Review of physiology, clinical manifestations, and management of hypothalamic obesity in humans

Obesity in patients with craniopharyngioma in the South Asian region - A distinct phenotype

Background

Craniopharyngiomas are rare benign tumors located in the sellar and suprasellar region, with an incidence of 0.5-2 cases per million as reported in Western studies. Post-treatment, including surgery and/or radiotherapy, many patients develop significant obesity, primarily due to hypothalamic damage and associated complications such as hypopituitarism. In the South Asian population, genetic predisposition to obesity at lower BMIs, coupled with a carbohydrate-rich diet, may exacerbate obesity in craniopharyngioma patients, presenting a unique challenge.

Methods

This submission is a commentary based on a comprehensive literature review. The authors conducted the review using PubMed to focus on English-language articles covering hypothalamic obesity, craniopharyngioma and obesity in the South Asian population from 1939 to the present.

Results

The literature review revealed that 50-60 % of patients treated for craniopharyngioma develop obesity, predominantly linked to hypothalamic damage, although these data are mainly derived from Western studies. Hypopituitarism was frequently observed, further contributing to the obesity. Despite a caloric intake appropriate for the age and gender, these patients exhibited reduced physical activity as measured by wrist accelerometers. Patients with hypothalamic obesity due to craniopharyngioma are at risk for metabolic syndrome and cardiovascular morbidity. Additionally, visual impairment was common, leading to a decreased quality of life. The South Asian population, genetically predisposed to visceral obesity and a carbohydrate-rich diet, may display a distinct phenotype. Although multiple treatment modalities have been tried, there is no definite treatment modality available to counteract this condition at present.

Conclusion

South Asian phenotype of craniopharyngioma-related obesity is characterized by significant metabolic and hormonal dysregulation, influenced by both dietary and genetic factors. Nevertheless, there may be a lot to be still understood about this devastating, rapid, relentless hypothalamic obesity syndrome. Also, a higher morbidity rate within this population, underscores the need for further research to develop targeted interventions.

From Hypothalamic Obesity to Metabolic Dysfunction-Associated Steatotic Liver Disease: Physiology Meets the Clinics via Metabolomics

Metabolic health is tightly regulated by neuro-hormonal control, and systemic metabolic dysfunction may arise from altered function of the hypothalamic-anterior pituitary axis (HAPA). Ancient experimental observations of hypothalamic obesity (HO) and liver cirrhosis occurring among animals subjected to hypothalamic injury can now be explained using the more recent concepts of lipotoxicity and metabolic dysfunction-associated steatotic liver disease (MASLD). Lipotoxicity, the range of abnormalities resulting from the harmful effects of fatty acids accumulated in organs outside of adipose tissue, is the common pathogenic factor underlying closely related conditions like hypothalamic syndrome, HO, and MASLD. The hormonal deficits and the array of metabolic and metabolomic disturbances that occur in cases of HO are discussed, along with the cellular and molecular mechanisms that lead, within the MASLD spectrum, from uncomplicated steatotic liver disease to steatohepatitis and cirrhosis. Emphasis is placed on knowledge gaps and how they can be addressed through novel studies. Future investigations should adopt precision medicine approaches by precisely defining the hormonal imbalances and metabolic dysfunctions involved in each individual patient with HO, thus paving the way for tailored management of MASLD that develops in the context of altered HAPA.

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.

Determinants of Short-Term Weight Gain Following Surgical Treatment for Craniopharyngioma in Adults

Objective

Craniopharyngiomas (CPs) are associated with hypothalamic damage that causes hypothalamic obesity, however, the mechanisms underlying CP-related postoperative weight gain remain debatable. This study aimed to elucidate whether the major determinant of postoperative weight gain in patients with CP is hypothalamic injury or steroid replacement therapy.

Methods

We included 48 adult patients with CP (age ≥18 years) who underwent transsphenoidal surgery between 2010 and 2018 in a single tertiary center, and whose body weight was measured pre- and postoperatively (<120 days after the surgery). We recruited 144 age- and body mass index-matched patients with non-functioning pituitary adenoma (NFPA) as controls.

Results

Patients with CP experienced greater postoperative weight gain than patients with NFPA (3.0±5.1 vs. 0.1±3.6 kg, p<0.001). The prevalence of postoperative steroid use was significantly higher in patients with CP than in those with NFPA (89.6% vs. 34.0%, p<0.001). Steroid replacement therapy and CP were associated with postoperative weight gain after adjusting for covariates in overall patients (p=0.032 and 0.007, respectively). In subgroup analysis with postoperative steroid users, weight gain was significantly greater in patients with CP (n=43, 0.96±0.25 kg/month) than in patients with NFPA (n=49, 0.26±0.23 kg/month) even after adjusting for the daily steroid dose (p=0.048).

Conclusion

Patients with CP experience greater postoperative weight gain than those with NFPA. Hypothalamic damage itself as well as steroid replacement may contribute to the postoperative weight gain in patients with CP.

Exploring eating behavior and psychological mechanisms associated with obesity in patients with craniopharyngioma: a scoping review protocol

OBJECTIVE

The objective of the review is to explore the evidence that investigates behavioral and psychological mechanisms underlying the development of obesity in patients with craniopharyngioma, in order to map that evidence, identify gaps in the literature, and find avenues of future intervention.

INTRODUCTION

Craniopharyngiomas are low-grade intracranial tumors of the supersellar region. Obesity is associated with the tumor or surgery or radiotherapy to treat the tumor, however, the behavioral and psychological processes contributing to that association are not clear. This review will provide a synthesized evidence base of the relevant research.

INCLUSION CRITERIA

The scoping review will consider published studies with all types of study designs, including patients with childhood- or adult-onset craniopharyngioma. Articles assessing factors that may impact eating behavior will be included based on the following categories: eating behavior, obesity, neuroimaging, endocrine response, energy expenditure, sleep, and neuropsychology.

METHODS

MEDLINE, Embase, and PsycINFO will be searched, in addition to Cochrane Library, Web of Science, Scopus, Clinical trials.gov, NICE evidence search, and International Standard Randomised Controlled Trial Number (ISRCTN). No limits will be placed on the scope of the search. Methodology will follow the proposed three-stage process with two independent reviewers at each stage, including an initial database search, screening of titles and abstracts of retrieved studies, full-text assessment for inclusion criteria, and hand searching of reference lists. Data will be extracted using a standardized charting form and summarized in tables. The data will be synthesized using a narrative summary and diagrammatic map and will be based on the evidence for each of the proposed research categories.

Multidisciplinary Approach for Hypothalamic Obesity in Children and Adolescents: A Preliminary Study

Hypothalamic obesity (HO) is delineated by an inexorable weight gain in subjects with hypothalamic disorder (congenital or acquired). The aim of the present study was to evaluate the effect of a multidisciplinary approach on weight trend and metabolic outcome in children and adolescents with hypothalamic disease who were overweight or obese. Thirteen patients (aged 8.1–16.1 years) received a personalized diet, accelerometer-based activity monitoring, and psychological assessment. Height, weight, body mass index (BMI), and serum metabolic parameters were assessed at baseline (T0) and after six months (T1). Metformin was introduced at T1 in four subjects who were then re-evaluated after six months (T2). At T1, weight gain was significantly reduced compared with T0 (0.29 ± 0.79 kg/month vs. 0.84 ± 0.55 kg/month, p = 0.03), and weight standard deviation score (SDS) and BMI SDS did not change significantly, as serum metabolic parameters. The four subjects treated with metformin showed a reduction of weight SDS and BMI SDS at T2. In conclusion, patients treated with our multidisciplinary approach showed, after 6 months, favorable results characterized by decreased weight gain and stabilization of weight SDS and BMI SDS in a condition usually characterized by inexorable weight gain. However, further analysis, larger cohorts, and longer follow-up are needed to confirm these preliminary data.

Clinical Implication of Individually Tailored Segmentation Method for Distorted Hypothalamus in Craniopharyngioma

OBJECTIVE

Several attempts have been done to capture damaged hypothalamus (HT) using volumetric measurements to predict the development of hypothalamic obesity in patients with craniopharyngioma (CP). This study was to develop a novel method of HT volume measurement and examine the associations between postoperative HT volume and clinical parameters in patients with CP.

METHODS

We included 78 patients with adult-onset CP who underwent surgical resection. Postoperative HT volume was measured using T1- and T2-weighted magnetic resonance imaging (MRI) with a slice thickness of 3 mm, and corrected for temporal lobe volume. We collected data on pre- and postoperative body weights, which were measured at the time of HT volume measurements.

RESULTS

The corrected postoperative HT volume measured using T1- and T2-weighted images was significantly correlated (r=0.51 [95% confidence interval (CI) 0.32 to 0.67], P<0.01). However, HT volume was overestimated using T1-weighted images owing to obscured MR signal of the thalamus in patients with severe HT damage. Therefore, we used T2-weighted images to evaluate its clinical implications in 72 patients with available medical data. Postoperative HT volume was negatively associated with preoperative body weight and preoperative tumor volume (r=-0.25 [95% CI -0.45 to -0.04], P=0.04 and r=-0.26 [95% CI -0.40 to -0.15], P=0.03, respectively). In the subgroup analysis of CP patients who underwent primary surgery (n=56), pre- and postoperative body weights were negatively associated with HT volume (r=-0.30 [95% CI -0.53 to -0.03], P=0.03 and r=-0.29 [95% CI -0.53 to -0.02], P=0.03, respectively).

CONCLUSIONS

Adult-onset CP patients showed negative associations between postoperative HT volume and preoperative/postoperative body weight using a new method of HT volume measurement based on T2-weighted images.

A comprehensive diagnostic approach to detect underlying causes of obesity in adults

Obesity is a worldwide growing problem. When confronted with obesity, many health care providers focus on direct treatment of the consequences of adiposity. We plead for adequate diagnostics first, followed by an individualized treatment. We provide experience-based and evidence-based practical recommendations (illustrated by clinical examples), to detect potential underlying diseases and contributing factors. Adult patients consulting a doctor for weight gain or obesity should first be clinically assessed for underlying diseases, such as monogenetic or syndromic obesity, hypothyroidism, (cyclic) Cushing syndrome, polycystic ovarian syndrome (PCOS), hypogonadism, growth hormone deficiency, and hypothalamic obesity. The most important alarm symptoms for genetic obesity are early onset obesity, dysmorphic features/congenital malformations with or without intellectual deficit, behavioral problems, hyperphagia, and/or striking family history. Importantly, also common contributing factors to weight gain should be investigated, including medication (mainly psychiatric drugs, (local) corticosteroids, insulin, and specific β-adrenergic receptor blockers), sleeping habits and quality, crash diets and yoyo-effect, smoking cessation, and alcoholism. Other associated conditions include mental factors such as chronic stress or binge-eating disorder and depression.Identifying and optimizing the underlying diseases, contributing factors, and other associated conditions may not only result in more effective and personalized treatment but could also reduce the social stigma for patients with obesity.

Interventions for the Treatment of Craniopharyngioma-Related Hypothalamic Obesity: A Systematic Review

OBJECTIVE

Craniopharyngiomas (CPs) and their treatment are associated with hypothalamic damage that causes hypothalamic obesity (HO) in 30%-70% of cases. Thus, there is ongoing research regarding tangible solutions for HO, because these patients have unrelenting resistance to basic weight-loss interventions. This review aims to summarize the interventions that are used to treat CP-related HO (CP-HO), including pharmacotherapy and bariatric surgery.

METHODS

The Cochrane Library, EMBASE, and PubMed databases were searched up to June 2017 for relevant reports. Two reviewers conducted independent evaluations of the studies identified.

RESULTS

Eighteen articles were included in the systematic review, with 3 reports describing pharmacotherapy in randomized controlled trials and 15 reports describing bariatric surgery. Although several studies described effective interventions for treating CP-HO, the evidence base was limited by its low quality and our inability to perform a meta-analysis, which was related to a lack of adequate or integrated data.

CONCLUSIONS

Octreotide appears to be a preferred treatment for patients with CP-HO, based on limited data. Gastric bypass surgery may also be suitable for select patients with CP-HO, based on a review of various procedures in this setting. Microsurgical preservation of the hypothalamic structures is mandatory to decrease CP-HO-related morbidity and mortality. Further studies with adequate analytical power and sufficient follow-up are needed to identify effective strategies for CP-HO treatment.

Endocrine and metabolic assessment in adults with Langerhans cell histiocytosis

CONTEXT

Diabetes insipidus (DI) is one of most common complications of Langerhans cell histiocytosis (LCH) but prevalence of anterior pituitary deficiencies and metabolic alterations have not been clearly defined yet.

OBJECTIVES

Evaluate prevalence of endocrine and metabolic manifestations in a cohort of patients affected by Pulmonary LCH.

METHODS

Observational cross-sectional study on 18 adults (7 M/11 F, 42±12years) studied for complete basal and dynamic endocrine lab tests and glucose metabolism.

RESULTS

Hypothalamic-pituitary endocrine alterations were found in 9 patients: 9 had DI, 5 Growth Hormone Deficiency (GHD), 5 central hypogonadism, 3 central hypothyroidism and 1 central hypoadrenalism. Hyperprolactinemia and hypothalamic syndrome were found in 2 patients each. All these central endocrine alterations were always associated to DI. Five of the 10 MRI performed showed abnormalities. Prevalence of obesity and glucose alterations (either DM or IFG/IGT) were respectively 39% and 33%, higher than expected basing on epidemiological data on general Italian population. Multi-system-LCH without risk-organ involvement (LCH MS-RO^-) seems to have slightly higher prevalence of insulin resistance, glucose alterations and metabolic syndrome than LCH with isolated lung involvement (LCH SS lung⁺). A papillary BRAFV600E positive thyroid carcinoma was diagnosed in one patient.

CONCLUSIONS

The presence of anterior pituitary deficiencies should be systematically sought in all LCH patients with DI both at diagnosis and during the follow-up by basal and dynamic hormonal assessment. Patients with pulmonary LCH, particularly those with MS disease, have a worse metabolic profile than general population. Occurrence of papillary thyroid carcinoma has been reported.

A randomized, placebo-controlled trial of beloranib for the treatment of hypothalamic injury-associated obesity

AIMS

Hypothalamic injury-associated obesity (HIAO) results from damage to the hypothalamus that often occurs with surgical removal/radiation therapy of tumours in the hypothalamic region, such as craniopharyngioma. There is currently no rigorously studied pharmaceutical treatment for the intractable weight gain and cardiometabolic consequences that occur in patients with HIAO. We aimed to assess efficacy, safety and tolerability of beloranib treatment for 4 to 8 weeks in patients with HIAO.

MATERIALS AND METHODS

This Phase 2a, double-blind, placebo-controlled study included 14 patients with HIAO, randomized to receive beloranib 1.8 mg or placebo subcutaneously twice weekly for 4 weeks with an optional 4-week open-label extension in which all patients received beloranib. The primary endpoint was change in weight from baseline to Week 4.

RESULTS

Participants were 64% female, with a mean (SD) age of 32 (9) years, BMI of 43 (7) kg/m² and weight of 126 (22) kg. Compared with placebo (N = 4), beloranib 1.8 mg (N = 8) resulted in a mean (95% CI) difference in weight of -3.2 (-5.4, -0.9) kg after 4 weeks. Weight loss continued through the 8 weeks in patients randomized to beloranib (mean -6.2 [-8.2, -4.1] kg). Beloranib treatment was associated with improvements in high-sensitivity CRP. Adverse events were mild to moderate. No patients who received beloranib discontinued treatment.

CONCLUSION

Beloranib treatment resulted in progressive weight loss in patients with HIAO that was comparable to that observed with beloranib in patients with exogenous obesity. These findings indicate a novel mechanism for treating obesity in patients with HIAO.

Hypothalamic obesity in children: pathophysiology to clinical management

Hypothalamic obesity (HyOb) is a complex neuroendocrine disorder caused by damage to the hypothalamus, which results in disruption of energy regulation. The key hypothalamic areas of energy regulation are the ARC (arcuate nucleus), the VMH (ventromedial hypothalamus), the PVN (paraventriculer nuclei) and the LHA (lateral hypothalamic area). These pathways can be disrupted mechanically by hypothalamic tumors, neurosurgery, inflammatory disorders, radiotherapy and trauma or functionally as such seen in genetic diseases. Rapid weight gain and severe obesity are the most striking features of HyOb and caused by hyperphagia, reduced basal metabolic rate (BMR) and decreased physical activity. HyOb is usually unresponsive to diet and exercise. Although, GLP-1 and its anologs seem to be a new agent, there is still no curative treatment. Thus, prevention is of prime importance and the clinicians should be alert and vigilant in patients at risk for development of HyOb.

Overweight and obesity in children and adolescents

Obesity among children, adolescents and adults has emerged as one of the most serious public health concerns in the 21st century. The worldwide prevalence of childhood obesity has increased remarkably over the past 3 decades. The growing prevalence of childhood obesity has also led to appearance of obesity-related comorbid disease entities at an early age. Childhood obesity can adversely affect nearly every organ system and often causes serious consequences, including hypertension, dyslipidemia, insulin resistance, dysglycemia, fatty liver disease and psychosocial complications. It is also a major contributor to increasing healthcare expenditures. For all these reasons, it is important to prevent childhood obesity as well as to identify overweight and obese children at an early stage so they can begin treatment and attain and maintain a healthy weight. At present, pharmacotherapy options for treatment of pediatric obesity are very limited. Therefore, establishing a comprehensive management program that emphasizes appropriate nutrition, exercise and behavioral modification is crucial. The physician's role should expand beyond the clinical setting to the community to serve as a role model and to advocate for prevention and early treatment of obesity.

Food intake regulating hormones in adult craniopharyngioma patients

INTRODUCTION

Patients with craniopharyngioma (CP) have disturbances of the hypothalamic-pituitary axis and serious comorbidities such as obesity. We hypothesized that the secretion of hormones regulating the nutritional status is altered in adult patients with CP compared with patients with non-functioning pituitary adenoma (NFPA).

METHODS

WE INCLUDED 40 CP (50% MALES, MEAN AGE: 49.6±14.3 years) and 40 NFPA (72.5% males, mean age: 63.4±9.8 years) patients. We measured glucose, insulin, leptin, total ghrelin, peptide-YY (PYY) and cholecystokinin (CCK) during oral glucose tolerance test (OGTT). Fat mass (FM) was determined by dual X-ray absorptiometry.

RESULTS

Gender distribution was not significantly different, but CP patients were significantly younger (P<0.001). CP patients had significantly higher BMI and FM than NFPA patients (BMI 32±8 vs 28±4 kg/m(2), P=0.009 and FM 37±9 vs 33±9%, P=0.02). Fasting glucose level (84±12 vs 78±11 mg/dl, P=0.03), leptin (27.9±34.2 vs 11.9±11.6 μg/l, P=0.008) and leptin levels corrected for percentage FM (0.66±0.67 vs 0.32±0.25 μg/l%, P=0.005) were significantly higher in CP than in NFPA patients, whereas ghrelin was significantly lower (131±129 vs 191±119 ng/l, P=0.035). Insulin, PYY and CCK did not differ significantly between groups. After glucose load, leptin decreased significantly in CP patients (P=0.019). In both groups, ghrelin decreased significantly during OGTT (both P<0.001). The percentage decline was significantly smaller for CP. PYY and CCK increased equally after glucose in both groups.

CONCLUSION

Our patients with CP have more metabolic complications than our patients with NFPA. The levels of leptin and ghrelin at fasting status and after glucose seem to be altered in CP, whereas changes in insulin, PYY and CCK do not seem to be responsible for the metabolic changes in these patients.

How to approach endocrine assessment in severe obesity?

The increasing numbers of severely obese patients (body mass index BMI >40 kg/m(2) ) represent a significant management challenge. These patients are at risk of obesity-related complications that may be driven by changes in endocrine function. Their care may potentially be complex at times, and therefore, an appropriate assessment strategy will be relevant to timely diagnosis and management. In this article, we discuss an approach to the endocrine assessment of the severely obese patient. We consider the clinical question in three categories that may also represent different complexities in terms of subsequent management: (i) obesity as a consequence of structural lesions at the hypothalamic-pituitary region; (ii) obesity as a consequence of inherited and genetic syndromes; and (iii) functional neuroendocrine hormone abnormalities relating to obesity. The first two categories are associated with hypothalamic dysfunction, of which hypothalamic obesity is a consequence. Additionally, the implications and difficulties associated with imaging severely obese patients are discussed from an endocrinological perspective and we provide practical guidance on which to base practice.

Successful treatment of hyperphagia by resection of a hypothalamic hamartoma

Hypothalamic hamartomas (HHs) are benign lesions that are often associated with central precocious puberty and may present with gelastic seizures. Treatment modalities for HH include medical therapy with long-term gonadotropin-releasing hormone analogs or resection. The authors report the case of a 7-year-old girl who was diagnosed with an HH due to precocious puberty and was treated medically with a gonadotropin-releasing hormone analog for 3 years. Despite normalization of her plasma levels of luteinizing hormone, follicle-stimulating hormone, and estradiol and arrest of her precocious puberty, the patient developed progressive weight gain associated with extreme hyperphagia and morbid obesity by the age of 10 years. Her compulsive eating patterns were refractory to counseling and other interventions attempted by her parents and physicians. After resection of the HH, her hyperphagia resolved and her weight stabilized. To the authors' knowledge, this is the first report describing resection of an HH for the purpose of treating hyperphagia and obesity.

Tumor origin and growth pattern at diagnosis and surgical hypothalamic damage predict obesity in pediatric craniopharyngioma

Severe obesity is a major problem in pediatric craniopharyngioma. We investigated whether tumor origin, growth pattern, and surgical damage predict obesity in pediatric craniopharyngioma. Subjects were 58 patients (30 males) with no tumor recurrence during the first postoperative 18 months. Preoperative hypothalamic involvement was classified into no (pre_G0, n = 19), little (pre_G1, n = 21), and severe (pre_G2, n = 18) involvement groups based on sub- or supradiaphragmatic tumor origin and growth patterns. Postoperative hypothalamic involvement was classified into no (post_G0, n = 4), minimal (post_G1, n = 19), and significant (post_G2, n = 35) involvement groups according to follow-up imaging. The prevalence of obesity increased from 13.2 % at diagnosis (mean age = 8.1 years) to 37.9 % at last follow-up (mean duration = 9.1 years). Only the body mass index (BMI) Z-score increment of the first postoperative year (first-year ΔBMI_Z) was significant (P = 0.007). Both the preoperative BMI_Z (P = 0.001) and the first-year ΔBMI_Z (P = 0.017) showed an increasing trend from the pre_G0 to pre_G1 to pre_G2 group. For the 40 patients with pre_G0 or pre_G1, the first-year ΔBMI_Z was higher in the post_G2 group than the post_G1 group (0.02 ± 0.91 vs. 0.89 ± 0.72, P = 0.003). Tumor origin and growth pattern affect preoperative BMI_Z and postoperative weight gain. Despite little or no hypothalamic involvement at diagnosis, surgical damage contributes to postoperative weight gain in patients with craniopharyngioma.

Hypothalamic obesity: prevalence, associations and longitudinal trends in weight in a specialist adult neuroendocrine clinic

OBJECTIVE

Obesity is highly prevalent among adults with acquired, structural hypothalamic damage. We aimed to determine hormonal and neuroanatomical variables associated with weight gain and obesity in patients following hypothalamic damage and to evaluate the impact of early instigation of weight loss measures to prevent or limit the severity of obesity in these patients.

DESIGN

Retrospective study of 110 adults with hypothalamic tumours attending a specialist neuroendocrine clinic. BMI was calculated at diagnosis and at last follow-up clinic visit. Endocrine data, procedures, treatments and weight loss measures were recorded and all available brain imaging reviewed.

RESULTS

At last follow-up, 82.7% of patients were overweight or heavier (BMI≥25 kg/m(2)), 57.2% were obese (BMI≥30 kg/m(2)) and 14.5% were morbidly obese (BMI≥40 kg/m(2)). Multivariate analysis revealed that use of desmopressin (odds ratio (OR)=3.5; P=0.026), GH (OR=2.7; P=0.031) and thyroxine (OR=3.0; P=0.03) was associated with development of new or worsened obesity. Neuroimaging features were not associated with weight gain. Despite proactive treatments offered in clinic in recent years (counselling, dietetic and physical activity advice, and anti-obesity medications), patients have continued to gain weight.

CONCLUSIONS

Despite increased awareness, hypothalamic obesity is difficult to prevent and to treat. Improved understanding of the underlying pathophysiologies and multicentre collaboration to examine efficacy of novel obesity interventions are warranted.

Comparison of body composition, basal metabolic rate and metabolic outcomes of adults with Prader Willi syndrome or lesional hypothalamic disease, with primary obesity

CONTEXT

The care of patients with hypothalamic obesity is challenging.

OBJECTIVE

To compare body composition, basal metabolic rate (BMR) and metabolic outcomes of adults, with lesional or genetic hypothalamic obesity, with obese patients suffering from primary obesity, once matched for body mass index (BMI).

DESIGN AND PATIENTS

Adults with hypothalamic obesity of genetic origin (Prader Willi syndrome (PWS)) or acquired hypothalamic damage (HD), such as craniopharygioma, were compared with obese control candidates awaiting bariatric surgery (C), with a BMI between 35 and 65 kg m(-)(2), and aged between 18 and 50 years.

MAIN OUTCOME MEASURES

Body composition measured by whole-body dual-energy X-ray absorptiometry scanning, BMR using indirect calorimetry, hormonal and metabolic assessments.

RESULTS

A total of 27 adults with a genetic diagnosis of PWS, 15 obese subjects with HD and 206 obese controls with similar BMI were studied. Compared with the control group, PWS patients had an increased percentage of fat mass (FM), and a decreased percentage of android FM. The BMR of PWS patients was significantly lower than controls and highly correlated with lean body mass in PWS and C patients. Body composition of HD was similar with those of obese patients. A trend toward an increased prevalence of diabetes in HD patients and of cytolysis in PWS was observed in comparison with primary obese patients.

CONCLUSION

Genetic and lesional hypothalamic obesities have different consequences for phenotypic features such as body composition or BMR compared with primary obese patients. The mechanisms of adipose tissue development and metabolic complications may be different between genetic and lesional obesities.

Hypothalamic obesity syndrome: rare presentation of CNS+ B-cell lymphoblastic lymphoma

Hypothalamic obesity syndrome can affect brain tumor patients following surgical intervention and irradiation. This syndrome is rare at diagnosis in childhood cancer, but has been reported with relapse of acute lymphoblastic leukemia. Here we present a case of hypothalamic obesity syndrome as the primary presentation of a toddler found to have CNS+ B-cell lymphoblastic lymphoma. Cytogenetic studies on diagnostic cerebrospinal fluid revealed MLL gene rearrangement (11q23). Hyperphagia and obesity dramatically improved following induction and consolidation chemotherapy. We describe a novel presentation of hypothalamic obesity syndrome in CNS B-cell lymphoblastic lymphoma, responsive to chemotherapy.

Adipokines and central control in adenosine A1 receptor dependent glucose metabolism

Adenosine A1 receptor-deficient mice develop a phenotype of insulin resistance and grow fat. Participating pathophysiological pathways are not understood in detail yet, as discussed in our recent manuscript. This commentary further explores possible pathophysiological mechanisms with emphasis on the roles of the adipokines resistin, retinol-binding protein 4, adiponectin and the function of the gastric hormone ghrelin in adenosine mediated central regulation of energy balance. The postulate of an important function of ghrelin/A1AR axis provides a good hypothetical basis for further investigations to clarify the mechanism of A1AR-dependent metabolic homeostasis.

Impaired sympathoadrenal axis function contributes to enhanced insulin secretion in prediabetic obese rats

The involvement of sympathoadrenal axis activity in obesity onset was investigated using the experimental model of treating neonatal rats with monosodium L-glutamate. To access general sympathetic nervous system activity, we recorded the firing rates of sympathetic superior cervical ganglion nerves in animals. Catecholamine content and secretion from isolated adrenal medulla were measured. Intravenous glucose tolerance test was performed, and isolated pancreatic islets were stimulated with glucose and adrenergic agonists. The nerve firing rate of obese rats was decreased compared to the rate for lean rats. Basal catecholamine secretion decreased whereas catecholamine secretion induced by carbachol, elevated extracellular potassium, and caffeine in the isolated adrenal medulla were all increased in obese rats compared to control. Both glucose intolerance and hyperinsulinaemia were observed in obese rats. Adrenaline strongly inhibited glucose-induced insulin secretion in obese animals. These findings suggest that low sympathoadrenal activity contributes to impaired glycaemic control in prediabetic obese rats.

Obesity and craniopharyngioma

An epidemic of pediatric obesity has occurred across the world in recent years. There are subgroups within the population at high-risk of becoming obese and especially of having experience of precocious cardiovascular and metabolic co-morbidities of obesity. One of these subgroups comprises patients treated for childhood cancers and namely survivors of craniopharyngioma. The high incidence of obesity in this group makes these patients an important disease model to better understand the metabolic disturbances and the mechanisms of weight gain among cancer survivors. The hypothalamic-pituitary axis damage secondary to cancer therapies or to primary tumor location affect long-term outcomes. Nevertheless, the aetiology of obesity in craniopharyngioma is not yet fully understood. The present review has the aim of summarizing the published data and examining the most accepted mechanisms and main predisposing factors related to weight gain in this particular population.

Obesity, metabolic syndrome, and insulin dynamics in children after craniopharyngioma surgery

INTRODUCTION

Children after craniopharyngioma surgery often develop rapid weight gain and hyperphagia. We investigate the metabolic syndrome features, risk factors, and the insulin dynamics in these patients.

MATERIALS AND METHODS

Standard oral glucose tolerance tests (OGTT) were performed in 12 subjects, aged 7.7-18.1 years, after surgical removal of craniopharyngioma and their healthy age-, sex-, body mass index-, and pubertal stage-matched controls. Blood samples were obtained for measurement of levels of plasma glucose, insulin, lipids, liver enzymes, baseline hormonal profiles with calculation of insulin secretion, and insulin sensitivity indices derived from OGTT.

RESULTS AND DISCUSSION

Nine of 12 subjects were severely obese. All patients exhibited significant weight gain after surgery. The waist to hip ratio was higher in subjects compared to controls (P = 0.023). Subjects had higher fasting triglycerides (P = 0.019) and lower HDL/total cholesterol ratio (P = 0.012). Five of 12 subjects met the criteria for the metabolic syndrome, compared with one of 12 in controls. One patient had prediabetes and another patient had overt type 2 diabetes. Six of 12 subjects had nonalcoholic steatohepatitis. No significant risk factors were found between each group of patients with and without the metabolic syndrome. There were no differences of insulin secretion and insulin sensitivity indices between craniopharyngioma and control subjects.

CONCLUSION

Children after craniopharyngioma surgery are at risk of rapid weight gain and the development of metabolic syndrome. Further studies to better understand the mechanism are required to design effective treatment and prevention.

Risk factors for obesity in childhood survivors of suprasellar brain tumours: a retrospective study

AIM

To characterize postdiagnosis changes in body mass index (BMI) among childhood survivors of suprasellar brain tumours, and to determine the risk factors associated with obesity.

METHODS

We conducted a retrospective analysis of 46 children (16 boys and 30 girls) with median (IQR) age of 7.49 (3.47-11.59) years at tumour diagnosis, and followed up for 3.93 (1.68-7.27) years. Survival analyses were used to identify risks of developing obesity.

RESULTS

There were no sex differences in age at tumour diagnosis, duration of follow-up, tumour types, endocrinopathies, treatment modalities or baseline BMI SDS. In the first year after tumour diagnosis, ΔBMI SDS (median; IQR) was greater in girls (1.32; 0.07-2.08) than in boys (0.48; -0.40 to 0.89) (p = 0.01). At diagnosis, 3/46 children (6%) were obese; this increased to 20/46 (43%) by last follow-up (p < 0.001) and was more common in girls (17/30; 57%) than in boys (3/16; 19%). Female gender (hazard ratio 5.0, 95% CI 1.2-21.7; p = 0.04) and greater than average baseline BMI (hazard ratio 4.7, 95% CI 1.1-20.8; p = 0.02) were risk factors for subsequent obesity.

CONCLUSION

Accurate prediction of obesity risk is important and would allow early targeted intervention in high-risk patients.

Childhood obesity

Worldwide prevalence of childhood obesity has increased greatly during the past three decades. The increasing occurrence in children of disorders such as type 2 diabetes is believed to be a consequence of this obesity epidemic. Much progress has been made in understanding of the genetics and physiology of appetite control and from these advances, elucidation of the causes of some rare obesity syndromes. However, these rare disorders have so far taught us few lessons about prevention or reversal of obesity in most children. Calorie intake and activity recommendations need reassessment and improved quantification at a population level because of sedentary lifestyles of children nowadays. For individual treatment, currently recommended calorie prescriptions might be too conservative in view of evolving insight into the so-called energy gap. Although quality of research into both prevention and treatment has improved, high-quality multicentre trials with long-term follow-up are needed. Meanwhile, prevention and treatment approaches to increase energy expenditure and decrease intake should continue. Recent data suggest that the spiralling increase in childhood obesity prevalence might be abating; increased efforts should be made on all fronts to continue this potentially exciting trend.