Energy balance in hypothalamic obesity in response to treatment with a once-weekly GLP-1 receptor agonist

Use of glucagon-like-peptide 1 receptor agonist in the treatment of childhood obesity

PURPOSE OF REVIEW

Pediatric obesity is a growing epidemic. Lifestyle modifications remain central to obesity treatment, however pharmacologic options have gained traction, particularly glucagon-like peptide-1 receptor agonists (GLP-1RA). This review aims to summarize evidence on the use of GLP-1RAs in the management of pediatric obesity, physiological mechanisms of action of GLP-1RAs and their role in appetite regulation and glucose homeostasis and address the challenges and special considerations surrounding GLP-1RA use.

RECENT FINDINGS

Recent studies have highlighted the efficacy of GLP-1RAs, such as exenatide, liraglutide, and semaglutide, in promoting weight loss and improving metabolic parameters in children and adolescents. GLP-1RA's efficacy extends beyond glycemic control to include weight loss mechanisms such as delayed gastric emptying (gastroparesis), and appetite suppression. Semaglutide, the newest GLP-1RA, holds potential for substantial weight loss in adolescents and demonstrates a similar safety and efficacy as seen in adults.

SUMMARY

GLP-1RAs may offer a promising adjunct therapy for pediatric obesity, particularly in cases where lifestyle interventions alone are insufficient. However, further research is needed to elucidate long-term safety and efficacy outcomes and to address potential disparities in access to care. Overall, this review highlights the relevance and timeliness of incorporating GLP-1RAs into the comprehensive management of pediatric obesity.

Evaluating the effectiveness and underlying mechanisms of incretin-based treatments for hypothalamic obesity: A narrative review

Background

Hypothalamic obesity represents a clinical condition within the broader spectrum of obesity that frequently eludes detection and appropriate diagnosis. This subset of obesity is characterized by a dearth of established predictive markers and a paucity of standardized therapeutic protocols. The advent and rising prominence of glucagon-like peptide-1 (GLP-1) receptor agonists in the obesity treatment landscape present novel therapeutic avenues for hypothalamic obesity management. Nonetheless, critical inquiries persist concerning the efficacy of GLP-1 receptor (GLP-1R) agonists in this context, particularly regarding their central mechanisms of action and specific impact on hypothalamic obesity.

Methods

In this narrative review, we concentrate on analyzing research papers that delineate the detection and function of GLP-1 receptors across various hypothalamic and cerebral regions. Additionally, we examine clinical research papers and reports detailing the application of GLP-1 receptor agonists in treating hypothalamic obesity. Furthermore, we include a concise presentation of a clinical case from our unit for contextual understanding.

Results

Currently, the clinical evidence supporting the efficacy of GLP-1 receptor agonists in hypothalamic obesity, as well as the diverse characteristics of this obesity subtype, remains insufficient. Preliminary data suggest that GLP-1R agonists might offer an effective treatment option, albeit with variable outcomes, particularly in younger patient cohorts. From a mechanistic perspective, the presence of GLP-1 receptors in various hypothalamic and broader brain regions potentially underpins the efficacy of GLP-1R agonists, even in instances of hypothalamic damage. Nevertheless, additional research is imperative to establish the functional relevance of these receptors in said brain regions.

Conclusion

GLP-1R agonists represent a potential therapeutic option for patients with hypothalamic obesity. However, further clinical and basic/translational research is essential to validate the efficacy of these drugs across different presentations of hypothalamic obesity and to understand the functionality of GLP-1R in the diverse brain regions where they are expressed.

The role of glucagon-like peptide 1 receptor agonists for weight control in individuals with acquired hypothalamic obesity-A systematic review

Hypothalamic obesity does not respond well to conventional interventions for obesity. GLP-1 receptor agonists have mechanisms independent of the hypothalamus which may be potentially beneficial for managing hypothalamic obesity. This systematic review summarizes the efficacy and safety of GLP-1 receptor agonists use in hypothalamic obesity. A PRISMA-compliant systematic review was performed. Data was extracted from included studies and analysed based on change in weight, body mass index, glycaemic control, satiety, and safety profile with GLP-1 receptor agonist use. Ten studies comprising 5 case reports, 4 case series and 1 randomized-controlled trial included 54 patients (24 males, 30 females) with mean age of 25.2 (range 13-71) years with hypothalamic obesity who had received GLP-1 receptor agonists (exenatide = 48, liraglutide = 5 and dulaglutide = 1) over a mean duration of treatment of 12 (range 3-51) months. Mean weight reduction of 7.4 (SD 7.92) kg was observed in patients in whom weight was reported, with 85.7% of patients experiencing weight loss. All patients on liraglutide had weight reduction post-therapy. The sole trial had reported a non-significant reduction in BMI post-exenatide. Glycaemic control had either improved/maintained in all patients in whom this was measured. The main side effects of GLP-1 receptor agonist in individuals with hypothalamic obesity were nausea and vomiting; there were no major safety concerns. Based on limited published experience, GLP-1RA may be effective and safe for weight control in hypothalamic obesity, with the added benefit of improved glycaemic control in those with concurrent diabetes mellitus.

Bardet-Biedl syndrome: A clinical overview focusing on diagnosis, outcomes and best-practice management

Bardet-Biedl syndrome (BBS) is a genetic disorder characterized by early-onset obesity, polydactyly, genital and kidney anomalies, developmental delay and vision loss due to rod-cone dystrophy. BBS is an autosomal recessive disorder with >20 implicated genes. The genotype-phenotype relationship in BBS is not clear, and there may be additional modifying factors. The underlying mechanism is dysfunction of primary cilia. In BBS, receptor trafficking in and out of the cilia is compromised, affecting multiple organ systems. Along with early-onset obesity, hyperphagia is a prominent symptom and contributes significantly to clinical morbidity and caregiver burden. While there is no cure for BBS, setmelanotide is a new pharmacotherapy approved for treatment of obesity in BBS. The differential diagnosis for BBS includes other ciliopathies, such as Alstrom syndrome, and other genetic obesity syndromes, such as Prader-Willi syndrome. Careful clinical history and genetic testing can help determine the diagnosis and a multidisciplinary team is necessary to guide clinical management.

Acquired hypothalamic obesity: A clinical overview and update

Hypothalamic obesity (HO) is a rare and complex disorder that confers substantial morbidity and excess mortality. HO is a unique subtype of obesity characterized by impairment in the key brain pathways that regulate energy intake and expenditure, autonomic nervous system function, and peripheral hormonal signalling. HO often occurs in the context of hypothalamic syndrome, a constellation of symptoms that follow from disruption of hypothalamic functions, for example, temperature regulation, sleep-wake circadian control, and energy balance. Genetic forms of HO, including the monogenic obesity syndromes, often impact central leptin-melanocortin pathways. Acquired forms of HO occur as a result of tumours impacting the hypothalamus, such as craniopharyngioma, surgery or radiation to treat those tumours, or other forms of hypothalamic damage, such as brain injury impacting the region. Risk for severe obesity following hypothalamic injury is increased with larger extent of hypothalamic damage or lesions that contain the medial and posterior hypothalamic nuclei that support melanocortin signalling pathways. Structural damage in these hypothalamic nuclei often leads to hyperphagia, central insulin and leptin resistance, decreased sympathetic activity, low energy expenditure, and increased energy storage in adipose tissue, the collective effect of which is rapid weight gain. Individuals with hyperphagia are perpetually hungry. They do not experience fullness at the end of a meal, nor do they feel satiated after meals, leading them to consume larger and more frequent meals. To date, most efforts to treat HO have been disappointing and met with limited, if any, long-term success. However, new treatments based on the distinct pathophysiology of disturbed energy homeostasis in acquired HO may hold promise for the future.

Impact of exenatide on weight loss and eating behavior in adults with craniopharyngioma-related obesity: the CRANIOEXE randomized placebo-controlled trial

IMPORTANCE

A major issue in the management of craniopharyngioma-related obesity (CRO) is the ineffectiveness of the current therapeutic approaches.

OBJECTIVE

To study the efficacy of glucagon-like peptide-1 analogs compared with placebo in adults with obesity CRO.

DESIGN

A double-blind multicenter superiority randomized clinical in trial in two parallel arms.

SETTING

Eleven French University Hospital Centers.

PARTICIPANTS

Adults with CRO (body mass index > 30 kg/m²) without the sign of recurrence of craniopharyngioma in the past year.

INTERVENTIONS

Exenatide or placebo injected subcutaneously twice a day during 26 weeks.

MAIN OUTCOMES AND MEASURES

The primary outcome was the mean change in body weight at week 26 in the intention-to-treat population. Secondary outcomes were eating behavior, calories intake, energy expenditure, cardiovascular, metabolic risk factor, quality of life, and the tolerance profile.

RESULTS

At week 26, weight decreased from baseline by a mean of -3.8 (SD 4.3) kg for exenatide and -1.6 (3.8) kg for placebo. The adjusted mean treatment difference was -3.1 kg (95% confidence interval [CI] -7.0 to 0.7, P = 0.11). Results were compatible with a higher reduction of hunger score with exenatide compared with placebo (estimated treatment difference in change from baseline to week 26: -2.3, 95% CI -4.5 to -0.2), while all other outcomes did not significantly differ between groups. Adverse events were more common with exenatide versus placebo, and occurred in, respectively, 19 (95%) participants (108 events) and 14 (70%) participants (54 events).

CONCLUSIONS AND RELEVANCE

Combined with intensive lifestyle interventions, a 26-week treatment with exenatide was not demonstrated superior to placebo to treat craniopharyngioma-related obesity.

Modifiable Cardiometabolic Risk Factors in Survivors of Childhood Cancer: JACC: CardioOncology State-of-the-Art Review

The growing community of childhood cancer survivors faces a heavy burden of late onset morbidities and mortality, with cardiovascular diseases being the leading noncancer cause. In addition to demographics and cancer treatment exposures, which cannot be altered, cardiometabolic risk factors (obesity, hypertension, diabetes, and dyslipidemia) and frailty potentiate the risk of morbidity and mortality associated with chronic health conditions. Important opportunities exist to target these risk factors and improve late health outcomes for survivors. Unfortunately, limited evidence exists on the optimal methods to prevent, screen, and treat cardiometabolic risk factors among survivors, resulting in significant underdiagnosis and undertreatment. In this review, we discuss the prevalence of, risk factors for, current survivor-specific recommendations, and gaps in knowledge to mitigate potentially modifiable cardiometabolic risk factors and frailty among survivors of childhood cancer.

Treatment of hypothalamic obesity in people with hypothalamic injury: new drugs are on the horizon

Hypothalamic obesity (HO) is a complex and rare disorder affecting multiple regulatory pathways of energy intake and expenditure in the brain as well as the regulation of the autonomic nervous system and peripheral hormonal signaling. It can be related to monogenic obesity syndromes which often affect the central leptin-melanocortin pathways or due to injury of the hypothalamus from pituitary and hypothalamic tumors, such as craniopharyngioma, surgery, trauma, or radiation to the hypothalamus. Traditional treatments of obesity, such as lifestyle intervention and specific diets, are still a therapeutic cornerstone, but often fail to result in meaningful and sustained reduction of body mass index. This review will give an update on pharmacotherapies of HO related to hypothalamic injury. Recent obesity drug developments are promising for successful obesity intervention outcomes.

Evaluating Eating Behaviour, Energy Homeostasis, and Obesity in Childhood-Onset Craniopharyngioma: A Feasibility Study

INTRODUCTION

Craniopharyngiomas are rare brain tumours (incidence 1.1-1.7 cases/million/year). Although non-malignant, craniopharyngioma causes major endocrine and visual morbidities including hypothalamic obesity, yet mechanisms leading to obesity are poorly understood. This study investigated the feasibility and acceptability of eating behaviour measures in patients with craniopharyngioma to inform the design of future trials.

METHODS

Patients with childhood-onset craniopharyngioma and controls matched for sex, pubertal stage, and age were recruited. After an overnight fast, participants received the following measures: body composition, resting metabolic rate, oral glucose tolerance test including magnetic resonance imaging (patients only), appetite ratings, eating behaviour, and quality of life questionnaires, ad libitum lunch, and an acceptability questionnaire. Data are reported as median ± IQR, with effect size measure (Cliff's delta) and Kendall's tau for correlations, due to the small sample size.

RESULTS

Eleven patients (median age = 14 years; 5 F/6 M) and matched controls (median age = 12 years; 5 F/6 M) were recruited. All patients had received surgery, and 9/11 also received radiotherapy. Hypothalamic damage post-surgery was graded (Paris grading): grade 2 n = 6; grade 1 n = 1; grade 0 n = 2. The included measures were deemed highly tolerable by participants and their parent/carers. Preliminary data suggest a difference in hyperphagia between patients and controls (d = 0.5), and a relationship between hyperphagia with body mass index standard deviation score (BMISDS) in patients (τ = 0.46).

DISCUSSION

These findings demonstrate that eating behaviour research is feasible and acceptable to craniopharyngioma patients and there is an association between BMISDS and hyperphagia in patients. Thus, food approach and avoidance behaviours may be useful targets for interventions to manage obesity in this patient group.

Contemporary Biological Insights and Clinical Management of Craniopharyngioma

Craniopharyngiomas (CPs) are clinically aggressive tumors because of their invasive behavior and recalcitrant tendency to recur after therapy. There are 2 types based on their distinct histology and molecular features: the papillary craniopharyngioma (PCP), which is associated with BRAF-V600E mutations and the adamantinomatous craniopharyngioma (ACP), characterized by mutations in CTNNB1 (encoding β-catenin). Patients with craniopharyngioma show symptoms linked to the location of the tumor close to the optic pathways, hypothalamus, and pituitary gland, such as increased intracranial pressure, endocrine deficiencies, and visual defects. Treatment is not specific and mostly noncurative, and frequently includes surgery, which may achieve gross total or partial resection, followed by radiotherapy. In cystic tumors, frequent drainage is often required and intracystic instillation of drugs has been used to help manage cyst refilling. More recently targeted therapies have been used, particularly in PCP, but also now in ACP and clinical trials are underway or in development. Although patient survival is high, the consequences of the tumor and its treatment can lead to severe comorbidities resulting in poor quality of life, in particular for those patients who bear tumors with hypothalamic involvement. Accordingly, in these patients at risk for the development of a hypothalamic syndrome, hypothalamus-sparing treatment strategies such as limited resection followed by irradiation are recommended. In this review, we provide an update on various aspects of CP, with emphasis on recent advances in the understanding of tumor pathogenesis, clinical consequences, management, and therapies.

Approach to the Patient With Hypothalamic Obesity

Hypothalamic obesity (HO) is defined as abnormal weight gain due to physical destruction of the hypothalamus. Suprasellar tumors, most commonly craniopharyngiomas, are a classic cause of HO. HO often goes unnoticed initially as patients, families, and medical teams are focused on oncologic treatments and management of panhypopituitarism. HO is characterized by rapid weight gain in the first year after hypothalamic destruction followed by refractory obesity due to an energy imbalance of decreased energy expenditure without decreased food intake. Currently available pharmacotherapies are less effective in HO than in common obesity. While not a cure, dietary interventions, pharmacotherapy, and bariatric surgery can mitigate the effects of HO. Early recognition of HO is necessary to give an opportunity to intervene before substantial weight gain occurs. Our goal for this article is to review the pathophysiology of HO and to discuss available treatment options and future directions for prevention and treatment.

Pharmacological Support for the Treatment of Obesity-Present and Future

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

Liraglutide for Weight Management in Children and Adolescents With Prader-Willi Syndrome and Obesity

CONTEXT

Prader-Willi syndrome (PWS) is characterized by lack of appetite control and hyperphagia, leading to obesity. Pharmacological options for weight management are needed.

OBJECTIVE

To determine whether liraglutide treatment for weight management is superior to placebo/no treatment in pediatric individuals with PWS.

METHODS

This was a multicenter, 52-week, placebo-controlled trial with a 16-week double-blinded period. Adolescents (n = 31, aged 12-17 years; Tanner stage 2-5) and children (n = 24, aged 6-11 years; Tanner stage <2) with PWS and obesity were included. Patients were randomized 2:1 to liraglutide 3.0 mg (or maximum-tolerated dose) or placebo for 16 weeks, after which placebo was stopped. Liraglutide was continued for 52 weeks. All patients followed a structured diet and exercise program throughout the trial. The coprimary endpoints were change in body mass index (BMI) standard deviation score (SDS) from baseline to 16 and 52 weeks. Secondary endpoints included other weight-related parameters, hyperphagia, and safety.

RESULTS

Change in BMI SDS from baseline to weeks 16 and 52 was not significantly different between treatments in adolescents (estimated treatment difference: -0.07 at week 16 and -0.14 at week 52) and children (-0.06 and -0.07, respectively). Changes in other weight-related parameters between treatments were not significant. At week 52, hyperphagia total and drive scores were lower in adolescents treated with liraglutide vs no treatment. The most common adverse events with liraglutide were gastrointestinal disorders.

CONCLUSION

Although the coprimary endpoints were not met, changes in hyperphagia total and drive scores in adolescents warrant further studies on liraglutide in this population.

Glucose-lowering drugs with cardiovascular benefits as modifiers of critical elements of the human life history

The life history theory assumes that all organisms are under selective pressure to harvest external resources and allocate them to maximise fitness: only organisms making the best use of energy obtain the greatest fitness benefits. The trade-off of energy spans four functions: maintenance, growth, reproduction, and defence against pathogens. The innovative antihyperglycaemic agents glucagon-like peptide 1 (GLP-1) receptor agonists and sodium-glucose cotransporter 2 (SGLT2) inhibitors decrease bodyweight and have the potential to counter low-grade inflammation. These key activities could rewire two components of the life history theory operative in adulthood-ie, maintenance and defence. In this Personal View, we postulate that the benefits of these medications on the cardiovascular system, beyond their glucose-lowering effects, could be mediated by the reduction of the maintenance cost driven by obesity and efforts spent on blunting low-grade inflammation.

Hypothalamic syndrome

Hypothalamic syndrome (HS) is a rare disorder caused by disease-related and/or treatment-related injury to the hypothalamus, most commonly associated with rare, non-cancerous parasellar masses, such as craniopharyngiomas, germ cell tumours, gliomas, cysts of Rathke's pouch and Langerhans cell histiocytosis, as well as with genetic neurodevelopmental syndromes, such as Prader-Willi syndrome and septo-optic dysplasia. HS is characterized by intractable weight gain associated with severe morbid obesity, multiple endocrine abnormalities and memory impairment, attention deficit and reduced impulse control as well as increased risk of cardiovascular and metabolic disorders. Currently, there is no cure for this condition but treatments for general obesity are often used in patients with HS, including surgery, medication and counselling. However, these are mostly ineffective and no medications that are specifically approved for the treatment of HS are available. Specific challenges in HS are because the syndrome represents an adverse effect of different diseases, and that diagnostic criteria, aetiology, pathogenesis and management of HS are not completely defined.