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.

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

BACKGROUND/OBJECTIVES: Hypothalamic obesity (HO) frequently occurs following suprasellar tumors from a combination of decreased energy expenditure and increased energy intake. Glucagon-like peptide-1 receptor agonist (GLP1RA) therapy is associated with increased satiety and energy expenditure. We hypothesized GLP1RA therapy in patients with HO would cause both lower energy intake and increased energy expenditure. SUBJECTS/METHODS: Forty-two patients aged 10-26 years (median 16 years) with HO with suprasellar tumors were randomized to GLP1RA (exenatide extended release once-weekly, ExQW, n = 23) or placebo (n = 19). Thirty seven (81%) patients completed the 36-week double-blind placebo-controlled trial. Total energy expenditure (TEE) was measured with doubly labeled water, physical activity was assessed with actigraphy, and intake was estimated with ad libitum buffet meal. Results are presented as adjusted mean between-group difference. RESULTS: As compared with treatment with placebo, treatment with ExQW was associated with decreased energy intake during a buffet meal (-1800 kJ (-430 kcal), 95% CI -3 184 to -418 kJ, p = 0.02). There were no significant differences in physical activity between groups. ExQW (vs. placebo) treatment was associated with a decrease in TEE (-695 kJ/day (-166 kcal/day), 95% CI -1 130 to -264 kJ/day, p < 0.01, adjusted for baseline TEE). The treatment effect was still significant after further adjustment for change in body composition (-372 kJ/day (-89 kcal/day), 95% CI -699 to -42 kJ/day, p = 0.04) or change in leptin (-695 kJ/day (-166 kcal/day), 95% CI -1 130 to -264 kJ/day, p < 0.01). This decrease in TEE occurred despite an increase in lean mass and fat mass (1.7 vs. 1.3 kg lean mass, p = 0.88 and 1.5 vs. 4.6 kg fat mass, p = 0.04, ExQW vs. placebo). CONCLUSIONS: Treatment with a GLP1RA was associated with a decrease in food intake but also a decrease in TEE that was disproportionate to change in body composition.

Novel Long-Acting Oxytocin Analog with Increased Efficacy in Reducing Food Intake and Body Weight.

Oxytocin (OXT) analogues have been designed to overcome the limitation of the short half-life of the native OXT peptide. Here, we tested ASK2131 on obesity related outcomes in diet-induced obese (DIO) Sprague Dawley rats. In vitro function assays were conducted. The effects of daily subcutaneous injections of ASK2131 vs. OXT and pair-feeding were assessed on food intake and body weight in vivo. ASK2131 is a longer-lasting OXT analog with improved pharmacokinetics compared to OXT (T1/2: 2.3 vs. 0.12 h). In chronic 22-day administration, ASK2131 was administered at 50 nmol/kg, while OXT doses were titrated up to 600 nmol/kg because OXT appeared to be less effective at reducing energy intake relative to ASK2131 at equimolar doses. After 22 days, vehicle-treated animals gained 4.5% body weight, OXT rats maintained their body weight, while those treated with ASK2131 declined in weight continuously over the 22-day period, leading to a 6.6 ± 1.3% reduction (mean ± standard error) compared to baseline. Compared to their pair-fed counterparts, ASK2131-treated rats showed a more pronounced reduction in body weight through most of the study. In summary, ASK2131 is a promising OXT-based therapeutic, with extended in vivo stability and improved potency leading to a profound reduction in body weight partly explained by reduced food intake.

MRI measures of hypothalamic injury are associated with glucagon-like peptide-1 receptor agonist treatment response in people with hypothalamic obesity.

AIM: To evaluate whether neuroimaging-delineated regions of hypothalamic injury are associated with a differential treatment response to a glucagon-like peptide-1 receptor agonist (GLP-1RA) in patients with hypothalamic obesity (HO). MATERIALS AND METHODS: We performed a prespecified secondary analysis of a randomized, multicentre, double-blind, placebo-controlled trial of people aged 10-25 years with hypothalamic injury and HO randomized to the GLP-1RA exenatide once-weekly (ExQW) or placebo for 36 weeks. Subjects underwent MRI prior to enrolment and the degree of hypothalamic damage was assessed using an integrative hypothalamic lesion score (HLS). Mammillary body (MB) damage was specifically determined. The main clinical endpoints were % change in body mass index (BMI) and change in % body fat. Nested ANCOVA models including a treatment × imaging measure interaction were compared using partial F-tests to assess whether the effect of ExQW treatment differed by severity of hypothalamic damage. RESULTS: Complete data were available in 35/42 randomized participants (placebo, n = 15; ExQW, n = 20). ExQW-treated patients with worse HLS or bilateral MB damage had greater reductions in % body fat at 36 weeks (interaction coefficient estimates for HLS: -0.9%, 95% CI -1.6% to -0.2%, p = .02; for MB damage: -7.4%, 95% CI -10.1% to -4.7%, p < .001, respectively) but not for BMI % change. Similarly, patients with more damaged and smaller MB cross-sectional areas had greater reductions in % body fat following ExQW (interaction coefficient estimate 0.3%, 95% CI 0.2%-0.4%, p < .001). CONCLUSIONS: In people with HO, greater hypothalamic damage as determined by MRI, in particular MB injury, is associated with greater reductions in adiposity following GLP-1RA treatment.

A phase 3 randomized clinical trial using a once-weekly glucagon-like peptide-1 receptor agonist in adolescents and young adults with hypothalamic obesity.

AIM: To evaluate the efficacy, safety and tolerability of a glucagon-like peptide-1 receptor agonist (GLP-1 RA) in patients with hypothalamic obesity (HO). MATERIALS AND METHODS: A two-arm, randomized, multicentre, double-blind, placebo-controlled trial was conducted in 10- to 25-year-olds with hypothalamic injury following intracranial tumour and HO. Participants were randomized to once-weekly subcutaneous injections of a GLP-1 RA exenatide 2 mg (ExQW) or placebo for 36 weeks. The primary efficacy endpoint was 36-week % change in body mass index (BMI). Secondary outcomes included change in body composition (by dual energy x-ray absorptiometry). RESULTS: Forty-two participants were randomized to ExQW (n = 23) or placebo (n = 19). Participants were 5 ± 2 years (mean ± SD) postdiagnosis and development of HO (BMI 37.3 ± 7.1 kg/m2 ). In intention-to-treat analysis, the effect of 36-week ExQW vs. placebo on % Δ BMI was not significant (estimated treatment difference -1.7 ± 1.8%, 95% CI -4.1 to 0.6%, P = .40); however, total body fat mass was reduced (estimated treatment difference -3.1 ± 1.4 kg, 95% CI -5.7 to -0.4 kg, P = .02). There was a significant reduction in waist circumference (estimated effect of treatment -3.5 [95% CI -5.5 to -1.6] cm, P = .004). All patients treated with placebo increased % of adipose tissue, while 50% treated with ExQW had reductions (P < .001). Mean HbA1c, glucose tolerance and serum lipids did not change significantly with therapy. ExQW was well tolerated. The most frequent adverse events were transient gastrointestinal disturbances (ExQW vs. placebo: nausea 6/23 vs. 3/18, vomiting 4/23 vs. 4/18 and diarrhoea 7/23 vs. 3/18). CONCLUSIONS: GLP-1 RAs are a promising and safe treatment to improve or stabilize HO in children and young adults.

The link between obesity and puberty: what is new?

PURPOSE OF REVIEW: The objective of this review is to assess the most recent literature on pubertal trends in boys and girls as well as evaluate genetic, epigenetic, and environmental factors implicated in the timing of pubertal progression. RECENT FINDINGS: Recent studies confirm the previously described link between increased adiposity and earlier onset of puberty in girls, and more recent studies shed light onto the previously unclear situation in boys as a preponderance of recent longitudinal studies suggests that increased adiposity is linked with earlier pubertal timing also in boys. Discoveries of novel pathways highlights the complexity of pubertal development and suggest mechanistic links between nutrition, obesity, leptin, insulin resistance, and puberty. Furthermore, genetic and epigenetic variants can be linked to early puberty. Other factors, such as prenatal and postnatal environment, gut microbiota, and endocrine-disrupting chemicals have also been linked to both obesity and earlier puberty. SUMMARY: Understanding how the interactions of these factors contribute the relationship between obesity and early pubertal onset is crucial as early puberty has been linked with long-term consequences, such as short stature, earlier type 2 diabetes, cardiovascular disease, and poor psychological and behavioral outcomes.

Child neurobiology impacts success in family-based behavioral treatment for children with obesity.

BACKGROUND AND OBJECTIVES: Family-based behavioral treatment (FBT) is the recommended treatment for children with common obesity. However, there is a large variability in short- and long-term treatment response, and mechanisms for unsuccessful treatment outcomes are not fully understood. In this study, we tested if brain response to visual food cues among children with obesity before treatment predicted weight or behavioral outcomes during a 6-month behavioral weight management program and/or long-term relative weight maintenance over a 1-year follow-up period. SUBJECTS AND METHODS: Thirty-seven children with obesity (age 9-11 years, 62% male) who entered active FBT (attended two or more sessions) and had outcome data. Brain activation was assessed at pretreatment by functional magnetic resonance imaging across an a priori set of appetite-processing brain regions that included the ventral and dorsal striatum, mOFC, amygdala, substantia nigra/ventral tegmental area, and insula in response to viewing food images before and after a standardized meal. RESULTS: Children with more robust reductions in brain activation to high-calorie food cue images following a meal had greater declines in BMI z-score during FBT (r = 0.42; 95% CI: 0.09, 0.66; P = 0.02) and greater improvements in Healthy Eating Index scores (r = -0.41; 95% CI: -0.67, -0.06; P = 0.02). In whole-brain analyses, greater activation in the ventromedial prefrontal cortex, specifically by high-calorie food cues, was predictive of better treatment outcomes (whole-brain cluster corrected P = 0.02). There were no significant predictors of relative weight maintenance, and initial behavioral or hormonal measures did not predict FBT outcomes. CONCLUSIONS: Children's brain responses to a meal prior to obesity treatment were related to treatment-based weight outcomes, suggesting that neurophysiologic factors and appetitive drive, more so than initial hormone status or behavioral characteristics, limit intervention success.

A vitamin B12 conjugate of exendin-4 improves glucose tolerance without associated nausea or hypophagia in rodents.

AIMS: While pharmacological glucagon-like peptide-1 receptor (GLP-1R) agonists are FDA-approved for treating type 2 diabetes mellitus (T2DM) and obesity, a major side effect is nausea/malaise. We recently developed a conjugate of vitamin B12 (B12) bound to the GLP-1R agonist exendin-4 (Ex4), which displays enhanced proteolytic stability and retention of GLP-1R agonism. Here, we evaluate whether the conjugate (B12-Ex4) can improve glucose tolerance without producing anorexia and malaise. MATERIALS AND METHODS: We evaluated the effects of systemic B12-Ex4 and unconjugated Ex4 on food intake and body weight change, oral glucose tolerance and nausea/malaise in male rats, and on intraperitoneal glucose tolerance in mice. To evaluate whether differences in the profile of effects of B12-Ex4 vs unconjugated Ex4 are the result of altered CNS penetrance, rats received systemic injections of fluorescein-Ex4 (Flex), Cy5-B12 or Cy5-B12-Ex4 and brain penetrance was evaluated using confocal microscopy. Uptake of systemically administered Cy5-B12-Ex4 in insulin-containing pancreatic beta cells was also examined. RESULTS: B12-Ex4 conjugate improves glucose tolerance, but does not elicit the malaise and anorexia produced by unconjugated Ex4. While Flex robustly penetrates into the brain (dorsal vagal complex, paraventricular hypothalamus), Cy5-B12 and Cy5-B12-Ex4 fluorescence were not observed centrally, supporting an absence of CNS penetrance, in line with observed reduction in CNS-associated Ex4 side effects. Cy5-B12-Ex4 colocalizes with insulin in the pancreas, suggesting direct pancreatic action as a potential mechanism underlying the hypoglycaemic effects of B12-Ex4. CONCLUSION: These novel findings highlight the potential clinical utility of B12-Ex4 conjugates as possible future T2DM therapeutics with reduced incidence of adverse effects.

Betatrophin: no relation to glucose metabolism or weight status in obese children before and after lifestyle intervention.

OBJECTIVE: The influences of obesity, glucose metabolism, gender, and puberty on betatrophin levels and the longitudinal relationships between weight loss, metabolic changes and betatrophin have not yet been studied in childhood. METHODS: Cross-sectional and longitudinal analysis of weight status (standard deviation score-body mass index (SDS-BMI)), homeostasis model assessment insulin resistance (HOMA-IR), gender, and pubertal stage were evaluated in 69 obese children (51% female, age 11.9 ± 2.0 years) participating in lifestyle intervention over a 1-year period. An oral glucose tolerance test was performed in 53 of the 69 children. Twenty normal weight children (50% female, age 12.3 ± 3.0 years) served as controls. RESULTS: Circulating betatrophin did not differ significantly between obese and lean children (1.99 ± 0.90 vs 2.35 ± 0.28, mean ± SD, P = .155). At baseline, betatrophin did not differ in obese patients with vs without glucose intolerance (1.89 ± 0.96 vs 2.031 ± 0.91 ng/mL; P = .591) and obese with (delta SDS-BMI >0.4) vs without successful obesity intervention (1.89 ± 0.94 vs. 2.07 ± 0.87 ng/mL; P = 0.396). In multiple linear regression analyses, pubertal stage was associated with betatrophin (b: 0.48, P = .027), while gender, age, BMI, blood pressure, fasting glucose, HOMA-IR, triglycerides, LDL- and HDL-cholesterol were not related to betatrophin at baseline. At the end of the 1-year intervention, changes of betatrophin were not significantly associated with any parameter after controlling for multiple covariates including age and changes of pubertal stages. CONCLUSIONS: Our data do not support a relationship between betatrophin and weight status or glucose tolerance, insulin resistance, and lipid metabolism in children.

Vitamin D Deficiency Is Associated With Increased Risk of Non-alcoholic Steatohepatitis in Adults With Non-alcoholic Fatty Liver Disease: Possible Role for MAPK and NF-κB?

OBJECTIVES: The objective of this study was to determine the relationship of serum vitamin D deficiency (VDD) to histologic features of non-alcoholic fatty liver disease (NAFLD), and associated demographic, clinical, laboratory, and transcriptomic data in the well-characterized Non-alcoholic Steatohepatitis Clinical Research Network (NASH CRN) cohort. METHODS: Serum vitamin D 25(OH)D (VD) was quantified by liquid chromatography-tandem mass spectrometry in 190 adults (>18 years) with biopsy-proven NAFLD. Subjects were categorized according to their level of VD as either sufficient (>30 ng/ml), insufficient (≥20≤30 ng/ml), or deficient (VDD; <20 ng/ml). Multivariable logistic regression was used to investigate the association of VDD and the presence of definite NASH and individual histological features of NAFLD after adjusting for age, sex, race, body mass index, alanine aminotransferase, and diabetes status. Hepatic transcriptomic data was compared between VDD and non-VDD subjects. RESULTS: VDD was present in 55% of subjects and was independently associated with definitive NASH (odds ratio (OR) 3.15, 95% confidence interval (CI), 1.62-6.15, P=0.001), increased lobular inflammation (OR=1.98, 95% CI, 1.08-3.61, P=0.026), more ballooning (OR=2.38, 95% CI, 1.32-4.30, P=0.004), and the presence of fibrosis (OR=2.32, 95% CI, 1.13-4.77, P=0.022). There was a significant inverse relationship between lower levels of serum resistin and increased VD level category (P=0.013). The KRT10, SEMA3B, SNORD3C, ARSD, and IGKV4-1 genes were differentially expressed (false discovery rate <0.05) between VDD and non-VDD subjects. Gene ontology and pathway analysis suggest activation of the mitogen-activated protein kinase and nuclear factor-κB pathways in VDD NAFLD subjects. CONCLUSIONS: VDD is prevalent among US adult NAFLD patients and is independently associated with a definitive diagnosis of NASH and increased histological severity. Novel associations in proinflammatory pathways were identified, which suggest the mechanism for VDD in the pathogenesis of NASH and support dietary and/or lifestyle modifications to increase vitamin D levels in these patients.

Reduced adiponectin signaling due to weight gain results in nonalcoholic steatohepatitis through impaired mitochondrial biogenesis.

UNLABELLED: Obesity and adiponectin depletion have been associated with the occurrence of nonalcoholic fatty liver disease (NAFLD). The goal of this study was to identify the relationship between weight gain, adiponectin signaling, and development of nonalcoholic steatohepatitis (NASH) in an obese, diabetic mouse model. Leptin-receptor deficient (Lepr(db/db) ) and C57BL/6 mice were administered a diet high in unsaturated fat (HF) (61%) or normal chow for 5 or 10 weeks. Liver histology was evaluated using steatosis, inflammation, and ballooning scores. Serum, adipose tissue, and liver were analyzed for changes in metabolic parameters, messenger RNA (mRNA), and protein levels. Lepr(db/db) HF mice developed marked obesity, hepatic steatosis, and more than 50% progressed to NASH at each timepoint. Serum adiponectin level demonstrated a strong inverse relationship with body mass (r = -0.82; P < 0.0001) and adiponectin level was an independent predictor of NASH (13.6 µg/mL; P < 0.05; area under the receiver operating curve (AUROC) = 0.84). White adipose tissue of NASH mice was characterized by increased expression of genes linked to oxidative stress, macrophage infiltration, reduced adiponectin, and impaired lipid metabolism. HF lepr (db/db) NASH mice exhibited diminished hepatic adiponectin signaling evidenced by reduced levels of adiponectin receptor-2, inactivation of adenosine monophosphate activated protein kinase (AMPK), and decreased expression of genes involved in mitochondrial biogenesis and ß-oxidation (Cox4, Nrf1, Pgc1α, Pgc1ß and Tfam). In contrast, recombinant adiponectin administration up-regulated the expression of mitochondrial genes in AML-12 hepatocytes, with or without lipid-loading. CONCLUSION: Lepr(db/db) mice fed a diet high in unsaturated fat develop weight gain and NASH through adiponectin depletion, which is associated with adipose tissue inflammation and hepatic mitochondrial dysfunction. We propose that this murine model of NASH may provide novel insights into the mechanism for development of human NASH.

Relation between vitamin D status and nonalcoholic fatty liver disease in children.

OBJECTIVES: In adults, vitamin D deficiency is common in patients with nonalcoholic fatty liver disease (NAFLD) and has been associated with the severity of histology. There are known differences between adult and pediatric NAFLD, with little data regarding the relation between vitamin D and pediatric NAFLD. The aim of the present study was to examine the relation between vitamin D levels and NAFLD in children. METHODS: Clinical and histological data were used from children ages 2 to 18 years with biopsy-proven NAFLD enrolled in the Nonalcoholic Steatohepatitis Clinical Research Network studies. 25(OH) vitamin D levels were measured from serum. Data examined included demographics, anthropometrics, laboratory markers, and liver histology. Data were analyzed using 3 categories of vitamin D level: deficient (≤ 20 ng/mL), insufficient (21-29 ng/mL), and sufficient (≥ 30 ng/mL). RESULTS: A total of 102 children were studied. There was a high prevalence (80/102, 78%) of vitamin D deficiency or insufficiency; however, there were no significant associations between vitamin D level and the histological characteristics or severity of NAFLD. Significantly higher levels of triglycerides were found in those with vitamin D deficiency (P = 0.004), but there was no association with other features of the metabolic syndrome. CONCLUSIONS: There is a high prevalence of vitamin D deficiency and insufficiency in children with biopsy-proven NAFLD; however, no association was found between vitamin D deficiency and the severity of disease on biopsies. This differs from adult NAFLD studies in which vitamin D deficiency correlates with histological severity, suggesting differences in the risk factors for or consequences of pediatric NAFLD.

Obesity management in Prader-Willi syndrome.

Prader-Willi Syndrome (PWS) is one of the most common genetic causes of obesity. The phenotype of obesity in PWS is unique and characterized by hyperphagia, earlier meal initiation, delayed meal termination, reduced energy expenditure, abnormal gut hormone profiles, as well as irregular responses to food in areas of the brain associated with satiety and reward. Management of obesity is necessary to avoid major morbidity. The relentless food-seeking behavior associated with PWS such as stealing, hoarding food, eating inedibles, and lying about eating, can cause turmoil both inside and outside of the home. Management is challenging for both patients and caretakers, but at this time there are limited medical therapies available besides dietary restriction and behavior management. However, current research shows promise for discovery of additional treatment options for hyperphagia and obesity management in PWS.

Initial evidence that GLP-1 receptor blockade fails to suppress postprandial satiety or promote food intake in humans.

Glucagon-like peptide 1 (GLP-1) has incretin effects that are well-documented, but the independent role of GLP-1 action in human satiety perception is debated. We hypothesized that blockade of GLP-1 receptors would suppress postprandial satiety and increase voluntary food intake. After an overnight fast, eight normal weight participants (seven men, BMI 19-24.7 kg/m(2), age 19-29 year) were enrolled in a double-blind, placebo-controlled, randomized crossover study of the GLP-1 antagonist Exendin-[9-39] (Ex-9) to determine if the satiating effects of a meal are dependent on GLP-1 signaling in humans. Following a fasting blood draw, iv infusion of Ex-9 (600-750 pmol/kg/min) or saline began. Thirty minutes later, subjects consumed a standardized breakfast followed 90 min later (at the predicted time of maximal endogenous circulating GLP-1) by an ad libitum buffet meal to objectively measure satiety. Infusions ended once the buffet meal was complete. Visual analog scale ratings of hunger and fullness and serial assessments of plasma glucose, insulin, and GLP-1 concentrations were done throughout the experiment. Contrary to the hypothesis, during Ex-9 infusion subjects reported a greater decrease in hunger due to consumption of the breakfast (Ex-9 -62 ± 5; placebo -41 ± 9; P=0.01) than during placebo. There were no differences in ad libitum caloric intake between Ex-9 and placebo. Ex-9 increased glucose, insulin, and endogenous GLP-1, which may have counteracted any effects of Ex-9 infusion to block satiety signaling. Blockade of GLP-1 receptors failed to suppress subjective satiety following a standardized meal or increase voluntary food intake in healthy, normal-weight subjects.

Reductions of food intake and body weight in diet-induced obese rats following chronic treatment with a monomeric peptide multiagonist.

INTRODUCTION: While therapies based on endogenous gut peptides such as glucagon-like peptide-1 (GLP-1) receptor agonists (GLP-1RAs) have been compelling therapeutic agents for obesity and type 2 diabetes (T2D), only a few have achieved long-term weight loss and all have shown significant side-effects, including nausea/malaise and gastrointestinal ailments. OBJECTIVE: As the pathophysiology of obesity is driven by dysregulation of multiple, inter-related, pathways, we tested a novel peptide targeting multiple receptors of complementary neurocircuits regulating the controls of energy balance. METHODS: Response to daily injections of GEP44, a GLP-1R and neuropeptide Y1R and Y2R receptor (Y1R/Y2R) triple agonist was tested vs. the GLP-1R agonist liraglutide (LIRA) in diet-induced obese (DIO) male and female rats. Glucose tolerance tests after intraperitoneal injection of glucose (IPGTT) were performed at baseline and after 14-d of treatment in GEP44 treated rats. Other metabolic parameters were assessed in blood at the end of a 28-d intervention. RESULTS: Upon conclusion at 28-d, body weight reduction compared to vehicle was -15.6%/-11.9% in response to GEP44, vs. -9.7%/-5.1% after LIRA, males, and females, respectively. Significant reductions of cumulative food intake occurred over 28-d in female rats treated with GEP44 (-30%; p < 0.0001), vs. LIRA (-10%), and in male rats GEP44 (-39%; p < 0.0001), vs. LIRA (-20%; p = 0.003). In IPGTTs, a similar stimulation glucose induced insulin secretion was noted in rats treated with GEP44 and LIRA. CONCLUSION: The strong reductions of body weight in response to long-term applications of the triple agonist GEP44 confirms the therapeutic potential of targeting multiple receptors for achieving more robust and potentially more sustained improvement of energy balance.

Setmelanotide for the treatment of acquired hypothalamic obesity: a phase 2, open-label, multicentre trial.

BACKGROUND: Hypothalamic obesity resulting from hypothalamic damage might affect melanocortin signalling. We investigated the melanocortin-4 receptor agonist setmelanotide for treatment of hypothalamic obesity. METHODS: This phase 2, open-label, multicentre trial was done in five centres in the USA. Eligible patients were aged between 6 and 40 years with obesity and history of hypothalamic injury or diagnosis of a non-malignant tumour affecting the hypothalamus that was treated with surgery, chemotherapy, or radiation. Setmelanotide was titrated up to a dose of 3·0 mg and administered subcutaneously once a day for a total duration of 16 weeks. The primary endpoint was the proportion of patients with a reduction in BMI of at least 5% from baseline after 16 weeks, compared with a historic control rate of less than 5% in this population. The primary endpoint was analysed using the full analysis set, which includes all patients with baseline data who received at least one dose of setmelanotide. Safety was assessed in all patients who received at least one dose of study drug. This trial is registered with ClinicalTrials.gov (NCT04725240) and is complete. FINDINGS: Between June 6, 2021, and Jan 13, 2022, 19 patients were screened for inclusion. One patient was excluded, and 18 were enrolled and received at least one dose of setmelanotide. Patients were primarily White (n=14 [78%]) and male (n=11 [61%]). Enrolled patients had a mean age of 15·0 years (SD 5·3) and a mean BMI of 38·0 kg/m2 (SD 6·5). Of 18 patients enrolled, 16 (89%) of 18 patients completed the study and met the primary endpoint of reduction in BMI of at least 5% from baseline after 16 weeks (p<0·0001). The mean reduction in BMI across all patients was 15% (SD 10). A composite proportion of patients had a clinically meaningful change (89%, 90% CI 69-98%; p<0·0001), comprising a reduction in BMI Z score of at least 0·2 points for patients younger than 18 years (92%, 68-100%; p<0·0001) and reduction in bodyweight of at least 5% for patients aged 18 years or older (80%, 34-99%; p<0·0001). Patients aged 12 years or older had a mean reduction in hunger score of 45%. Frequent adverse events included nausea (61%), vomiting (33%), skin hyperpigmentation (33%), and diarrhoea (22%). Of 14 patients who continued treatment in a long-term extension study (NCT03651765), 12 completed at least 12 months of treatment at the time of publication and had a mean change in BMI of -26% (SD 12) from index trial baseline. INTERPRETATION: These findings support setmelanotide as a novel effective treatment of hypothalamic obesity. FUNDING: Rhythm Pharmaceuticals.

Investigation of setmelanotide, an MC4R agonist, for obesity in individuals with Smith-Magenis syndrome.

BACKGROUND: Smith Magenis Syndrome (SMS) is a rare genetic disorder caused by RAI1 haploinsufficiency. Obesity in people with SMS is believed partially due to dysfunction of the proximal melanocortin 4 receptor (MC4R) pathway. We therefore studied effects of treatment with the MC4R agonist setmelanotide on obesity and hunger, as well as metabolic, cardiac and safety, in individuals with SMS. METHODS: People with SMS received once-daily setmelanotide injections, with the dose titrated bi-weekly to a maximum of 3 mg over ∼1 month; and a full-dose treatment duration of 3mo. The primary outcome was percent change in body weight. Secondary outcomes included hunger, waist circumference, body composition, and safety. RESULTS: 12 individuals, ages 11-39 y, enrolled and 10 completed the full-dose treatment phase. Mean percent change in body weight at end-treatment was - 0.28 % [(95 % CI, -2.1 % to 1.5 %; n = 12; P = 0.66]. Participants experienced a significant decrease in total cholesterol associated with a significant decrease in HDL-cholesterol and a trend for lower LDL-cholesterol. Self-reported hunger was reduced at end-treatment (p = 0.011). All participants reported adverse events (AEs), most commonly injection-site reactions and skin hyperpigmentation. No AEs led to withdrawal or death. CONCLUSIONS: In this trial, setmelanotide did not significantly reduce body weight in participants with SMS. Participants reported significant differences in hunger, but such self-reports are difficult to interpret without a placebo-treated group. The changes in lipid profiles require further investigation. Results of this study do not suggest that dysfunction of the proximal MC4R pathway is the main etiology for obesity in people with SMS.

The Novel Chimeric Multi-Agonist Peptide (GEP44) Reduces Energy Intake and Body Weight in Male and Female Diet-Induced Obese Mice in a Glucagon-Like Peptide-1 Receptor-Dependent Manner.

We recently reported that a novel chimeric peptide (GEP44) targeting both the glucagon-like peptide-1 receptor (GLP-1R) and neuropeptide Y1- and Y2 receptor (Y1R and Y2R) reduced energy intake and body weight (BW) in diet-induced obese (DIO) rats. We hypothesized that GEP44 reduces energy intake and BW primarily through a GLP-1R dependent mechanism. To test this hypothesis, GLP-1R +/+ mice and GLP-1R null (GLP-1R -/- ) mice were fed a high fat diet for 4 months to elicit diet-induced obesity prior to undergoing a sequential 3-day vehicle period, 3-day drug treatment (5, 10, 20 or 50 nmol/kg; GEP44 vs the selective GLP-1R agonist, exendin-4) and a 3-day washout. Energy intake, BW, core temperature and activity were measured daily. GEP44 (10, 20 and 50 nmol/kg) reduced BW after 3-day treatment in DIO male GLP-1R +/+ mice by - 1.5±0.6, -1.3±0.4 and -1.9±0.4 grams, respectively ( P <0.05), with similar effects being observed in female GLP-1R +/+ mice. These effects were absent in male and female DIO GLP-1R -/- mice suggesting that GLP-1R signaling contributes to GEP44-elicited reduction of BW. Further, GEP44 decreased energy intake in both male and female DIO GLP-1R +/+ mice, but GEP44 appeared to produce more consistent effects across multiple doses in males. In GLP-1R -/- mice, the effects of GEP44 on energy intake were only observed in males and not females, suggesting that GEP44 may reduce energy intake, in part, through a GLP-1R independent mechanism in males. In addition, GEP44 reduced core temperature and activity in both male and female GLP-1R +/+ mice suggesting that it may also reduce energy expenditure. Lastly, we show that GEP44 reduced fasting blood glucose in DIO male and female mice through GLP-1R. Together, these findings support the hypothesis that the chimeric peptide, GEP44, reduces energy intake, BW, core temperature, and glucose levels in male and female DIO mice primarily through a GLP-1R dependent mechanism.

Vitamin D deficiency in obese rats exacerbates nonalcoholic fatty liver disease and increases hepatic resistin and Toll-like receptor activation.

UNLABELLED: Childhood obesity is associated with type 2 diabetes mellitus and nonalcoholic fatty liver disease (NAFLD). Recent studies have found associations between vitamin D deficiency (VDD), insulin resistance (IR), and NAFLD among overweight children. To further explore mechanisms mediating these effects, we fed young (age 25 days) Sprague-Dawley rats with a low-fat diet (LFD) alone or with vitamin D depletion (LFD+VDD). A second group of rats was exposed to a Westernized diet (WD: high-fat/high-fructose corn syrup) that is more typically consumed by overweight children, and was either replete (WD) or deficient in vitamin D (WD+VDD). Liver histology was assessed using the nonalcoholic steatohepatitis (NASH) Clinical Research Network (CRN) scoring system and expression of genes involved in inflammatory pathways were measured in liver and visceral adipose tissue after 10 weeks. In VDD groups, 25-OH-vitamin D levels were reduced to 29% (95% confidence interval [CI]: 23%-36%) compared to controls. WD+VDD animals exhibited significantly greater hepatic steatosis compared to LFD groups. Lobular inflammation as well as NAFLD Activity Score (NAS) were higher in WD+VDD versus the WD group (NAS: WD+VDD 3.2 ± 0.47 versus WD 1.50 ± 0.48, P < 0.05). Hepatic messenger RNA (mRNA) levels of Toll-like receptors (TLR)2, TLR4, and TLR9, as well as resistin, interleukins (IL)-1ß, IL-4, and IL-6 and oxidative stress marker heme oxygenase (HO)-1, were higher in WD+VDD versus WD animals (P < 0.05). Logistic regression analyses showed significant associations between NAS score and liver mRNA levels of TLRs 2, 4, and 9, endotoxin receptor CD14, as well as peroxisome proliferator activated receptor (PPAR)γ, and HO-1. CONCLUSION: VDD exacerbates NAFLD through TLR-activation, possibly by way of endotoxin exposure in a WD rat model. In addition it causes IR, higher hepatic resistin gene expression, and up-regulation of hepatic inflammatory and oxidative stress genes.

Glucocorticoids and insulin resistance in children with acute lymphoblastic leukemia.

BACKGROUND: Children treated for acute lymphoblastic leukemia (ALL) are more likely to become overweight. Prolonged exposure to high-dose glucocorticoids may cause insulin resistance and facilitate development of this phenotype. PROCEDURE: Body mass indices (BMI) and insulin resistance (homeostatic model assessment [HOMA]-IR) were prospectively measured among on- (n = 31) and off-therapy participants (n = 29). On-therapy participants were assessed prior to and while on glucocorticoids (5 days of prednisone 40 mg m(-2) or dexamethasone 6 mg m(-2)) given as part of routine maintenance chemotherapy, with a subset (n = 10) receiving an intravenous glucose tolerance test (IVGTT) while on glucocorticoids. RESULTS: Baseline HOMA-IR values among on- and off-therapy participants were similar, but among on-therapy participants, HOMA-IR increased significantly with glucocorticoid exposure (median 3.39 vs. 1.26; P < 0.01) with 45.2% of participants having values >4.39 (upper 2.5th percentile among normal weight adolescents). Although baseline HOMA-IR was significantly correlated with current BMI (r = 0.48, P < 0.01), change in HOMA-IR following steroid exposure was not correlated with any demographic or treatment characteristic including current BMI. Among those with IVGTT data, HOMA estimates in general correlated with values derived from a minimal model analysis (r ~ 0.7). CONCLUSIONS: High-dose glucocorticoids given as part of routine chemotherapy were associated with a significantly increased insulin resistant state. Given the amount and duration of glucocorticoids children with ALL experience, these physiologic changes could be an important contributor to the development of therapy-related obesity.