Percentilos de referencia de la circunferencia y de las áreas muscular y grasa del brazo para la población infantojuvenil argentina (4-14 años) / Reference percentiles for mid-upper arm circumference, upper arm muscle and fat areas in the Argentine child and adolescent population (4-14 years old)

Introducción: La circunferencia del brazo (CB) se reconoce como buen indicador del estado nutricional. Objetivo: Estimar los percentilos de referencia para la CB y las áreas muscular (AM) y grasa (AG) del brazo en la población infantojuvenil argentina mediante el empleo del método LMS (lambda, mu, sigma, en inglés). Materiales y métodos: La muestra estuvo constituida por escolares de 4,0 a 13,9 años residentes en Jujuy, Catamarca, Misiones, Buenos Aires, Mendoza y Chubut. Las mediciones antropométricas de la CB y del pliegue tricipital se realizaron entre 2003 y 2008 siguiendo protocolos estandarizados. Se estimaron las AM, AG, se calcularon los percentilos por edad y sexo, y se compararon mediante el análisis de la varianza. Resultados: Se incluyeron 22 736 escolares (11 397 varones y 11 339 mujeres). Los valores correspondientes al percentilo 50 fueron superiores, en las mujeres, para CB y AG, y, en los varones, para AM. Las curvas de CB presentaron incrementos más marcados a partir de los 7 años en todos los percentilos, para ambos sexos. Un patrón similar se observó para AM, con valores superiores en los varones. Por último, el AG mostró aumento constante en las mujeres y estabilización en los varones a partir de los 11 años. Se observaron diferencias para la edad. Conclusiones: Los valores de percentilos, tabulados y graficados, de la CB y de las AM y AG del brazo pueden constituir una referencia local para estudios epidemiológicos y antropológicos.

Introduction: Mid-upper arm circumference (MUAC) is widely recognized as an adequate indicator of nutritional status. Objective: To estimate the reference percentiles for MUAC, upper arm muscle area (UAMA), and upper arm fat area (UAFA) in the Argentine child and adolescent population using the LMS method (lambda, mu, sigma) Materials and methods: The sample was made up of schoolchildren aged 4.0-13.9 years living in Jujuy, Catamarca, Misiones, Buenos Aires, Mendoza, and Chubut. MUAC and tricipital skinfold anthropometric measurements were obtained between 2003 and 2008 as per standardized protocols. UAMA and UAFA were calculated, and percentiles by age and sex were estimated and compared using an analysis of variance. Results: A total of 22 736 schoolchildren (11 397 boys and 11 339 girls) were included. The 50th percentile was higher for the MUAC and UAFA among girls and for the UAMA among boys. The MUAC curves showed sharper increases as of 7 years old in all percentiles among both boys and girls. A similar pattern was observed for the UAMA, with higher values among boys. Lastly, the UAFA showed a constant increase among girls and a stabilization among boys as of 11 years old. Differences for age were observed. Conclusions: The tabulated and plotted percentiles and the MUAC, UAMA, and UAFA may be used as local references for epidemiological and anthropological studies.

Reference percentiles for mid-upper arm circumference, upper arm muscle and fat areas in the Argentine child and adolescent population (4-14 years old). / Percentilos de referencia de la circunferencia y de las áreas muscular y grasa del brazo para la población infantojuvenil argentina (4-14 años).

INTRODUCTION: Mid-upper arm circumference (MUAC) is widely recognized as an adequate indicator of nutritional status. OBJECTIVE: To estimate the reference percentiles for MUAC, upper arm muscle area (UAMA), and upper arm fat area (UAFA) in the Argentine child and adolescent population using the LMS method (lambda, mu, sigma). MATERIALS AND METHODS: The sample was made up of schoolchildren aged 4.0-13.9 years living in Jujuy, Catamarca, Misiones, Buenos Aires, Mendoza, and Chubut. MUAC and tricipital skinfold anthropometric measurements were obtained between 2003 and 2008 as per standardized protocols. UAMA and UAFA were calculated, and percentiles by age and sex were estimated and compared using an analysis of variance. RESULTS: A total of 22 736 schoolchildren (11 397 boys and 11 339 girls) were included. The 50th percentile was higher for the MUAC and UAFA among girls and for the UAMA among boys. The MUAC curves showed sharper increases as of 7 years old in all percentiles among both boys and girls. A similar pattern was observed for the UAMA, with higher values among boys. Lastly, the UAFA showed a constant increase among girls and a stabilization among boys as of 11 years old. Differences for age were observed. CONCLUSIONS: The tabulated and plotted percentiles and the MUAC, UAMA, and UAFA may be used as local references for epidemiological and anthropological studies.

Introducción: La circunferencia del brazo (CB) se reconoce como buen indicador del estado nutricional. Objetivo: Estimar los percentilos de referencia para la CB y las áreas muscular (AM) y grasa (AG) del brazo en la población infantojuvenil argentina mediante el empleo del método LMS (lambda, mu, sigma, en inglés). Materiales y métodos: La muestra estuvo constituida por escolares de 4,0 a 13,9 años residentes en Jujuy, Catamarca, Misiones, Buenos Aires, Mendoza y Chubut. Las mediciones antropométricas de la CB y del pliegue tricipital se realizaron entre 2003 y 2008 siguiendo protocolos estandarizados. Se estimaron las AM, AG, se calcularon los percentilos por edad y sexo, y se compararon mediante el análisis de la varianza. Resultados: Se incluyeron 22 736 escolares (11 397 varones y 11 339 mujeres). Los valores correspondientes al percentilo 50 fueron superiores, en las mujeres, para CB y AG, y, en los varones, para AM. Las curvas de CB presentaron incrementos más marcados a partir de los 7 años en todos los percentilos, para ambos sexos. Un patrón similar se observó para AM, con valores superiores en los varones. Por último, el AG mostró aumento constante en las mujeres y estabilización en los varones a partir de los 11 años. Se observaron diferencias para la edad. Conclusiones: Los valores de percentilos, tabulados y graficados, de la CB y de las AM y AG del brazo pueden constituir una referencia local para estudios epidemiológicos y antropológicos.

[Obesity screening: updated criteria and their clinical and populational validity]. / Diagnosis de la obesidad: actualización de criterios y su validez clínica y poblacional.

OBJECTIVES: The primary aim of this study was to compare the frequency of overweight and obesity in Spanish children and teenagers by using national and international standards for the body mass index (BMI). The second aim was to establish the association between criteria based on BMI and body composition. The third aim was to propose new standards of fat percentages in order to increase diagnostic accuracy in patients with excess weight. MATERIAL AND METHODS: The sample was composed of 7,228 boys and girls aged between 6 and 20 years. Anthropometric measurements were taken (height, weight and subcutaneous skinfolds), and BMI and the percentage of fat were obtained using the methods of Durnin and Womersley, Siri and Slaughter et al. To classify obesity and overweight, the national standards of Hernández et al and the international standards published by Cole et al were used. The correlation between BMI and percentage of fat was established using Spearman's method and the variability fat percentage was estimated in relation to the BMI cut-off points proposed by the International Obesity Task Force (IOTF). RESULTS AND CONCLUSIONS: Overweight and obesity were more frequent in boys than in girls and in the youngest individuals. According to national standards, between 9.6 % (6-12 years) and 9.5 % (13-20 years) of girls and between 10.62 % (13-20 years) and 12.50 % (6-12 years) of boys were overweight. According to international standards, between 4.68 % (13-20 years) and 6 % (6-12 years) of boys were obese and between 18.83 % (13-20 years) and 21.6 % (6-12 years) were overweight. The proportion of obesity in girls ranged from 2.81 % (13-20 years) to 5.9 % (6-12 years); the prevalence of overweight was 25.99 % in the group aged 6-12 years and was 14.55 % in that aged 13-20 years. The analysis carried out shows that the association between BMI and adiposity differs in normal individuals and in those with excess weight. The international standards of Cole et al tend to underestimate obesity and to overestimate overweight. Therefore, their usefulness is limited to comparative studies and their use cannot be recommended in clinical diagnosis, where it would be more effective to use of specific population standards, especially those for fat percentage.