food intake upon treatment. However, research during the weight maintenance phase and objective measurements of food intake are notably sparse. Additionally, verbal reports have been primarily used to examine food intake, which can be susceptible to subjectivity.

CONCLUSIONS

Elucidating the relationship between GLP-1 analogs and ingestive behavior could reveal additional parameters which contribute to their anti-obesity effects. To better understand these mechanisms, it is imperative to consider objective measurements of food intake in future studies. Several measurement tools have been adapted to measure variables of food behavior in humans, and each must be carefully considered with their strengths and limitations to develop optimal investigations.

Effect of glucagon-like peptide-1 receptor agonists and co-agonists on body composition: Systematic review and network meta-analysis

BACKGROUND AND AIMS

While glucagon-like peptide-1 receptor agonists (GLP-1RAs) effectively reduce body weight, their impact on lean mass remains uncertain. This meta-analysis evaluated the effects of GLP-1RAs and GLP-1/GIP receptor dual agonists (GLP-1/GIP-RAs) on body composition, focusing on total weight, fat mass, and lean mass in adults with diabetes and/or overweight/obesity.

METHODS

A systematic search of Medline, Embase, and the Cochrane Library was conducted through November 12, 2024. Data were analyzed using random-effects pairwise and network meta-analyses to compare interventions with placebo or active comparators.

RESULTS

Twenty-two randomized controlled trials (2258 participants) were included. GLP-1RAs significantly reduced total body weight (MD -3.55 kg, 95 %-CI [-4.81, -2.29]), fat mass (MD -2.95 kg, 95 %-CI [-4.11, -1.79]), and lean mass (MD -0.86 kg, 95 %-CI [-1.30, -0.42]), with lean mass loss comprising approximately 25 % of the total weight loss. However, the relative lean mass, defined as percentage change from baseline, was unaffected. Liraglutide, at 3.0 mg weekly or 1.8 mg daily, was the only GLP-1RA to achieve significant weight reduction without significantly reducing lean mass. Tirzepatide (15 mg weekly) and semaglutide (2.4 mg weekly) were the most effective for weight and fat mass reduction but were among the least effective in preserving lean mass.

CONCLUSIONS

Potent GLP-1 RAs, such as tirzepatide and semaglutide, demonstrate greater overall weight loss but are associated with a significant reduction in lean mass.

Effects of GLP-1 Receptor Agonists in Alcohol Use Disorder

In the search for novel treatment strategies for alcohol use disorder (AUD), glucagon-like peptide-1 (GLP-1) receptor agonists (GLP-1RAs) approved for treating Type 2 diabetes and obesity have caught much attention. GLP-1 is a naturally occurring peptide produced in the small intestines and the brain, regulating plasma glucose levels and satiety. This focused review will report on the preclinical studies, case stories, register-based cohort studies, brain-imaging data and secondary analysis of clinical data supporting the role of GLP-1RAs as a novel treatment of AUD. Several clinical trials are ongoing, examining the potential effects of the GLP-1RA semaglutide in AUD.

Methodological insights into intervention and outcomes in randomised controlled trials of herbal medicine for obesity: a scoping review

Background

With rising obesity rates worldwide, clinical trials focused on identifying effective treatments are increasing. While guidelines exist for pharmaceutical drugs targeting obesity, there are none for herbal medicine clinical trials for anti-obesity. Both industries refer to the same guidelines for clinical trials.

Objectives

This scoping review aimed to gather information from herbal medicine anti-obesity randomised controlled trials (RCTs), analyse the methodologies and assess their alignment with international guidelines.

Eligibility criteria

This review included RCTs of participants of all ages with obesity utilising herbal medicine with any comparators and focusing on various outcome measures.Sources of evidence: Only published journal articles were included.

Charting methods

Articles were extracted from MEDLINE, CENTRAL and EMBASE using predetermined keywords. Relevant data, such as the study characteristics, types of herbal interventions and controls, treatment durations, outcome measures and safety monitoring methods were recorded in a table format for comparative analysis.

Results

We included 99 RCTs that showed participant sample sizes ranging from 8 to 182, ages 18 to 80 years and body mass indexes (BMIs) between 25 and 49.9 kg/m2. Herbal interventions used single herbs (n = 57) and mixtures (n = 42), given for 14 days to 56 weeks. Studies implementing diet modifications include restricted calorie diets (n = 35), food-portion controlled diets (n = 7) and fixed calorie diets (n = 7). Of the 28 studies implementing exercise, most were of moderate intensity (n = 22). All studies collected BMI and weight as primary outcomes. Body fat composition was measured in over 50% of studies using a body analyser (n = 57). Waist, hip and abdominal circumferences were infrequently measured. Radiological tools used include dual-energy X-ray absorptiometry (n = 16), computed tomography scans (n = 10) and ultrasound (n = 2). Safety monitoring methods were reported in most studies (n = 76).

Conclusion

In conclusion, almost 50% of the studies adhered to international pharmaceutical clinical trial guidelines, addressing dietary, lifestyle, physical activity and cardiovascular risk factors. Nonetheless, more herbal anti-obesity studies need to consider the assessment of weight maintenance.

GLP1Ra-based therapies and DXA-acquired musculoskeletal health outcomes: a focused meta-analysis of placebo-controlled trials

OBJECTIVE

The objective of this study was to evaluate the effect of glucagon-like peptide-1 receptor agonist (GLP1Ra)-based therapies on change in dual-energy x-ray absorptiometry (DXA)-acquired lean mass (LM) or bone mineral density (BMD).

METHODS

PubMed and Web of Science were searched from database inception through January 29, 2024, for randomized, placebo-controlled trials reporting on change in DXA-acquired LM or BMD measures associated with 12+ weeks of GLP1Ra-based treatment. Of 2618 articles, 9 trials met prespecified search criteria, with 7 reporting on change in total body LM and 2 reporting on change in BMD. For LM outcomes, a hierarchical Bayesian model was used to estimate treatment mean differences. BMD outcomes were described narratively.

RESULTS

LM was reported in a total of 659 participants (GLP1Ra-based therapies: n = 419; placebo: n = 240), with follow-up times ranging from mean (SD) 12 to 72 (33.5) weeks. At baseline, participants were aged mean (SD) 41.7 (7.6) years, and 75% were female, with BMI values ranging from 30 to 43 kg/m2. Compared with placebo, GLP1Ra-based treatment was associated with significantly reduced total body weight (-6.9 kg; 95% credible interval [CI]: -10.7 to -3.0). GLP1Ra-based treatment was also associated with significantly reduced LM (-1.9 kg; 95% CI: -3.5 to -0.2).

CONCLUSIONS

Approximately 30% of body weight lost with GLP1Ra-based therapy is LM. More data are needed assessing BMD outcomes.

Early Reinitiation of Obesity Pharmacotherapy Post Laparoscopic Sleeve Gastrectomy in Youth: A Retrospective Cohort Study

BACKGROUND

Bariatric surgery is the most effective intervention for severe pediatric obesity, but a subset of youth experience suboptimal weight loss and/or recurrent weight gain. Early re-initiation of obesity pharmacotherapy postoperatively may improve outcomes, though this has not been evaluated in pediatric populations.

METHODS

A retrospective cohort study at a tertiary care children's hospital evaluated the safety and efficacy of reintroducing obesity pharmacotherapy within six weeks after laparoscopic sleeve gastrectomy (LSG). Youth were offered obesity pharmacotherapy reinitiation at their 2-week postoperative visit. The study compared outcomes between 25 youth who chose early obesity pharmacotherapy reinitiation and 21 who received standard care without restarting medication. Primary outcomes included weight trajectory, eating behaviors, complications, readmissions, and reoperation rates, analyzed using independent t-tests, Chi-squared tests, and logistic regressions.

RESULTS

Between November 2023 and July 2024, 53 youth had surgical consults, and 46 (86% conversion rate; mean age 16.5 ± 1.9 years, mean BMI 53 ± 9.7 kg/m2; 70% (32/46) female, 80% (37/46) Hispanic, 87% (40/46) publicly insured) underwent LSG, with 93% (43/46) using obesity pharmacotherapy preoperatively. Mixed-effects multivariate regression, adjusting for baseline BMI, age, and sex, revealed that early reinitiation (5.1 weeks [IQR 3.7, 8.4]) significantly reduced BMI, percent BMI, percent total weight loss (TWL), and percent excess weight loss (EWL) at 3 and 6 months compared to standard care, with no significant differences in complications or readmissions. At 6 months, the mean differences were: %BMI: -6.5% (95% CI: -9.13, -3.86), p < 0.001; %TWL: -5.9% (95% CI: -8.52, -3.25), p < 0.001; %EWL: Reinitiators: -45.5% vs. standard care: -39.4%; mean difference: -8.2% (95% CI: -14.69, -1.63), p < 0.001. Early reinitiation also resulted in a significant reduction in emotional overeating at 3 and 6 months compared to standard care, with mean differences of -2.5 points (95% CI: -3.29, -1.76), p < 0.001, and -3.5 points (95% CI: -4.38, -2.69), p < 0.001, respectively on self-reported eating behavior questionnaires.

CONCLUSION

Early obesity pharmacotherapy reinitiation after LSG was safe and well tolerated, improving weight outcomes without negatively impacting complication or readmission rates.

Research progress of GLP-1RAs in the treatment of type 2 diabetes mellitus

Glucagon-like peptide-1 (GLP-1) is a 30-amino acid intestinal insulin-stimulating factor, which is mainly secreted by L cells in the distal ileum and colon. It has various physiological functions, such as promoting insulin secretion and synthesis, stimulating β-cell proliferation, inducing islet regeneration, inhibiting β-cell apoptosis and glucagon release, delaying gastric emptying and controlling appetite, etc. It plays a role through a specific GLP-1 receptor (GLP-1R) distributed in many organs or tissues and participates in the regulation of glucose homeostasis in the body. GLP-1 receptor agonists (GLP-1RAs) has the similar physiological function of GLP-1. Because of its structural difference from natural GLP-1, it is not easy to be degraded by dipeptidyl peptidase-4 (DPP-4), thus prolonging the action time. GLP-1RAs have been recognized as a new type of hypoglycemic drugs and widely used in the treatment of type 2 diabetes mellitus (T2DM). Compared with other non-insulin hypoglycemic drugs, it can not only effectively reduce blood glucose and glycosylated hemoglobin (HbA1c), but also protect cardiovascular system, nervous system and kidney function without causing hypoglycemia and weight gain. Therefore, GLP-1RAs has good application prospects and potential for further development.

Does semaglutide reduce alcohol intake in Danish patients with alcohol use disorder and comorbid obesity? Trial protocol of a randomised, double-blinded, placebo-controlled clinical trial (the SEMALCO trial)

INTRODUCTION

Alcohol use disorder (AUD) is a massive burden for the individual, relatives and society. Despite this, the treatment gap is wide compared with other mental health disorders. Treatment options are sparse, with only three Food and Drug Administration (FDA)-approved pharmacotherapies. Glucagon-like peptide-1 (GLP-1) receptor agonists have shown promising effects in reducing alcohol consumption in preclinical experiments, and clinical trials are in high demand to investigate these potentially beneficial effects in patients diagnosed with AUD.

METHODS AND ANALYSIS

The effects of the once-weekly GLP-1 receptor agonist semaglutide will be investigated in a 26-week, randomised, placebo-controlled, double-blinded clinical trial. 108 patients diagnosed with AUD and comorbid obesity (body mass index (BMI)≥30 kg/m2)) will be randomised to treatment with either semaglutide or placebo in combination with cognitive behavioural therapy. A subgroup of the patients will have structural, functional and neurochemical brain imaging performed at baseline and after 26 weeks of treatment. The primary endpoint is the reduction in heavy drinking days, defined as days with excess consumption of 48/60 g of alcohol per day (women and men, respectively). Secondary endpoints include changes from baseline to week 26 in alcohol consumption, smoking status, quality of life, fibrosis-4 score, plasma concentration of phosphatidylethanol, brain gamma-aminobutyric acid (GABA) levels, alcohol cue reactivity, functional connectivity and white matter tract integrity.

STATUS

Recruitment started in June 2023.

ETHICS AND DISSEMINATION

The study is approved by the Ethics Committee of the Capital Region of Denmark, the Danish Board of Health and the Danish Data Protection Agency. All patients will sign the written consent form before being included in the trial. Results will be disseminated through peer-reviewed publications and conference presentations. After the results are published, all de-identified data will be available in the Mendeley database.

TRIAL REGISTRATION NUMBER

NCT05895643.

Characterizing body composition modifying effects of a glucagon-like peptide 1 receptor-based agonist: A meta-analysis

AIM

Diabetes is an independent risk factor for muscle mass loss, with possible mechanisms including impaired insulin signalling and chronic inflammation. The use of a glucagon-like peptide 1 (GLP-1) receptor-based agonist could lead to weight reduction, which might result from the loss of both fat and skeletal muscle. However, the body composition-modifying effects of GLP-1 receptor-based agonists have not been systematically characterized.

METHODS

PubMed, EMBASE, the Cochrane Center Register of Controlled Trials for Studies and Clinicaltrial.gov were searched from inception to October 2023. Randomized controlled trials of GLP-1 receptor agonist or glucose-dependent insulinotropic polypeptide/GLP-1 receptor dual agonist, which reported the changes of body composition, were included. The results were computed as weighted mean differences (WMDs) and 95% confidence intervals (CIs) in a random-effects model.

RESULTS

In all, 19 randomized controlled trials were included. When compared with controls, substantial reductions in fat body mass were observed in patients using GLP-1 receptor-based agonist treatment (WMD = -2.25 kg, 95% CI -3.40 to -1.10 kg), with decrease in areas of both subcutaneous fat (WMD = -38.35 cm2, 95% CI, -54.75 to -21.95 cm2) and visceral fat (WMD = -14.61 cm2, 95% CI, -23.77 to -5.44 cm2). Moreover, greater reductions in lean body mass were also observed in GLP-1 receptor-based agonist users compared with non-users (WMD = -1.02 kg, 95% CI, -1.46 to -0.57 kg), while the changes in lean mass percentage were comparable between GLP-1 receptor-based agonist users and non-users.

CONCLUSION

Compared with the controls, GLP-1 receptor-based agonist users experienced greater reductions in fat body mass, with body shaping effects in terms of both subcutaneous fat mass and visceral fat mass. Although greater reductions in lean body mass were also observed in GLP-1 receptor-based agonist users, the changes in lean mass percentage were comparable between the users and non-users.

Effects of liraglutide on body composition in people living with obesity or overweight: A systematic review

AIM

To evaluate the effect of liraglutide on body composition in people living with obesity or overweight.

METHODS

A systematic search was conducted in PubMed, Embase, and Cochrane Library databases up to June 10, 2024. Randomized controlled trials (RCTs) comparing liraglutide to placebo and reporting body composition outcomes were included.

RESULTS

Data from 15 studies involving 960 participants were analyzed. Liraglutide consistently demonstrated significant reductions in total weight, fat mass, and visceral adipose tissue (VAT) compared to placebo across the included studies. VAT reductions ranged from 12.49 % to 23 %, highlighting liraglutide's effectiveness in targeting visceral fat, a key factor in cardiometabolic risk. Fat mass reductions were also substantial and consistent, reinforcing the efficacy of liraglutide in improving overall body composition. In contrast, lean mass outcomes were more variable, with some studies reporting preservation or even gains in lean mass, while others indicated losses.

CONCLUSIONS

Liraglutide effectively reduces fat mass and VAT, supporting its use in managing obesity and related cardiometabolic risks. However, the inability to accurately calculate lean and fat mass proportions underscores the need for standardized reporting and availability of individual-level data. Future research should prioritize these elements and include muscle function assessments to better evaluate the clinical impacts of GLP-1 receptor agonists on body composition.

Effects of liraglutide on abdominal fat distribution and glucose metabolism in Chinese subjects with obesity

AIMS

To observe the effects of liraglutide on abdominal fat distribution in Chinese subjects with obesity in 12 weeks, and further to explore the correlation between abdominal fat content and glucose metabolism after monotherapy.

METHODS

This study recruited 71 obese subjects. All the subjects have received liraglutide monotherapy (0.6 mg-1.8 mg/d) for 12 weeks. Clinical assessment, laboratory assays and magnetic resonance imaging (MRI) examination were accessed at baseline and after 12 weeks treatment. MRI was applied to measure abdominal fat distribution, calculated by proton-density fat fraction (PDFF).

RESULTS

After 12 weeks of liraglutide monotherapy, body weight in the obese participants decreased significantly (P < 0.001). Fasting blood glucose (FBG) levels, 2 h post-load blood glucose (2hPBG) levels, and glycosylated hemoglobin (HbA1c) were remarkably improved after liraglutide monotherapy (all P < 0.001). Subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) were significantly reduced after liraglutide monotheraphy (both P < 0.001). There was a notable reduction in liver fat content (LFC) after liraglutide monotherapy (P < 0.001). In the further analysis, LFC was greater in obese subjects with impaired glucose regulation (IGR) at baseline compared to those with normal glucose tolerance (NGT) (P = 0.002). The LFC reduction in IGR group was significantly greater than those in NGT group after liraglutide treatment (P < 0.001). Pearson correlation analysis showed that reduction of LFC was significantly correlated with improvement of FBG (r = 0.587, P < 0.001) and HbA1c (r = 0.607, P < 0.001) in obese patients.

CONCLUSION

LFC was significantly reduced after liraglutide monotherapy for 12 weeks in subjects with obesity. The LFC reduction is likely to be associated with IGR remission in obese subjects.

Investigating GLP-1 Injections: Potential Mitochondrial Dysfunction in Non-Diabetic Patients Presenting with Migraines and Hypoglycemia: A Case Report

Introduction

GLP-1 medications are widely used for weight loss in patients with and without type 2 diabetes. However, limited research exists on their effects in non-diabetic patients, particularly concerning mitochondrial function. This case report investigates the potential of altered mitochondrial dysfunction as a cause of side effects of GLP-1 medications in patients without type 2 diabetes.

Case Presentation

The patient, a 43-year-old female with a BMI of 32, presented with hypoglycemia and persistent migraines with auras after Ozempic and Mounjaro injections.

Outcomes

The patient changed her diet to include 90 grams of protein and frequent small meals throughout the day. She took CoQ10, D-ribose, vitamin B complex, and acetyl-l-carnitine, to address the migraines, and this also improved the mitochondrial function. The patient reported balanced blood sugar after changing her diet; her migraines improved and did not return after taking supplementation.

Conclusion

This case report emphasizes the need for awareness and monitoring of potential mitochondrial side effects from GLP-1 injections in patients without type 2 diabetes. Nutritional and supplemental interventions effectively managed the patient's symptoms and emphasized the need for tailored interventions in patients using GLP-1 medications. Further research is needed to understand how GLP-1 injections impact mitochondrial function.

Glucagon-like peptide-1 receptor agonist-based agents and weight loss composition: Filling the gaps

Excess adiposity is at the root of type 2 diabetes (T2D). Glucagon-like peptide-1 receptor agonists (GLP-1RAs) have emerged as first-line treatments for T2D based on significant weight loss results. The composition of weight loss using most diets consists of <25% fat-free mass (FFM) loss, with the remainder from fat stores. Higher amounts of weight loss (achieved with metabolic bariatric surgery) result in greater reductions in FFM. Our aim was to assess the impact that GLP-1RA-based treatments have on FFM. We analysed studies that reported changes in FFM with the following agents: exenatide, liraglutide, semaglutide, and the dual incretin receptor agonist tirzepatide. We performed an analysis of various weight loss interventions to provide a reference for expected changes in FFM. We evaluated studies using dual-energy X-ray absorptiometry (DXA) for measuring FFM (a crude surrogate for skeletal muscle). In evaluating the composition of weight loss, the percentage lost as fat-free mass (%FFML) was equal to ΔFFM/total weight change. The %FFML using GLP-1RA-based agents was between 20% and 40%. In the 28 clinical trials evaluated, the proportion of FFM loss was highly variable, but the majority reported %FFML exceeding 25%. Our review was limited to small substudies and the use of DXA, which does not measure skeletal muscle mass directly. Since FFM contains a variable amount of muscle (approximately 55%), this indirect measure may explain the heterogeneity in the data. Assessing quantity and quality of skeletal muscle using advanced imaging (magnetic resonance imaging) with functional testing will help fill the gaps in our current understanding.

Super response to liraglutide in people with obesity: A case report and literature review

GLP1 receptor agonists (GLP1-RAs) are currently the most widely used pharmacological option to treat obesity. However, considerable heterogeneity in weight loss response has been observed with different anti-obesity drugs and response predictors to these drugs still remain ambiguous. Furthermore, very few published data have been available on cases of high-responders to treatment with GLP1-RAs. In this article, we present the case of a patient with grade 4 obesity (initial body mass index, 50.2kg/m2) with associated mechanical and metabolic complications who achieved an initial weight loss of 40% at 1 year with hygienic-dietary measures and drug treatment with liraglutide. We also review the available literature on factors potentially contributing to variations in weight loss with GLP1-RAs in general and liraglutide, in particular.

Incretin impact on gastric function in obesity: physiology, and pharmacological, surgical and endoscopic treatments

The aims of this review are to appraise the role of the stomach in satiation, the effects of incretin and other hormone agonists on weight loss and the role of altered gastric functions in their effects on obesity or glycaemic control. In addition to the gut in its role in enzymatic digestion and hormonal responses to nutrient ingestion, gastric motor functions include accommodation, trituration and emptying [gastric emptying (GE)] of food and elicitation of postprandial satiation and satiety. The postprandially released hormones most extensively studied and utilized therapeutically are glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP). Their mechanisms of action include stimulation of pancreatic β cells to produce insulin. However, GLP-1 reduces glucagon and slows GE, whereas GIP increases glucagon and does not alter GE. Molecular modifications of GLP-1 (which has a T1/2 of 3 min) led to the development of long-acting subcutaneous or oral pharmacological agents that have been approved for the treatment of obesity, and their effects on gastric function are documented. Other medications in development target other molecular mechanisms, including glucagon and amylin. Small-molecule GLP-1 receptor agonists are promising for the treatment of obesity and may also slow GE. Bariatric surgery and endoscopy increase satiation by restricting gastric size; in addition Roux-en-Y gastric bypass and to a lesser extent sleeve gastrectomy (but not endoscopic gastroplasty) increase postprandial circulating incretins, reducing appetite. In conclusion the stomach's function is integral to the impact of the most effective pharmacological and procedural reversal of obesity related to the incretin revolution.

GLP-1 Receptor Agonists: A Promising Therapy for Modern Lifestyle Diseases with Unforeseen Challenges

Modern lifestyle diseases remain a persistent challenge in healthcare. Currently, about 422 million people worldwide are affected by diabetes, while 1 in 8 people are living with obesity. The development of glucagon-like peptide 1 receptor agonists (GLP-1RAs) has marked a significant milestone in treating these conditions. Interest in GLP-1RAs has grown due to evidence that, beyond their established role in diabetes management, these drugs influence other metabolic disorders. This is attributed to the fact that GLP-1 receptors are found in various healthy human tissues. However, a potential cause for concern is the expression of GLP-1 receptors in certain cancers. This review focuses on the most recent findings concerning the actions of GLP-1RAs, detailing their documented impact on the thyroid gland and pancreas. It addresses concerns about the long-term use of GLP-1RAs in relation to the development of pancreatitis, pancreatic cancer, and thyroid neoplasms by exploring the mechanisms and long-term effects in different patient subgroups and including data not discussed previously. This review was conducted through an examination of the literature available in the MedLine (PubMed) database, covering publications from 1978 to 10 May 2024. The collected articles were selected based on their relevance to studies of GLP-1 agonists and their effects on the pancreas and thyroid and assessed to meet the established inclusion criteria. The revised papers suggest that prolonged use of GLP-1RA could contribute to the formation of thyroid tumors and may increase the risk of acute inflammatory conditions such as pancreatitis, particularly in high-risk patients. Therefore, physicians should advise patients on the need for more frequent and detailed follow-ups.

Innovative Glucagon-based Therapies for Obesity

Obesity poses a significant global health challenge, with an alarming rise in prevalence rates. Traditional interventions, including lifestyle modifications, often fall short of achieving sustainable weight loss, ultimately leading to surgical interventions, which carry a significant burden and side effects. This necessitates the exploration of effective and relatively tolerable pharmacological alternatives. Among emerging therapeutic avenues, glucagon-based treatments have garnered attention for their potential to modulate metabolic pathways and regulate appetite. This paper discusses current research on the physiological mechanisms underlying obesity and the role of glucagon in energy homeostasis. Glucagon, traditionally recognized for its glycemic control functions, has emerged as a promising target for obesity management due to its multifaceted effects on metabolism, appetite regulation, and energy expenditure. This review focuses on the pharmacological landscape, encompassing single and dual agonist therapies targeting glucagon receptors (GcgRs), glucagon-like peptide-1 receptors (GLP-1Rs), glucose-dependent insulinotropic polypeptide receptors (GIPRs), amylin, triiodothyronine, fibroblast growth factor 21, and peptide tyrosine tyrosine. Moreover, novel triple-agonist therapies that simultaneously target GLP-1R, GIPR, and GcgR show promise in augmenting further metabolic benefits. This review paper tries to summarize key findings from preclinical and clinical studies, elucidating the mechanisms of action, safety profiles, and therapeutic potential of glucagon-based therapies in combating obesity and its comorbidities. Additionally, it explores ongoing research endeavors, including phase III trials, aimed at further validating the efficacy and safety of these innovative treatment modalities.

Fundamental Body Composition Principles Provide Context for Fat-Free and Skeletal Muscle Loss With GLP-1 RA Treatments

During weight loss, reductions in body mass are commonly described using molecular body components (eg, fat mass and fat-free mass [FFM]) or tissues and organs (eg, adipose tissue and skeletal muscle). While often conflated, distinctions between body components established by different levels of the 5-level model of body composition-which partitions body mass according to the atomic, molecular, cellular, tissue/organ, or whole-body level-are essential to recall when interpreting the composition of weight loss. A contemporary area of clinical and research interest that demonstrates the importance of these concepts is the discussion surrounding body composition changes with glucagon-like peptide-1 receptor agonists (GLP-1RA), particularly in regard to changes in FFM and skeletal muscle mass. The present article emphasizes the importance of fundamental principles when interpreting body composition changes experienced during weight loss, with a particular focus on GLP-1RA drug trials. The potential for obligatory loss of FFM due to reductions in adipose tissue mass and distribution of FFM loss from distinct body tissues are also discussed. Finally, selected countermeasures to combat loss of FFM and skeletal muscle, namely resistance exercise training and increased protein intake, are presented. Collectively, these considerations may allow for enhanced clarity when conceptualizing, discussing, and seeking to influence body composition changes experienced during weight loss.

The Impact of Gastrointestinal Hormones on Human Adipose Tissue Function

BACKGROUND

Obesity is a global issue, the development of which depends on many interacting factors. Among these, hormones secreted in the gastrointestinal tract play an important role. The aim of this review was to assess the impact of these hormones on the functions of adipose tissue.

METHODS

The analysis was based on the latest research concerning both adipose tissue and gastrointestinal hormones.

RESULTS

It was found that these hormones can significantly affect adipose tissue, both directly and indirectly. Some hormones, when secreted in excess, can stimulate adipose tissue formation processes, while others can inhibit them. The impact of hormones depends on the location and type of adipose tissue as well as the physiological state of the body. It should also be noted that no hormone acts in isolation but in close cooperation with other factors.

CONCLUSIONS

The relationship between gastrointestinal hormones and adipose tissue, and their role in obesity, is a complex and evolving field of study. Further research is necessary, particularly into the interactions between hormones and other factors, as well as their mutual interactions.

Dietary intake by patients taking GLP-1 and dual GIP/GLP-1 receptor agonists: A narrative review and discussion of research needs

Background

Obesity and type 2 diabetes mellitus (T2DM) are increasingly common in the United States and worldwide. Because both conditions are associated with serious health consequences, weight reduction is recommended by professional medical and nutrition societies to improve outcomes. Due to the striking efficacy of glucagon-like peptide receptor agonists (GLP-1RAs) and dual mechanism glucose-dependent insulinotropic polypeptide/glucagon-like peptide receptor agonists (GIP/GLP-1RAs) for weight reduction and glycemic control, there is increased utilization for patients with obesity and/or T2DM. Yet, the impact of these medications on dietary intake is less understood.

Methods

This narrative literature review summarizes clinical studies quantifying and characterizing dietary intake in people with obesity and/or T2DM using GLP-1 or GIP/GLP-1 RAs.

Results

Though data from these studies reveal that total caloric intake was reduced by 16-39 %, few studies evaluated the actual composition of the diet.

Conclusions

Further research is needed to understand the unique nutritional needs of adults on GLP-1 or dual GIP/GLP-1RAs and to support the development of nutritional guidelines for these individuals.

The role of glucagon-like peptide-1 receptor agonists (GLP1-RAs) in the management of the hypertensive patient with metabolic syndrome: a position paper from the Korean society of hypertension

Obesity is the one of the most important components of metabolic syndrome. Because obesity related hypertension accounts for two thirds of essential hypertension, managing obesity and metabolic syndrome is a crucial task in the management of hypertension. However, the current non-pharmacological therapies have limitations for achieving or maintaining ideal body weight. Recently, glucagon-like peptide-1 receptor agonists (GLP1-RAs) have demonstrated excellent weight control effects, accompanied by corresponding reductions in blood pressure. GLP1-RAs have shown cardiovascular and renal protective effects in cardiovascular outcome trials both in primary and secondary prevention. In this document, the Korean Society of Hypertension intends to remark the current clinical results of GLP1-RAs and recommend the government and health-policy makers to define obesity as a disease and to establish forward-looking policies for GLP1-RA treatment for obesity treatment, including active reimbursement policies.

Tirzepatide ameliorates eating behaviors regardless of prior exposure to glucagon-like peptide receptor agonists in Japanese patients with type 2 diabetes mellitus

AIMS

To investigate effects of tirzepatide, a dual receptor agonist for glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 (GLP-1), on eating behaviors.

METHODS

Eating behaviors were evaluated by using a validated questionnaire survey in 33 Japanese patients with type 2 diabetes mellitus (T2DM) (mean age: 51.8 years) who were treated with tirzepatide (2.5 mg/week for 4 weeks and then 5.0 mg/week) for 6 months (M).

RESULTS

Treatment with tirzepatide significantly decreased median hemoglobin A1c (HbA1c) (baseline/3 M/6 M: 7.3 %/6.0 %/5.8 %), mean body weight (BW) (baseline/3 M/6 M: 87.7 kg/82.0 kg/79.6 kg) and mean relative score of eating behaviors (baseline/3 M/6 M: 57.0/50.7/45.9). In the GLP-1 receptor agonist (GLP-1RA) naïve group (n = 20, men/women: 13/7), HbA1c and BW were continuously decreased up to 6 M. Changes in eating behaviors were mainly observed in the first 3 M. In the GLP-1RA non-naïve group (n = 13, men/women: 8/5), reductions in HbA1c and BW were predominant in the first 3 M, and changes in eating behaviors were observed up to 6 M. There were no significant correlations of changes in scores of eating behaviors with changes in glycemic control or those in BW.

CONCLUSIONS

Tirzepatide ameliorates eating behaviors as well as glycemic management and obesity in Japanese patients with T2DM, and the patterns of improvement are partially dependent on prior exposure to GLP-1RAs.

Cardiovascular Benefits of GLP-1 Receptor Agonists in Patients Living with Obesity or Overweight: A Meta-analysis of Randomized Controlled Trials

BACKGROUND

GLP-1 receptor agonists (GLP-1 RAs) have emerged as an effective therapeutic class for weight loss. However, the efficacy of these agents in reducing cardiovascular endpoints among patients living with obesity or overweight is unclear.

METHODS

We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) comparing GLP-1 RAs versus placebo in patients with obesity or overweight. We searched PubMed, Cochrane, and Embase databases. A random-effects model was used to calculate risk ratios (RRs) and mean differences (MDs), with 95% confidence intervals (CIs).

RESULTS

A total of 13 RCTs were included, with 30,512 patients. Compared with placebo, GLP-1 RAs reduced systolic blood pressure (MD - 4.76 mmHg; 95% CI - 6.03, - 3.50; p < 0.001; I2 = 100%) and diastolic blood pressure (MD - 1.41 mmHg; 95% CI - 2.64, - 0.17; p = 0.03; I2 = 100%). GLP-1 RA significantly reduced the occurrence of myocardial infarction (RR 0.72; 95% CI 0.61, 0.85; p < 0.001; I2 = 0%). There were no significant differences between groups in unstable angina (UA; RR 0.84; 95% CI 0.65, 1.07; p = 0.16; I2 = 0%), stroke (RR 0.91; 95% CI 0.74, 1.12; p = 0.38; I2 = 0%), atrial fibrillation (AF; RR 0.49; 95% CI 0.17, 1.43; p = 0.19; I2 = 22%), and deep vein thrombosis (RR 0.30; 95% CI 0.06, 1.40; p = 0.13; I2 = 0%).

CONCLUSIONS

In patients living with obesity or overweight, GLP-1 RA reduced systolic and diastolic blood pressure and the occurrence of myocardial infarction, with a neutral effect on the occurrence of UA, stroke, AF, and deep vein thrombosis.

REGISTRATION

PROSPERO identifier number CRD42023475226.

Potential Role of Phytochemicals as Glucagon-like Peptide 1 Receptor (GLP-1R) Agonists in the Treatment of Diabetes Mellitus

Currently, there is no known cure for diabetes. Different pharmaceutical therapies have been approved for the management of type 2 diabetes mellitus (T2DM), some are in clinical trials and they have been classified according to their route or mechanism of action. Insulin types, sulfonylureas, biguanides, alpha-glucosidase inhibitors, thiazolidinediones, meglitinides, sodium-glucose cotransporter type 2 inhibitors, and incretin-dependent therapies (glucagon-like peptide-1 receptor agonists: GLP-1R, and dipeptidyl peptidase 4 inhibitors: DPP-4). Although some of the currently available drugs are effective in the management of T2DM, the side effects resulting from prolonged use of these drugs remain a serious challenge. GLP-1R agonists are currently the preferred medications to include when oral metformin alone is insufficient to manage T2DM. Medicinal plants now play prominent roles in the management of various diseases globally because they are readily available and affordable as well as having limited and transient side effects. Recently, studies have reported the ability of phytochemicals to activate glucagon-like peptide-1 receptor (GLP-1R), acting as an agonist just like the GLP-1R agonist with beneficial effects in the management of T2DM. Consequently, we propose that careful exploration of phytochemicals for the development of novel therapeutic candidates as GLP-1R agonists will be a welcome breakthrough in the management of T2DM and the co-morbidities associated with T2DM.

Liraglutide 3.0 mg in the treatment of adults with obesity and prediabetes using real-world UK data: A clinical evaluation of a multi-ethnic population

UK guidelines recommend liraglutide 3.0 mg in adults treated within specialist weight management services with BMI ≥35 kg/m2, prediabetes and high cardiovascular disease risk. We aimed to clinically evaluate liraglutide 3.0 mg in specialist weight management services. We evaluated liraglutide 3.0 mg in weight management services at Guys and St Thomas' NHS Foundation Trust. Objective body weight (BW) was measured at baseline and 4 months, allowing classification as 'responders' (≥5% BW reduction) and 'non-responders' (<5% BW reduction). One hundred and twenty-one patients were evaluated. At 4 months, 76.0% attended follow-up (82.6% responders, 17.4% non-responders); BW (-8.6 kg, 95%CI:-9.8, -7.4 kg), BMI (-3.2 kg/m2, 95%CI: -3.6, -2.8) and %-BW (-6.6%, IQR: -8.8%, -5.2%) significantly reduced. In responders, HbA1c reduced by -5.0 mmol/mol (IQR: -7.0. -4.0 mmol/mol). In responders BW continued to reduce up to 12 months (4 m: -10.2 kg, p < .0001; 6 m: -15.6 kg, p < .0001; 9 m: -16.5 kg, p < .0001; 12 m: -16.7 kg, p < .01). Those of Black African and Caribbean ethnicity experienced less BW loss than those of white ethnicity (4.12 kg, p = .017) and had a greater attrition rate. In adults with obesity and prediabetes who are treated within specialist weight management services, liraglutide 3.0 mg reduces BW and HbA1c. Those of Black African and Caribbean ethnicity experienced less BW reduction and greater attrition at 4 months. Further evaluation of the ethnic differences in response to obesity pharmacotherapy is required.

Newer pharmacological interventions directed at gut hormones for obesity

The objective is to review the newer pharmacological interventions for obesity, specifically single, dual and triple incretin receptor agonists that are either available or in the pipeline for treatment of obesity. The three incretin receptor targets are glucagon like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide (GIP) and glucagon. There are several approved single or dual incretin agonists which can be administered subcutaneously daily (e.g., liraglutide) or weekly (e.g., semaglutide, dulaglutide, and exenatide QW), and other experimental dual or triple incretin agonists. Analogues of amylin, peptide YY and oxyntomodulin, as well as the combination of a GLP1R agonist and GIPR antagonist also are in development. Oral semaglutide (administered daily) is approved for type 2 diabetes mellitus and is on track for regulatory review for obesity. The review includes specifically perspectives on the effects of these mechanisms and pharmacological agents on gastric emptying, which contribute to satiation and weight loss, in addition to the established evidence on effects on central mechanisms controlling appetite. In the future, it is anticipated that small molecule GLP-1 receptor agonists (e.g., oral danuglipron) will be developed for treating obesity. These pharmacological agents are having significant impact on glycaemic control and obesity and on their co-morbidities.

Neuroscience of eating: Pace and portion control

Satiety-promoting neurons of the hindbrain have long been known for their role in meal termination. An innovative new study now reveals how different hindbrain cell types mediate appetite on distinct timescales.

Prevention of cardiorenal complications in people with type 2 diabetes and obesity

Traditional approaches to prevention of the complications of type 2 diabetes (T2D) and obesity have focused on reduction of blood glucose and body weight. The development of new classes of medications, together with evidence from dietary weight loss and bariatric surgery trials, provides new options for prevention of heart failure, chronic kidney disease, myocardial infarction, stroke, metabolic liver disease, cancer, T2D, and neurodegenerative disorders. Here I review evidence for use of lifestyle modification, SGLT-2 inhibitors, GLP-1 receptor agonists, selective mineralocorticoid receptor antagonists, and bariatric surgery, for prevention of cardiorenal and metabolic complications in people with T2D or obesity, highlighting the contributions of weight loss, as well as weight loss-independent mechanisms of action. Collectively, the evidence supports a tailored approach to selection of therapeutic interventions for T2D and obesity based on the likelihood of developing specific complications, rather than a stepwise approach focused exclusively on glycemic or weight control.

The role of gastric function in control of food intake (and body weight) in relation to obesity, as well as pharmacological and surgical interventions

PURPOSE

The objectives of this review are to summarize the role of gastric motor functions in the development of satiation (defined broadly as postprandial fullness) and satiety (reduced appetite or postponing desire to eat after a meal) and their impact on weight change. The specific topics are the methods of measurement of gastric emptying and accommodation and their impact on food intake, satiation, and satiety. A second focus contrasts bariatric surgery to endoscopic gastroplasty that alter gastric emptying and incretin responses in markedly divergent manners.

BACKGROUND

The hormone, GLP-1, retards gastric emptying and increases gastric accommodation through vagally-mediated effects. Indeed, these effects provide the basis for the association of altered gastric emptying in the appetite and weight loss responses to pharmacological interventions particularly by those acting on receptors of incretin agonists such as liraglutide and the dual agonists, tirzepatide and cotadutide, all of which retard gastric emptying. In fact, retardation of gastric emptying and gastrointestinal adverse effects have been shown to contribute in part to the weight loss in response to this class of pharmacological agents.

SUMMARY

The motor functions of the stomach are relevant to postprandial fullness and to interventions aimed at weight loss in people with obesity.

Review article: Pharmacologic management of obesity - updates on approved medications, indications and risks

BACKGROUND

Obesity has reached epidemic proportions, with >40% of the US population affected. Although traditionally managed by lifestyle modification, and less frequently by bariatric therapies, there are significant pharmacological advancements.

AIMS

To conduct a narrative review of the neurohormonal and physiological understanding of weight gain and obesity, and the development, clinical testing, indications, expected clinical outcomes, and associated risks of current FDA-approved and upcoming anti-obesity medications (AOMs).

METHODS

We conducted a comprehensive review in PubMed for articles on pathophysiology and complications of obesity, including terms 'neurohormonal', 'obesity', 'incretin', and 'weight loss'. Next, we searched for clinical trial data of all FDA-approved AOMs, including both the generic and trade names of orlistat, phentermine/topiramate, bupropion/naltrexone, liraglutide, and semaglutide. Additional searches were conducted for tirzepatide and retatrutide - medications expecting regulatory approval. Searches included combinations of terms related to mechanism of action, indications, side effects, risks, and future directions.

RESULTS

We reviewed the pathophysiology of obesity, including specific role of incretins and glucagon. Clinical data supporting the use of various FDA-approved medications for weight loss are presented, including placebo-controlled or, when available, head-to-head trials. Beneficial metabolic effects, including impact on liver disease, adverse effects and risks of medications are discussed, including altered gastrointestinal motility and risk for periprocedural aspiration.

CONCLUSION

AOMs have established efficacy and effectiveness for weight loss even beyond 52 weeks. Further pharmacological options, such as dual and triple incretins, are probable forthcoming additions to clinical practice for combating obesity and its metabolic consequences such as metabolic dysfunction-associated steatotic liver disease.

A bioactive compound digested chia protein is capable of modulating NFκB mediated hepatic inflammation in mice fed a high-fat diet

The consumption of diets high in saturated fat can induce damages in liver morphology and function, which leads to increased inflammation, oxidative stress, and hepatic steatosis. Chia seed (Salvia hispanica L.) is rich in protein, which provides bioactive peptides with potential benefits, including antioxidant and anti-inflammatory functions. Then, this study aimed to analyze the effect of digested total protein (DTP) of chia on inflammation, oxidative stress, and morphological changes in liver of C57BL/6 mice fed a diet rich in saturated fat. Male C57BL/6 mice (n = 8/group), 8 weeks old, were fed standard diet (AIN), high-fat diet (HF), standard diet added digested protein (AIN + DTP) or high-fat diet added digested protein (HF + DTP) for 8 weeks. In animals fed a high-fat diet, chia DTP was able to reduce weight gain, food efficiency ratio and hepatosomatic index. In addition, it presented antioxidant capacity, which reduced catalase activity and lipid peroxidation. DTP was also able to reduce hepatic inflammation by reducing p65-NFκB expression and IL-1β expression and quantification. The APSPPVLGPP peptide present in chia DTP presented binding capacity with PPAR-α, which contributed to the reduction of hepatic fat accumulation evidenced by histological analysis. Thus, chia DTP improved hepatic inflammatory and histological parameters, being an effective food in reducing the liver damage caused by a high-fat diet.

A randomized controlled trial investigating the effect of liraglutide on self-reported liking and neural responses to food stimuli in participants with obesity

BACKGROUND/OBJECTIVES

Obesity is a complex condition and the mechanisms involved in weight gain and loss are not fully understood. Liraglutide, a GLP-1 receptor agonist, has been demonstrated to successfully promote weight loss in patients with obesity (OB). Yet, it is unclear whether the observed weight loss is driven by an alteration of food liking. Here we investigated the effects of liraglutide on food liking and the cerebral correlates of liking in OB.

SUBJECTS/METHODS

This study was a randomized, single-center, double-blind, placebo-controlled, parallel group, prospective clinical trial. 73 participants with OB and without diabetes following a multidisciplinary weight loss program, were randomly assigned (1:1) to receive liraglutide 3.0 mg (37.40 ± 11.18 years old, BMI = 35.89 ± 3.01 kg) or a placebo (40.04 ± 14.10 years old, BMI = 34.88 ± 2.87 kg) subcutaneously once daily for 16 weeks.

INTERVENTIONS/METHODS

We investigated liking during food consumption. Participants reported their hedonic experience while consuming a high-calorie food (milkshake) and a tasteless solution. The solutions were administered inside the scanner with a Magnetic Resonance Imaging (MRI)-compatible gustometer to assess neural responses during consumption. The same procedure was repeated during the pre- and post-intervention sessions.

RESULTS

None of the effects involving the intervention factor reached significance when comparing liking between the pre- and post-intervention sessions or groups. Liking during food reward consumption was associated with the activation of the ventromedial prefrontal cortex (vmPFC) and the amygdala. The liraglutide group lost more weight (BMI post-pre = -3.19 ± 1.28 kg/m2) than the placebo group (BMI post-pre = -0.60 ± 1.26 kg/m2).

CONCLUSIONS

These results suggest that liraglutide leads to weight loss without self-report or neural evidence supporting a concomitant reduction of food liking in participants with OB.

Restoring autophagic function: a case for type 2 diabetes mellitus drug repurposing in Parkinson's disease

Parkinson's disease (PD) is a predominantly idiopathic pathological condition characterized by protein aggregation phenomena, whose main component is alpha-synuclein. Although the main risk factor is ageing, numerous evidence points to the role of type 2 diabetes mellitus (T2DM) as an etiological factor. Systemic alterations classically associated with T2DM like insulin resistance and hyperglycemia modify biological processes such as autophagy and mitochondrial homeostasis. High glucose levels also compromise protein stability through the formation of advanced glycation end products, promoting protein aggregation processes. The ability of antidiabetic drugs to act on pathways impaired in both T2DM and PD suggests that they may represent a useful tool to counteract the neurodegeneration process. Several clinical studies now in advanced stages are looking for confirmation in this regard.

Do GLP-1 Analogs Have a Place in the Treatment of PCOS? New Insights and Promising Therapies

Polycystic ovary syndrome (PCOS) is the most prevalent endocrinopathy in women of reproductive age. This condition is characterized by hyperandrogenism and either oligo- or anovulation. PCOS patients often present comorbidities such as obesity, insulin resistance, impaired glucose metabolism, dyslipidemia, hypertension, metabolic syndrome, and an increased risk of diabetes. Given the profound implications of metabolic impairment in PCOS, the accurate diagnosis and management of these facets are imperative. The first-line approach to treatment involves lifestyle modifications, including dietary adjustments and exercise aimed at achieving weight loss, a strategy consistently emphasized across the literature. Supplementation with probiotics, vitamin D, and L-carnitine have also provided additional benefits to patients. In select cases, pharmacological interventions are needed for optimal therapeutic results. The most common medications used in PCOS include metformin, thiazolidinediones, inositols, and two classes of antidiabetic agents: dipeptidyl peptidase-IV (DPP-IV) inhibitors, and sodium-glucose cotransporter-2 (SGLT-2) inhibitors. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are a new addition to the therapeutic arsenal for the metabolic management of PCOS. GLP-1 receptor agonists cause insulin release in a glucose-dependent manner, yielding clinical benefits such as heightened satiety, reduced appetite, and appetite regulation. GLP-1RAs have demonstrated efficacy in reducing glycated hemoglobin levels and promoting weight loss while ameliorating hyperlipidemia. Prior to initiating GLP-1RA therapy, patients should undergo screening for contraindications, including history of pancreatitis, diabetic retinopathy, or thyroid cancer. The effects of treatment should be monitored using laboratory testing and body weight measurements. Effective communication between clinician and patient should be maintained with regular check-in for a period of 6 to 12 months.

The Weight-loss Effect of GLP-1RAs Glucagon-Like Peptide-1 Receptor Agonists in Non-diabetic Individuals with Overweight or Obesity: A Systematic Review with Meta-Analysis and Trial Sequential Analysis of Randomized Controlled Trials

BACKGROUND

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are new drugs for the treatment of obesity.

OBJECTIVE

To assess the weight-loss effects of GLP-1RAs in the treatment of patients with overweight or obesity without diabetes.

METHODS

This is a systematic review with meta-analysis and trial sequential analysis. PubMed, Embase, and Cochrane Central Register of Controlled Trials were searched from their inception to January 1, 2022. Eligible trials report on outcomes including body weight (BW), body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), or total body fat (TBF). Mean differences (MDs) and standardized mean differences (SMDs) were summarized using random-effects models.

RESULTS

Forty-one trials involving 15,135 participants were included. Compared with controls, GLP-1RAs significantly reduced BW (MD -5.319 kg, 95% CI: -6.465, -4.174), BMI (MD -2.373 kg/m2, 95% CI: -2.821, -1.924), WC (MD -4.302 cm, CI:-5.185 to -3.419), WHR (MD -0.011, CI -0.015 to -0.007), but not TBF (MD -0.320%, CI -1.420 to -0.780). Trial sequential analysis (TSA) supported conclusive evidence of the effects of GLP-1RAs on BW, BMI, and WC for weight loss. GLP-1RAs had nonlinear dose-response relationships with weight loss. Extensive sensitivity analyses demonstrated the robustness of the results, though the GRADE certainty of the evidence ranged from high to very low. High to moderate GRADE certainty of evidence suggested semaglutide as the most effective GLP-1RA agent, with the best efficacy and low to moderate risk of adverse effects.

CONCLUSIONS

The present study provides conclusive evidence for the effect of GLP-1RAs on weight loss in a nonlinear dose-response manner in patients with obesity or overweight without diabetes. In terms of changes in BW, BMI, and WC, there is firm evidence for the overall weight-loss effects of GLP-1RAs. Of the GLP-1RAs, semaglutide might be the most effective agent.

Current Role and Potential of Polymeric Biomaterials in Clinical Obesity Treatment

The rise of obesity and associated fatal diseases has taken a massive toll worldwide. Despite the existing pharmaceuticals and bariatric surgeries, these approaches manifest limited efficacy or accompany various side effects. Therefore, researchers seek to facilitate the prolonged and specific delivery of therapeutics. Or else, to mimic the essential part of "gastric bypass" by physically blocking excessive absorption via less invasive methods. To achieve these goals, polymeric biomaterials have gained tremendous interest recently. They are known for synthesizing hydrogels, microneedle patches, mucoadhesive coatings, polymer conjugates, and so forth. In this Review, we provide insights into the current studies of polymeric biomaterials in the prevention and treatment of obesity, inspiring future improvements in this regime of study.

Effect of the glucagon-like peptide-1 receptor agonist liraglutide, compared to caloric restriction, on appetite, dietary intake, body fat distribution and cardiometabolic biomarkers: A randomized trial in adults with obesity and prediabetes

AIMS

To investigate the hypothesis that weight loss with the glucagon-like peptide-1 receptor agonist (GLP-1RA) liraglutide alone would lead to a greater reduction in the proportion of fat to lean tissue mass when compared to caloric restriction (CR) alone, as well as when compared to treatment with sitagliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor, that also enhances GLP-1 activity - to determine the independent effects of each treatment.

METHODS

A total of 88 adults with obesity and prediabetes were randomized to 14 weeks of intervention with CR (-390 kcal/d), liraglutide (1.8 mg/d), or the dipeptidyl peptidase-4 inhibitor sitagliptin (100 mg/d) as a weight-neutral comparator. Changes between groups in appetite and hunger ratings measured via visual analogue scales, dietary intakes, body weight, body composition via dual energy x-ray absorptiometry, and resting energy expenditure via indirect calorimetry were assessed using the Kruskal-Wallis test or Pearson's chi-squared test.

RESULTS

Weight loss ≥5% of baseline body weight occurred in 44% of participants in the CR group, 22% of the liraglutide group and 5% of the sitagliptin group (p = 0.02). The ratio of fat to lean mass decreased by 6.5% in the CR group, 2.2% in the liraglutide group, and 0% in the sitagliptin group (p = 0.02). Visceral fat reduced by 9.5% in the CR group, 4.8% in the liraglutide group, and 0% in the sitagliptin group (p = 0.04). A spontaneous reduction in dietary simple carbohydrates in the CR group was associated with improved homeostatic model assessment of insulin resistance score (HOMA-IR).

CONCLUSIONS

Although both liraglutide and CR are valuable strategies for cardiometabolic risk reduction, CR was associated with greater weight loss and more favourable improvements in body composition than treatment with liraglutide alone. Differences in the response to each of these interventions enables patients to be stratified to the most optimal intervention for their personal risk factors.

No Evidence That Circulating GLP-1 or PYY Are Associated with Increased Satiety during Low Energy Diet-Induced Weight Loss: Modelling Biomarkers of Appetite

Bariatric surgery and pharmacology treatments increase circulating glucagon-like peptide-1 (GLP-1) and peptide YY (PYY), in turn promoting satiety and body weight (BW) loss. However, the utility of GLP-1 and PYY in predicting appetite response during dietary interventions remains unsubstantiated. This study investigated whether the decrease in hunger observed following low energy diet (LED)-induced weight loss was associated with increased circulating 'satiety peptides', and/or associated changes in glucose, glucoregulatory peptides or amino acids (AAs). In total, 121 women with obesity underwent an 8-week LED intervention, of which 32 completed an appetite assessment via a preload challenge at both Week 0 and Week 8, and are reported here. Visual analogue scales (VAS) were administered to assess appetite-related responses, and blood samples were collected over 210 min post-preload. The area under the curve (AUC_0-210), incremental AUC (iAUC_0-210), and change from Week 0 to Week 8 (∆) were calculated. Multiple linear regression was used to test the association between VAS-appetite responses and blood biomarkers. Mean (±SEM) BW loss was 8.4 ± 0.5 kg (-8%). Unexpectedly, the decrease in ∆AUC_0-210 hunger was best associated with decreased ∆AUC_0-210 GLP-1, GIP, and valine (p < 0.05, all), and increased ∆AUC_0-210 glycine and proline (p < 0.05, both). The majority of associations remained significant after adjusting for BW and fat-free mass loss. There was no evidence that changes in circulating GLP-1 or PYY were predictive of changes in appetite-related responses. The modelling suggested that other putative blood biomarkers of appetite, such as AAs, should be further investigated in future larger longitudinal dietary studies.

GLP-1 analogs and regional adiposity: A systematic review and meta-analysis

BACKGROUND

Glucagon-like peptide 1 (GLP-1) analogs regulate body weight and liver steatosis. Different body adipose tissue (AT) depots exhibit biological variability. Accordingly, GLP-1 analog effects on AT distribution are unclear.

OBJECTIVES

To investigate GLP1-analog effects on adiposity distribution.

SEARCH METHODS

PubMed, Cochrane, and Scopus databases were screened for eligible randomized human trials. Pre-defined endpoints included visceral AT (VAT), subcutaneous AT (SAT), total AT (TAT), epicardial AT (EAT), liver AT (LAT), and waist-to-hip ratio (W:H). Search was conducted until May 17, 2022.

DATA COLLECTION AND ANALYSIS

Data extraction and bias assessment were performed by two independent investigators. Treatment effects were estimated using random effects models. Analyses were performed on Review Manager v5.3.

MAIN RESULTS

Out of the 367 screened studies, 45 were included in the systematic review and 35 were used in the meta-analysis. GLP-1 analogs reduced VAT, SAT, TAT, LAT, and EAT, with non-significant effects on W:H. Overall bias risk was low.

CONCLUSIONS

GLP-1 analog treatment reduces TAT, affecting most studied AT depots, including the pathogenic VAT, EAT, and LAT. GLP-1 analogs may have significant roles in combating metabolic, obesity-associated diseases via reductions of key AT depot volumes.