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/m2, or BMI above 40 kg/m2 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.

Prader-Willi syndrome (PWS) is caused by a loss of paternally expressed genes in an imprinted region of chromosome 15q. Among the canonical PWS phenotypes are hyperphagic obesity, central hypogonadism, and low growth hormone (GH). Rare microdeletions in PWS patients define a 91-kb minimum critical deletion region encompassing 3 genes, including the noncoding RNA gene SNORD116. Here, we found that protein and transcript levels of nescient helix loop helix 2 (NHLH2) and the prohormone convertase PC1 (encoded by PCSK1) were reduced in PWS patient induced pluripotent stem cell-derived (iPSC-derived) neurons. Moreover, Nhlh2 and Pcsk1 expression were reduced in hypothalami of fasted Snord116 paternal knockout (Snord116p-/m+) mice. Hypothalamic Agrp and Npy remained elevated following refeeding in association with relative hyperphagia in Snord116p-/m+ mice. Nhlh2-deficient mice display growth deficiencies as adolescents and hypogonadism, hyperphagia, and obesity as adults. Nhlh2 has also been shown to promote Pcsk1 expression. Humans and mice deficient in PC1 display hyperphagic obesity, hypogonadism, decreased GH, and hypoinsulinemic diabetes due to impaired prohormone processing. Here, we found that Snord116p-/m+ mice displayed in vivo functional defects in prohormone processing of proinsulin, pro-GH-releasing hormone, and proghrelin in association with reductions in islet, hypothalamic, and stomach PC1 content. Our findings suggest that the major neuroendocrine features of PWS are due to PC1 deficiency.

Klinefelter syndrome is a major cause of infertility in the male. Nevertheless, pregnancies were recently obtained by intracytoplasmic injection of sperm retrieved by surgery or ejaculation, underscoring the need to understand the role of Sertoli and Leydig cell secretions during development. In 18 infants with prenatally diagnosed homogenous 47,XXY karyotype, blood samples were taken from birth to 3 yr of age. Inhibin B (INHB), anti-Müllerian hormone (AMH), testosterone, FSH, and LH levels were compared with those in six adolescents with XXY karyotype and reference values established in 215 control infants. In XXY infants FSH, LH, INHB, and AMH did not differ from controls. Testosterone levels during the first trimester exhibited a physiological increase but were lower than in controls (P = 0.0001). Significant correlations were found between testosterone and LH (P < 0001), between INHB and FSH (P = 0.0011), and between AMH and INHB (P = 0.025). In XXY adolescents, AMH and INHB were undetectable. Our findings demonstrate that testosterone secretion is impaired in infants with Klinefelter syndrome. By contrast, INHB and AMH secretions were not altered, which raises the question of the mechanism(s) governing the decline of Sertoli cell function after puberty.

Obesity and premature adrenarche (PA) are both associated with bone age (BA) advancement of unclear etiology, which may lead to earlier puberty, suboptimal final height and obesity in adulthood. Our objective was to understand the hormonal and anthropometric characteristics of BA advancement in a spectrum of prepubertal children with and without obesity and PA. In this cross-sectional study of 66 prepubertal children (35 PA, 31 control, 5–9 years), body mass index (BMI) z-score, hormonal values and response to an oral glucose tolerance test were the main outcome measures. Subjects were divided into tertiles by BA divided by chronological age (BA/CA), an index of BA advancement. Subjects in the top tertile for BA/CA had the highest dehydroepiandrosterone sulfate (DHEAS), free testosterone (%), hemoglobin A1C, BMI z-score and weight (P < 0.05). BMI z-score (r = 0.47), weight (r = 0.40), free testosterone (%) (r = 0.34) and DHEAS (r = 0.30) correlated with BA/CA (P<0.02). Regression analysis showed greater BA/CA in PA compared to controls after controlling for weight (0.21 ± 0.56, p<0.004). An exploratory stepwise regression model showed that weight, estradiol and DHEAS were the strongest predictors of BA/CA accounting for 24% of its variance. Obesity was highly associated with BA advancement in this study of prepubertal children. In addition, children with PA had greater BA/CA at any given weight when compared to controls. These findings suggest a possible hormonal factor, which potentiates the effect of obesity on BA advancement in children with obesity and/or PA.

Short-term school-based health, nutrition, and exercise intervention is beneficial to all students and affects multiple diabetes risk factors.