A 52-week pilot study of the effects of exenatide on body weight in patients with hypothalamic obesity.

OBJECTIVE: Hypothalamic obesity (HO) is a common complication of hypothalamic tumors, and effective therapies are lacking. The objective of this pilot study was to investigate changes in body weight before and during treatment with exenatide. METHODS: This was a prospective, open-label, 52-week pilot study of exenatide (10 mcg b.i.d.) in adults with HO. Ten patients enrolled, and eight completed the study. Study measures included indirect calorimetry, body composition, buffet meals, diet recall, actigraphy, and hormone assays. RESULTS: Participants had obesity with a baseline weight of 137.2 ± 37.6 kg. Exenatide therapy was well tolerated. Change in weight with exenatide therapy was not significant (-1.4 ± 4.3 kg [95% CI -4.9 to 2.2], P = 0.40), but six out of eight completers lost weight (-6.2 to -0.2 kg). Participants reported significantly lower intake on food recall during treatment compared with baseline (7837.8 ± 2796.6 vs. 6258.4 ± 1970.7 kJ [95% CI -2915.8 to -242.6], P = 0.027), but there was no change in intake during buffet meals. CONCLUSIONS: Significant weight loss was not observed in patients with HO treated with exenatide, but 75% of completers had stable or decreasing weight. Further studies are needed to evaluate weight loss efficacy in patients with HO.

Insulin resistance is not associated with thermogenic effect of a high-fat meal in obese children.

In adults, insulin resistance may decrease the thermogenic effect of food, contributing to weight gain. We aimed to determine the effect of insulin resistance on energy expenditure in children with long-standing obesity. We hypothesized that thermogenic effect of food would decrease with increasing insulin resistance. Energy expenditure was measured using whole room indirect calorimetry in obese children 7 to 18 years old. Participants were fed a high-fat meal with energy content equal to 35% of measured resting energy expenditure. Thermogenic effect of food was measured for 180 minutes posttest meal and expressed as a percent of calories consumed. Body composition was assessed using whole-body dual-energy x-ray absorptiometry. Fasting glucose, insulin, and hemoglobin A1C were measured. Complete data were available for 25 children (median age, 12.1 years; 52% male). As expected, a significant decrease in resting energy expenditure was observed with increasing Tanner stage (P = .02 by Kruskal-Wallis test). Insulin sensitivity, as determined by homeostasis model assessment index equation, did not significantly affect resting energy expenditure (P = .3) or thermogenic effect of food (P = .7) after adjustment for Tanner stage. In conclusion, our study did not find an association between insulin resistance and energy expenditure in obese children.

Generic levothyroxine compared with synthroid in young children with congenital hypothyroidism.

CONTEXT: Clinicians who prescribe levothyroxine (LT4) for hypothyroidism often feel strongly about using a brand-name drug instead of a generic. OBJECTIVE: The objective of the study was to determine whether Synthroid resulted in better control of congenital hypothyroidism than generic LT4. DESIGN: This was a 5-year retrospective study. SETTING: The study was conducted at 1 tertiary care center. PATIENTS: Children who were 0-36 months old with congenital hypothyroidism followed up at our center from 2006 to 2011 were treated with either Synthroid exclusively (35 subjects) or generic LT4 exclusively (27 subjects). INTERVENTIONS: We recorded the subjects' TSH and free T(4) measurements, how often their LT4 dose was adjusted, and the duration of follow-up. MAIN OUTCOME MEASURE: TSH variance between the groups was measured. Secondary end points were the frequency of LT4 dose changes and the variance in free T(4). RESULTS: Using the Wilcoxon rank sum test, there was no difference in TSH SD in the Synthroid group compared with the generic group (median 3.0 vs 2.2, P = .27). Using a linear mixed model, children treated with the generic LT4 had lower TSH estimated SD [1.35 with 95% confidence interval (CI) (1.194, 1.526)] than the Synthroid group [1.66 with 95% CI (1.536, 1.803)]. Similarly, no difference was observed in free T(4) SD between the groups using the Wilcoxon rank sum test (median 0.29 generic vs 0.36 Synthroid, P = .11), but the generic group had lower free T(4) estimated SD than the Synthroid group using the linear mixed model [0.216 with 95% CI (0.187, 0.249) vs 0.298 with 95% CI (0.273,0.326)]. Frequency of LT4 dosing adjustments was similar between the groups, both in total (median 2.0 for generic vs 3.0 for Synthroid, P = .097) and when adjusted for number of TSH checks (ratio 0.25 generic vs 0.31 Synthroid, P = .45). CONCLUSIONS: In our study of congenital hypothyroidism, generic LT4 treatment resulted in similar or better control of hypothyroidism compared with Synthroid, as assessed by the clinical outcomes of TSH variance and the frequency of LT4 dosing adjustments.

Delayed diagnosis of hypothyroidism following excision of a thyroglossal duct cyst.

Thyroglossal duct cysts can contain ectopic thyroid tissue, and in some cases this tissue may be the only functional thyroid gland. We present the case of a 6-year-old girl with delayed diagnosis of iatrogenic hypothyroidism that developed after excision of a thyroglossal duct cyst.

Activation of invariant natural killer T cells by lipid excess promotes tissue inflammation, insulin resistance, and hepatic steatosis in obese mice.

Obesity triggers a low-grade systemic inflammation, which plays an important role in the development of obesity-associated metabolic diseases. In searching for links between lipid accumulation and chronic inflammation, we examined invariant natural killer T (iNKT) cells, a subset of T lymphocytes that react with lipids and regulate inflammatory responses. We show that iNKT cells respond to dietary lipid excess and become activated before or at the time of tissue recruitment of inflammatory leukocytes, and that these cells progressively increase proinflammatory cytokine production in obese mice. Such iNKT cells skew other leukocytes toward proinflammatory cytokine production and induce an imbalanced proinflammatory cytokine environment in multiple tissues. Further, iNKT cell deficiency ameliorates tissue inflammation and provides protection against obesity-induced insulin resistance and hepatic steatosis. Conversely, chronic iNKT cell stimulation using a canonical iNKT cell agonist exacerbates tissue inflammation and obesity-associated metabolic disease. These findings place iNKT cells into the complex network linking lipid excess to inflammation in obesity and suggest new therapeutic avenues for obesity-associated metabolic disorders.

Peptide tyrosine tyrosine levels are increased in patients with urea cycle disorders.

Nutritional management is essential for patients with inborn errors of metabolism, such as urea cycle disorders (UCDs). Lack of appetite is common in these patients and can lead to underconsumption of calories, catabolism, and subsequently loss of metabolic control. The etiology of anorexia in these patients is largely unexplored. The neuroendocrine hormone peptide tyrosine tyrosine (PYY), secreted postprandially from endocrine cells of the ileum and colon, induces feelings of satiety and decreases food intake. While plasma PYY levels have been characterized in a number of populations, they have not been examined in UCD patients. In a retrospective study, plasma PYY concentrations were measured in UCD (n=42) patients and controls (n=28) via an ELISA to determine if levels of this anorexigenic hormone are altered in this patient population. Median PYY levels were significantly higher in UCD patients compared to controls (p=3.5×10(-5)). Body mass index was significantly associated with increased PYY levels in controls (p=0.02), while UCD diagnosis subtype was associated with PYY levels (p=1×10(-3)) in cases. Median PYY levels were significantly lower in ornithine carbamoyltransferase deficient patients compared with all other UCD subtypes (p=9×10(-3)), but significantly higher compared to controls (p=1.6×10(-3)). Overall, this study demonstrates that UCD cases have increased PYY levels compared to controls, suggesting that regulation of PYY may be altered in these patients. These observations may lead to a better understanding of the development of anorexia in UCD patients.

Phthalate exposure and precocious puberty in females.

OBJECTIVE: To determine whether phthalate exposure is associated with precocious puberty in girls. STUDY DESIGN: This was a multicenter cross-sectional study in which 28 girls with central precocious puberty (CPP) and 28 age- and race-matched prepubertal females were enrolled. Nine phthalate metabolites and creatinine were measured in spot urine samples from these 56 children. RESULTS: Levels of 8 of the 9 phthalate metabolites were above the limit of detection (LOD) in all 56 subjects. Mono (2-ethylhexyl) phthalate (MEHP) was below the LOD in 25/56 samples (14 subjects with precocious puberty and 11 controls). No significant differences between the children with CPP and the controls in either absolute or creatinine-normalized concentrations of any of the 9 phthalate metabolites were measured. CONCLUSIONS: Although phthalates may be associated with certain other toxicities in humans, our study suggests that their exposure is not associated with precocious puberty in female children.

Effects of meals high in carbohydrate, protein, and fat on ghrelin and peptide YY secretion in prepubertal children.

CONTEXT: Ghrelin and peptide YY (PYY) are two hormones produced by the gastrointestinal tract that have effects on appetite. However, little is known about their secretion in response to meals high in individual macronutrients in prepubertal children. OBJECTIVE: We sought to understand how meals high in carbohydrate, protein, and fat affect serum concentrations of total ghrelin and total PYY, hypothesizing that these macronutrients would exert differential effects on their secretion. DESIGN AND SETTING: This was a cross-sectional study at one tertiary care center. SUBJECTS: Subjects were 7- to 11-yr-old healthy normal-weight (NW) and obese (OB) volunteers recruited from local advertisements. INTERVENTIONS: After an overnight fast, the subjects were given a breakfast high in carbohydrate, protein, or fat at 0800 h. Blood samples for total ghrelin and total PYY were taken at baseline, 30 min, and hourly from 0900 to 1200 h. MAIN OUTCOME MEASURE: We assessed postprandial ghrelin suppression and PYY elevation, as well as changes in reported hunger and satiety, after the three test meals. RESULTS: After the high-protein meal, ghrelin declined gradually in both groups over the study period without subsequent increase, whereas ghrelin suppressed more rapidly to a nadir at 60 min after the high-carbohydrate meal in both NW and OB children, followed by rebound in ghrelin levels. Similarly, after the high-protein meal, PYY concentrations increased steadily over the course of the morning in both groups without decline, whereas PYY levels peaked 30 min after the high-carbohydrate meal in both NW and OB subjects with significant decline thereafter. Ghrelin and PYY responses to the high-fat meal were somewhat intermediate between that observed with high carbohydrate and high protein. The OB children reported higher hunger and lower satiety after the high-carbohydrate meal compared to the NW subjects, whereas appetite ratings were similar between the groups after the high-protein and high-fat meals. Additionally, within the OB group, area under the curve (AUC) analysis revealed significantly greater PYY response, as well as lower AUC hunger and higher AUC satiety, to the high-protein meal than the high-carbohydrate and high-fat meals. CONCLUSIONS: The patterns of secretion of ghrelin and PYY in our study of prepubertal children suggest that they may play a role in the effectiveness of high-protein/low-carbohydrate diets in promoting weight loss.

Glucagon-like peptide 1 and pancreatic polypeptide responses to feeding in normal weight and overweight children.

BACKGROUND: Glucagon-like peptide 1 (GLP-1) and pancreatic polypeptide (PP) are intestinal hormones that are involved in the post-prandial satiety response. We sought to assess meal-related changes in these hormones in young children and determine whether differences exist between normal weight (NW) and overweight (OW) children. METHODS: Seven to 11-year-old healthy NW (n=20) and OW (n=12) volunteers were given a standardized breakfast and lunch following an overnight fast and had measurements of GLP-1 and PP over 9 hours. We characterized whether GLP-1 and PP changed from the pre-prandial to the post-prandial state and whether the serum levels corresponded to reported appetite. RESULTS: GLP-1 did not increase after eating, did not decline prior to the next meal, and did not correspond to satiety ratings in either group. PP increased post-prandially in OW children after both breakfast and lunch, but in the NW group PP only increased after breakfast. PP levels did not decline in either group as the next meal approached. CONCLUSIONS: In our study of school-age children, feeding had little effect on GLP-1 secretion and a variable effect on serum PP levels. Observed differences in the GLP-1 and PP responses between the NW and OW groups do not suggest there is an intrinsic abnormality in their secretion that causes weight gain.

Prevalence of adrenal insufficiency following systemic glucocorticoid therapy in infants with hemangiomas.

OBJECTIVE: To determine the prevalence of adrenal insufficiency in infants with hemangiomas following treatment with systemic glucocorticoids (GCs). DESIGN: Prospective study for 18 months. SETTING: Hemangioma and vascular malformation center at a tertiary care children's hospital. PATIENTS: Sixteen infants with hemangiomas had an adrenal axis evaluation as soon as possible following the completion of GC therapy. Ten healthy control infants were also evaluated for comparison. INTERVENTIONS: Prednisolone at a starting dose of 2 to 3 mg/kg/d for 4 weeks, followed by a tapering period. The mean duration of GC treatment was 7.2 months. MAIN OUTCOME MEASURE: Prevalence of adrenal insufficiency in GC-treated subjects as assessed by a combination low-dose/high-dose corticotropin stimulation test. RESULTS: Subjects underwent corticotropin testing at a mean of 13 days after the completion of therapy. Only 1 of the 16 GC-treated infants (6%) had adrenal insufficiency. This subject was tested 1 day after GC treatment was stopped, and results from retesting 3 months later were normal. All control subjects had normal adrenal function. CONCLUSION: Infants with hemangiomas are at low risk of adrenal insufficiency following the completion of GC therapy, as used in our hemangioma center.

Meal-related changes in ghrelin, peptide YY, and appetite in normal weight and overweight children.

OBJECTIVE: Ghrelin and peptide YY (PYY) are two gut hormones that have effects on appetite. Our objectives were to characterize the patterns of secretion of these hormones in response to feeding in school-age children and determine whether there were differences between normal weight (NW) and overweight (OW) subjects. METHODS AND PROCEDURES: This was a cross-sectional study at one tertiary care center. Subjects were 7- to 11-year-old healthy NW and OW volunteers recruited from local advertisements. Following an overnight fast, the subjects were given a standardized breakfast and lunch and had nine hourly blood samples for total ghrelin and total PYY. We assessed whether ghrelin and PYY levels changed from the preprandial to postprandial state and corresponded to reported hunger/satiety. RESULTS: Hunger ratings were similar between the two groups throughout the study period. Ghrelin was not suppressed after eating, did not rise prior to the next meal, and did not correspond to hunger ratings in either group. PYY increased postprandially and decreased preprandially in the NW group, but OW children exhibited this pattern for only part of the day. PYY levels incompletely corresponded to reported satiety in the OW group. DISCUSSION: Mixed meal consumption had little effect on ghrelin secretion and a variable effect on PYY secretion in young children in our study. Differences that were observed between the groups do not suggest that an abnormality in their secretion contributes to the development of obesity.

Effect of levo-thyroxine treatment on weight and body mass index in children with acquired hypothyroidism.

OBJECTIVE: To determine whether normalization of thyroid-stimulating hormone (TSH) in children with acquired hypothyroidism is associated with a decrease in weight or body mass index (BMI). STUDY DESIGN: We retrospectively identified 68 subjects with acquired hypothyroidism who were seen at least once in our center in follow-up between 1995 and 2006. RESULTS: Treatment with levo-thyroxine decreased the mean TSH level from 147 microU/mL initially to 5.0 microU/mL at the second visit 4.4 months later. This was not associated with a significant change in weight or BMI. Of the 68 subjects, 31% lost weight by the second visit (mean 2.3 kg). The mean initial TSH level of this group was 349 microU/mL. Thirty of the 68 children had at least 2 years of follow-up, and 19/68 had at least 4 years of follow-up. Over those intervals, weight and BMI percentiles and z scores did not change significantly from baseline values. CONCLUSIONS: Most children treated for acquired hypothyroidism exhibited little short-term or long-term change in weight or BMI despite near-normalization of TSH. Those children who lost weight tended to have severe hypothyroidism and to have only a small weight loss. Consequently, practitioners should not expect significant decreases in weight after treatment in most children with hypothyroidism.

Low-dose adrenocorticotropic hormone stimulation testing in term infants.

BACKGROUND: Low-dose adrenocorticotropic hormone (ACTH) stimulation testing is a commonly accepted way to evaluate adrenal function in children. However, there are no published data on the use of this test in term infants less than 12 months of age outside the newborn period. METHODS: We identified 14 infants at our center who were full term and had one or more ACTH tests at less than 12 months of age to evaluate for secondary adrenal insufficiency (AI). We retrospectively assessed peak cortisol response in these infants to determine whether a cut-off of 20 microg/dl is appropriate to distinguish normal from abnormal adrenal function in this age group. RESULTS: Five infants had peak cortisol > or =20 microg/dl on their first ACTH test and had a clinical picture consistent with normal adrenal function. Nine infants had peak cortisol <20 microg/dl on their first ACTH test. When retested later in infancy, four of these patients achieved peak cortisol > or =20 microg/dl. CONCLUSIONS: In term infants, the low-dose ACTH stimulation test is useful for demonstrating normal adrenal function but is of limited value in diagnosing secondary AI. For infants with peak cortisol <20 microg/dl, clinical observation and repeat ACTH testing later in infancy clarified diagnosis.

Transcription factor FOXF1 regulates growth hormone variant gene expression.

Deletion analysis of the human growth hormone variant (GHV) promoter in transient transfection studies in BeWo choriocarcinoma and HepG2 cells indicated that the region extending from nt -158/+57 retained full transcriptional activity. DNase I footprint analysis of the fragment revealed a protected region at nt -82/-77, which is in a putative FOXF1/FOXF2 binding site. Supershift assays using an antiserum to human FOXF1 demonstrated that the protected region binds FOXF1. Overexpression of FOXF1 in BeWo and HepG2 cells induced the GHV promoter, whereas overexpression of FOXF2 was without effect. Mutagenesis of the FOXF1/FOXF2 site reduced basal promoter activity by 50-60% and markedly attenuated transactivation of the promoter by FOXF1. These studies indicate that FOXF1 induces GHV expression by interaction with a FOXF1/FOXF2 cis-element in the proximal promoter.

Growth, bone mineral accretion, and adrenal function in glucocorticoid-treated infants with hemangiomas-- a retrospective study.

Hemangiomas, common proliferative vascular tumors, can grow rapidly in the first months of life. Although therapy with high-dose oral glucocorticoids is standard for lesions that threaten vital functions or are disfiguring, little is known about the endocrine consequences of this treatment. Using retrospective data, we examined growth velocity, changes in bone mineral density, and adrenal function in infants with hemangiomas treated with systemic glucocorticoids. Treatment consisted of oral prednisolone 2 to 4 mg/kg/day or dexamethasone 1 mg/kg/day. Mean growth velocity Z score on glucocorticoid therapy was -1.41 standard deviations in 13 patients. In four infants with adequate follow-up, growth velocity increased to +1.90 standard deviations after glucocorticoid treatment (Delta growth velocity +3.31 standard deviations). Mean lumbar spine bone mineral density Z score was -2.46 standard deviations before glucocorticoid treatment and -1.08 standard deviations at the end of treatment in six infants. Adrenal function after glucocorticoid therapy was assessed by low-dose adrenocorticotropic hormone stimulation test in 10 infants. Eight had a normal cortisol response, and one had a borderline response. One infant, who had been treated with dexamethasone, had an abnormal test result. In conclusion, systemic glucocorticoid treatment in infants with hemangiomas slowed linear growth, but "catch-up" growth was observed after treatment ceased. Glucocorticoids did not affect bone mineralization adversely. Only 1 of 10 glucocorticoid-treated infants had clear evidence of adrenal insufficiency after therapy was stopped.

Autoimmune thyroiditis in 18q deletion syndrome.

Deletion of a segment of the long arm of chromosome 18 causes characteristic physical features and mental retardation. Autoimmune disorders have been described with this syndrome in a limited number of reports. We describe 2 cases of autoimmune hypothyroidism in children with 18q deletion syndrome.

Amiodarone-induced neonatal hypothyroidism: a unique form of transient early-onset hypothyroidism.

Amiodarone is an iodine-rich drug used to treat cardiac dysrhythmias. The structure of amiodarone resembles that of thyroxine, and treatment with amiodarone may alter thyroid function. The effects of antenatal amiodarone use on fetal/neonatal thyroid function have only been addressed in a limited number of patient reports. We describe two cases of transient neonatal hypothyroidism due to in utero amiodarone exposure, followed by a brief review of the available literature.