Estimation of Pubertal Growth-Spurt Parameters in Children and Adolescents in Colombia: Comparison between Low and Moderate Altitudes.

Context-specific information, including differences in geographical areas, such as distinct altitudes, can be important to explain variations in physical growth. We aimed to compare the estimation of maximum growth velocity and pubertal growth-spurt parameters of children and adolescents living at low and moderate altitudes in Colombia. A cross-sectional study, including a representative cohort of 30.305 (51% boys) children and adolescents aged 1−18 years from Colombia, was performed. The heights were measured with standardized techniques. The Preece−Baines growth model was used to estimate the mathematical and biological parameters of the height-growth velocities and growth spurts for both sexes. The altitudes were categorized as low (18 to 564 m above sea level) or moderate (2420 to 2640 m above sea level). There were no differences in final height (h1), peak height velocity size (hθ), age at peak height velocity (APHV), or peak height velocity PHV (cm/y) between the subjects living in both altitudes (p > 0.05). The APHV was estimated at 12.75 ± 0.75 years in the boys and at 10.05 ± 0.65 years in the girls. The girls reached the APVH 2.70 years earlier than the boys. Regarding the PHV, the boys reached higher growth velocity, which was 6.85 ± 0.55 cm/y. In conclusion, there were no significant differences in final height, peak height, APHV, or PHV between the children and adolescents living at distinct altitudes in Colombia. The PHV occurred approximately 3 years earlier in the girls than in the boys. Furthermore, the girls' estimated PHV, APHV, and final height were lower than those of the boys. This study allows additional insight into pubertal growth-spurt parameters and also provides a valuable reference database for the assessment of Colombian children and adolescents.

Estimation of Pubertal Growth Spurt Parameters in Children and Adolescents Living at Moderate Altitude in Colombia.

Objective: Knowledge of the biological parameters of pubertal growth spurt allows verification of secular changes and exploration of the timing of puberty. The aim of the study was to estimate final height, age at peak height velocity (APHV), and peak height velocity PHV (cm/y) in children and adolescents living at moderate altitude in Colombia. Methods: A cross-sectional study was designed in 2.295 schoolchildren from Bogotá (Colombia) with an age range from 5.0 to 18.9 years. Height (cm) was assessed. Preece-Baines model 1 (1PB) was used to make inferences about mathematical and biological parameters. Results: The five mathematical parameters estimated in general have reflected quality in the fit to the model, reflecting a small residual error. Final height was reached in boys at 170.8 ± 0.4 cm and in girls at 157.9 ± 0.2 cm. APHV was estimated at 12.71 ± 0.1 years in boys and 10.4 ± 0.2 years in girls. Girls reached APHV 2.2 years earlier than boys. In relation to PHV (cm/y), boys reached higher growth speed in height (7.4 ± 0.4 cm/y), and in girls it was (7.0 ± 0.2 cm/y). Conclusion: It was determined that final height was reached at 170.8 ± 0.4 cm in boys and 157.9 ± 0.2 cm in girls, and APHV (years) and PHV (cm/ye) were reached relatively early and with average peak velocity similar to Asian and Western populations. A large-scale longitudinal study is needed to confirm these findings.

Association Between Endocrine Markers, Accumulated Workload, and Fitness Parameters During a Season in Elite Young Soccer Players.

The purpose of this study was to analyze differences between endocrine markers in soccer players, based on playing positions, and correlations between endocrine markers (testosterone, cortisol, growth hormone, and insulin-like growth factor-1), with accumulated workload training and fitness parameters [maximal oxygen uptake (VO2max), countermovement jump (CMJ), and isometric maximal strength (1-RM) of the knee for hamstring (ISH) and quadriceps (ISQ) muscles] during early-, mid-, and end-seasons. Twenty-four elite soccer players under 17 participated in this study. The results showed that there was no difference between levels of the endocrine markers among the different positions of the players. Significant correlations were observed between endocrines parameters and fitness performance (ISQ, ISH, VO2max, and CMJ). Regression analysis showed that 1-RM and VO2max were the best predictors of endocrine markers. These findings demonstrated that the activity profiles of youth soccer players were not influenced by endocrine markers. Also, it may be assumed that endocrines levels can be used to better explain the physical capacities of this population. Finally, endocrines markers may help to predict changes in 1-RM and VO2max.

Ultrasound reference values for the calcaneus of children and adolescents at moderate altitudes in Peru

Abstract Objective: a) Establish reference values for bone parameters by using the speed of sound (SOS, m/s) of broadband ultrasound attenuation (BUA, dB/MHz) and establish a bone quality index (BQI = αSOS + βBUA) for children and adolescents living in a region of moderate altitude, b) compare bone parameters with an international standard (with different ethnic, socio-economic, and lifestyle backgrounds) by using ultrasound of the calcaneus (heel bone) (QUS). Methods: A descriptive cross-sectional study was carried out with children and adolescents between the ages of 6.0 and 16.9 years old. The sample was selected randomly. A total of 1322 subjects were studied. Weight, height, and bone parameters, using ultrasound of the calcaneus, were evaluated SOS, BUA, and BQI. Body Mass Index BMI was calculated. Results: The average age of males was 11.44 ± 0.35 years old, and for females, it was 11.43 ± 0.35 years old. The students in this research showed slightly higher values of SOS, BUA, and BQI for both sexes when compared with the international reference (the 50th percentile). Percentiles were generated (P3, P10, P25, P50, P75, P90, and P97) using the LMS method [median (M), standard deviation (S), and power of the Box-Cox transformation (L)] by age and sex. Conclusion: The students living at a moderate altitude showed slightly higher values in bone parameters in relation to the international reference. This pattern depicted a population with a better state of bone health. The proposed percentiles may be used to categorize adequate to at risk bone parameters based on age and sex.

Ultrasound reference values for the calcaneus of children and adolescents at moderate altitudes in Peru.

OBJECTIVE: a) Establish reference values for bone parameters by using the speed of sound (SOS, m/s) of broadband ultrasound attenuation (BUA, dB/MHz) and establish a bone quality index (BQI=αSOS+ßBUA) for children and adolescents living in a region of moderate altitude, b) compare bone parameters with an international standard (with different ethnic, socio-economic, and lifestyle backgrounds) by using ultrasound of the calcaneus (heel bone) (QUS). METHODS: A descriptive cross-sectional study was carried out with children and adolescents between the ages of 6.0 and 16.9 years old. The sample was selected randomly. A total of 1322 subjects were studied. Weight, height, and bone parameters, using ultrasound of the calcaneus, were evaluated SOS, BUA, and BQI. Body Mass Index BMI was calculated. RESULTS: The average age of males was 11.44±0.35 years old, and for females, it was 11.43±0.35 years old. The students in this research showed slightly higher values of SOS, BUA, and BQI for both sexes when compared with the international reference (the 50th percentile). Percentiles were generated (P3, P10, P25, P50, P75, P90, and P97) using the LMS method [median (M), standard deviation (S), and power of the Box-Cox transformation (L)] by age and sex. CONCLUSION: The students living at a moderate altitude showed slightly higher values in bone parameters in relation to the international reference. This pattern depicted a population with a better state of bone health. The proposed percentiles may be used to categorize adequate to at risk bone parameters based on age and sex.

Physical Growth and Body Adiposity Curves in Students of the Maule Region (Chile).

Objectives: Physical growth and body adiposity patterns provide relevant information to infer the nutritional and health status of students. Our objectives were (a) to compare the variables of body adiposity and physical growth of Chilean children and adolescents with data from the CDC-2012 and international studies, and (b) to develop regional reference curves to evaluate growth and body adiposity. Methods: 8,261 children and adolescents were studied. We evaluated the weight, height, and waist circumference (WC). The Body Mass Index (BMI) was calculated. Their physical growth and body adiposity were compared with the CDC-2012 references as well as with other international references. Percentile curves for weight, height, BMI, and WC were constructed with the LMS method. Results: The Chilean students showed reduced weight and height during adolescence when compared with the CDC-2012 reference. During early ages, the BMI for the Chilean sample was lower while at advanced ages, the WC values were greater in comparison to the CDC-2012 reference. Graphic comparisons with international studies indicated that Chilean students weighed more at all ages. However, height was slightly greater until age 14 for males and age 11 for females. Body adiposity (BMI and WC) for the Chilean students was slightly higher at early ages while at later ages, adiposity values were relatively similar for both sexes. Conclusions: Discrepancies were observed between the physical growth and body adiposity trajectories and the American CDC-2012 references and the international studies. The proposed percentiles for weight, height, BMI, and WC for each age and sex may be useful for health sciences professionals and researchers.

Predictores de adiposidad corporal en jóvenes con síndrome de Down / Predictors of body adiposity in young people with Down syndrome

Fundamentos: Analizar los pliegues cutáneos que mejor predicen los indicadores de adiposidad corporal en jóvenes síndrome de Down (SD). Métodos: Se diseñó un estudio descriptivo transversal (correlacional). Fueron seleccionados de forma no-probabilística por conveniencia 67 jóvenes (33 mujeres y 34 hombres) con SD de la provincia de Talca (Chile). El rango de edad oscila entre 10 y 25 años. Se evaluó el peso, estatura, circunferencia de la cintura, cadera y cinco pliegues cutáneos (bicipital, tricipital, subescapular,suprailiaco y muslo). Se calculó el índice de masa corporal (IMC) y el índice cintura-cadera (ICC). Resultados: En hombres, tanto en adolescentes, como en jóvenes adultos, la circunferencia de la cintura y cadera explicaron entre 30 a 62%, mientras que en mujeres adolescentes la circunferencia de la cadera predijo la adiposidad en un 19%, y en mujeres adultas el ICC explica el 12%. El IMC en ambos sexos y grupos (adolescentes y adultos) evidenció valores de R2 inferiores a los demás indicadores (R2=0,09 a16%). Conclusión: La circunferencia de la cadera y la cintura deben ser utilizadas para valorar la adiposidad corporal en hombres adolescentes y jóvenes adultos con SD, mientras que, en mujeres adolescentes, únicamente la circunferencia de la cadera mostró ser predictor de la adiposidad corporal y el ICC en mujeres adultas

Background: To analyze the skin folds that better predict body adiposity indicators in young Down syndrome (DS).Methods: A transversal (correlational) descriptive study was designed. 67 young people (33 women and 34 men) with DS from the province of Talca (Chile) were selected in a non-probabilistic manner for convenience. The age range varies between 10 and 25 years. The weight, height, circumference of the waist, hip and five skin folds (bicipital, tricipital, subscapular, suprailiac and thigh) were evaluated. The body mass index (BMI) and the waist-hip index (BCI) were calculated. Results: In men, both in adolescents, and in young adults, waist circumference and hip circumference explained between 30 to 62%, while in adolescent women the circumference of the hip predicted adiposity in 19%, and in adult women the ICC explains 12%. The BMI in both sexes and groups (adolescents and adults) showed R2 values lower than the other indicators (R2 = 0.09 to 16%). Conclusion: Hip circumference and waist circumference should be used to assess body adiposity in adolescent males and young adults with DS, while in adolescent females, only hip circumference showed to be a predictor of bodily adiposity and the ICC in adult women

Reference norms for evaluating maximum expiratory flow of children and adolescents of the Maule Region in Chile.

BACKGROUND: The norms for evaluating the maximum expiratory flow (MEF) usually are developed according to chronological age and height. However, to date, little research has been conducted using reference values that take into account the temporal changes of biological maturation. The objectives of this study were to (a) compare the MEF with those of other international studies, (b) align the MEF values with chronological and biological age, and (c) propose reference standards for children and adolescents. METHODS: The sample studied consisted of 3,566 students of both sexes (1,933 males and 1,633 females) ranging in age from 5.0 to 17.9 years old. Weight, standing height, and sitting height were measured. Body mass index was calculated. Biological maturation was predicted by using age of peak height velocity growth (APHV). MEF (L/min) was obtained by using a forced expiratory manoeuvre. Percentiles were calculated using the LMS method. RESULTS AND DISCUSSION: Predicted APHV was at age 14.77 ± 0.78 years for males and for females at age 12.74 ± 1.0 years. Biological age was more useful than chronological age for assessing MEF in both sexes. Based on these findings, regional percentiles were created to diagnose and monitor the risk of asthma and the general expiratory status of paediatric populations.

Reference standards to assess physical fitness of children and adolescents of Brazil: an approach to the students of the Lake Itaipú region-Brazil.

BACKGROUND: The importance of assessing body fat variables and physical fitness tests plays an important role in monitoring the level of activity and physical fitness of the general population. The objective of this study was to develop reference norms to evaluate the physical fitness aptitudes of children and adolescents based on age and sex from the lake region of Itaipú, Brazil. METHODS: A descriptive cross-sectional study was carried out with 5,962 students (2,938 males and 3,024 females) with an age range of 6.0 and 17.9 years. Weight (kg), height (cm), and triceps (mm), and sub-scapular skinfolds (mm) were measured. Body Mass Index (BMI kg/m2) was calculated. To evaluate the four physical fitness aptitude dimensions (morphological, muscular strength, flexibility, and cardio-respiratory), the following physical education tests were given to the students: sit-and-reach (cm), push-ups (rep), standing long jump (cm), and 20-m shuttle run (m). RESULTS AND DISCUSSION: Females showed greater flexibility in the sit-and-reach test and greater body fat than the males. No differences were found in BMI. Percentiles were created for the four components for the physical fitness aptitudes, BMI, and skinfolds by using the LMS method based on age and sex. The proposed reference values may be used for detecting talents and promoting health in children and adolescents.

Desempeño de la condición física de pre-escolares en función de la estatura y el área muscular del brazo / Performance preschool fitness depending on height and arm muscle area

Fundamentos: Analizar el desempeño físico de niños pre-escolares en función de la edad cronológica y variables antropométricas. Métodos: Se estudió 217 pre-escolares de una Comuna (Maule) de Talca-Chile (106 niños y 114 niñas). El rango edad oscila entre 4,0 a 5,9 años. Se evaluó las variables antropométricas: Peso, estatura, pliegue tricipital y perímetro del brazo. Se calculó el Índice de masa corporal (IMC), Área muscular braquial (AMB) y Área grasa braquial (AGB) y variables de desempeño motor: lanzamiento de bola y salto horizontal. Resultados: En relación a la edad cronológica, los niños de ambos sexos de 5 años mostraron mayor peso y estatura y mejor desempeño en el lanzamiento de bola y salto horizontal. No hubo diferencias entre sexos a los 4 y 5 años (p<0,05). Se verificó correlaciones positivas significativas entre lanzamiento de bola con la edad, estatura y AMB en ambos sexos (r=0,13, 0,37), mientras que en el salto horizontal, además de relacionarse con la edad, estatura y AMB, el peso mostró también correlación positiva significativa (r=0,11, 0,41). Los niños de ambos sexos con mayor estatura y AMB mostraron mejor desempeño físico, además hubo diferencias marcadas entre ambos sexos (p<0,05). Conclusión: Además de la edad cronológica, las variables somáticas de la estatura y el área muscular del brazo podrían servir como indicadores de crecimiento para valorar el desempeño físico de pre-escolares de ambos sexos, aunque es necesario desarrollar más estudios abarcando mayor número de sujetos, rangos de edad en otros contextos socioculturales (AU)

Background: To analyze the physical performance of pre-school children according to chronological age and anthropometric variables. Methods: 217 pre-school children from a Commune (Maule) of Talca-Chile (106 boys and 114 girls) were studied. The age range ranges from 4.0 to 5.9 years. The anthropometric variables were evaluated: Weight, height, triceps fold and perimeter of the arm. The Body mass index (BMI), Arm muscular area (AMA) and Arm fat area (AFA) and motor performance variables were calculated: ball throw and horizontal jump. Results: In relation to the chronological age, children of both sexes of 5 years showed greater weight and stature and better performance in the ball throw and horizontal jump. There were no differences between sexes at 4 and 5 years (p<0.05). It was verified significant positive correlations between ball throw with age, height and AMB in both sexes (r = 0.13-0.37), while in the horizontal jump, in addition to relating to age, height and AMB, the weight also showed correlation significant positive (r = 0.11-0.41). Children of both sexes with greater stature and AMB showed better physical performance, in addition there were marked differences between both sexes (p<0.05). Conclusion: In addition to the chronological age, the somatic variables of the stature and the muscular area of the arm could serve as growth indicators to assess the physical performance of pre-school children of both sexes, although it is necessary to develop more studies covering a greater number of subjects, age ranges in other socio-cultural contexts (AU)

Densidad mineral ósea en una muestra de jóvenes chilenos practicantes de diversas modalidades deportivas / Bone mineral density in a sample of young Chilean practitioners of different sports

Resumen Objetivos: Objetivos: a) Comparar la densidad mineral ósea de una muestra de jóvenes chilenos practicantes de diversas modalidades deportivas y b) Analizar la densidad mineral ósea en función de la maduración biológica. Métodos: Se estudiaron 146 adolescentes de sexo masculino, con un rango de edad entre 10 a 18 años. Se organizaron cinco grupos de trabajo: Grupo control (escolares n= 40), Canotaje (n= 30), Ciclismo (n=14), Fútbol (n=28) y Natación (n=34). Se evaluó el peso, estatura, altura tronco-cefálica. Se calculó el índice de Masa Corporal y la maduración biológica por medio de años de pico de velocidad de crecimiento. La densidad mineral ósea de cuerpo total y el porcentaje de grasa corporal se determinó por medio de la absorciometría de rayos X de doble energía. Resultados: Los adolescentes que practicabanfútbol evidenciaron mayor densidad mineral ósea (1,23±0,12g/cm 2 ) en relación a los jóvenes del ciclismo (0,99±0,11g/cm 2 ), canotaje (1,09±0,17g/cm 2 ), natación (1,10±0,11g/cm 2 ) y al grupo control de escolares (1,04±0,14g/ cm 2 ) (p<0.001). Hubo diferencias entre los tres niveles de maduración biológica en las cuatro modalidades deportivas y en el grupo control (p<0.001). La mayor densidad mineral ósea en función de la maduración somática se observó en los futbolistas. Conclusión: Los adolescentes que practican fútbol evidenciaron mayor densidad mineral ósea con relación a las demás modalidades deportivas y con relación al grupo control, además la maduración somática juega un papel relevante en el incremento de densidad mineral ósea, en especial en los futbolistas. Los resultados sugieren desarrollar actividades físico-deportivas de alto impacto antes, durante y después de producirse la maduración biológica en adolescentes de edad escolar.

Abstract Objectives: a) to compare bone mineral density of a sample of young Chilean practitioners of various sports and modalities b) to analyze the bone mineral density function of biological maturation. Methods: We studied 146 male adolescents, ranging in age from 10-18 years. Five working groups were organized: Control group (school n = 40), Canoeing (n = 30), Cycling (n = 14), Football (n = 28) and Swimming (n = 34). Weight, height, and trunk-cephalic height were evaluated. Body Mass Index and biological maturation were calculated through years of peak growth rate. Bone mineral density of whole body and percentage body fat was determined by dual energy X-ray absorptiometry (DXA). Results: Teens who practiced football showed higher bone mineral density (1.23 ± 0.12 g/cm2) in relation to young cyclists (0.99 ± 0.11g / cm2), canoeing (1.09 ± 0.17g / cm2), swimming (1.10 ± 0.11g / cm2) and control of school (1.04 ± 0.14g / cm2) (p <0.001). There were differences between the three levels of biological maturation in the four sports modalities and in the control group (p <0.001). Most bone mineral density depending on the somatic maturation was observed in the football players. Conclusion: Adolescents who play football showed higher bone mineral density compared to other sports and in relation to the control group. In addition, somatic maturation plays an important role in increasing bone mineral density, especially in football. The results suggest practicing high-impact physical activities before, during and after biological maturation occurs in adolescents of school age.

[Not Available]. / Validación y propuesta normativa para la valoración de la preocupación por la alimentación de adolescentes chilenos: estudio EPACH.

Objetivo: validar un cuestionario para medir la preocupación por la alimentación de los adolescentes, verificar la fiabilidad y desarrollar valores normativos en función de la edad, sexo y categoría. Metodología: se estudió a 3.121 (1.645 hombres y 1.476 mujeres) adolescentes de 11,0 a 18,9 años de cinco establecimientos municipales de la región del Maule, Chile. Se evaluó el peso, estatura y se calculó el índice de masa corporal. Se aplicó un cuestionario que mide la preocupación por la alimentación de adolescentes escolares. Se validó por análisis confirmatorio y la fiabilidad se determinó por consistencia interna. Resultados: el análisis factorial confirmó la presencia de cuatro factores (preocupación por la restricción de la comida, preocupación por el consumo de comida, preocupación por la forma de comer y preocupación por el peso corporal). Se eliminaron 5 preguntas que mostraron saturaciones inferiores a 0,39. El instrumento quedó conformado con 24 preguntas que explican 51,8% de la varianza. El alpha de Cronbach mostró valores entre 0,85 y 0,88. Se construyeron percentiles (p15, p50 y p85) a partir del método LMS para valorar la preocupación por la alimentación por categoría, edad y sexo. Conclusión: el instrumento desarrollado es válido y confiable y sirve para valorar el nivel de preocupación por la alimentación de adolescentes escolares. Además, las normas propuestas podrían servir a los profesionales del sistema educativo para llevar a cabo tareas de prevención con los jóvenes que evidencien bajos niveles de preocupación por su alimentación.

Validación y propuesta normativa para la valoración de la preocupación por la alimentación de adolescentes chilenos: estudio EPACH / Validation and regulatory proposal for assessing the concern by feeding Chilean adolescents: study EPACH

Objetivo: validar un cuestionario para medir la preocupación por la alimentación de los adolescentes, verificar la fiabilidad y desarrollar valores normativos en función de la edad, sexo y categoría. Metodología: se estudió a 3.121 (1.645 hombres y 1.476 mujeres) adolescentes de 11,0 a 18,9 años de cinco establecimientos municipales de la región del Maule, Chile. Se evaluó el peso, estatura y se calculó el índice de masa corporal. Se aplicó un cuestionario que mide la preocupación por la alimentación de adolescentes escolares. Se validó por análisis confirmatorio y la fiabilidad se determinó por consistencia interna. Resultados: el análisis factorial confirmó la presencia de cuatro factores (preocupación por la restricción de la comida, preocupación por el consumo de comida, preocupación por la forma de comer y preocupación por el peso corporal). Se eliminaron 5 preguntas que mostraron saturaciones inferiores a 0,39. El instrumento quedó conformado con 24 preguntas que explican 51,8% de la varianza. El alpha de Cronbach mostró valores entre 0,85 y 0,88. Se construyeron percentiles (p15, p50 y p85) a partir del método LMS para valorar la preocupación por la alimentación por categoría, edad y sexo. Conclusión: el instrumento desarrollado es válido y confiable y sirve para valorar el nivel de preocupación por la alimentación de adolescentes escolares. Además, las normas propuestas podrían servir a los profesionales del sistema educativo para llevar a cabo tareas de prevención con los jóvenes que evidencien bajos niveles de preocupación por su alimentación (AU)

Objective: To validate a questionnaire to measure the concern on feeding habits in adolescents, verifying the reliability and develop normative values based on age, sex and category. Methodology: We studied 3,121 (1,645 men and 1,476 women) adolescents from 11.0 to 18.9 years from five municipal establishments in the region of Maule, Chile. Weight, height were assessed and body mass index was calculated. A questionnaire measuring concern for school feeding was applied to adolescents. It was validated by confirmatory analysis and reliability was determined by internal consistency. Results: Factor analysis confirmed the presence of four factors (Concern about the restriction of food, concern about food consumption, concern about the way you eat and concern about body weight). Five questions with saturation under 0.39 were eliminated. The instrument was formed with 24 questions that explain 51.8% of variance. Cronbach’s alpha showed values between 0.85 to 0.88. Percentiles (p15, p50 and p85) from the LMS method for assessing the concern for food by category, age and sex were built. Conclusion: The developed instrument is valid and reliable and used to assess the level of concern about the supply of school adolescents, the proposed rules would also serve education professionals to carry on prevention work with youth that demonstrate low levels of concern for food (AU)

Reproductibilidad de un cuestionario que valora la actividad física en adolescentes escolares de altitud / Reproducibility of a questionnaire that valúes physical activity in school adolescents altitude

Objetivo: Analizar la fiabilidad de un cuestionario que valora la Actividad Física en una muestra de escolares adolescentes que viven a elevada altitud por medio de consistencia interna y test re-test. Materiales y métodos: Descriptivo-transversal (Survey). Institución: Universidad Nacional del Altiplano (Puno, Perú). Adolescentes escolares de 12 a 17 años. Fueron seleccionados de forma sistemática 109 escolares de ambos sexos. Se valoró las medidas antropométricas de peso, estatura, estatura sentada y circunferencia del abdomen. Además se aplicó un cuestionario de actividad física con 11 preguntas (test y re-test) con un intervalo de 7 días. Valoración de la capacidad de reproductibilidad por consistencia interna y estabilidad. Resultados: Los valores de alpha de Cronbach (consistencia interna) mostraron valores de 0,73 a 0,77 para ambos sexos. El Error Técnico de Medida (ETM) fue de 0,50 a 1,61% y el coeficiente de correlación de Spearman osciló entre 0,91 y 0,95. Conclusión: El cuestionario de actividad física muestra altos valores de confiabilidad, tanto en su consistencia interna como en la estabilidad de las medidas.

Objective: To analyze the reliability of a questionnaire to assess physical activity in a sample of school adolescents living at high altitude through internal consistency and test re-test. Materials and methods: Descriptive, transversal (Survey). Universidad Nacional del Altiplano (Puno, Peru). School Teens 12 to 17 years. There were systematically selected 109 students of both sexes. We evaluated anthropometric measurements of weight, height, sitting height and circumference of the abdomen. In addition we applied a physical activity questionnaire with 11 questions (test and re-test) with an interval of 7 days. capacity rating for internal consistency, reproducibility and stability. Results: Cronbach's alpha values (internal consistency) showed values from 0.73 to 0.77 for both sexes. Measuring technical error (SEM) was from 0.50 to 1.61% and the Spearman correlation coefficient ranges from 0.91 to 0.95. Conclusion: The physical activity questionnaire shows high values of reliability, consistency both internally and in the stability of the measures.

Influence of parents and physical education teachers in adolescent physical activity / Influencia de los padres y los profesores de Educación Física en la actividad física de los adolescentes

The objective of this study was to analyze the influence of parents and Physical Education teachers on adolescent's extracurricular Physical Activity. Data were obtained from the Chilean System for the Assessment of Educational Quality test with a large representative sample of 23,180 students (11,927 females and 11,253 males aged 13.7 and 13.8 years respectively). The analyzed variables were the extracurricular physical activity of adolescents, parents’ and physical education teachers’ encouragement to do physical activity and parents’ physical activity behavior. Associations between variables were analyzed using chi-squared tests. Two logistic regression models, one adjusted and the other unadjusted, were performed for each physical activity variable (vigorous, moderate, mild and total) in order to obtain odds ratios from parents’ and physical education teachers’ influence variables. Results showed that parents’ influence is more relevant than physical education teachers’ influence in order to promote physical activity in adolescents, regardless of age, sex and physical condition (AU)

El objetivo del estudio fue analizar la influencia de los padres y los profesores de Educación Física en la Actividad Física extracurricular de los adolescentes. Los datos fueron obtenidos del Sistema Chileno de Medición de la Calidad de Educación, en una muestra representativa de 23,180 estudiantes (11,927 niñas y 11,253 niños, con una edad media de 13,7 y 13,8 años). Las variables analizadas fueron la Actividad Física extracurricular de los adolescentes, la influencia que ejercían los padres y los profesores de Educación Física para que realicen Actividad Física y la Actividad Física de los padres. Se analizó la asociación entre las variables a través del chi-cuadrado. Dos regresiones logísticas, con y sin ajuste del modelo, fueron realizadas para cada nivel de la Actividad Física (vigorosa, media, baja y total) con el objetivo de obtener los Odds Ratios de las variables relativas a la experiencia de los padres y los profesores de Educación Física. Los resultados muestran que la influencia de los padres es más relevante que la de los profesores de Educación Física a la hora de promover la Actividad Física en los adolescentes, independientemente de la edad, el género o la condición física (AU)

Waist Circumferences of Chilean Students: Comparison of the CDC-2012 Standard and Proposed Percentile Curves.

The measurement of waist circumference (WC) is considered to be an important means to control overweight and obesity in children and adolescents. The objectives of the study were to (a) compare the WC measurements of Chilean students with the international CDC-2012 standard and other international standards, and (b) propose a specific measurement value for the WC of Chilean students based on age and sex. A total of 3892 students (6 to 18 years old) were assessed. Weight, height, body mass index (BMI), and WC were measured. WC was compared with the CDC-2012 international standard. Percentiles were constructed based on the LMS method. Chilean males had a greater WC during infancy. Subsequently, in late adolescence, males showed values lower than those of the international standards. Chilean females demonstrated values similar to the standards until the age of 12. Subsequently, females showed lower values. The 85th and 95th percentiles were adopted as cutoff points for evaluating overweight and obesity based on age and sex. The WC of Chilean students differs from the CDC-2012 curves. The regional norms proposed are a means to identify children and adolescents with a high risk of suffering from overweight and obesity disorders.

Aplicabilidad del IMC en adolescentes escolares que viven a moderada altitud del Perú / Applicability of BMI in aolescent students living at moderate altitude of Peru

Introducción y objetivos: El uso del IMC es muy cuestionado, sobretodo, en poblaciones en fase de crecimiento que se caracterizan por presentar baja estatura para su edad. El objetivo es verificar si el IMC es aplicable a una muestra de escolares adolescentes que viven en una región de moderada altitud del Perú. Material y Métodos: Estudio descriptivo transversal realizado en 319 adolescentes escolares (181 hombres y 138 mujeres) de 12,0 a 17,9 años de edad. Se evaluó las variables antropométricas del peso y la estatura. Se calculó el Índice de Masa Corporal (IMC). Se utilizó la referencia del CDC-2000 para comparar el peso y estatura a partir del Z-score y el IMC por medio de diferencia de medias. Resultados: El Z-score para el peso corporal mostró pequeñas variaciones (entre -0,3 a 0,3 kg). En la estatura se observa valores negativos para ambos sexos (hombres entre -0,3 a -1,3 cm y mujeres entre -0,5 a 1,3 cm). Respecto al IMC, hubo diferencias significativas en todas la edades y en ambos sexos (p<0,05). Conclusión: Los valores medios del IMC en adolescentes de ambos sexos se ven incrementados debido a la baja estatura observada. Estos resultados sugieren que el IMC no sería aplicable a escolares adolescentes que viven en una región de moderada altitud del Perú (AU)

Introduction and Objectives: The use of BMI is highly contested, especially in populations in which growth phase is characterized by short stature for his age. The aim is to verify if the BMI is applicable to a school sample of adolescents living in a region of moderate altitude of Peru. Material and Methods: A descriptive cross-sectional study in 319 adolescent students (181 men and 138 women) from 12.0 to 17.9 years of age. Anthropometric variables of height and weight were evaluated. Body Mass Index (BMI) was calculated. The CDC -2000 reference was used to compare weight and height from Z- score and BMI by mean difference. Results: The Z - score showed body weight to small variations (from -0.3 to 0.3 kg). In stature negative values for both sexes (men between -0.3 to -1.3 cm and women between -0.5 to 1.3 cm) is observed. For BMI, there were significant differences in all ages and in both sexes (p <0.05). Conclusion: The mean values of BMI in adolescents of both sexes are increased due to the observed low stature. These results suggest that BMI would not apply to school adolescents living in a region of moderate altitude of Peru (AU)

Influence of parents and physical education teachers in adolescent physical activity.

The objective of this study was to analyze the influence of parents and Physical Education teachers on adolescent's extracurricular Physical Activity. Data were obtained from the Chilean System for the Assessment of Educational Quality test with a large representative sample of 23,180 students (11,927 females and 11,253 males aged 13.7 and 13.8 years respectively). The analyzed variables were the extracurricular physical activity of adolescents, parents' and physical education teachers' encouragement to do physical activity and parents' physical activity behavior. Associations between variables were analyzed using chi-squared tests. Two logistic regression models, one adjusted and the other unadjusted, were performed for each physical activity variable (vigorous, moderate, mild and total) in order to obtain odds ratios from parents' and physical education teachers' influence variables. Results showed that parents' influence is more relevant than physical education teachers' influence in order to promote physical activity in adolescents, regardless of age, sex and physical condition.

El objetivo del estudio fue analizar la influencia de los padres y los profesores de Educación Física en la Actividad Física extracurricular de los adolescentes. Los datos fueron obtenidos del Sistema Chileno de Medición de la Calidad de Educación, en una muestra representativa de 23,180 estudiantes (11,927 niñas y 11,253 niños, con una edad media de 13,7 y 13,8 años). Las variables analizadas fueron la Actividad Física extracurricular de los adolescentes, la influencia que ejercían los padres y los profesores de Educación Física para que realicen Actividad Física y la Actividad Física de los padres. Se analizó la asociación entre las variables a través del chi-cuadrado. Dos regresiones logísticas, con y sin ajuste del modelo, fueron realizadas para cada nivel de la Actividad Física (vigorosa, media, baja y total) con el objetivo de obtener los Odds Ratios de las variables relativas a la experiencia de los padres y los profesores de Educación Física. Los resultados muestran que la influencia de los padres es más relevante que la de los profesores de Educación Física a la hora de promover la Actividad Física en los adolescentes, independientemente de la edad, el género o la condición física.

Referencial values for the physical growth of school children and adolescents in Campinas, Brazil.

AIMS: To compare the values of weight, height and IMC with the regional curve (Cariri); to compare with the international references of the CDC-2000; and to construct references that will measure physical growth from childhood to adolescence. SUBJECTS AND METHODS: The sample consists of 6531 individuals with an age range of 6.0-17.9 years. Comparisons (weight, height and BMI) between the means of the group were made with the regional reference Cariri and the international reference CDC-2000. RESULTS: The students of both sexes from Campinas were taller, heavier and presented more IMC than those from Cariri. With respect to CDC-2000, the girls were heavier until 12 years old and the boys were heavier until 15 years old. For height, the students of both sexes from Campinas were taller until age 10. In IMC, the students from Campinas showed superior qualities in relation to the reference in both sexes (for girls until age 14 and boys until 16 years old). CONCLUSION: Patterns of physical growth of children in Campinas are different in relation to the regional and international reference curve. The regional standards proposed are a possibility to assess the trajectory of physical growth of school children of Campinas in clinical or epidemiological settings.

Growth and body composition in Brazilian female rhythmic gymnastics athletes.

The aim was to analyse the physical growth and body composition of rhythmic gymnastics athletes relative to their level of somatic maturation. This was a cross-sectional study of 136 athletes on 23 teams from Brazil. Mass, standing height and sitting height were measured. Fat-free and fat masses, body fat percentages and ages of the predicted peak height velocity (PHV) were calculated. The z scores for mass were negative during all ages according to both WHO and Brazilian references, and that for standing height were also negative for all ages according to WHO reference but only until 12 years old according to Brazilian reference. The mean age of the predicted PHV was 12.1 years. The mean mass, standing and sitting heights, body fat percentage, fat-free mass and fat mass increased significantly until 4 to 5 years after the age of the PHV. Menarche was reached in only 26% of these athletes and mean age was 13.2 years. The mass was below the national reference standards, and the standing height was below only for the international reference, but they also had late recovery of mass and standing height during puberty. In conclusion, these athletes had a potential to gain mass and standing height several years after PHV, indicating late maturation.