Marcadores de síndrome metabólico como predictores de elevación de alanino aminotransferasa en niños / Association of metabolic syndrome markers with abnormal alanine aminotransferase levels in healthy children

Background: There is a high prevalence of non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) among pediatric patients. The identification of clinical predictors of these conditions would allow a timely treatment. Aim: To evaluate the relationship between serum alanine aminotransferase levels and parameters of metabolic syndrome in asymptomatic school students without hepatic illness. Subjects and Methods: A randomized sample of 175 children aged between 9 and 14 years (54% females) was selected, from a database of 3010 students living in Santiago, Chile. Weight, height, abdominal circumference, systolic and diastolic blood pressure were measured. A fasting blood sample was obtained to measure glucose, total cholesterol, HDL, LDL-cholesterol, triglycerides, alanine aminotransferase (ALT) and insulin levels. Results: Forty percent of participants were obese, 17% had metabolic syndrome and 13.1% had abnormal ALT levels. Compared with children with normal ALT levels, the latter had significantly higher waist obesity, body mass index, systolic and diastolic blood pressure and triglycerides. However on multiva-riate analysis, only waist obesity was independently associated with abnormal ALT levels (adjusted odds ratio 3.93, 95% confidence intervals 1.44-10.78, p = 0.008). Conclusions: Only waist obesity was independently associated with abnormal ALT levels in this sample of children.

Utilidad de la determinación basal de la hormona luteinizante para determinar la activación del eje hipotalamo-hipofisiario-gonadal (HHG) / Basal luteinizing hormone values to determine activation of the hypothalamic-pituitary-gonadal axis

Background: The stimulation test with gonadotropin-releasing factor (GnRH) is considered the gold standard to study the activation of the hypothalamic-pituitary-gonadal axis (HPG). A maximum luteinizing hormone (LH) response of more than > 5 mIU/min in girls confirms the activation of the HPG axis. With the advent of more sensitive methods of LH measurement, such as immuno chemiluminescence (ICMA), basal LH values have been proposed to predict the response and replace the GnRH test. Aim: To determine which basal LH value correlates with a GnRH test > 5 uUI/ml. Material and Methods: We retrospectively analyzed LH values, measured by ICMA, in the basal period and after GnRH stimulation, in 120 girls aged 8 +/- 1 years (60 with activated axis and 60 without activation), during 2009. The sensitivity and specificity of the different values were determined by receiver operating characteristic (ROC) curves. Results: In patients with and without activation of the HPG axis, basal LH was 0.5 +/- 0.53 and 0.15 +/- 0.12 mUI/ml, respectively (p < 0.01). According to ROC curves, a basal LH value greater or equal than 0.4 mUI/ml had a specificity of 93.2 percent and a sensitivity of 61 percent to determine activation of the HPG axis. Conclusions: A basal LH > 0.4 mUI/ml in girls with precocious puberty has a specificity of 93.2 percent to determine activation of the HPG axis.

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.

Razón cintura estatura como predictor de riesgo cardiometabólico en niños y adolescentes / Waist-Height ratio as a predictor if cardio-metabolic risk in children

En niños, la obesidad general y visceral se asocian con mayor riesgo cardiometabólico. El aumento en la prevalencia del síndrome metabólico (SM) en niños y adolescentes empeora el riesgo cardiovascular. Necesitamos contar con nuevos marcadores que permitan predecir el SM en niños. Objetivo: Comparar índice de masa corporal (zIMC) con razón cintura estatura (RCE) como predictores de SM en niños chilenos. Método: Estudio transversal en 618 escolares, edad 10.8 +/- 1.9 años, 51.6 por ciento mujeres, 190 eutróficos, 174 sobrepeso, 254 obesos, estrato socioeconómico medio y medio bajo, área urbana de Santiago. Determinamos peso, talla, circunferencia de cintura, presión arterial, perfil lipídico y glicemia. Diagnóstico de SM basado en la presencia de > 3 criterios de Cook. El SM se modeló en función de RCE y z score IMC , con modelos de regresión logística. Se usaron curvas ROC para comparar RCE y zIMC como predictores de SM. Punto de corte según índice de YOUDEN. Resultados: La prevalencia de SM fue 15.37 por ciento. Promedio de z IMC + 1.22 +/- 0.90 y de RCE 0.52 +/-0.07. Punto de corte óptimo para SM: RCE 0.55 (sensibilidad 72 por ciento, especificidad 70 por ciento) yzIMC: 1.76 (sensibilidad 71 por ciento, especificidad 74 por ciento). Conclusión: RCE y zIMC predicen igualmente el riesgo cardiometabólico en niños y adolescentes. Dada la mayor facilidad de calcular RCE, la transforma en mejor herramienta definiendo riesgo en este grupo. El punto de corte > 0.55 sería buen predictor de SM en niños y adolescentes.

Among children both general and visceral obesity are associated with increased cardio-metabolic risk. The increasing prevalence of the metabolic syndrome (MS) in children and adolescents increases cardiovascular risk. Studies of new clinical markers which can easily and accurately predict MS in children and adolescents are needed. Aim: To compare zBMI and waist to height ratio (WHR) as predictors of MS in Chilean children. Method: We performed a crossectional study of 618 schoolchildren, age 11 +/- 2 years, 52 percent females, 190 eutrophic, 174 overweight, 254 obese, from middle and low social economic strata from the Santiago urban area. We determined weight, height, waist circumference, blood pressure and fasting lipids and glycemia. MS diagnosis was based on the presence of > 3 Cook criteria. MS was modeled in function of WHR and z score BMI, through logistic regression models. ROC curves were used to compare zBMI and WHR as predictors of MS. The cut off point by YOUDEN index was used. Results: The prevalence of MS was 15 percent. Mean zBMI was +1.22 +/- 0.90 and WHR 0.52 +/- 0.07. Cut off point for MS were: WHR 0,55 (sensitivity 72 percent, specificity 70 percent)and zBMI: 1.76 (sensitivity 71 percent, specificity 74 percent). Conclusions: Both WHR and zBMI similarly predicted cardio metabolic risk in children and adolescents. The greater feasibility of calculating WHR makes it a good tool for defining risk in this group. A cut off point >0.55 might be a good predictor of MS in children and adolescents.

Pubarquia precoz: Experiencia en 173 casos / Precocious pubarche: Experience in 173 cases

Background: Precocious pubarche (PP), defined as the development of sexual pubic hair before 8 years of age in females and before 9 years in males, is usually a benign condition but it can also be the first sign of an underlying disease. Aim: To analyze the etiology andperform a short term follow up in a cohort of patients with PP. Material and methods: A group of 173 patients (158 females) consulted for PP with a mean age of 7.4±0.1 years. These patients were followed between 15 to 60 months. Anthropometric measurements, bone age, serum levels of total testosterone, 17 OH progesterone (17 OHP) and dehydroepiandrosterone sulphate (DHEAS) were evaluated. Results: Mean birth weight and length was 3024.1±50.5 g and 48.5±0.3 cm,respectively. Ten percent of children were small for gestational age at birth. Bone age was accelerated by 1.1±0.01 years. One hundred and twelve patients were classified as having idiopathicPP (64.7%; 105 females), 29 as central precocious puberty (16.8%; only females), 16 as exaggerated adrenarche (EA 9.2%; 13 females) and 16 as non classical adrenal hyperplasia (9.2%; 11 females). Conclusions: PP represents a common and usually benign sign. However, 26% of cases had apathologic underlying condition. Therefore, all children with PP should be evaluated by a pediatric endocrinologist. Low birth weight was not frequent in this cohort and these patients did not show EA