Hypothalamic Obesity: The Sixth Cranial Endocrinopathy:

The insulin resistant brain: impact on whole-body metabolism and body fat distribution

Insulin exerts its actions not only on peripheral organs but is also transported into the brain where it performs distinct functions in various brain regions. This review highlights recent advancements in our understanding of insulin's actions within the brain, with a specific emphasis on investigations in humans. It summarises current knowledge on the transport of insulin into the brain. Subsequently, it showcases robust evidence demonstrating the existence and physiological consequences of brain insulin action, while also introducing the presence of brain insulin resistance in humans. This pathophysiological condition goes along with an impaired acute modulation of peripheral metabolism in response to brain insulin action, particularly in the postprandial state. Furthermore, brain insulin resistance has been associated with long-term adiposity and an unfavourable adipose tissue distribution, thus implicating it in the pathogenesis of subgroups of obesity and (pre)diabetes that are characterised by distinct patterns of body fat distribution. Encouragingly, emerging evidence suggests that brain insulin resistance could represent a treatable entity, thereby opening up novel therapeutic avenues to improve systemic metabolism and enhance brain functions, including cognition. The review closes with an outlook towards prospective research directions aimed at further elucidating the clinical implications of brain insulin resistance. It emphasises the critical need to establish feasible diagnostic measures and effective therapeutic interventions.

Appetite- and Weight-Regulating Neuroendocrine Circuitry in Hypothalamic Obesity

Since hypothalamic obesity (HyOb) was first described over 120 years ago by Joseph Babinski and Alfred Fröhlich, advances in molecular genetic laboratory techniques have allowed us to elucidate various components of the intricate neurocircuitry governing appetite and weight regulation connecting the hypothalamus, pituitary gland, brainstem, adipose tissue, pancreas, and gastrointestinal tract. On a background of an increasing prevalence of population-level common obesity, the number of survivors of congenital (eg, septo-optic dysplasia, Prader-Willi syndrome) and acquired (eg, central nervous system tumors) hypothalamic disorders is increasing, thanks to earlier diagnosis and management as well as better oncological therapies. Although to date the discovery of several appetite-regulating peptides has led to the development of a range of targeted molecular therapies for monogenic obesity syndromes, outside of these disorders these discoveries have not translated into the development of efficacious treatments for other forms of HyOb. This review aims to summarize our current understanding of the neuroendocrine physiology of appetite and weight regulation, and explore our current understanding of the pathophysiology of HyOb.

Resting energy expenditure in children at risk of hypothalamic dysfunction

OBJECTIVE

Children with suprasellar brain damage are at risk of hypothalamic dysfunction (HD). HD may lead to decreased resting energy expenditure (REE). Decreased REE, however, is not present in all children with HD. Our aim was to assess which children suspect for HD have low REE, and its association with clinical severity of HD or radiological hypothalamic damage.

PATIENTS AND METHODS

A retrospective cohort study was performed. Measured REE (mREE) of children at risk of HD was compared to predicted REE (pREE). Low REE was defined as mREE <90% of predicted. The mREE/pREE quotient was associated to a clinical score for HD symptoms and to radiological hypothalamic damage.

RESULTS

In total, 67 children at risk of HD (96% brain tumor diagnosis) with a mean BMI SDS of +2.3 ± 1.0 were included. Of these, 45 (67.2%) had low mREE. Children with severe HD had a significant lower mean mREE/pREE quotient compared to children with no, mild, or moderate HD. Mean mREE/pREE quotient of children with posterior hypothalamic damage was significantly lower compared to children with no or anterior damage. Tumor progression or tumor recurrence, severe clinical HD, and panhypopituitarism with diabetes insipidus (DI) were significant risk factors for reduced REE.

CONCLUSION

REE may be lowered in children with hypothalamic damage and is associated to the degree of clinical HD. REE is, however, not lowered in all children suspect for HD. For children with mild or moderate clinical HD symptoms, REE measurements may be useful to distinguish between those who may benefit from obesity treatment that increases REE from those who would be better helped using other obesity interventions.

Prevalence of Endocrine and Metabolic Comorbidities in a National Cohort of Patients with Craniopharyngioma

OBJECTIVE

The major part of craniopharyngioma (CP) morbidity is the tumor and/or treatment-related damage, which results in impaired function of the hypothalamic-pituitary axes and metabolic derangements. The aim of the study was to analyze the prevalence of long-term endocrine and metabolic comorbidities in a national cohort of CP patients based on the age at diagnosis and histology criteria.

DESIGN

A retrospective-prospective longitudinal cohort analysis.

METHODS

Forty-six patients with CP treated from 1979 onwards (19 with childhood-onset disease) in a single university institution were included in our study. Median follow-up from presentation was 12.8 years (interquartile range: 8.3-22.2 years) and comparable between age-at-diagnosis and histological subtype groups. Data on tumor histology were extracted from patients' records and re-evaluated if tissue samples were available (n = 32).

RESULTS

Childhood-onset patients presented more frequently with headache, and adult-onset with visual impairment. Prevalence of at least one pituitary axis affected increased from 54% at presentation to 100% at follow-up in childhood-onset and from 41 to 93% in adult-onset CP. Growth hormone deficiency, central diabetes insipidus, and panhypopituitarism were more prevalent in childhood-onset adamantinomatous CP (aCP) and least prevalent in adult-onset papillary CP (pCP). At follow-up, metabolic syndrome (MetS) was diagnosed in 80% of childhood-onset and 68% of adult-onset patients (p = 0.411). In the latter group, it tended to be more frequent in the aCP than pCP subtype (80 vs. 50%, p = 0.110).

CONCLUSIONS

Long-term endocrine and metabolic complications are very frequent in childhood- and adult-onset CP patients of both histological subtypes. The prevalence of MetS was higher compared to the largest cohort previously reported.

The effect of metformin on indomethacin-induced gastric ulcer: Involvement of nitric oxide/Rho kinase pathway

Gastric ulcer is a very common disease that represent an economic burden. Non-steroidal anti-inflammatory drugs induce ulcer in old patients and in patients with comorbidities. Indomethacin is widely used to induce gastric ulcer in animal models. Diabetic patients are highly susceptible to develop gastric ulcer. Metformin, the first line medication for the treatment of type II diabetes melilites that have many off label uses in non-diabetic patients, has been recently reported to have anti-inflammatory activities. Therefore, this research was conducted to assess the possible healing effects of metformin on gastric ulcers induced by indomethacin in rats. Indomethacin (48 mg/kg) single dose increased stomach acidity, ulcer index and induced histopathological changes. Indomethacin also decreased mucin levels and increased the activity of tumor necrosis factor-α (TNF-α), nuclear factor kappa-B (NF-κB), Rho-associated protein kinas-1 (ROCK-1) and decreased the levels of the protective nitric oxide (NO). After the induction of ulcer, rats were treated by omeprazole (30 mg/kg) or metformin (50, 100 or 200 mg/kg). Omeprazole and metformin were found to decrease stomach acidity and ulcer index, restored the histological features and increased mucin levels. Both also decreased the levels of NF-κB, TNF-α, ROCK-1 and increased NO. Metformin exerted ulcer healing effects comparable to that of omeprazole. This can be attributed, at least partly, to its anti-inflammatory activity and increasing NO levels.

Insulin Action in the Hypothalamus Increases Second-Phase Insulin Secretion in Humans

BACKGROUND

Animal studies and initial correlative data in humans indicate that insulin action in the brain may affect pancreatic insulin secretion. An important brain region for this process is the hypothalamus, an area that can develop insulin resistance.

METHODS

Fifteen young, healthy men (27 ± 3 years) with a wide BMI spectrum (20-30 kg/m2) underwent 2 hyperglycemic clamps (target blood glucose: 10 mmol/L). In this double-blind study, subjects received 160 U of insulin or placebo as a nasal spray on 2 days in randomized order. On another day, insulin sensitivity of the hypothalamus was determined by functional magnetic resonance imaging.

RESULTS

Glucose levels were comparable on both study days. In the whole group, C-peptide levels were not significantly different between conditions. Though, there was a significant interaction between insulin sensitivity of the hypothalamus × nasal spray × time on C-peptide levels (p = 10-6). The group was therefore divided according to median hypothalamic insulin sensitivity. C-peptide concentrations were higher after intranasal insulin compared to placebo spray in the group with a strong hypothalamic insulin response (p < 0.0001, β = 6.00 ± 1.24) and lower in the brain insulin-resistant group (p = 0.005, β = -2.68 ± 0.95). Neither somatostatin nor glucagon kinetics was altered by the nasal spray.

CONCLUSIONS

In participants with high hypothalamic insulin sensitivity, insulin action in the brain enhanced second-phase insulin secretion from pancreatic beta cells. This reaction could, for example, contribute to late postprandial glucose regulation by suppressing hepatic glucose production by portal venous insulin.

Detailed assessment of hypothalamic damage in craniopharyngioma patients with obesity

BACKGROUND/OBJECTIVES

Hypothalamic obesity (HO) occurs in 50% of patients with the pituitary tumor craniopharyngioma (CP). Attempts have been made to predict the risk of HO based on hypothalamic (HT) damage on magnetic resonance imaging (MRI), but none have included volumetry. We performed qualitative and quantitative volumetric analyses of HT damage. The results were explored in relation to feeding related peptides and body fat.

SUBJECTS/METHODS

A cross-sectional study of childhood onset CPs involving 3 Tesla MRI, was performed at median 22 years after first operation; 41 CPs, median age 35 (range: 17-56), of whom 23 had HT damage, were compared to 32 controls. After exclusions, 35 patients and 31 controls remained in the MRI study. Main outcome measures were the relation of metabolic parameters to HT volume and qualitative analyses of HT damage.

RESULTS

Metabolic parameters scored persistently very high in vascular risk particularly among HT damaged patients. Patients had smaller HT volumes compared to controls 769 (35-1168) mm³ vs. 879 (775-1086) mm³; P < 0.001. HT volume correlated negatively with fat mass and leptin among CP patients (r_s = -0.67; P < .001; r_s = -0.53; P = 0.001), and explained 39% of the variation in fat mass. For every 100 mm³ increase in HT volume fat mass decreased by 2.7 kg (95% CI: 1.5-3.9; P < 0.001). Qualitative assessments revealed HT damage in three out of six patients with normal volumetry, but HT damage according to operation records.

CONCLUSIONS

A decrease in HT volume was associated with an increase in fat mass and leptin. We present a method with a high inter-rater reliability (0.94) that can be applied by nonradiologists for the assessment of HT damage. The method may be valuable in the risk assessment of diseases involving the HT.

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.

The effectiveness of interventions to treat hypothalamic obesity in survivors of childhood brain tumours: a systematic review

BACKGROUND

Survivors of childhood brain tumours (SCBT) are at risk of type 2 diabetes and cardiovascular diseases. Obesity is a major driver of cardiometabolic diseases in the general population, and interventions that tackle obesity may lower the risk of these chronic diseases. The goal of this systematic review was to summarize current evidence for the presence of interventions to manage obesity, including hypothalamic obesity, in SCBT.

METHODS

The primary outcome of this review was the body mass index z-score change from baseline to the end of the intervention and/or follow-up. Literature searches were conducted in PsycINFO, CINAHL, the Cochrane Library, Medline, SPORTDiscus, EMBASE and PubMed. Two reviewers completed study evaluations independently.

RESULTS

Eleven publications were included in this systematic review (lifestyle intervention n = 2, pharmacotherapy n = 6 and bariatric surgery n = 3). While some studies demonstrated effectiveness of interventions to manage obesity in SCBT and alter markers of obesity and cardiometabolic risk, the evidence base was limited and of low quality, and studies focused on hypothalamic obesity. We conclude that there is urgent need to conduct adequately powered trials of sufficient duration, using existing and novel therapies to manage obesity, reduce the burden of cardiometabolic disorders and improve outcomes in SCBT.

Outcome of Radical Surgical Resection for Craniopharyngioma with Hypothalamic Preservation: A Single-Center Retrospective Study of 1054 Patients

OBJECTIVE

A retrospective review of the surgical outcome for patients with craniopharyngioma (CP) treated in a single neurosurgical center with surgical resection using visualization to ensure hypothalamic preservation.

METHODS

The study included 1054 patients. Before 2003, a pterional cranial approach was preferred for 78% of patients; after 2004, the unifrontal basal interhemispheric approach was performed in 79.1% of patients.

RESULTS

Complete tumor resection was achieved in 89.6% of patients; vision improved in 47.1% of patients who had preoperative vision impairment. However, diabetes insipidus worsened in 70.4% of patients and new-onset diabetes insipidus occurred in 29.7% of the remaining patients. Pituitary stalk preservation occurred in 48.9% of cases. There were 89.6% of patients with total tumor removal; 13.3% of patients showed tumor recurrence within an average of 2.8 years. Of 69 follow-up patients with a subtotal or partial resection, 94.2% showed tumor recurrence within an average of 4.3 months. Of the total patients, 82.3% fully recovered.

CONCLUSIONS

This study has shown that radical surgical resection of CP using microsurgical excision can be effective with a good patient outcome without more limitations on each individual tumor of distinct features despite the impact of recent endoscopic techniques on CP surgery. The surgical approach depends on a direct and wider visualization of CP located in the midline with preserving hypothalamic structures by identifying some hypothalamic landmark structures. After surgery, most patients can resume their normal activities even after aggressive tumor removal, although patients require postoperative hormonal replacement.

Adult NG2-Glia Are Required for Median Eminence-Mediated Leptin Sensing and Body Weight Control

While leptin is a well-known regulator of body fat mass, it remains unclear how circulating leptin is sensed centrally to maintain energy homeostasis. Here we show that genetic and pharmacological ablation of adult NG2-glia (also known as oligodendrocyte precursors), but not microglia, leads to primary leptin resistance and obesity in mice. We reveal that NG2-glia contact the dendritic processes of arcuate nucleus leptin receptor (LepR) neurons in the median eminence (ME) and that these processes degenerate upon NG2-glia elimination, which explains the consequential attenuation of these neurons' molecular and electrical responses to leptin. Our data therefore indicate that LepR dendrites in the ME represent the principal conduits of leptin's anorexigenic action and that NG2-glia are essential for their maintenance. Given that ME-directed X-irradiation confirmed the pharmacological and genetically mediated ablation effects on body weight, our findings provide a rationale for the known obesity risk associated with cranial radiation therapy.

Uncertainties in endocrine substitution therapy for central endocrine insufficiencies: growth hormone deficiency

The growth hormone deficiency (GHD) syndrome is associated with several metabolic abnormalities and it has been postulated that the increased cardiovascular disease (CVD) morbidity and mortality in GHD patients may be related to the missing metabolic effects of GH. Many CVD risk factors show improvements after GH therapy. Reduced bone mineral density (BMD) has been recorded both in patients with isolated GHD and in those with multiple pituitary deficiencies, indicating that GHD per se is responsible for the low BMD in both types of patients. These matters are, however, more complicated, as hypopituitary patients with GHD may have different phenotypes due to differences in underlying diagnoses. These phenotypes may not be clear-cut in individual patients. Moreover, patients may transit between different phenotypes over time due to extension of the pathology in the pituitary and/or the consequences of the treatment (surgery and/or radiotherapy). Three different phenotypes of hypopituitary patients will be discussed, with a focus on CVD risk and bone health: (1) patients with isolated GHD, e.g. due to prophylactic cranial radiotherapy for lymphoblastic leukaemia in childhood; (2) patients with GHD and multiple hormone deficiencies due to pituitary macroadenomas treated by surgery; (3) patients with GHD caused by craniopharyngiomas with multiple hormone deficiencies and hypothalamic involvement, where hypothalamic damage frequently dominates the positive metabolic effects of GH therapy. These phenotypes illustrate the differential impact of various pituitary pathologies on the phenotype of patients with GHD.

A review of childhood and adolescent craniopharyngiomas with particular attention to hypothalamic obesity

BACKGROUND

Although craniopharyngiomas are considered "benign" neoplasms by the World Health Organization classification, these tumors may create significant morbidity and mortality in patients. Hypothalamic obesity is a frequent complication of craniopharyngiomas and is refractory to current management options.

PATIENTS/METHODS

We reviewed 24 cases of craniopharyngiomas treated from 1992 to 2010 in patients <18 years of age regarding clinical presentation, neuroimaging, recurrence, morbidity, and mortality, with particular attention to hypothalamic obesity.

RESULTS

Our cohort conformed to published data in regard to neuroimaging characteristics, and clinical findings in the areas of endocrine, visual, neurological, neurobehavioral, and hypothalamic domains. At last follow-up, 53% of our patients were overweight (8%) or obese (46%). Only 25% of our patients had a healthy body mass index. Contrasting these data with body mass indices at diagnosis, where 21% of patients were overweight and 17% were obese, we found that there was a significant trend towards obesity over time. A significant portion of our mortality appears to be related to complications of obesity. The Native American population in Arizona appears to have a statistically greater incidence of obesity in childhood. Despite our small sample size, 75% of our Native Americans were obese at last follow-up and accounted for 50% of the mortality.

CONCLUSION

Hypothalamic obesity is a significant complication of craniopharyngiomas associated with increased mortality. The development of hypothalamic obesity is influenced by premorbid obesity, genetics, and therapy received, specifically radiation. Because of the intractability of hypothalamic obesity, improved understanding of neuroendocrine mechanisms, genomics, and newer antiobesity medications will be necessary to curb this significant complication.

Growth and weight of children with craniopharyngiomas based on the tumour location and growth pattern

This study aimed to characterise the weight and growth of children with craniopharyngiomas and to analyse the role of the tumour location and growth pattern in the development of obesity and growth retardation in these children. We retrospectively analysed the records of 109 consecutive children with primary craniopharyngiomas. The patients were divided into two subgroups according to the location of the tumour: intrasellar (Group A); and the floor of the third ventricle (Group B). Height and body mass index were measured at standardised ages and at time points before, after, and at the time of diagnosis. Endocrinological and hypothalamic measurements before and after surgery were compared. Reduced growth rates occurred in early infancy and persisted until diagnosis in Group A, but were only present from age 5-6 in Group B. Therefore, reduced growth rates occur early in the history of intrasellar tumours, whereas rapid postoperative weight gain invariably occurs in patients with third ventricle tumours, which is a significant predictive factor for severe long term obesity in patients with childhood craniopharyngiomas.

Mortality and morbidity in adult craniopharyngioma

A craniopharyngioma (CP) is an embryonic malformation of the sellar and parasellar region. The annual incidence is 0.5-2.0 cases/million/year and approximately 60 % of CP are seen in adulthood. Craniopharyngiomas have the highest mortality of all pituitary tumors. Typical initial manifestations at diagnosis in adults are visual disturbances, hypopituitarism and symptoms of elevated intracranial pressure. The long-term morbidity is substantial with hypopituitarism, increased cardiovascular risk, hypothalamic damage, visual and neurological deficits, reduced bone health, and reduction in quality of life and cognitive function. Therapy of choice is surgery, followed by cranial radiotherapy in about half of the patients. The standardised overall mortality rate varies 2.88-9.28 in cohort studies. Patients with CP have a 3-19 fold higher cardiovascular mortality in comparison to the general population. Women with CP have an even higher risk.

Enhanced insulin secretion and glucose tolerance in rats exhibiting low plasma free fatty acid levels and hypertriglyceridaemia due to congenital albumin deficiency

Congenitally analbuminaemic individuals and rats (NARs) exhibit several metabolic abnormalities, including hypertriglyceridaemia and plasma free fatty acid deficiency. Our aim was to study glucose homeostasis and insulin secretion in NARs. Plasma concentrations of lipids, glucose and insulin and secretion of insulin from the pancreatic islets were measured in female NARs and control animals (Sprague-Dawley rats; SDRs). Glucose homeostasis tests were also performed. Plasma glucose levels were similar between NARs and SDRs, irrespective of feeding status. However, fed insulinaemia was ∼37% higher (P 0.05) in NARs than in SDRs. The NARs displayed a markedly increased glucose tolerance, i.e. the integrated glycaemic response was one-third that of the control animals. Enhanced glucose tolerance was associated with threefold higher insulinaemia at peak glycaemia after a glucose load than in the control animals. Similar peripheral insulin sensitivity was observed between groups. Isolated pancreatic islets from NARs secreted significantly more insulin than islets from SDRs in response to a wide range of glucose concentrations (2.8-33.3 mm). Despite having similar liver glycogen contents in the fully fed state, NARs had ∼40% (P 0.05) lower glycogen contents than SDRs after 6 h fasting. The injection of a gluconeogenic substrate, pyruvate, elicited a faster rise in glycaemia in NARs compared with SDRs. Overall, NARs displayed enhanced glucose tolerance, insulin secretion and gluconeogenic flux. The higher glucose tolerance in NARs compared with SDRs is attributed to enhanced islet responsiveness to secretagogues, while peripheral insulin sensitivity seems not to be involved in this alteration. We propose that the enhanced glucose metabolism is a chronic compensatory adaptation to decreased free fatty acid availability in NARs.

MRI atlas of the human hypothalamus

Gaining new insights into the anatomy of the human hypothalamus is crucial for the development of new treatment strategies involving functional stereotactic neurosurgery. Here, using anatomical comparisons between histology and magnetic resonance images of the human hypothalamus in the coronal plane, we show that discrete gray and white hypothalamic structures are consistently identifiable by MRI. Macroscopic and microscopic images were used to precisely annotate the MRI sequences realized in the coronal plane in twenty healthy volunteers. MRI was performed on a 1.5 T scanner, using a protocol including T1-weighted 3D fast field echo, T1-weighted inversion-recovery, turbo spin echo and T2-weighted 2D fast field echo imaging. For each gray matter structure as well as for white matter bundles, the different MRI sequences were analyzed in comparison to each other. The anterior commissure and the fornix were often identifiable, while the mammillothalamic tract was more difficult to spot. Qualitative analyses showed that MRI could also highlight finer structures such as the paraventricular nucleus, the ventromedial nucleus of the hypothalamus and the infundibular (arcuate) nucleus, brain nuclei that play key roles in the regulation of food intake and energy homeostasis. The posterior hypothalamic area, a target for deep brain stimulation in the treatment of cluster headaches, was readily identified, as was the lateral hypothalamic area, which similar to the aforementioned hypothalamic nuclei, could be a putative target for deep brain stimulation in the treatment of obesity. Finally, each of the identified structures was mapped to Montreal Neurological Institute (MNI) space.

Late effects of therapy for pediatric brain tumor survivors

Approximately 2 of every 3 of all pediatric patients with brain tumors will be long-term survivors. However, there is a steep cost for pediatric brain tumor survivors, and the group as a whole faces significantly more late effects than many other survivors of pediatric cancers. Most of these effects can be attributed to direct neurologic damage to the developing brain caused by the tumor and its removal, the long-term toxicity of chemotherapy, or the effects of irradiation on the central nervous system. The late effects experienced by childhood brain tumor survivors involve multiple domains. This article will review the significant late effects that occur within the medical, neurocognitive, psychosocial, and economic domains of the survivorship experience. We conclude by discussing how the late effects in different domains often coexist and can create a complex set of obstacles that pose significant challenges for a survivor of a pediatric brain tumor on a daily basis.

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

Hypothalamic injury from acquired structural damage due to infiltrative disease, tumor, or their treatment aftereffects frequently results in the development of an obesity syndrome characterized by a rapid, unrelenting weight gain that may be accompanied by severe hyperphagia. Weight gain occurs from the disruption of the normal homeostatic functioning of the hypothalamic centers responsible for controlling satiety and hunger and regulating energy balance with resulting hyperphagia, autonomic imbalance, reduction of energy expenditure, and hyperinsulinemia. Curtailment of weight increase has traditionally been refractory to usual dietary and lifestyle interventions. Pharmacotherapy targeting insulin secretion and augmenting sympathetic output have been attempted to promote weight loss or attenuate weight gain. In addition, case reports suggest that bariatric surgery may be an effective treatment option for these patients. Hormonal deficits are often present, and their management may also have consequences for weight control. Hypothalamic obesity confers significant morbidity and mortality, and there is a need for greater elucidation of its risk factors and pathogenesis so that more effective interventions can be developed.

Prevention and treatment of pediatric obesity: an endocrine society clinical practice guideline based on expert opinion

OBJECTIVE

Our objective was to formulate practice guidelines for the treatment and prevention of pediatric obesity.

CONCLUSIONS

We recommend defining overweight as body mass index (BMI) in at least the 85th percentile but < the 95th percentile and obesity as BMI in at least the 95th percentile against routine endocrine studies unless the height velocity is attenuated or inappropriate for the family background or stage of puberty; referring patients to a geneticist if there is evidence of a genetic syndrome; evaluating for obesity-associated comorbidities in children with BMI in at least the 85th percentile; and prescribing and supporting intensive lifestyle (dietary, physical activity, and behavioral) modification as the prerequisite for any treatment. We suggest that pharmacotherapy (in combination with lifestyle modification) be considered in: 1) obese children only after failure of a formal program of intensive lifestyle modification; and 2) overweight children only if severe comorbidities persist despite intensive lifestyle modification, particularly in children with a strong family history of type 2 diabetes or premature cardiovascular disease. Pharmacotherapy should be provided only by clinicians who are experienced in the use of antiobesity agents and aware of the potential for adverse reactions. We suggest bariatric surgery for adolescents with BMI above 50 kg/m(2), or BMI above 40 kg/m(2) with severe comorbidities in whom lifestyle modifications and/or pharmacotherapy have failed. Candidates for surgery and their families must be psychologically stable and capable of adhering to lifestyle modifications. Access to experienced surgeons and sophisticated multidisciplinary teams who assess the benefits and risks of surgery is obligatory. We emphasize the prevention of obesity by recommending breast-feeding of infants for at least 6 months and advocating that schools provide for 60 min of moderate to vigorous daily exercise in all grades. We suggest that clinicians educate children and parents through anticipatory guidance about healthy dietary and activity habits, and we advocate for restricting the availability of unhealthy food choices in schools, policies to ban advertising unhealthy food choices to children, and community redesign to maximize opportunities for safe walking and bike riding to school, athletic activities, and neighborhood shopping.

Modulation of food intake following deep brain stimulation of the ventromedial hypothalamus in the vervet monkey

Object

Deep brain stimulation (DBS) has become an effective therapy for an increasing number of brain disorders. Recently demonstrated DBS of the posterior hypothalamus as a safe treatment for chronic intractable cluster headaches has drawn attention to this target, which is involved in the regulation of diverse autonomic functions and feeding behavior through complex integrative mechanisms. In this study, the authors assessed the feasibility of ventromedial hypothalamus (VMH) DBS in freely moving vervet monkeys to modulate food intake as a model for the potential treatment of eating disorders.

Methods

Deep brain stimulation electrodes were bilaterally implanted into the VMH of 2 adult male vervet monkeys by using the stereotactic techniques utilized in DBS in humans. Stimulators were implanted subcutaneously on the upper back, allowing ready access to program stimulation parameters while the animal remained conscious and freely moving. In anesthetized animals, intraoperatively and 6–10 weeks postsurgery, VMH DBS parameters were selected according to minimal cardiovascular and autonomic nervous system responses. Thereafter, conscious animals were subjected to 2 cycles of VMH DBS for periods of 8 and 3 days, and food intake and behavior were monitored. Animals were then killed for histological verification of probe placement.

Results

During VMH DBS, total food consumption increased. The 3-month bilateral implant of electrodes and subsequent periods of high-frequency VMH stimulation did not result in significant adverse behavioral effects.

Conclusions

This is the first study in which techniques of hypothalamic DBS in humans have been applied in freely moving nonhuman primates. Future studies can now be conducted to determine whether VMH DBS can change hypothalamic responsivity to endocrine signals associated with adiposity for long-term modulation of food intake.

Childhood Obesity: Adrift in the “Limbic Triangle”

The prevalence and severity of childhood obesity have increased steadily over the past three decades. The human species evolved to rigorously defend its lower limit for weight and adiposity but is tolerant of the upper limit, which, until recent times, was rarely approached. Neuroendocrine mechanisms within the limbic core of the brain prevent starvation (ventromedial hypothalamus), heighten reward (ventral tegmental area and nucleus accumbens), and attenuate stress (amygdala), in order to promote food-seeking and ingestive behavior and to conserve energy output. In a stressful modern environment with ready access to calorie-dense, highly palatable foods and limited venues for activity, normal, reflexive responsiveness to these three drives makes weight gain all but inevitable. The obesity that ensues often engenders insulin resistance, which undermines the ability of normal hunger and satiety signals to accurately modulate energy intake versus expenditure. Obesity interventions that rely on cognitive information alone cannot free children from this "limbic triangle." Integrated multidisciplinary family- and community-based education, effective stress reduction, and a societal commitment to alter the food and built environments are all necessary components to battle the global obesity epidemic.

A multicenter, randomized, double-blind, placebo-controlled, dose-finding trial of a long-acting formulation of octreotide in promoting weight loss in obese adults with insulin hypersecretion

OBJECTIVE

To compare changes in weight in obese patients who received long-acting octreotide (octreotide LAR) at one of three dose levels (20, 40, or 60 mg) or placebo over 6 months and to identify the lowest dose of octreotide LAR that safely achieved optimal weight loss.

DESIGN

Randomized, double-blind, placebo-controlled trial of octreotide LAR at three dose levels.

PATIENTS

A total of 172 adults (28 men and 144 women) with at least moderate obesity (body mass index (BMI) range 30-65 kg/m2) and evidence of insulin hypersecretion were enrolled. Patients were predominantly either Caucasian (50.0%) or African American (45.3%). The mean age (38 +/- 11 year), weight (110.7 +/- 23 kg), and BMI (39.8 +/- 6.5 kg/m2) were similar across the four treatment groups.

MEASUREMENTS

Efficacy measures included weight, BMI, fasting serum glucose; triglycerides; percentage of total body fat and abdominal fat as measured by dual-energy X-ray absorptiometry; skin fold thickness; waist-to-hip circumference; leptin; percentage of carbohydrates, fat, and protein ingested; nutritional evaluation (including dietary analysis--3-day food record); quality of life (QoL; using the Impact of Weight on Quality of Life-Lite); Beck Depression Inventory; and Carbohydrate Craving Questionnaire. Safety measures included medical history, vital signs, physical examinations, hematology, blood chemistries, thyroid function tests, hemoglobin A1c, gallbladder ultrasound, electrocardiograms, and adverse events.

RESULTS

After 6 months of treatment, patients receiving 40 or 60 mg of octreotide LAR experienced statistically significant weight loss compared to baseline, with mean differences from placebo in percent weight change of -1.98 and -1.87%, respectively. This finding was accompanied by statistically significant mean decreases in BMI compared to baseline, that is, a mean decrease of 0.73 and 0.79 kg/m2 for the 40 and 60 mg treatment arms, respectively. The observed weight loss was progressive during the 6-month treatment in the two higher dose groups. The lowest dose to reach statistical significance in weight loss after 6 months' treatment was 40 mg. Post hoc analysis revealed a 3.5-3.8% weight loss at month 6 in the two higher dose groups among Caucasian patients having insulin secretion greater than the median of the cohort, defined as CIR(gp) (corrected insulin response at the glucose peak) > or = 1.43. There were no statistically significant changes in QoL scores, body fat, leptin concentration, Beck Depression Inventory, or macronutrient intake. Mean changes of blood glucose AUC(0-180 min) during an oral glucose tolerance test in patients taking octreotide LAR were 39-40 mg/dl h higher than those on placebo. A total of 7-21% of the patients taking octreotide LAR reached a 5% or greater decrease in body weight from Baseline, compared to 11% for the placebo group. This was not statistically significant. The most common adverse events included diarrhea, headache, cholelithiasis, nausea, and abdominal pain.

CONCLUSION

Octreotide LAR given at 40 or 60 mg resulted in statistically significant weight loss. A post hoc analysis stratifying patients by race and CIR(gp) indicated that Caucasian patients with the greater degree of insulin hypersecretion appeared to derive the most benefit from treatment. The observed safety profile was consistent with the known effects of octreotide from previous studies.

Quality of Life Among Long-Term Adolescent and Adult Survivors of Childhood Cancer

Purpose

We assessed effects of childhood or adolescent cancer on quality of life among adolescent and adult cancer survivors, a group who are thought to be at particular risk for adverse late effects.

Patients and Methods

We studied 1,334 survivors and 1,477 age- and sex-matched, general population controls from across Canada using a mailed questionnaire which included the Short Form-36 (SF-36) and measures of self-esteem, optimism, and life satisfaction. General linear models and logistic regression were used. Survivor-control differences corresponding to an effect size (ES) ≥ 0.5 were considered clinically important.

Results

Participants were age 15 years to 37 years. Most survivors (83.8%) were diagnosed ≥ 10 years earlier. Fewer survivors (62.1%) than controls (71.1%) reported very good or excellent general health (adjusted odds ratio, 0.6; 95% CI, 0.5 to 0.7). However, quality of life differences between survivors and controls were small, and for the most part probably not clinically important. Three clinical characteristics—having had CNS or bone cancer, more than one treatment series, and ≥ two organs with a dysfunction at treatment end—were independently associated with poorer quality of life in the physical dimensions. Only survivors with ≥ two organs with dysfunction (8.7%) reported poorer quality of life in both physical and psychosocial domains, with several clinically important ES. The largest ES for the SF-36 physical summary scores were found in the 8% of survivors with two or three of these characteristics simultaneously, compared with those survivors who had none (−0.79 and −1.13, respectively).

Conclusion

Overall, a sizeable majority of adolescent and adult long-term survivors of childhood cancer in Canada appear to have adapted well.

Dexamphetamine use for management of obesity and hypersomnolence following hypothalamic injury

Unrelenting weight gain, morbid obesity and disturbance of the sleep-wake cycle are well-recognized sequelae of hypothalamic injury. These health problems and their risk of significant associated co-morbidity drive the search for potential treatment modalities.

OBJECTIVE

To report effects on weight change and wakefulness in a cohort of 12 patients with structural hypothalamic lesions treated with low-dose dexamphetamine.

METHOD

Retrospective review of case notes.

RESULTS

Twelve patients received dexamphetamine 5 mg twice daily (median duration 13 months in males, 15 months in females). Ten of 12 patients experienced either stabilisation of weight or weight loss on treatment (median loss -0.7 SDS in males, -0.44 SDS in females). Eleven patients reported improvement in daytime wakefulness and/or concentration and exercise tolerance.

CONCLUSION

Low-dose dexamphetamine therapy has a positive impact on inexorable weight gain and daytime somnolence following hypothalamic injury.

Insulin dynamics predict body mass index and z-score response to insulin suppression or sensitization pharmacotherapy in obese children

OBJECTIVE

To assess the use of oral glucose tolerance testing (OGTT) to predict efficacy of insulin sensitization (metformin) or suppression (octreotide) because insulin resistance and insulin hypersecretion may impact pharmacotherapeutic efficacy in obese children.

STUDY DESIGN

Forty-three and 24 obese children, with and without central nervous system (CNS) insult, underwent OGTT. Insulin sensitivity was expressed as composite insulin sensitivity index (CISI), and secretion as corrected insulin response (CIRgp). Those without CNS insult received metformin (weight-based dosing) for 6 to 16 months. Those with CNS insult received octreotide SQ 15 microg/kg/d for 6 months. Body mass index (BMI) and z-score responses were modeled using CIRgp and CISI.

RESULTS

Metformin: With CIRgp and CISI = 1, BMI z-score in white children declined by 0.23 over the first 4 months (P < .001), and by 0.14 over the next year (P = .33). Each 2-fold increase in CIRgp or CISI attenuated BMI z-score reduction, but with wide uncertainty (P = .24). Black children exhibited little response. Octreotide: With CIRgp and CISI = 1, BMI z-score decreased by 0.23 in the first 4 months (P = .052). Efficacy was dependent on an interaction between CIRgp and CISI (P = .051).

CONCLUSIONS

Efficacy of metformin was predicted by pretreatment insulin resistance. Efficacy of octreotide was predicted by insulin hypersecretion and sensitivity.

Craniopharyngioma in childhood

In summary, much progress has been made in our understanding of childhood craniopharyngiomas. These histologically benign but "geographically malignant" tumors are challenging to treat and require experienced clinicians from multiple disciplines including neurosurgery, radiology, hematology/oncology, ophthalmology, endocrinology, and general pediatrics to address the multiple issues that arise with diagnosis, treatment, and long-term follow-up of affected children. The study and close observation of patients who have craniopharyngiomas may also be beneficial for our general understanding of pathophysiologic processes such as the observed "growth without growth hormone" phenomenon or the well-described and studied hypothalamic obesity phenotypes.

Fast Food, Central Nervous System Insulin Resistance, and Obesity

Rates of obesity and insulin resistance have climbed sharply over the past 30 years. These epidemics are temporally related to a dramatic rise in consumption of fast food; until recently, it was not known whether the fast food was driving the obesity, or vice versa. We review the unique properties of fast food that make it the ideal obesigenic foodstuff, and elucidate the mechanisms by which fast food intake contributes to obesity, emphasizing its effects on energy metabolism and on the central regulation of appetite. After examining the epidemiology of fast food consumption, obesity, and insulin resistance, we review insulin’s role in the central nervous system’s (CNS) regulation of energy balance, and demonstrate the role of CNS insulin resistance as a cause of leptin resistance and in the promotion of the pleasurable or “hedonic” responses to food. Finally, we analyze the characteristics of fast food, including high-energy density, high fat, high fructose, low fiber, and low dairy intake, which favor the development of CNS insulin resistance and obesity.

Endocrine late effects of cancer treatment

Endocrinopathies are significant consequences of the treatment of childhood cancers. The risk of developing these adverse events is related to the underlying disease and its treatment with cytotoxic agents and radiation therapy. This article reviews hypothalamic-pituitary, thyroid, and gonadal dysfunction, as well as osteopenia-osteoporosis and obesity.

'Programming' of orexigenic and anorexigenic hypothalamic neurons in offspring of treated and untreated diabetic mother rats

Exposure to maternal diabetes in utero (GD) may 'program' for obesity. Orexigenic neuropeptides, like neuropeptide Y (NPY) and agouti-related peptide (AGRP), and anorexigenic neuropeptides, like proopiomelanocortin (POMC) and alpha-melanocyte-stimulating hormone (MSH), are decisively involved in body weight regulation. We investigated consequences of GD and its treatment by pancreatic islet transplantation in rats for development of neuropeptidergic neurons in the arcuate hypothalamic nucleus (ARC) in weanling offspring. In GD, islet transplantation on d15 of pregnancy led to normalized blood glucose. Sham-transplanted GD mothers (TSGD) remained hyperglycemic. Twenty-one-day-old TSGD offspring developed hypothalamic 'malorganization'. Despite of normal leptin and insulin levels in TSGD offspring, increased immunopositivity of NPY and AGRP appeared. TSGD offspring showed unchanged POMC, but decreased MSH-immunopositivity. In conclusion, untreated diabetes in pregnant rats leads to 'malprogramming' of hypothalamic neuropeptidergic neurons in offspring, probably contributing to later development of overweight. These acquired alterations are preventable by treatment of maternal GD.

Craniopharyngioma Therapy

BACKGROUND

Craniopharyngiomas are the most common intracranial tumor of extraneural origin in childhood.

REVIEW SUMMARY

In this review, we discuss the presentation, diagnosis, and treatment of craniopharyngioma. As the survival prognosis of patients with craniopharyngioma is quite optimistic, long-term side effects of both the tumor and its treatment are now better appreciated. Aside from well-recognized hormonal deficiencies and visual deficits related to tumor location, patients are now acknowledged to experience pathologic obesity and deficits of higher cortical function, memory, and behavior. The combination of these deficits can have profoundly detrimental effects on quality of life.

CONCLUSIONS

Careful attention to issues related to hormonal balance, visual field defects, cognitive function, and mood disorders is essential to optimize long-term outcome of patients with craniopharyngioma.

Changes in height, weight, and body mass index in children with craniopharyngioma after three years of growth hormone therapy: analysis of KIGS (Pfizer International Growth Database)

Extreme degrees of obesity may occur in association with hypothalamic tumors, usually after surgical intervention. This phenomenon has been reported to occur in as many as 25-75% of children undergoing extensive surgical extirpation of craniopharyngiomas (Cranio). Because less is known about the auxology of children with Cranio with milder alterations in growth, we undertook a 3-yr longitudinal analysis, using the KIGS database (Pfizer International Growth Database), to study their growth patterns and evolution of weight. We compared the effect of GH therapy on height, weight, and body mass index (BMI) in 199 prepubertal children with diagnosed Cranio treated by surgery and/or radiotherapy to two other groups of children with other causes of organic GH deficiency (OGHD): one with postsurgical and/or postirradiated OGHD (OGHD + S/I; n = 92) and the other with OGHD not due to Cranio and not having undergone either surgery or irradiation (OGHD - S/I; n = 85). At the start of GH therapy, 1) mean chronological (P < 0.0001) and bone (P = 0.0002) ages were youngest in OGHD - S/I and oldest in OGHD + S/I; 2) the mean height sd score (SDS) was lowest in OGHD - S/I and comparably higher in the other two groups (P < 0.0001); 3) mean weight and BMI SDS were greatest in Cranio and least in OGHD - S/I (both P < 0.0001); and 4) the mean initial GH dose prescribed was highest in OGHD - S/I and comparable in the other two groups (P < 0.0001). After 3 yr of GH therapy, 1) mean bone age remained youngest in OGHD - S/I and oldest in OGHD + S/I (P < 0.0001); 2) mean height SDS was highest in Cranio and comparably lower in the other two groups (P = 0.0159); 3) mean weight and BMI SDS remained greatest in Cranio and least in OGHD - S/I (P < 0.0001 and P = 0.0003, respectively); and 4) the mean GH dose remained highest in the OGHD - S/I group and least in the Cranio group (P = 0.0082). There were statistically significant increases within each group between the start of treatment and after 3 yr of GH therapy in height and weight, but not in BMI SDS. Lastly, after 3 yr of GH treatment, children in the Cranio group continued to have disproportionately heavier weight and higher BMI (with the greatest values in those with lower stimulated peak GH concentrations) compared with members of the other two groups, with no salutary effect of GH treatment on weight SDS and a mild improvement in BMI SDS. After S/I treatment, children with Cranio are disproportionately prone to varying degrees of weight gain compared with children with other forms of OGHD. In the present cohort of prepubertal children with Cranio, GH therapy induced excellent linear growth, but failed to have an ameliorative effect on weight gain and had only a slight beneficial effect on BMI gain. Because affected children may have resultant significant long-term medical morbidity and diminished quality of life, it is critical that the mechanism of this phenomenon be determined to devise helpful preventive or therapeutic interventions.

Longitudinal study on growth and body mass index before and after diagnosis of childhood craniopharyngioma

We analyzed whether childhood craniopharyngioma predisposes to obesity and growth impairment. Height/length, body mass index (BMI), and hypothalamic involvement were evaluated in 90 patients at standardized ages and time points before, after, and at the time of diagnosis. Relevant decreases in height sd score (SDS) started at 10-12 months of age and persisted until diagnosis of childhood craniopharyngioma. Relevant increases in BMI SDS were detectable between 4 and 5 yr of age. Postoperative BMI SDS (yr 1-6) had a weak positive correlation with BMI SDS at the time of diagnosis. In linear regression analysis, hypothalamic tumor involvement (P < 0.001), ponderal index at birth (P = 0.014), and BMI SDS at age 6-7 months (P = 0.029) and at age 5 yr (P < 0.001) had relevant and independent impacts on the development of obesity. Patients with hypothalamic involvement (n = 48) presented lower ponderal index and BMI SDS at birth and higher BMI SDS at the time of diagnosis (P < 0.001) as well as during annual follow-up (P < 0.001) compared with patients without hypothalamic involvement (n = 42). From childhood (3.5-4 yr) to the time of diagnosis, growth rates were reduced for patients with hypothalamic tumor involvement. Patients without hypothalamic involvement presented reduced growth rates in early infancy (age 10-12 months) that persisted until diagnosis. We conclude that reduced growth rates occur quite early in history; BMI SDS increases occur later and are predictive of obesity. Hypothalamic involvement is the major risk factor for obesity in patients with childhood craniopharyngioma.

Nonalcoholic fatty liver disease among patients with hypothalamic and pituitary dysfunction

Patients with hypopituitarism develop a phenotype similar to metabolic syndrome with central obesity and diabetes. Similarly, patients with hypothalamic damage may develop central obesity, insulin resistance, and hyperphagia. We sought to examine the clinical associations between hypopituitarism, hypothalamic dysfunction, and nonalcoholic fatty liver disease (NAFLD). A case series of patients seen at our institution with diagnoses of hypopituitarism, hypothalamic obesity, or craniopharyngioma and NAFLD was undertaken. Clinical, laboratory, and liver biopsy features were reviewed. Twenty-one patients were identified. NAFLD was diagnosed 6.4 +/- 7.5 years (median 3 years) after the diagnosis of hypothalamic/pituitary dysfunction. Mean gain in body mass index (BMI) between diagnoses of hypothalamic/pituitary disease and NAFLD was 11.3 +/- 8.9 kg/m(2) at an average yearly rate of 2.2 +/- 2.2 kg/m(2). The majority of patients developed elevated glucose levels and dyslipidemia by time of diagnosis of NAFLD. Of the 10 patients biopsied, six were cirrhotic, two had nonalcoholic steatohepatitis (NASH) with fibrosis, and two had simple steatosis. Long-term follow-up of 66 +/- 33 months (range 12-120) was available for 18 patients. Two required liver transplantation. Six patients died, two from liver related causes. In conclusion, patients with hypothalamic and/or pituitary disease are at risk of excessive weight gain, impaired glucose tolerance, and dyslipidemia with subsequent development of NAFLD. This group has a high prevalence of cirrhosis placing them at risk for liver-related death. The novel evidence that hypothalamic/pituitary dysfunction may be accompanied by progressive NAFLD has important implications for the work-up and management of patients with hypothalamic/pituitary disease.

Cross-fostering to diabetic rat dams affects early development of mediobasal hypothalamic nuclei regulating food intake, body weight, and metabolism

Exposure to maternal gestational diabetes (GD) "programs" offspring for obesity in childhood and later life. Recent clinical data suggest that neonatal ingestion of breast milk from diabetic mothers might be crucially involved. Mediobasal hypothalamic nuclei such as the ventromedial nucleus (VMN), the paraventricular nucleus (PVN) and the arcuate nucleus (ARC) play a key role in the central nervous system regulation of food intake and body weight. In the ARC, orexigenic neuropeptides such as neuropeptide Y (NPY), galanin (GAL), and agouti-related peptide (AGRP) and anorexigenic neuropeptides such as proopiomelanocortin (POMC) and alpha-melanocyte-stimulating hormone (MSH) are expressed. We investigated the effects of neonatal exposure to milk from GD rat dams on the development of hypothalamic nuclei in weanling rats. Offspring of control (CO) rat dams cross-fostered to GD rat dams (CO-GD) developed early postnatal growth delay. On d 21 of life, CO-GD rats showed structural and functional hypothalamic "malprogramming." The ARC of CO-GD rats showed increased immunopositivity of both NPY and AGRP under basal conditions, despite normal levels of glucose, leptin, and insulin. Conversely, CO-GD rats showed decreased immunopositivity of both POMC and MSH and decreased density of immunopositive neurons, compared with offspring of control rat dams cross-fostered to control rat dams. No morphometric alterations were found in the VMN, whereas CO-GD rats showed an increased total number of neurons in the PVN. In summary, neonatal exposure to maternal diabetes through the intake of dam's milk in rats leads to a complex malprogramming of hypothalamic orexigenic and anorexigenic circuits that are critically involved in the lifelong regulation of food intake, body weight, and metabolism.

Prevention by maternal pancreatic islet transplantation of hypothalamic malformation in offspring of diabetic mother rats is already detectable at weaning

Exposure to gestational diabetes (GD) in rats leads to dysplasia of the ventromedial hypothalamic nucleus (VMN), decisively involved into the regulation of body weight and metabolism. Recently, we have shown here that VMN malformation is absent in adult offspring of GD mothers treated by pancreatic islet transplantation during gestation. We therefore now investigated whether VMN malformation and its prevention are already present at the early postnatal end of the critical hypothalamic differentiation period. Already at weaning, the total number of VMN neurons, the volume of the VMN relative to total brain volume, and the numerical density of neurons in the anterior subnucleus of the VMN were reduced in offspring of sham-transplanted mothers (all P<0.05), but did not differ between offspring of islet-transplanted mothers and controls. No morphometric alterations occurred in the paraventricular hypothalamic nucleus. In conclusion, prevention of VMN malformation in offspring of islet-transplanted diabetic mothers is a direct consequence of normalized maternal metabolism during critical perinatal development.

Obesity in patients with craniopharyngioma: assessment of food intake and movement counts indicating physical activity

Patients with childhood-onset craniopharyngioma (CP) often suffer from obesity. We evaluated two important etiological factors of obesity development, energy intake and physical activity. Energy intake was supposed to be high due to a disturbed hypothalamic regulation of appetite. We used a validated nutritional diary to determine the 1-wk food intake in 27 CP patients (12 with intrasellar tumors and 15 with hypothalamic tumors) and 1027 controls who were a representative sample of the 7- to 16-yr-old German population. In 2 accelerometry settings, we determined movement counts indicating physical activity. Nineteen CP patients were comparable to 26 controls for age and body mass index. One setting was a clinical one during weight reduction; the other was an out-patient setting. Daily energy intake was 1916 +/- 677 kcal (mean +/- SD) in intrasellar CP patients, 2075 +/- 877 kcal in hypothalamic CP patients, and 2476 +/- 815 kcal in non-CP controls. Patients suffering from CP showed fewer movement registrations [clinical setting, 228 vs. 298 cpm for obese controls (P = 0.01); out-patient setting, 228 vs. 282 cpm for controls (P = 0.08)]. Differences were most pronounced during leisure time (382 cpm in CP patients vs. 546 cpm in obese controls; P = 0.002; clinical setting). Our findings suggest that reduced physical activity, rather than increased energy intake, in CP patients is responsible for the obesity development noted in these subjects.

The therapeutic potential of somatostatin receptor ligands in the treatment of obesity and diabetes

Since the development of synthetic somatostatin analogues, several therapeutic applications for somatostatin receptor agonist molecules have been defined. Established applications for somatostatin analogue treatment include pituitary tumours (growth hormone and thyrotropin-secreting adenomas), neuroendocrine tumours of the pancreas and gastrointestinal tract (so-called carcinoid tumours, vasoactive intestinal tumours) and gastroenterological conditions (pancreatitis, gastrointestinal bleedings, refractory diarrhoeas, pancreatic and intestinal fistulas, diarrhoea in AIDS). Further areas for development of somatostatin analogue therapy include obesity, polycystic ovary syndrome and diabetes mellitus, dysmetabolic conditions that are often interrelated. The challenge for the future will be to transform results from clinical trials conducted in heterogeneous clinical situations into novel options of somatostatin analogue use. Since obesity and diabetes mellitus both are disorders of marked heterogeneity, the subgroup of patients that will benefit most from somatostatin analogue treatment has yet to be defined. In addition, the development of more universal ligands covering all of the known somatostatin receptor molecules as well as receptor subtype specific agents is currently underway. The establishment of slow-release depot formulations of octreotide and lanreotide has already provided a more acceptable and consistent delivery mechanism. Use of biodegradable polymer microsphere formulations provides the basis for the development of novel applications, which include hyperinsulinaemia, obesity and polycystic ovary syndrome as components of the dysmetabolic syndrome. The most developed thus far is the use of octreotide in hyperinsulinaemic forms of obesity and in distinct stages of diabetic retinopathy.

Endocrine late effects of cancer treatment

Endocrinopathies are significant consequences of childhood cancers and their treatments. The risk of developing these adverse events is related to the underlying disease and its treatment with cytotoxic drugs and radiation therapy. This article will explore the current literature about endocrine late effects of hypothalamic-pituitary, thyroid, and gonadal dysfunction, as well as osteoporosis and obesity.

Use of somatostatin receptor ligands in obesity and diabetic complications

Somatostatin (SMS) is a potent inhibitory molecule. It inhibits both exocrine and endocrine secretory functions of the pancreas, suppresses growth hormone secretion and reduces the level of insulin-like growth factor-1. Long-acting somatostatin analogues were currently investigated for potential clinical benefits in two settings: (a) control of hyperinsulinaemia in obesity and (b) control of an excess of pro-angiogenic factors in diabetes-associated retinal complications. In two randomized, controlled trials the long-acting somatostatin analogue octreotide retarded progression of the microvascular complications in pre-proliferative and advanced stages of diabetic retinopathy. Inhibition of the early phase of insulin secretion by use of octreotide in patients with hypothalamic obesity resulted in weight loss and improved quality of life. Efficacy of octreotide correlated to residual beta-cell activity prior to the treatment. Obesity and diabetes mellitus are the most common chronic metabolic disorders in the world. The use of somatostatin analogues addressing the various hormonal imbalances of these disorders may provide a novel concept for their pharmacological treatment.