Pediatric endocrine disorders of energy balance

The complex web of obesity: from genetics to precision medicine

INTRODUCTION

Obesity is a growing public health concern affecting both children and adults. Since it involves both genetic and environmental components, the management of obesity requires both, an understanding of the underlying genetics and changes in lifestyle. The knowledge of obesity genetics will enable the possibility of precision medicine in anti-obesity medications.

AREAS COVERED

Here, we explore health complications and the prevalence of obesity. We discuss disruptions in energy balance as a symptom of obesity, examining evolutionary theories, its multi-factorial origins, and heritability. Additionally, we discuss monogenic and polygenic obesity, the converging biological pathways, potential pharmacogenomics applications, and existing anti-obesity medications - specifically focussing on the leptin-melanocortin and incretin pathways. Comparisons between childhood and adult obesity genetics are made, along with insights into structural variants, epigenetic changes, and environmental influences on epigenetic signatures.

EXPERT OPINION

With recent advancements in anti-obesity drugs, genetic studies pinpoint new targets and allow for repurposing existing drugs. This creates opportunities for genotype-informed treatment options. Also, lifestyle interventions can help in the prevention and treatment of obesity by altering the epigenetic signatures. The comparison of genetic architecture in adults and children revealed a significant overlap. However, more robust studies with diverse ethnic representation is required in childhood obesity.

Harmful effects of high amounts of glucose on the immune system: An updated review

Release and storage of energy can be regulated by the metabolic parameter dependent on the central nervous system. Macrophages are one of the most professional antigen-presenting cells that are formed by the accumulation of dead or damaged cells or in response to the infection, which has the main function of phagocytosis, secretion of cytokines, and presenting antigen to T cells. A proper immune response is needed for the production of effector cytokines along with comprehensive and rapid cell proliferation and growth. Activation of the immune system and immune cells is needed to increase glucose metabolism. When the immune system responds to pathogens, chemokines inform immune cells such as macrophages and T cells to travel to the infected area. Although glucose is vital for the proper function of immune cells and their proliferation, a high amount of glucose may lead to impaired function of the immune system and pathological conditions. However, a suitable amount of glucose is indispensable for the immune system, but its elevated amount leads to excessive proinflammatory cytokines production. In this study, we focused on the master regulatory role of glucose on the immune system.

The Adoption of the Healthy Eating Standards in Local Afterschool Programs Does Not Improve Quality of Snacks

OBJECTIVES

In 2011, the National Afterschool Association adopted the Healthy Eating and Physical Activity (HEPA) standards to address snack quality and physical activity in afterschool programs. Although research has indicated promise in the adoption of these policies by national organizations, less is known about local adoption, implementation, and effectiveness. In this study, we aimed to compare the quality of snacks served at program sites pre- and post-adoption and to determine the quality of non-program snacks compared to program snacks.

METHODS

An interrupted time series design was used to measure snack quality and consumption at 3 policy adopting sites and 2 non-policy adopting sites that served as a comparison control. Trained research staff collected snack type, brand, and amount consumed using a modified quarter-waste method. Analysis on nutrient content of snacks was completed using Nutrition Data System for Research software.

RESULTS

Adoption of the HEPA standards among policy adopting sites did not result in significantly better snack quality. Across all sites, program snacks were healthier than non-program snacks.

CONCLUSION

Pursuing additional components of the HEPA standards related to implementation may be necessary to significantly improve snack quality. Environmental supports such as limiting the amount of non-program snacks available onsite may improve snack quality.

Endocrine Long-Term Follow-Up of Children with Neurofibromatosis Type 1 and Optic Pathway Glioma

BACKGROUND/AIMS

Children with optic pathway glioma (OPG) face sequelae related to tumour location and treatment modalities. We aimed to assess the prevalence of hypothalamic-pituitary dysfunctions in children with neurofibromatosis type 1 (NF1) and OPG who did not receive radiotherapy or surgical resection. The causative role of tumour location on endocrinopathy development is investigated.

METHODS

A retrospective follow-up study of 40 children with NF1 and OPG evaluated between August 1996 and May 2015 was undertaken. Patients who underwent radiotherapy or surgical resection were excluded and 36 patients were studied. Tumour location was classified according to the Dodge criteria: stage I, optic nerve alone; stage II, optic chiasm with or without optic nerve involvement; and stage III, involvement of the hypothalamus or other adjacent structures.

RESULTS

Endocrinopathies were diagnosed in 20/36 (55.6%) children during a mean follow-up of 9.1 (0.2-13.6) years: 0/4 OPGs were Dodge stage I, 12/21 (57.1%) stage II, and 8/11 (72.7%) stage III. The first endocrinopathy was found at a mean age of 7.4 (5.0-13.2) years, 2.4 (0-6.7) years after tumour diagnosis. We found growth hormone deficiency (GHD; 36.1%), central precocious puberty (33.3%), obesity with insulin resistance/impaired glucose tolerance (11.1%), early puberty (5.5%), GH excess (5.5%), ACTH deficiency (5.5%), hypogonadotropic hypogonadism (2.7%), and thyrotropin deficiency (2.7%). GHD was transient in all of those who were retested.

CONCLUSION

This population is at high risk of endocrinopathies due to tumour location. Lifelong endocrine follow-up is recommended.
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Evaluation and Treatment of Severe Obesity in Childhood

Pediatric obesity is highly prevalent in developed countries globally (and worsening in developing countries) and threatens to shorten the lifespan of the current generation. At highest risk for weight-related comorbidities including Type 2 diabetes mellitus, non-alcoholic fatty liver disease and dyslipidemia is a sub-set of children with severe obesity, often defined as a body mass index (BMI) percentile ≥99^th percentile for age and sex. The pathophysiology of severe obesity in childhood is complex, resulting from the dynamic interplay of a myriad of individual and societal factors including genetic predisposition and health behaviors contributing to energy imbalance. Approximately 4–6% of children have severe obesity, representing a common scenario encountered by providers, and intervention is critical to halt ongoing weight gain and, when possible, reverse the trend. Clinical approaches promoting behavioral weight loss may result in modest, albeit clinically significant, reductions in BMI; however, such changes are often difficult to maintain long-term. Data regarding the impact of targeted pharmacotherapy including agents such as orlistat are limited in the pediatric population and again only suggest modest results. However, increasing evidence suggest that surgical treatment, as an adjunct to ongoing lifestyle changes, may be a promising option in carefully-screened adolescents with severe obesity and weight-related comorbidities who are motivated to adhere to the long-term treatment needs.

Insulin sensitivity and secretion in children and adolescents with hypothalamic obesity following treatment for craniopharyngioma

BACKGROUND

Craniopharyngioma (CP), a tumour occurring in the hypothalamic-pituitary area, results in morbid obesity in 25-60% of affected children. It has been suggested that abnormalities of insulin secretion and/or insulin action due to hypothalamic injury may be associated with weight gain and the metabolic syndrome in this population.

AIM

To evaluate: (i) insulin secretion (IS) and insulin sensitivity (Si); (ii) features of the metabolic syndrome (MS) and (iii) factors involved in risk for diabetes and heart disease in obese youth treated for CP.

METHODS

Obese subjects treated for CP were compared to BMI-matched control subjects. All subjects underwent anthropometric, blood pressure, resting energy expenditure and body fat assessment. Cholesterol and inflammatory markers, oral glucose tolerance test (OGTT) and frequent sampling intravenous glucose tolerance test (FSIGT), with calculation of IS and Si, were performed.

RESULTS

Fifteen CP subjects and 15 controls (C) were studied. There were no differences between CP and C for age, gender, BMI or pubertal status. MS was present in 10/15 CP and 3/15 C (P = 0.03), including impaired glucose tolerance (IGT) in 6/15 CP and 0/15 C (P = 0.02). Measures of IS, including first and second phase IS, and insulin area-under-the-curve (AUC(ins)) during OGTT, were significantly higher in CP. Si, measured by frequent sampled intravenous glucose tolerance test (Si-FSIGT), was significantly lower in CP subjects (0.96 +/- 0.34 vs. 1.67 +/- 0.7; P = 0.01). AUC(ins) was negatively correlated with Si-FSIGT (r = -0.62; P = 0.003).

CONCLUSION

Children with CP and hypothalamic obesity have more features of MS, increased IS and IGT prevalence and lower Si compared with BMI-matched controls.