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E Schoenau, C Land, A Stabrey, T Remer, and A Kroke

Bone densitometry is currently one of the mainstays in the evaluation of systemic bone diseases in adults and is also increasingly used to assess primary or secondary bone disorders in children and adolescents. The purpose of carrying out densitometric studies in such circumstances is to measure the densitometric indicators of bone stability. Following procedures which were established for diagnosing adult osteoporosis, a decrease in densitometric surrogates of bone stability is usually interpreted as indicating increased fracture risk. The most basic densitometric parameter is bone mineral content (BMC), which can be measured with most densitometric techniques. BMC is either defined as the mass of mineral contained in an entire bone or as the mass of mineral per unit bone length. While mineral mass can be expected to be a good surrogate for bone stability, BMC is obviously a size-dependent parameter, since small bones weigh less than big bones. This is a drawback in paediatric use, since many children and adolescents who are examined by densitometry suffer from chronic disorders and are small-for-age. Short children will have a lower BMC than their healthy age-matched peers, even if their (smaller) bones are otherwise completely normal.

Free access

Juliet E Jennings, Marianthi Georgitsi, Ian Holdaway, Adrian F Daly, Maria Tichomirowa, Albert Beckers, Lauri A Aaltonen, Auli Karhu, and Fergus J Cameron

Objective

Mutations in the aryl hydrocarbon receptor-interacting protein (AIP) were recently shown to confer a pituitary adenoma predisposition in patients with familial isolated pituitary adenomas (FIPA). We report a large Samoan FIPA kindred from Australia/New Zealand with an R271W mutation that was associated with aggressive pituitary tumors.

Design and methods

Case series with germline screening of AIP and haplotype analyses among R271W families.

Results

This previously unreported kindred consisted of three affected individuals that either presented with or had first symptoms of a pituitary macroadenoma in late childhood or adolescence. The index case, a 15-year-old male with incipient gigantism and his maternal aunt, had somatotropinomas, and the maternal uncle of the index case had a prolactinoma. All tumors were large (15, 40, and 60 mm maximum diameter) and two required transcranial surgery and radiotherapy. All three affected subjects and ten other unaffected relatives were found to be positive for a germline R271W AIP mutation. Comparison of the single nucleotide polymorphism patterns among this family and two previously reported European FIPA families with the same R271W mutation demonstrated no common ancestry.

Conclusions

This kindred exemplifies the aggressive features of pituitary adenomas associated with AIP mutations, while genetic analyses among three R271W FIPA families indicate that R271W represents a mutational hotspot that should be studied further in functional studies.

Free access

Myriam Rosilio, Jean-Claude Carel, Emmanuel Ecosse, and Jean-Louis Chaussainon

Group-author : on behalf of the 0908 Lilly Study Group

Objective: Human GH (hGH) treatment leads to catch-up growth in children with short stature born small for gestational age (SGA). However, long-term efficacy and safety results in this patient group remain scarce. The present study assessed the efficacy and safety of late childhood treatment with biosynthetic hGH (Humatrope) in a group of short children born SGA (height <−2 standard deviation scores (SDS)).

Design: Patients in this open-label, Phase III, multicenter study received a daily hGH dose of 0.067 mg/kg for 2 years, and then received no treatment for the following 2 years. After the fourth year on study, patients whose height had decreased more than 0.5 SDS but who still showed growth potential based on bone age were allowed to resume treatment until they reached adult height.

Methods: Height gain SDS was assessed for 11 girls and 24 boys (mean age±s.d. 9.6±0.9 years) at the end of the 2 years of hGH treatment, during the subsequent 2-year off-treatment period, and upon reaching adult height.

Results: At the end of the initial 2-year treatment period, 83% of patients had reached a height within the normal range, with a mean increase in height SDS vs baseline of 1.3±0.3 (P <0.001). Adult heights (n = 20) were within the normal range for 50% of patients, and mean height gain from baseline was statistically significant (0.7±0.8 SDS, P <0.001). Fasting glucose and glycosylated hemoglobin levels were not significantly modified during treatment.

Conclusions: High-dose hGH treatment for a minimum of 2 years in short children born SGA was well tolerated and resulted in a significant increase in adolescent and adult height.

Free access

Valérie Bernard, Bruno Donadille, Tiphaine Le Poulennec, Mariana Nedelcu, Laetitia Martinerie, and Sophie Christin-Maitre

Turner syndrome (TS), affecting 1/2000 to 1/2500 live born girls, is a chromosomal aberration with a total or partial loss of one of the X chromosomes. The diagnosis can be established from the intra-uterine life to adulthood. TS is a chronic disease with particular morbidity and mortality. The loss to follow-up rate, during transition, between children and adult units, remains a crucial issue. This review focusses on the adolescent and young adult patients with TS. The different goals of TS transition are presented as well as some of the tools available in order to improve this transition. The involvement of the patient’s family, advocacy groups and therapeutic educational programs are discussed. A specificity concerning TS transition, as compared to other chronic diseases, relies on the fact that patients with TS may present a peculiar neurocognitive profile. They are in general more anxious than the general population. Therefore, psychological support should be offered to optimize transition. Data illustrating the beneficial impact of an organised transition of TS, from paediatric units to multidisciplinary adult care systems, within the same reference centre are presented. Further studies are required to evaluate the mid-to-long-term transition of paediatric patients with TS referred to adult units.

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N Weintrob, E Sprecher, Z Josefsberg, P Vardi, C Weininger, Y Aurbach-Klipper, A Pertzelan, and M Phillip

OBJECTIVE: To determine the feasibility of using the combined oral clonidine and the short-ACTH test instead of the sometimes dangerous insulin-induced hypoglycemia test as a screening procedure, for the simultaneous assessment of growth hormone reserve and hypothalamic-pituitary-adrenal axis integrity in children with growth retardation. DESIGN: Evaluative study. METHOD: Seventy-three children (52 males) aged 11+/-3 years with attenuated growth (group 1) were tested by combined clonidine (150 microg/m(2)) and short-ACTH test (either the standard 250 microg or the low-dose 1 microg/1. 73 m(2)). Thirty-one children received no pretreatment (nonprimed) (subgroup 1NP), and 42 were primed with ethynylestradiol 40 microg/m(2)/day two days before testing (subgroup 1P). The control group for the short-ACTH test (group 2) consisted of 42 children and adolescents (13 males) aged 12+/-3 years with early or accelerated puberty or premature closure of epiphyses, who received ACTH only (21 standard, 21 low-dose) with no evidence of adrenal or pituitary pathology. The peak GH response was compared between the primed and the nonprimed group 1 subjects, and the cortisol levels were compared between the combined test subgroups and the controls. The peak pass level for growth hormone was 10 ng/ml; the peak pass level for cortisol was 520 nmol/l. RESULTS: Sixty-four of the 73 children in group 1 (87.7%) showed a growth hormone level of >/=10 ng/ml on the first stimulation test, including 26/31 (84%) nonprimed and 38/42 (90.5%) primed. Of the 9 patients who failed the first clonidine test, 4 also failed the second, primed test, including 1/5 nonprimed patients (20%) and 3/4 primed patients (75%). This yielded a GH deficiency/insufficiency rate of 5.5% and a rather low false-positive rate of 13.3% (4/30) for the nonprimed subjects and 2. 6% (1/39) for the primed subjects. Peak 30-min cortisol in response to ACTH stimulation was similar in the patients who underwent the 250 microg or the 1 microg test within each group (subgroup 1NP, subgroup 1P and group 2); therefore, the results for the two tests were considered together. Compared with group 2, subgroup 1NP patients had a similar 30-min cortisol response (P=NS), and subgroup 1P patients had a much higher response (P<0.05) (group 2=690+/-145 nmol/l, subgroup 1NP=772+/-195 nmol/l, subgroup 1P=934+/-209 nmol/l). However, there was no significant difference in the increment in cortisol response between the three groups. CONCLUSIONS: Our results suggest that the combined clonidine-short-ACTH test is a reliable and safe tool for the simultaneous assessment of growth hormone reserve and hypothalamic-pituitary-adrenal axis integrity in children.

Free access

Francesco Chiarelli and Maria Loredana Marcovecchio

Childhood obesity is a significant health problem that has reached epidemic proportions around the world and is associated with several metabolic and cardiovascular complications. Insulin resistance is a common feature of childhood obesity and is considered to be an important link between adiposity and the associated risk of type 2 diabetes and cardiovascular disease. Insulin resistance is also a key component of the metabolic syndrome, and its prevalence in the paediatric population is increasing, particularly among obese children and adolescents. Several factors are implicated in the pathogenesis of obesity-related insulin resistance, such as increased free fatty acids and many hormones and cytokines released by adipose tissue.

Valid and reliable methods are essential to assess the presence and the extent of insulin resistance, the associated risk factors and the effect of pharmacological and lifestyle interventions. The two most common tests to assess insulin resistance are the hyperinsulinemic euglycemic clamp and the frequently sampled i.v. glucose tolerance test utilizing the minimal model. However, both these tests are not easily accomplished, are time consuming, expensive and invasive. Simpler methods to assess insulin resistance based on surrogate markers derived from an oral glucose tolerance test or from fasting insulin and glucose levels have been validated in children and adolescents and widely used.

Given the strong association between obesity, insulin resistance and the development of metabolic syndrome and cardiovascular disease, prevention and treatment of childhood obesity appear to be essential to prevent the development of insulin resistance and the associated complications.

Restricted access

Akimasa Okuno, Koichi Yano, Fumie Inyaku, Yutaka Suzuki, Nobutaka Sanae, Megumi Kumai, and Yoshihiro Naitoh

Abstract. Methimazole concentrations in plasma and in the thyroid glands were measured by means of high-performance liquid chromatography. Pharmacokinetics of methimazole were studied after a single oral dose (175 μmol/m2) in nine children and adolescent who were in the thyrotoxic state. Plasma levels of methimazole showed peak concentrations of 4.4 to 12.6 (median 9.2) μmol/l at 0.5 to 4 h after drug administration. Plasma half-life, area under the curve, and distribution volume ranged from 2.73 to 6.04 h, 32.8 to 77.9 μmol · l−1 · h−1, and 0.516 to 0.913 l/kg, respectively. These pharmacokinetic parameters showed a wide variation among the patients, but were quite reproducible in the same subject. Intrathyroidal concentrations of methimazole were measured in another nine subjects including four adolescents and five adults who underwent thyroidectomy. The drug concentrations in the thyroid glands ranged between 3.5 and 23.8 μmol/kg tissue and were far higher than those in the plasma obtained at the time of surgery. In this series of experiments, the dose of the drug varied from 76 to 319 μmol/m2, time after the last dose to surgery from 5 to 24 h, and the mode of drug administration from a single to three divided doses. Among these variable factors, only the daily dose of methimazole corrected by body surface area showed significant correlation with the intrathyroidal concentration, whereas the time after the last dose of the drug and the mode of drug administration did not. Our results revealed that methimazole was concentrated in the thyroid gland and that the intrathyroidal concentrations were maintained for 16 to 24 h in spite of a short plasma half-life. It is suggested that a single daily dose of methimazole is adequate for the treatment of Graves' disease in children and adolescents.

Free access

Emilia Sbardella, Carlotta Pozza, Andrea M Isidori, and Ashley B Grossman

Introduction

The transition age is the period between childhood to adulthood; it refers to a broad set of physical, cognitive and sociocultural modifications, arbitrarily defined as starting in late puberty and ending with full adult maturation. Pituitary disorders in adolescence represent a challenge that requires careful management during the transition to adult care.

Methods

Given the complexity of care of pituitary disorders in the transition age, we have reviewed the relevant medical literature focusing on aetiology, clinical manifestations, treatment strategies of GH deficiency (GHD), hypogonadotrophic hypogonadism (HH) in male and female adolescents, central hypothyroidism (CH), central adrenal insufficiency (CAI) and cranial diabetes insipidus (CDI) at this time. The objective of the present review is to provide an up-to-date evaluation of the transition period to evaluate the specific needs of adolescents with chronic pituitary disease in order to optimise their management.

Results

We provide an overview of current clinical management of GHD, HH, CH, CAI and CDI in the transition age.

Conclusions

Specific changes occur in pituitary function during the transition period. A holistic approach including discussion of patients’ concerns and emotional support should constitute a key component of managing pituitary disorders in adolescence. Special transition clinics where paediatric and adult endocrinologists work together, should be increasingly created and strengthened to bridge care, to promote continuity and adherence to treatment and to limit potential negative development, metabolic, skeletal and cardiovascular sequelae of discontinuity of care among adolescents with pituitary disorders.

Free access

Celia Aradillas-García, Martha Rodríguez-Morán, María Eugenia Garay-Sevilla, Juan Manuel Malacara, Ramón Alberto Rascon-Pacheco, and Fernando Guerrero-Romero

Objective

Several cutoff points of the homeostasis model assessment of insulin resistance (HOMA-IR; varying from 2.5 to 4.0) have been suggested for diagnosing IR in youth. In this study, we determined the distribution of the HOMA-IR in Mexican children and adolescents.

Design and methods

A total of 6132 children and adolescents from San Luis Potosi, León, Queretaro, and Durango, which are cities in central and northern Mexico, were enrolled in a population-based cross-sectional study. Eligible participants were apparently healthy children and adolescents aged 6–18 years. Pregnancy and the presence of chronic illnesses were exclusion criteria.

Results

A total of 3701 (60.3%) girls and 2431 (39.7%) boys were included in this study. In the overall population, the mean body mass index, insulin levels, and fasting glucose levels were 21.8±1.3 kg/m2, 7.1±3.2 μU/ml, and 86.2±10.0 mg/dl respectively. The concentrations of insulin and fasting glucose gradually increased from 6 to 12 years of age, whereas the concentrations tended to plateau in the 13- to 18-year-old population. The absolute mean of the HOMA-IR was 2.89±0.7. The HOMA-IR gradually increased with age and reached a plateau at 13 years of age.

Conclusions

Because the insulin concentrations, glucose levels, and HOMA-IR exhibited a gradual increase with age that was not related to obesity, our results suggested that the evaluation of IR in children should be based on percentiles of the HOMA-IR rather than a dichotomous value derived from a single cutoff point.

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L Even, V Bronstein, and Z Hochberg

The mechanism of growth retardation in Turner's syndrome has not been resolved. It is often referred to as a bone dysplasia, although endocrine derangement has not been ruled out. The present study was undertaken to evaluate the maturation of individual bones of the hand and wrist in girls with Turner's syndrome and thereby obtain information which may aid in elaborating the possible mechanism of the growth retardation in girls with Turner's syndrome. Hand and wrist films of 24 girls with Turner's syndrome, 11 normal girls with short stature and 23 normal controls were evaluated, using the references of Greulich and Pyle. Each bone or epiphysis was given an individual 'age'. During childhood the Turner patients showed the greatest delay in bone age of the phalangeal bones while the least delayed were the radius and ulna (long bones) and metacarpals. The carpal bones showed intermediate retardation. This pattern and extent of maturational retardation was clearly different from that of the short stature normal group, who showed uniform retardation of all bones. During adolescence, the phalangeal bones were further retarded and the carpal bones showed a moderate retardation. The unique profile of bone maturation in Turner's syndrome suggests an insult to chondroplasia, which may be related to estrogen deficiency or to an as yet undetermined endocrine or paracrine derangement.