Chilean reference of length at birth.

BACKGROUND: To generate a reference of length at birth (LB) according to sex and gestational age (GA) of the Chilean population. METHODS: This cross-sectional observational study used public pooled Chilean newborn (NB) population data registered by the Civil Registry and Identification Service in Chile from 2000 to 2016. Multiple births, entries without information for LB, GA, and sex, and birth lengths <-4SD and > 4SD, were excluded. After applying the selection and randomization criteria, the final sample was made up of 5 010 963 NB (2 560 310 boys; 2 450 653 girls). Length at birth centiles by sex and GA (24-42 weeks) were calculated using the GAMLSS method and then compared with the INTERGROWTH-21st standard. RESULTS: Girls had a lower LB than boys. For most GA and in both sexes, the absolute and percentage differences of percentiles as compared with INTERGROWTH-21st were lower than 1 cm and 1%, respectively. CONCLUSIONS: We present a reference for LB by sex and GA in the Chilean population, developed following updated methodological criteria for neonatal anthropometry, which is acceptably consistent with the INTERGROWTH-21st standard. The reference we propose may be used in clinical and epidemiological studies to identify either Chilean individuals or populations, respectively, at higher risk of perinatal and infant adverse events related to LB.

Referencias de índice de masa corporal. Precisión diagnóstica con área grasa braquial en escolares argentinos / Body mass index references. Diagnostic accuracy with the upper-arm fat area in Argentine schoolchildren

El índice de masa corporal (IMC) es una eficaz herramienta para detectar la sobrecarga ponderal en niños y adolescentes, asociado a la adiposidad corporal. Objetivo. Analizar la concordancia, sensibilidad y especificidad de tres referencias internacionales de IMC/edad (OMS, IOTF y CDC) para diagnosticar el exceso ponderal y conocer su precisión diagnóstica para identificar el exceso de adiposidad con relación al área grasa braquial (AGB) en población infanto juvenil de Argentina. Materiales y métodos. Se realizó un estudio multicéntrico, descriptivo-comparativo y transversal entre 2003 y 2008, en 22.658 niños y adolescentes argentinos de 4 a 13 años de edad. A partir del peso, talla, circunferencia del brazo y pliegue tricipital, se calcularon IMC y AGB. Se analizó la concordancia, sensibilidad y especificidad de referencias de IMC/edad (OMS, CDC, IOTF) y la precisión diagnóstica (curvas ROC) para identificar exceso de adiposidad, a partir del AGB, así como el punto de corte óptimo (PCO). Resultados. Las tres referencias tuvieron buena concordancia. La mayor sensibilidad correspondió a OMS y la mayor especificidad a IOTF. El área bajo la curva (ABC) fue mayor en Z-IMC/IOTF en varones y en Z-IMC/OMS en mujeres. Los PCO mostraron discrepancias, siendo mayores con OMS. Conclusión. Las tres referencias muestran similar precisión diagnóstica para detectar alta reserva calórica, con puntos de corte óptimo para las puntuaciones Z-IMC menores a 2 Z scores. Esto resulta relevante para la identificación de exceso de adiposidad en poblaciones, en relación con la implementación de políticas públicas de prevención de enfermedades crónicas no transmisibles(AU)

The body mass index (BMI) is an effective tool to detect weight overload in children and adolescents, associated with body adiposity. Objective. To analyze the concordance, sensitivity and specificity of three international BMI/age references (WHO, IOTF and CDC) to diagnose excess weight and to know their diagnostic accuracy to identify excess adiposity in relation to the brachial fat area (BFA) in Argentine child-youth population. Materials and methods. A multicenter, descriptive- comparative and cross-sectional study was carried out between 2003 and 2008 in 22.658 Argentine children and adolescents between aged 4 to 13 years. From the weight, height, arm circumference and tricipital fold, BMI and BFA were calculated. The concordance, sensitivity, and specificity of BMI / age references (WHO, IOTF, CDC,) were analyzed and the diagnostic precision (ROC curves) to identify excess adiposity, from the BFA, as well as the optimal cut-off point (OCP). Results. The three references had good agreement, the highest sensitivity corresponded to WHO and the highest specificity to IOTF. The area under the curve (AUC) was greater in Z-BMI/IOTF in men and in Z-BMI/WHO in women. The OCPs showed discrepancies, being higher with WHO. Conclusion. The three references show similar diagnostic accuracy to detect high caloric reserve, but with cut-off points for Z-BMI scores less than 2 Z scores. This is relevant for the identification of excess adiposity in populations in relation to the implementation of public policies for the prevention of chronic non-communicable diseases(AU)

Waist circumference percentiles for Hispanic-American children and comparison with other international references.

INTRODUCTION: Waist circumference (WC) constitutes an indirect measurement of central obesity in children and adolescents. OBJECTIVE: To provide percentiles of WC for Hispanic-American children and adolescents, and compare them with other international references. MATERIALS AND METHODS: The sample comprised 13 289 healthy children between 6 and 18 years coming from public schools of middle and low socioeconomic levels in different parts of Argentina, Cuba, Spain, Mexico, and Venezuela. The LMS method to calculate WC percentiles was applied. Sex and age differences were assessed using Student's t test and ANOVA (SPSS v.21.0). Comparisons were established with references from the United States, Colombia, India, China, Australia, Kuwait, Germany, Tunisia, Greece, and Portugal. RESULTS: WC increases with age in both sexes. Boys show higher WC in P3, P50, and P97. Comparison of 50th and 90th percentiles among populations from diverse sociocultural and geographical contexts shows high variability, not all justified by the measurement method. DISCUSSION AND CONCLUSIONS: Specific WC percentiles for sex and age, and P90 cut-off points are provided; these values are potentially useful to assess central obesity in Hispanic-American adolescent children.

Relación entre el Índice Córmico y el Índice de Masa Corporalentre los 6 y 18 años / Relationship between Cormic Index and Body Mass Index between 6 and 18 years old

INTRODUCCIÓN: El Índice de Masa Corporal (IMC) se utiliza para valorar la condición nutricional en niños y adultos, pero su principal limitación es que no tiene en cuenta la composición corporal ni la longitud de los segmentos corporales. El índice Córmico (IC) se utiliza para valorar la proporcionalidad y relaciona a talla sentado con la estatura. OBJETIVOS: Analizar la evolución del IMC y del IC con la edad y la asociación entre ambos. METODOLOGÍA: se parte de una muestra internacional de 7.688 niños y niñas entre 6 y 18 años. Se analizó la variabilidad ontogénica del IMC e IC por edad y su dimorfismo sexual así como la asociación entre condición nutricional y tamaño relativo del tronco. RESULTADOS: El IMC aumenta con la edad análogamente en ambos sexos. El IC disminuye hasta los 12 años, momento en el que comienza a aumentar alcanzando promedios superiores en el sexo femenino. Valores de IC elevados están relacionados con sobrepeso u obesidad, mientras valores de IC bajos lo están con insuficiencia ponderal (p < 0,001). CONCLUSIONES: Los sujetos con extremidad inferior más corta respecto a la estatura tienen un mayor riesgo de clasificarse con sobrepeso u obesidad, porque el tronco supone la mayor proporción del peso corporal total. La combinación del IC y del IMC podría mejorar el diagnóstico de la condición nutricional de los individuos

INTRODUCTION: The Body Mass Index (BMI) is used to assess nutritional status in children and adults, but its main limitation is that it does not take into account body composition or length of body segments. The Cormic Index (CI) is used to assess proportionality and relates setting height to total height. OBJECTIVES: To analyse the evolution of BMI and CI with age and the association between them. METHODOLOGY: an international sample of 7,688 boys and girls between 6 and 18 years old is used. The ontogenetic variability of BMI and CI by age and their sexual dimorphism were analysed, as well as the association between nutritional condition and relative size of the trunk. RESULTS: BMI increases with age in both sexes. The CI decreases until 12 years, at which time it begins to increase reaching higher averages in the female sex. High CI values are related to overweight or obesity, while low CI values are related to underweight (p < 0.001). CONCLUSIONS: subjects with shorter lower extremities in relation to height have a greater risk of being classified as overweight or obese, because the trunk accounts for the largest proportion of total body weight. The combination of CI and BMI could improve the diagnosis of the nutritional condition of individuals

Indicadores bioquímicos de riesgo cardiometabólico, exceso de peso y presión arterial en estudiantes universitarios. Catamarca, Argentina / Biochemical indicators of cardiometabolic risk excess weight and blood pressure in university students. Catamarca, Argentina

El exceso de grasa corporal y su relación con lípidos en sangre, glucemia y presión arterial, está asociado con el aumento de riesgo a desarrollar enfermedades coronarias y metabólicas. Su detección temprana puede prevenir la aparición de tales enfermedades o permitir un inicio temprano de tratamiento. En 133 estudiantes, ingresantes a la Universidad Nacional de Catamarca, Argentina, cohortes 2011 a 2013, entre 17 y 22 años, se analizaron las variables: peso, talla, índice de masa corporal, glucemia, colesterol total, triglicéridos y presión arterial diastólica y sistólica. Los estudiantes analizados presentaron alta prevalencia de exceso de peso y colesterolemia. En menor medida hiperglucemia, hipertrigliceridemia e hipertensión arterial, sin diferencias significativas entre sexos. Se observó correlación positiva del índice de masa corporal con glucemia y presión arterial sistólica

Excess body fat and its relationship to blood lipids, glucose and blood pressure, is associated with an increased risk of developing coronary and metabolic diseases. His early detection may prevent the onset of such diseases or allow early initiation of treatment. In 133 students from the National University of Catamarca, Argentina, cohorts 2011 to 2013, between 17 and 22 years, were analyzed: Weight, height, body mass index, blood glucose, total cholesterol, triglycerides and diastolic and systolic blood pressure. The analyzed students presented high prevalence of excess weight and cholesterolemia. To a lesser extent hyperglycemia, hypertriglyceridemia and hypertension. No statistically significant differences between sexes. There was a positive correlation of body mass index with glycemia and systolic blood pressure

Subscapular and triceps skinfolds reference values of Hispanic American children and adolescents and their comparison with the reference of Centers for Disease Control and Prevention (CDC) / Valores de referencia para los pliegues adiposos subescapular y tricipital de niños y adolescentes hispanoamericanos y su comparación con la referencia de los centros para el control y prevención de enfermedades (CDC)

Introduction: the assessment of the skinfold thickness is an objective measure of adiposity. Therefore, it is a useful tool for nutritional diagnosis and prevention of metabolic risk associated with excess fat in chilhood and adolescence. Objective: to provide percentiles of subscapular and triceps skinfolds for Hispanic American schoolchildren and compare them with those published by the Centers for Disease Control and Prevention (CDC) from United States, that it have been commonly used as a reference in most of these countries. Methods: subscapular and triceps skinfolds were measured in 9.973 schoolchildren 4-19 aged from Spain, Argentina, Cuba, Venezuela and Mexico with Holtain caliper with 0.2 mm accuracy. Percentiles were obtained with the LMS statistical method and were presented in tables divided in stages of 6 months and in curves graphics. The difference between Hispanic American and CDC mean values were provided for P3, P50 and P97 in mm and also were graphically represented. Results: skinfolds measurements obviously increased with age in both sexes but, in boys, this increase is much more marked in highest percentiles between 8 and 13 years; this maximum is reached earlier than what occurs in CDC reference. In both sexes, all percentiles analized in Hispanic American schoolchildren were higher than the CDC reference except P97 up to 10 or 13 years that was notably smaller. Conclusions: the skinfolds percentiles of Hispanic American children and adolescents differ from CDC that are usually used as reference. The values of subscapular and triceps skinfolds provided in this study, could be applied to populations of a similar ethnic background, especially in comparative studies of body composition (AU)

Introducción: la evaluación del grosor de los pliegues subcutáneos es una medida objetiva de la adiposidad. Es por tanto una herramienta útil para el diagnóstico nutricional y la prevención del riesgo metabólico asociado al exceso de grasa en la infancia y adolescencia. Objetivo: proporcionar valores percentilares de los pliegues adiposos subcutáneos subescapular y tricipital para escolares hispanoamericanos y compararlos con los valores publicados por los Centros para el Control y Prevención de Enfermedades (CDC) de los Estados Unidos, que comunmente se emplean como referencia en estos países. Métodos: se midió el pliegue subescapular y tricipital en 9.973 escolares entre 4 y 19 años procedentes de España, Argentina, Cuba, Venezuela y México con un calibre Holtain de 0,2 mm de precisión. Los percentiles fueron calculados mediante el método estadístico LMS y presentados en tablas divididas en intervalos de seis meses y en gráficos de curvas. La diferencia entre los valores medios hispanoamericanos y los valores del CDC se muestran para el P3, P50 y P97 en mm, y también gráficamente. Resultados: las medidas de los pliegues subcutáneos se incrementan obviamente con la edad pero, en niños, este incremento es mucho más marcado en los percentiles superiores entre los 8 y 13 años; este máximo es alcanzado antes que en la referencia del CDC. En ambos sexos, todos los percentiles analizados fueron superiores en los escolares hispanoamericanos, exceptuando el P97 por encima de los 10 o 13 años, donde resultó notablemente inferior. Conclusiones: los percentiles de pliegues adiposos de los niños y adolescentes hispanoamericanos difieren de la referencia del CDC. Los valores del pliegie subescapular y tricipital proporcionados en este estudio podrían ser aplicados en poblaciones de similar origen étnico, especialmente en estudios comparativos de la composición corporal (AU)

Curvas percentilares de peso al nacimiento por edad gestacional para la población de la provincia de Catamarca (Argentina) / Weight for age perentile curves for the popultion of catamarca province (Argentina)

Introducción: La evaluación del desarrollo fetal y del peso al nacimiento es un objetivo prioritario en el ámbito de la epidemiología nutricional y de la salud pública. En la actualidad, la Organización Mundial de la Salud (OMS) no dispone de curvas específicas de peso al nacimiento para las distintas semanas gestacionales al considerar que las características socioeconómicas, ecológicas y étnicas de los distintos grupos humanos influyen en sus propios patrones de crecimiento. Objetivo: La presente investigación desarrolla las curvas percentilares de peso por edad gestacional para las poblaciones residentes en la provincia de Catamarca.Métodos: El procesamiento de los datos se llevó a cabo con el programa SPSS y para la posterior realización delas curvas percentilares se utilizó el programa LMS Chart Maker pro, a partir de un total de 22.576 nacimientos ocurridos entre 1994 y 2003. Discusión y conclusiones: Dichas curvas posibilitarán en el futuro una mejor valoración del desarrollo intrauterino y del peso de los recién nacidos en esta región delNoroeste de Argentina (AU)

Introduction: The assessment of fetal development and birth weight is a priority in the field of nutritional epidemiology and public health. Nowadays, the World Health Organization (WHO) does not have specific birth weight curves for the distinct gestational weeks considering that socio-economic, ecological and ethnic characteristics of the different human groups are found influencing their own growth patterns. Objective: This research develops centile curves for weight by gestational age concerning to resident populations in the province of Catamarca. Methods: In order to process data, SPSS statistical program was used, as well as LMS Chart Maker pro program for the subsequent performing of centile curves. The sample ascended to a total of 22,576 childbirths between 1994 and 2003. Discussion and Conclusion: In the future, these curves make possible a better assessment of intrauterine development and birth weight in this region of Northwest of Argentina (AU)

Altitude effect on birth weight and prematurity in the Province of Catamarca (Argentina).

OBJECTIVES: To analyze the effect of altitude on weight and prematurity at birth in the Province of Catamarca (Argentina), between the years 1994 and 2003. METHODS: Records of 22,628 newborns were collected from the vital statistics of the census of Catamarca. Weight was recategorized to include low birth weight (<2,500 g), and gestational age was divided into births that had occurred before or after 37 weeks (preterm or at term births). Altitude was also recategorized (<1,500 m, 1,500-2,000 m, and > 2,000 m). Nonparametric statistical tests were performed. RESULTS: Differences were found in birth weight between sexes and in the incidence of low birth weight depending on altitude. This pattern changed according to gestational age, because those sexual differences were nonexistent or lower in preterm neonates with certain advantages for females. Moreover, it was found that the effects of hypoxia were not reflected in birth weight until later stages of intrauterine development. CONCLUSIONS: To be female appears to be a benefit under conditions of prematurity and high altitude. The increased incidence of prematurity due to altitude increase may reflect an adaptive advantage of preterm birth under these conditions.

[Weight-for-age percentile curves for the population of Catamarca province (Argentina)]. / Curvas percentilares de peso al nacimiento por edad gestacional para la población de la provincia de Catamarca (Argentina).

INTRODUCTION: The assessment of fetal development and birth weight is a priority in the field of nutritional epidemiology and public health. Nowadays, the World Health Organization (WHO) does not have specific birth weight curves for the distinct gestational weeks considering that socio-economic, ecological and ethnic characteristics of the different human groups are found influencing their own growth patterns. OBJECTIVE: This research develops centile curves for weight by gestational age concerning to resident populations in the province of Catamarca. METHODS: In order to process data, SPSS statistical program was used, as well as LMS Chart Maker pro program for the subsequent performing of centile curves. The sample ascended to a total of 22,576 childbirths between 1994 and 2003. DISCUSSION AND CONCLUSION: In the future, these curves make possible a better assessment of intrauterine development and birth weight in this region of Northwest of Argentina.

Introducción: La evaluación del desarrollo fetal y del peso al nacimiento es un objetivo prioritario en el ámbito de la epidemiología nutricional y de la salud pública. En la actualidad, la Organización Mundial de la Salud (OMS) no dispone de curvas específicas de peso al nacimiento para las distintas semanas gestacionales al considerar que las características socioeconómicas, ecológicas y étnicas de los distintos grupos humanos influyen en sus propios patrones de crecimiento. Objetivo: La presente investigación desarrolla las curvas percentilares de peso por edad gestacional para las poblaciones residentes en la provincia de Catamarca. Métodos: El procesamiento de los datos se llevó a cabo con el programa SPSS y para la posterior realización de las curvas percentilares se utilizó el programa LMS Chart Maker pro, a partir de un total de 22.576 nacimientos ocurridos entre 1994 y 2003. Discusión y conclusiones: Dichas curvas posibilitarán en el futuro una mejor valoración del desarrollo intrauterino y del peso de los recién nacidos en esta región del Noroeste de Argentina.

Anthropometric parameters in screening for excess of adiposity in Argentinian and Spanish adolescents: evaluation using receiver operating characteristic (ROC) methodology.

BACKGROUND: Various anthropometric parameters have been proposed for defining overweight in adolescence, but few studies have evaluated their diagnostic accuracy in comparative terms, using samples from different regions. AIM: To compare the performance of anthropometric parameters in determining the excess of adiposity in Argentinian and Spanish adolescents. SUBJECTS AND METHODS: The sample is composed of 1781 Argentinian and 1350 Spanish subjects, aged 12-17 years. Excess adiposity was defined as percentage BF in the 90th percentile or higher. ROC curves established the validity of parameters to define excess adiposity. RESULTS: Descriptive statistics showed differences between the Argentinian and Spanish samples. ROC curves indicate that all the parameters analysed had, in the Spanish and Argentinian samples, a positive and elevated association with excess of adiposity. The waist-to-height ratio had the highest value of the area under ROC curve (AUC), while conicity index and waist-to-hip ratio had the lowest. CONCLUSIONS: Differences exist with respect to size and body composition between the Argentinian and Spanish samples. ROC curves reflect a general pattern of variation. Waist-to-hip ratio and conicity index are less desirable in the diagnosis of excess adiposity and the most desirable is waist-to-height ratio.