Variación estacional de 25-hidroxi-vitamina D3, hormona paratiroidea y fosfatasa alcalina en niños escolares / Seasonal variations in 25-hydroxy vitamin D3, parathormone and alkaline phosphatase in school-aged children

INTRODUCCIÓN: El principal rol de la vitamina D es la regulación del metabolismo del calcio, cuya principal fuen te es la vitamina D3 que se obtiene principalmente por la acción de la luz ultravioleta (UV) en la piel. OBJETIVO: Evaluar las diferencias estacionales en las concentraciones de 25-hidroxi-vitamina D3 (25OHVitD3), hormona paratiroidea (PTH), fosfatasa alcalina (FA) y calcio en niños en edad esco lar. SUJETOS Y MÉTODO: Se midieron las concentraciones de 25OHVitD3, PTH, FA y calcio en niños de 5 a 8 años, sin suplementación de Vitamina D, reclutados en Santiago de Chile (latitud -33.4372) en distintas estaciones del año. El estatus de VitD fue definido como suficiente con concentraciones de 25OHVitD3 > 20 ng/mL (50 nmol/L), insuficiente 12-20 ng/mL (30-50 nmol/L) y deficiente 20 ng/mL) en verano, lo que disminuyó significativamente en invierno (54,3%, p < 0,0001). CONCLUSIONES: Las concentraciones de 25OHVitD3 disminuyeron en aproximadamente la mitad de los niños durante el invierno, lo que se vio acompañado de un aumento de la PTH y FA, asociado a concentraciones normales de calcio. De acuerdo a nuestros resultados, la suplementación con VitD en niños podría ser necesaria durante otoño e invierno.

INTRODUCTION: The main role of Vitamin D is to regulate calcium metabolism, whose main source is vitamin D3 ob tained mostly from the action of ultraviolet (UV) light on the skin. OBJECTIVE: To evaluate the seaso nal differences in the concentrations of 25-hydroxy-vitamin D3 (25OHVitD3), parathyroid hormone (PTH), alkaline phosphatase (ALP), and calcium in school-age children. SUBJECTS AND METHOD: The concentrations of 25OHVitD3, PTH, ALP, and calcium were measured in children from Santiago, Chile (latitude -33.4372), aged 5 to 8 years, without Vitamin D supplementation, in different seasons of the year. VitD status was defined as sufficient with concentrations of 25OHVitD3 >20 ng/mL (50 nmol/L), insufficient 12-20 ng/mL (30-50 nmol/L) and deficient 20 ng/mL), which decreased significantly in winter to 54.3% (p <0.0001). CONCLUSIONS: In winter, 25OHVitD3 concentrations decreased in approximately half of the children, which was associated with an increase in PTH and ALP, and normal calcium concentrations. According to our results, children may need VitD supple mentation during fall and winter.

Estatura final en niños con talla baja idiopática tratados con hormona del crecimiento / Adult height of children with idiopathic short stature treated with growth hormone therapy

Introducción: La talla baja idiopática (TBI) se define como talla ≤ 2 desviaciones estándar (DE) sin causa precisada. El uso de la hormona de crecimiento (GH) en TBI es controvertido y no existen resultados de talla final (TF) en pacientes chilenos. El objetivo de este trabajo es comparar la TF de pacientes con TBI tratados con GH con la predicción de talla adulta al inicio de tratamiento. Pacientes y método: 18/47 pacientes con TBI tratados con GH y que alcanzaron su TF. Se definió TF con edad ósea (EO) ≥ 17 años en hombres y ≥ 15 años en mujeres. Para comparar se consideró la DE de la talla según curvas NCHS al inicio y final de tratamiento. El pronóstico de talla adulta (PTA) se calculó utilizando la EO mediante el método de Bayley-Pinneau. Resultados: La talla inicial fue 133,1 ± 6,8 cm (-2,1 ± 0,85 DE) y el PTA de -1,94 ± 0,86 DE. Los pacientes se trataron desde los 11,6 ± 1,2 años durante un tiempo de 1,56 ± 0,65 años. Al año de tratamiento su talla fue -1,64 ± 0,69 DE y la talla final fue -1,28 ± 0,62 DE (163,76 ± 7,22 cm). Se obtuvo un aumento en la TF de 2,67 ± 5,88 cm (equivalente a 0,67 ± 0,9 DE). Conclusión: Nuestros resultados demuestran que el tratamiento con GH fue eficaz para incrementar TF en pacientes con TBI, con una duración mayor a un año de tratamiento. Hasta donde sabemos este constituye el primer reporte de talla final en pacientes chilenos con TBI tratados con GH.

Introduction: Idiopathic short stature (ISS) is defined as a height of < - 2 standard deviations (SD) from the mean for age. The use of Growth Hormone (GH) in ISS is controversial, and there are not results for adult height (AH) in Chilean patients with ISS treated with GH. The objective of the study is to compare AH in patients treated with GH with the height prediction at beginning of treatment. Patients and Method: AH was considered with bone age ≥ 17 in males and ≥15 in females. The height SD according to the NCHS curves at beginning and ending of treatment were used for the comparison. Height prediction (HP) was calculated by Bayley-Pinneau method. Results: AH was reached by 18/47 patients with ISS treated with GH. Initial height -2.1 ± 0.85 SD (133.1 ± 6.8 cm) and HP -1.94 ± 0.86 SD, and were treated since 11.6 ±1.2 years old. After one year of treatment their height was -1.64 ±0.69 SD, and AH was -1.28 + -0.62 SD (163.76 +-7.22 cm). Conclusion: It is suggested that treatment with GH for ISS is effective to increase AH. Although with wide individual variability, a mean increase of 0.67 ± 0.9 SD (+2.67 cm) was obtained in the AH. This is the first report on Adult Height in Chilean patients.

Concordancia de la citología por punción con aguja fina para la detección de cáncer de tiroides en pediatría / Diagnostic yield of fine-needle aspiration cytology for the detection of thyroid cancer in pediatric patients

Background: Despite the low frequency of thyroid nodules (TN) in children, one of every four is malignant. Fine-needle aspiration cytology (FNAC) has a high accuracy detecting thyroid cancer. Aim: To evaluate the performance of FNAC in TN in Chilean children to detect thyroid cancer. Patients and Methods: The pathological reports of 77 thyroidectomies and 103 FNAC carried out in patients aged less than 18 years, between 2002 and 2013 were reviewed. In 36 patients aged 15 ± 2 years (77% women), both the reports of the thyroidectomy and FNAC were available. The cytological specimens were reclassified based on Bethesda 2010. The histology was classified as benign (nodular hyperplasia and follicular adenoma, n = 18), or malignant (papillary, follicular and medullar carcinoma, n = 18). The concordance of the cytology with the final biopsy report was calculated. Results: FNAC classified 13 specimens as definitively benign and 13 as definitively malignant. Among these, these concordances with the pathological study of the biopsy was 100%. Of six cytology tests considered "suspicious for follicular neoplasm" by FNAC, four were benign (67%), and two malignant (33%). Of four cytology tests considered "suggestive of carcinoma" by FNAC, one was benign (25%), and three malignant (75%). Conclusions: Among the studied children, there was a good concordance between FNAC and surgical biopsies. Therefore a FNAC should be carried out when malignancy is suspected in pediatric patients with a TN.

Hipotiroidismo congénito: un diagnóstico que no debemos olvidar / Congenital hypothyroidism: a diagnosis not to forget

Summary: Congenital hypothyroidism (CH) is the most common cause of preventable mental retardation. Since 1994, Chile has a national plan for mass screening all newborns to diagnose the disease. Currently, the CH incidence is approximately 1:3163 newborn (NB). Approximately, 10 percent of these cannot be identified by screening programs, so the clinical suspicion is fundamental in the diagnosis. The most frequently clinical features observed in neonates or young infants are the presence of a posterior fontanelle greater than 5 mm, umbilical hernia and dry skin. It is important to determine the etiology of CH, but the etiological study should not delay the start of treatment. Early treatment determines a better prognosis of neurological development. A review of the CH screening program, pathophysiology, clinical presentation, and aspects of the study and treatment are presented in this study.

El hipotiroidismo congénito (HTC) es la causa más frecuente de discapacidad intelectual prevenible. Desde el año 1994 existe en Chile un plan nacional de tamizaje masivo a todos los recién nacidos para el diagnóstico de la enfermedad. Actualmente, la incidencia de HTC es de aproximadamente 1:3 163 recién nacidos (RN). Hasta un 10 por ciento de éstos puede no ser identificado por los programas de tamizaje, por lo que es importante la sospecha clínica del diagnóstico. Las características clínicas más frecuentemente observadas en RN o lactantes pequeños son la presencia de una fontanela posterior mayor de 5 mm, hernia umbilical y piel seca. Es importante determinar la etiología del HTC, pero el estudio etiológico no debe retrasar el inicio del tratamiento. El inicio precoz de éste determina un mejor pronóstico de desarrollo neurológico. Se presenta una revisión del programa de tamizaje de HTC, su fisiopatología, presentación clínica, y aspectos del estudio y tratamiento.

Prevalencia de hipertensión arterial y su asociación con la obesidad en edad pediátrica / Prevalence of hypertension in school age children and its association with obesity

Background: Hypertension in children is a frequently overlooked problem that is an important cardiovascular risk factor. Aim: To determine the prevalence of hypertension among school age children. Material and Methods: Cross-sectional study of 2980 children aged 10 ± 2years (48 percent females) from 10 schools of middle and lower class in Metropolitan Santiago. Blood pressure (BP) was measured in the sitting position on three occasions after a rest period, using a mercury sphygmomanometer with appropriate cuff arm diameter, averaging the results of the measurements. Systolic and diastolic hypertension were defined as blood pressure values over 95percentilefor age, sex and height. Results: The overall prevalence of hypertension was 12.2 percent in women and 15 percent in men (p < 0.05). According to nutritional status, the prevalence was 6.7, 8.9,13.6 and 26 percent in underweight, eutrophic, overweight and obese children, respectively (p < 0.01). Compared with normal weight children, the risk of being hypertensive for overweight children was 1.6 (95 percent confidence intervals (CI) 1.2-2.3) and for obese children was 3.6 (95 percent CI 2.8-4.7). Conclusions: The studied children had a high prevalence of hypertension, that was directly related to a higher body mass index.

Alteraciones genéticas en la producción, secreción y acción de las gonadotrofinas / Genetic disorders of gonadotropin synthesis, release and function

Pulsatile secretion of Gonadotropin-Releasing Hormone (GnRH) by the hipothalamus and its action on the pituitary gland is a complex process involving many pre and post natal events. For example, migration of GnRH neurons from the olfactory placode, GnRH release and signalling, normal anterior pituitary development and function are all needed to allow GnRH to stimulate pulsaltile pituitary secretion of follicle-stimulating hormone (FSH) and liteinizing hormone (LH). Hypogonadotropic hypogonadism can be the result of absent or inadequate GnRH secretion or action. Abnormalities in gonadotropin hormone release and function can arise from mutations in a variety of genes implicated in hypogonadotropic hypogonadism is continually growing. A given genotype at a single locus cannot reliably predict the phenotypic manifestations in any given member of affected families. Thus, the identification and characterization of these mutations are providing important information about the reproductive axis in humans and may result in improved treatment and counselling for patients with infertility.

Sensibilidad diagnóstica de los distintos tiempos de la prueba de estímulo con clonidina, indicada para descartar deficiencia de hormona de crecimiento en niños con talla baja / Timing of growth hormone peaks during the clonidine provocation test

Background: Clonidine provocative test is used for the diagnosis of growth hormone (GH) deficiency. The duration of the test is not uniform across places where it is performed. Aim: To evaluate the frequency and timing of GH peaks during the clonidine test. To determine the timing with the highest diagnostic yield for GH deficiency. Patients and Methods: Analysis of the GH response during a clonidine test performed to 93 children with low stature, aged 11 +/- 3 years (41 percent women), with mean z scores of -2.3 +/- 0.8 for height and of 0.4 +/- 0.9 for body mass index, that were consecutively studied. A oral dose of 0.15 mg/m2 of clonidine was administered and GH levels were determined by the chemiluminescent enzyme immunoassay method of solid phase at 0, +30, +60, +90 and +120 minutes after. The cut-off point for GH deficiency was set at 7 ng/dL. Results: In ten children GH levels were lower than 7 ng/dL during the test and were considered as having GH deficiency. In 86 percent of the 83 patients without GH deficiency, the peak over 7 ng/mL appeared at +60 minutes and in 89 percent the peak had appeared at +90 minutes. In only 11 percent of these children, the peak appeared at +120 minutes. Conclusions: The timing with the highest diagnostic yield for GH is +60 minutes after the administration of clonidine. However the sample at +120 minutes should not be eliminated, considering that the highest GH peak appears at that time in 11 percent of children.

Concentraciones plasmáticas de TSH y tiroxina e índice de masa corporal en niños y adolescentes eutiroideos con sobrepeso u obesidad / Association between serum thyroid hormones and body mass index in overweight and obese children

Background: There is a possible association between mild thyroid dysfunction and changes in body mass index (BMI) and lean body mass. Aim: To study the association between TSH and free thyroxin levels and BMI among euthyroid children with overweight or obesity. Material and methods: Prospective study of 49 patients (39 males) aged 7 to 16 years, consulting for overweight or obesity. Serum TSH and free thyroxine levels were measured and the BMI z score was calculated. The correlation between thyroid hormone levels and BMI was calculated. Also serum hormones were divided in terciles to look for differences in BMI. Results: No significant association was found between serum TSH and free thyroxin levels and BMI. Conclusions: In this series of pediatric patients, no association between serum thyroid hormones and BMI, was observed.

Enfermedad de Basedow Graves en pacientes pediátricos / Graves-Basedow disease in pediatric patients

Objective: Determine differences in the epidemiology, clinical features and diagnosis of Graves-Basedow disease (GBD) in prepubertal and pubertal patients. Method: Retrospective study analyzing medical records of 38 patients with GBD at Pontificia Universidad Católica de Chile between 1992-2007. Statistical analysis was performed with non parametric test of Mann-Whitney U and proportions difference with Fisher Test (SPSS 10.0 for Windows and Graphpad Prism 4). Results: 21 patients were prepubertal and 17 were pubertal, with ages between 3 and 15,9 years. There were more girls than boys in both groups (5:2 and 15:2, respectively; p = 0.2). The most common clinical presentations were diffuse goiter, hyperactivity, frequent bowel movements, insomnia and heat intolerance. The prepubertal group had a taller stature (+2.4 SDS) compared with the pubertal group (+0.2 SDS; p = 0.03) and the most frequent ocular manifestation was exophthalmus in both groups. Conclusions: We did not find any differences in the clinical presentations of Graves-Basedow disease among prepubertal and pubertal patients. Neuropsychiatric symptoms such as hyperactivity and insomnia, together with tall stature are common features in children with GBD.

Objetivo: Determinar si existen diferencias en las características epidemiológicas y clínicas al momento del diagnóstico de hipertiroidismo por Basedow Graves (BG) en sujetos pre-púberes y púberes. Pacientes y Método: Estudio descriptivo y retrospectivo. Universo: Pacientes con diagnóstico de BG en control en endocrinología pediátrica en la Pontificia Universidad Católica de Chile, entre 1991 y abril 2007 (n = 38). Se registraron los hallazgos clínicos y de laboratorio. Se evaluó las diferencias entre los grupos con pruebas no paramétricas (Mann-Whitney U), las diferencias de proporciones con la Prueba de Fisher (SPSS 10.0 para Windows y graphpad Prism 4). Resultados: El rango de edad fue 3 a 15,9 años. Veintiún sujetos eran pre-púberes y 17 eran púberes; hubo más mujeres que hombres (5: 2 y 15: 2, respectivamente; p = 0,2). Los síntomas y signos más frecuentes fueron bocio difuso, hiperactividad, polidefecación, insomnio e irradiación de calor. No hubo diferencias entre los pre-púberes y púberes. El grupo pre-púber tenía talla más alta que su carga genética (+2,4 DS) comparados con los púberes (+0,2 SDS; p = 0,03). El compromiso ocular más frecuente fue el exoftalmo. Conclusión: No encontramos diferencias en la forma de presentación del BG entre los niños pre-púberes y púberes. Los síntomas neuropsiquiátricos tales como hiperactividad e insomnio, y una talla mayor a la esperada para la diana familiar, fueron hallazgos frecuentes en los niños con BG.

Tiroides lingual como causa de disfagia: Caso clínico / Disphagia caused by a lingual thyroid: Report of one case

We report all year-old boy who presented with difficulty in swallowing without symptoms of hypothyroidism. The physical examination revealed a mass at the base of the tongue. The thyroid hormone profile showed a primary hypothyroidism (a serum TSH of 10.8 IU/mL with normal-low thyroxin of 6.0 fig/dL and low triiodothyronine of 57.8 ng/ dL). Antithyroid antibodies were negative. The fiberoptic endoscopy showed a reddish mass, without evidence of haemorrhage or ulceration, confirmed as a well circumscribed, hypodense mass in the base of the tongue by computed tomography of the oropharynx and neck. Tc-99-pertechnetate scanning showed an abnormal area of uptake at the base of the tongue and no uptake in the normal thyroid location, concordant with an ectopic lingual thyroid gland. Levothyroxine in a suppressive dose was started that resulted in a reduction of the size of the mass and disappearance of dysphagia.