Use of Gonadotropin-Releasing Hormone Analogs in Children: Update by an International Consortium.

This update, written by authors designated by multiple pediatric endocrinology societies (see List of Participating Societies) from around the globe, concisely addresses topics related to changes in GnRHa usage in children and adolescents over the last decade. Topics related to the use of GnRHa in precocious puberty include diagnostic criteria, globally available formulations, considerations of benefit of treatment, monitoring of therapy, adverse events, and long-term outcome data. Additional sections review use in transgender individuals and other pediatric endocrine related conditions. Although there have been many significant changes in GnRHa usage, there is a definite paucity of evidence-based publications to support them. Therefore, this paper is explicitly not intended to evaluate what is recommended in terms of the best use of GnRHa, based on evidence and expert opinion, but rather to describe how these drugs are used, irrespective of any qualitative evaluation. Thus, this paper should be considered a narrative review on GnRHa utilization in precocious puberty and other clinical situations. These changes are reviewed not only to point out deficiencies in the literature but also to stimulate future studies and publications in this area.

A novel dominant COL11A1 mutation in a child with Stickler syndrome type II is associated with recurrent fractures.

This case describes a child with blindness, recurrent low-impact fractures, low bone mass, and intermittent joint pain who was found to have a novel missense mutation in COL11A1, consistent with Stickler syndrome type II. The case illustrates the phenotypic variability of the syndrome, which may include increased fragility in childhood. INTRODUCTION: Stickler syndrome type II is an autosomal dominant disorder caused by mutations in the gene that encodes the type XI collagen chain α1 (COL11A1). Manifestations include craniofacial dysmorphology and ocular abnormalities that may lead to blindness, hearing loss, and skeletal anomalies that range from joint pain and arthritis to scoliosis and hypermobility. METHODS: Herein, we describe a child who carried the presumed diagnosis of osteoporosis-pseudoglioma syndrome because of the combined findings of recurrent low-impact fractures due to low bone mass and blindness. The child also suffered from joint pain but had no facial dysmorphism or hearing loss. RESULTS: Targeted sequencing and deletion analysis of the LRP5, COL1A1, and COL1A2 genes failed to identify any mutations, and whole exome sequence analysis revealed a novel missense mutation (c.3032C>A:p.P1011Q) in COL11A1, consistent with Stickler type II. CONCLUSION: This case highlights the phenotypic variability of Stickler type II, broadens the list of differential diagnosis of increased bone fragility in childhood, and highlights utility of unbiased genetic testing towards establishing the correct diagnosis in children with frequent fractures.

Polycythemia is associated with bone loss and reduced osteoblast activity in mice.

UNLABELLED: Increased fragility has been described in humans with polycythemia vera (PV). Herein, we describe an osteoporotic phenotype associated with decreased osteoblast activity in a mouse model of PV and another mouse of polycythemia and elevated circulating erythropoietin (EPO). Our results are important for patients with PV or those treated with recombinant EPO (rEPO). INTRODUCTION: PV and other myeloproliferative syndromes have been recently associated with an increased risk for fractures. However, the presence of osteoporosis in these patients has not been well documented. EPO, a hormone primarily known to stimulate erythropoiesis, has been shown recently to regulate bone homeostasis in mice. The aim of this study was to examine the bone phenotype of a mouse model of PV and compare it to that of animals with polycythemia caused by elevated circulating EPO. METHODS: Bone mass and remodeling were evaluated by micro-computed tomography and histomorphometry. The JAK2(V617F) knock-in mouse, a model of human PV, manifests polycythemia and low circulating EPO levels. Results from this mouse were compared to wild type (wt) controls and the tg6 transgenic mouse that shows polycythemia caused by increased constitutive expression of EPO. RESULTS: Compared to wt, both JAK2(V617F) and tg6 mice had a decrease in trabecular bone mass. Tg6 mice showed an additional modest decrease in cortical thickness and cortical bone volume per tissue volume (P < 0.01) suggesting a more severe bone phenotype than JAK2(V617F). Decreased osteoblast numbers and bone formation along with normal osteoclast numbers and activity were found in both mice. CONCLUSIONS: This study indicates that PV is associated with low bone mass and decreased osteoblast activity in mice. Our results support future studies of osteoporosis in affected humans. Polycythemia caused by chronically elevated circulating EPO also results in bone loss, and implications on patients treated with rEPO should be evaluated.

Screening markers of impaired glucose tolerance in the obese pediatric population.

BACKGROUND: With the epidemic of childhood obesity, it is crucial to devise a simple screening protocol to predict impaired glucose tolerance (IGT) or pre-diabetes. The oral glucose tolerance test (OGTT), which is the gold standard for the diagnosis of IGT, is impractical for screening purposes. This pilot study was designed to formulate a simple, sensitive algorithm to predict IGT using clinical and laboratory parameters. METHODS: Ethnicity, family history of diabetes, pubertal status, BMI z-score, blood pressure, lipids, hemoglobin A1c (HbA1c) and OGTT data were retrospectively collected from 209 overweight multi-ethnic subjects aged 3-21 years. Multivariate logistic regression was used to determine independent predictors of IGT. RESULTS: HbA1c was the only significant predictor of IGT (p = 0.001), whereas fasting glucose was not. A cut-off of 5.5% had the best combined sensitivity (85.7%) and specificity (56.9%) with an odds ratio of 7.9 of having IGT when HbA1c is > or =5.5%. The remaining clinical parameters were not significant predictors of IGT. CONCLUSION: While fasting blood glucose does not seem to be a predictor of IGT, we propose that HbA1c > or =5.5% can be used as a screening test to assess the risk of IGT and to determine who should undergo diagnostic OGTT. Large prospective studies validating our findings are warranted.

Prevalence of fractures among the Thalassemia syndromes in North America.

Historically, fractures are cited as a frequent problem in patients with Thalassemia prior to optimization of transfusion and chelation regimens. The aim of this study was to determine the prevalence of fractures in a contemporary sample of North American patients with Thalassemia. The North American Thalassemia Clinical Research Network (TCRN) database registry was used to gather historical data on 702 patients with common alpha and beta-Thalassemia diagnoses including Thalassemia Major (TM), Intermedia (TI), E/Beta, homozygous alpha Thalassemia (AT), Hemoglobin H disease (HbH) and HbH with Constant Spring (HbH/CS), who consented to a medical record chart review. Bone mineral density (BMD) measurements by DXA were available for review in a subgroup of patients (n = 312). The overall fracture prevalence among all Thalassemia syndromes was 12.1%, equally distributed between females (11.5%) and males (12.7%). Fractures occurred more frequently in TM (16.6%) and TI (12.2%) compared to E/Beta (7.4%) and alpha (2.3%). Prevalence increased with age (2.5% ages 0-10 years, 7.4% ages 11-19 years, 23.2% ages >20 years) and with use of sex hormone replacement therapy (SHRT) (P < 0.01). On average, BMD Z and T scores were 0.85 SD lower among patients with a history of fractures (mean Z/T score -2.78 vs. -1.93, 95% CI for the difference -0.49 to -1.22 SD, P = 0.02). Presence of other endocrinopathies (i.e. hypothyroidism, hypoparathyroidism and diabetes mellitus), anthropometric parameters, heart disease or hepatitis C were not significant independent predictors of fractures. These data indicate that fractures remain a frequent complication among the aging patients with both TM and TI beta-Thalassemia. However, the fracture prevalence has improved compared to published reports from the 1960s to 1970s. In addition, children with Thalassemia appear to have low fracture rates compared to the general population.

Long term outcome in adult males with classic congenital adrenal hyperplasia.

The effects of classic congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency on final height and fertility were evaluated in 30 affected males, aged 17-43 yr. The mean adult height of these patients was 165.64 +/- 8.4 cm (mean +/- SD), with a mean SD score of -1.65 +/- 1.2 cm. The difference between the mean final height SD score and mean target height SD score was -1.67 +/- 1.0 cm. All patients had short stature and did not reach their estimated target heights. There was no difference in height SD score between the salt-wasting and simple virilizing CAH patients. No correlation between the final height and degree of hormonal control or bone age advancement was observed. Of the 30 subjects, 18 had testicular sonograms. Abnormal sonogram findings of testicular adrenal rests were present in 9 patients (group 1), whereas sonogram without adrenal rests comprised the remaining 9 patients (group 2). In group 1, 8 of 9 patients and in group 2, 4 of 9 patients were salt-wasters; the remainder were simple virilizers. In group 1, 7 of 9 patients had semen analysis, and all were judged infertile. Of the 6 patients in group 2 who had semen analysis, 1 was azoospermic, and the remainder were normal. During optimal adrenal hormone suppression, gonadotropins at baseline and after GnRH stimulation were significantly higher in group 1 than in group 2, reflecting the loss of Leydig cell function to secrete testosterone. In conclusion, adult males affected with CAH due to 21-hydroxylase deficiency do not achieve the height predicted from parental heights. The presence of adrenal rests within the testes of adult males with classic CAH are more frequent in the salt-wasting form and are associated with a higher risk for infertility.

Growth hormone therapy alone or in combination with gonadotropin-releasing hormone analog therapy to improve the height deficit in children with congenital adrenal hyperplasia.

Short stature in the adult patient with congenital adrenal hyperplasia (CAH) is commonly seen, even among patients in excellent adrenal control during childhood and puberty. In this study we examine the effect of GH therapy on height prediction in children with both CAH and compromised height prediction. Leuprolide acetate, a GnRH analog (GnRHa), was given to patients with evidence of early puberty. GH (n = 12) or the combination of GH and GnRHa (n = 8) was administered to 20 patients with CAH while they continued therapy with glucocorticoids. Each patient in the treatment group was matched according to age, sex, bone age, puberty, and type of CAH with another CAH patient treated only with glucocorticoid replacement. The match was made at the start of GH treatment. Of the 20 patients, 12 have completed 2 yr of therapy. After 1 yr of GH or combination GH and GnRHa therapy, the mean growth rate increased from 5 +/- 1.9 to 7.8 +/- 1.6 cm/yr vs. 5.4 +/- 1.7 to 5 +/- 2 cm/yr in the group not receiving GH (P < 0.0001). During the second year of treatment, the mean growth rate was 6 +/- 1.6 vs. 4.2 +/- 2.1 cm/yr in the group not receiving GH (P < 0.001). The height SD score for chronological age in the treatment group at the end of 1 and 2 yr of treatment improved significantly more than the nontreatment group (P < 0.01). A similar improvement in the height SD score for bone age was found in the treatment group after 1 (-1.4 +/- 0.9 vs. -1.7 +/- 0.9; P < 0.0001) and 2 yr of therapy (-0.67 +/- 0.68 vs. -1.7 +/- 1.2; P < 0.0004). The mean predicted adult height improved from 159 +/- 11 (baseline) to 170 +/- 7.5 cm (after 2 yr of therapy) closely approximating target height (173 +/- 8 cm). All patients continued the hydrocortisone treatment. In patients with CAH and compromised height prediction, treatment with GH or the combination of GH and GnRHa results in an improvement of growth rate and height prediction and a reduction in height deficit for bone age.

Insulin does not stimulate protein synthesis acutely in prepubertal children with insulin-dependent diabetes mellitus.

Insulin treatment in adult type I diabetic patients decreases protein loss primarily by inhibiting protein breakdown without stimulating protein synthesis. In young growing rodents, insulin treatment has been reported to stimulate protein synthesis. We examined whether insulin stimulates protein synthesis in normally growing prepubertal children with insulin-dependent diabetes mellitus. Five prepubertal children with insulin-dependent diabetes mellitus (aged 8.6-11.25 yr) were studied in the postabsorptive state on two occasions: once during insulin deprivation (I-; blood glucose, 325 +/- 67.8 mg/dL; mean +/- SD) and once during insulin administration for 4 h (I+; blood glucose, 96 +/- 23.6 mg/dL). Leucine kinetics were measured using a 4-h primed continuous infusion of L-[1-13C]leucine. Serum insulin concentrations were lower (I- vs. I+, 0.6 +/- 0.3 vs. 7.5 +/- 4.3 microU/mL; mean +/- SD; P = 0.02), whereas serum beta-hydroxy-butyrate (I- vs. I+, 3.4 +/- 0.5 vs. 0.9 +/- 0.5 mg/dL; P < 0.001) and free fatty acid concentrations (I- vs. I+, 2.9 +/- 0.4 vs. 0.9 +/- 0.4 mEq/L; P < 0.001) were higher in the insulin-deprived state than during insulin administration. Leucine Ra, an index of protein breakdown (I- vs. I+, 200.5 +/- 23.4 vs. 167 +/- 17 mumol/kg.h; P = 0.008), and leucine oxidation (I- vs. I+, 56.5 +/- 20.7 vs. 29.6 +/- 9.3 mumol/kg.h; P = 0.03) were reduced by insulin treatment. Nonoxidative leucine disposal, an index of protein synthesis, was not affected by insulin treatment (I- vs. I+, 144 +/- 20.8 vs. 137.5 +/- 13.5 mumol/kg.h; P = 0.4). We conclude that the acute decline in net protein loss during insulin treatment in growing prepubertal children, like that in adults, is due primarily to an inhibition of protein breakdown without stimulation of protein synthesis.

Frequency and necessity of thyroid function tests in neonates and infants with congenital hypothyroidism.

OBJECTIVE: The American Academy of Pediatrics recommends frequent thyroid function tests in infants and children with congenital hypothyroidism (CH). Data supporting the recommended frequency are lacking. This review was conducted to assess the validity of these recommendations. METHODS: The thyroxine (T4) and thyroid-stimulating hormone (TSH) levels of 50 neonates diagnosed between 1988 to 1993 were reviewed to assess the length of time on a specific dose of levothyroxine. RESULTS: 1) Changes in the dose of levothyroxine occurred 35 times during the first year of life for the 39 children treated with .025 mg/day, five times during the first year of life for the 9 children treated with .0375 mg/day, and three times during the first year of life for the 2 children treated with .050 mg/day. 2) These dose changes occurred at varying time intervals. 3) The T4 and TSH levels obtained at visits requiring dose changes were statistically different from the T4 and TSH levels obtained at the previous two visits. The T4 and TSH levels at the two visits before the change in dosage did not differ statistically. CONCLUSIONS: 1) An initial levothyroxine dose of .0375 mg/day requires fewer dose changes than a dose of .025 mg/day. 2) A lack of statistical change in T4 or TSH levels obtained at visits before the change-in-dose visit and the variable time span between dose changes necessitate frequent monitoring regardless of the dose of levothyroxine, the previous T4 or TSH levels, or the length of time at a specific dose. 3) These data support the recommendations of the American Academy of Pediatrics regarding the frequency of thyroid function studies during the first 2 years of life.

Dehydroepiandrosterone in morbidly obese adolescents: effects on weight, body composition, lipids, and insulin resistance.

The hormone dehydroepiandrosterone (DHEA) has been reported to have beneficial effects on obesity, diabetes mellitus, and serum lipids in animal studies, but results in human studies are less clear. We conducted a randomized double-blind placebo-controlled trial to determine the effects of DHEA treatment on obesity and related physiologic conditions in adolescents and young adults. In this 10-week study, 13 morbidly obese subjects received a placebo for 2 weeks. After this run-in period, patients were randomized, with seven subjects (mean age, 15.5 years; body mass index [BMI, derived by dividing body weight in kilograms by height in meters squared], 48.2 +/- 9.7 [mean +/- SD]) receiving DHEA 40 mg sublingually twice daily for 8 weeks and six subjects (mean age, 18.0 years; BMI, 52.9 +/- 14) receiving placebo. Variables measured included body weight, body composition, resting metabolic rate (RMR), serum lipid levels, insulin sensitivity, and serum steroid levels. Treatment with DHEA resulted in a statistically significant increase in plasma DHEA and DHEA sulfate (DHEAS) concentrations (P < .01). Testosterone (T) levels were significantly increased in females who received DHEA. DHEA administration had no effect on body weight, sense of well-being, or any other measured variables. These findings suggest that DHEA 40 mg administered sublingually twice daily for 8 weeks has no positive effect on body weight, body composition, serum lipids, or insulin sensitivity in extremely obese adolescents and young adults.

Gastrointestinal symptoms and diabetes mellitus in children and adolescents.

Because it may be difficult to evaluate gastrointestinal diseases in children with insulin-dependent diabetes mellitus (IDDM), this report highlights several clinical features unique to diabetes and emphasizes the relationship between gastrointestinal pathology and glycemic control. Two children with IDDM are described whose hyperglycemia, ketosis, and abdominal pain were the presenting features of H. pylori-positive duodenal ulcer disease and acute appendicitis, respectively. A third nondiabetic child developed persistent postprandial hyperglycemia as the initial manifestation of dumping syndrome. These patients illustrate the relationship between glycemic control and gastrointestinal pathology in children with diabetes and the effects of gastrointestinal dysfunction on glucose regulation in nondiabetic children. In children with IDDM, gastrointestinal pathology can be confused with ketoacidosis and complicate diabetes control and management. Early recognition and treatment of the underlying gastrointestinal disease often improves glycemic control. Furthermore, severe gastrointestinal dysfunction in nondiabetic children may deleteriously influence glycemic regulation and may be confused with childhood diabetes.