Crescimento fisico e desempenho motor em crianças de 6 a 12 anos de condição socio-economica media da area urbana da provincia de Arequipa-Peru

Orientador: Miguel de ArrudaDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Educação FisicaMestradoCiencia do DesportoMestre em Educação Físic

Physical growth in children and adolescents of moderate altitude : physical growth in children and adolescents

Orientador: Miguel de ArrudaTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Educação FísicaResumo: O objetivo do presente estudo foi analisar o crescimento físico de crianças e adolescentes de moderada altitude. Foram selecionadas de forma probabilística estratificada 955 crianças de 6 a 12 anos, sendo 473 homens e 482 mulheres provenientes de escolas públicas da área urbana da região de Arequipa (Perú) localizada a 2320msnm. As variáveis mensuradas foram a massa corporal (kg), estatura (cm) e as circunferências corporais do braço relaxado, tórax e a panturrilha (cm). Para a relação da massa corporal com a estatura, utilizou-se o [IMC=Peso (kg)?Estatura (m)2]. As variáveis de massa corporal, estatura e o IMC foram comparados com a referência internacional da Organização Mundial da Saúde (OMS). Os valores das circunferências corporais foram distribuídos em percentís e escores Z, com a tentativa de propor curvas e tabelas referenciais para o monitoramento do crescimento e o estado nutricional das crianças de moderada altitude. A análise estatística descritiva utilizada foi de média, desvio padrão, percentis, e escores Z, e para avaliar as diferenças entre as crianças de moderada altitude e a referência internacional (OMS) utilizou-se o teste "t" para amostras pareadas, com uma probabilidade de p<0,001. Os resultados mostram que as crianças do estudo apresentam menor estatura que a referência. Os valores do IMC propostos pela OMS não pode ser aceito para crianças e adolescentes de moderada altitude, dado que superestima o excesso de peso e obesidade. Por tanto, as curvas e tabelas construídas com base nas circunferências corporais podem ser usadas junto às curvas de massa corporal e estatura propostas pela OMS para o seguimento do crescimento físico em crianças e adolescentes de moderada altitudeAbstract: The aim of this study was to analyze the physical growth of children and adolescents of moderate altitude. Were selected so stratified 955 children aged 6 to 12 years old, 473 boys and 482 girls from urban public schools in the region of Arequipa (Peru) located 2320 meters above the sea level. The variables measured were body mass (kg), height (cm) and body circumferences relaxed arm, chest and calf (cm). For the relationship of body mass to height, we used the [BMI = weight (kg) / height (m)2]. The variables of body weight, height and BMI were compared with the reference of the international World Health Organization (WHO). The values of body circumferences were divided into percentiles and Z scores, with the attempt to propose curves and reference tables for the monitoring of growth and nutritional status of children from moderate altitude. Descriptive statistical analysis was used to mean, standard deviation, percentiles and Z scores, and to evaluate the differences between children with moderate altitude and the international reference (WHO) used the t test for paired samples, with a probability p <0.001. The results show that children in the study have a lower height than the reference. BMI values proposed by the WHO cannot be accepted for children and adolescents of moderate altitude, because it overestimates the excess weight and obesity. Therefore, the curves and tables constructed on the basis of body circumferences can be used along the curves of weight and height proposed by WHO for monitoring the physical growth in children and adolescents of moderate altitudeDoutoradoCiencia do DesportoDoutor em Educação Físic

Relationship between age and handgrip strength: Proposal of reference values from infancy to senescence

Introduction: Measurement of hand grip strength (HGS) has been proposed as a key component of frailty and has also been suggested as a central biomarker of healthy aging and a powerful predictor of future morbidity and mortality. Objectives: (a) To determine whether a nonlinear relationship model could improve the prediction of handgrip strength (HGS) compared to the linear model and (b) to propose percentiles to evaluate HGS according to age and sex for a regional population of Chile from infancy to senescence. Methods: A cross-sectional descriptive study was developed in a representative sample of the Maule region (Chile). The volunteers amounted to 5,376 participants (2,840 men and 2,536 women), with an age range from 6 to 80 years old. Weight, height, HGS (right and left hand) according to age and sex were evaluated. Percentiles were calculated using the LMS method [(L (Lambda; asymmetry), M (Mu; median), and S (Sigma; coefficient of variation)]. Results and discussion: there were no differences in HGS from 6 to 11 years of age in both sexes; however, from 12 years of age onwards, males presented higher HGS values in both hands (p < 0.05). The linear regression between age with HGS showed values of R2 = 0.07 in males and R2 = 0.02 in females. While in the non-linear model (cubic), the values were: R2 = 0.50 to 0.51 in men and R2 = 0.26 in women. The percentiles constructed by age and sex were: P5, P15, P50, P85, and P95 by age range and sex. This study demonstrated that there is a nonlinear relationship between chronological age with HGS from infancy to senescence. Furthermore, the proposed percentiles can serve as a guide to assess and monitor upper extremity muscle strength levels at all stages of life

Correlation between body mass index and body circumference in children 4 to 10 year-old

Objetivos: Correlacionar el índice de masa corporal (IMC) con las circunferencias corporales de niños brasileros de 4 a 10 años. Diseño: Estudio de tipo descriptivo correlacional. Institución: Universidad Estatal de Campinas, Sao Paulo, Brasil. Participantes: Niños de 4 a 10 años de edad. Intervenciones: Se seleccionó 517 niños de ambos sexos de manera probabilística (estratificada), siendo 256 niños y 261 niñas. Se evaluó las medidas antropométricas de peso corporal (kg), estatura (cm), IMC [IMC=peso (kg)∕estatura (m)2] y las circunferencias corporales del brazo relajado, muslo y pantorrilla media (cm). Para el análisis de los datos se utilizó la estadística descriptiva de media aritmética (X), desviación estándar (DE) y el coeficiente de correlación producto-momento de Pearson (r), así como para inferir el análisis de regresión múltiple stepwise paso a paso. Principales medidas de resultados: Correlación del índice de masa corporal con las circunferencias corporales. Resultados: El IMC muestra elevados coeficientes de correlación (r) con las tres circunferencias corporales. Sin embargo, cuando se aplicó la regresión estadística simple, los mejores valores fueron observados a partir de la circunferencia del brazo relajado (R2=0,74) para niñas y la pantorrilla media para niños (R2=0,70). A su vez, cuando se utilizó la regresión múltiple (brazo y pantorrilla) el nivel de explicación para las niñas aumentó a (R2=0,80) y para los niños a (R2=0,75), respectivamente. Conclusiones: Las circunferencias corporales del brazo y la pantorrilla en forma individual y conjunta podrían ser utilizadas como variables independientes del IMC, puesto que este índice por sí solo no podría distinguir el sobrepeso y exceso de grasa en niños de ambos géneros de 4 a 10 años, sobre todo cuando se encuentran en fase de crecimiento y desarrollo somático.Objectives: To compare body mass index (BMI) with body circumferences in 4 to 10 year-old Brazilian children. Design: Descriptive correlational type study. Setting: Universidad Estatal de Campinas, Sao Paulo, Brazil. Participants: Children 4 to 10 year-old. Interventions: We selected in a probabilistic (stratified) manner a total of 517 children both sexes, 256 boys and 261 girls. We evaluated anthropometric measurements of body weight (kg), height (cm), BMI [BMI = weight (kg)/height (m)2] and relaxed mean arm girth, thigh and calf (cm). For data analysis descriptive statistics were used for arithmetic mean (X), standard deviation (SD) and Pearson’s coefficient correlation product moment (r) as well as to infer step by step the stepwise multiple regression analysis. Main outcome measures: Correlation of body mass index with body circumferences. Results: BMI had high correlation coefficients (r) with the three body circumferences. However, when simple statistical regression was applied, the best values were observed with the relaxed arm circumference (R2=0.74) for girls and children half calf (R2=0.70). In turn, when multiple regression was used (arm and calf) the level of explanation for girls increased to (R2=0.80) and children (R2=0.75), respectively. Conclusions: Arm circumferences and calf individually and together could be used as independent variables of BMI, since this index alone can not distinguish between overweight and excess fat in both gender children 4-10 year-old, especially when they are in the process of growth and somatic development

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

Proposed equations for predicting body composition of male wistar rats

Introducción: La evaluación de la composición corporal es importante, porque permite conocer el fraccionamiento del peso corporal en peso muscular, peso graso, peso residual y peso óseo, tanto en humanos, como en animales. Objetivos: Validar ecuaciones somáticas para predecir la composición corporal de un modelo tri-compartimental (peso graso, peso libre de grasa y peso residual) de ratas machos wistar. Diseño: Estudio de tipo descriptivo de corte transversal. Institución: Facultad de Biología de la universidad estatal UNICAMP, Sao Paulo, Brasil. Material biológico: Ratas machos wistar. Métodos: Se estudió a 10 ratas machos wistar, con un promedio de edad de (X=98,00±10,40 días), se les evaluó el peso corporal (g). Enseguida fueron sacrificados y se procedió al fraccionamiento del peso graso (piel), peso libre de grasa (músculo y hueso) y peso residual (PR) (g). Los resultados fueron analizados por estadística descriptiva de media aritmética (X), desviación estándar (DE) y correlación producto momento de Pearson (r). Para predecir los componentes, se aplicó regresiones estadísticas simples y múltiples, a partir del peso corporal (g) y la edad (días) como variables independientes. Por otro lado, para verificar la concordancia entre el método directo de disección in vitro con las ecuaciones de regresión, se utilizó el plotaje de Bland y Altman. Principales medidas de resultados: Validación de ecuaciones somáticas para predecir la composición corporal de ratas. Resultados: Se verificó altos coeficientes de correlación (r) con el peso corporal y edad, los cuales dieron origen a ecuaciones que permitieron predecir el peso graso (PG = -31,6+(0,361*PT)-(0,345*edad) (R2=0,73) y peso libre de grasa (PLG = 19,9+(0,453*PT) + (0,114*edad) (R2=0,94). Sin embargo, el peso residual (PR) fue obtenido por medio de una deducción matemática (PR=peso total-(PLG+PG)). Así mismo, el plotaje de Bland y Altman permitió determinar alta concordancia entre ambos procedimientos. Conclusión: Las ecuaciones de regresión como método doblemente indirecto (modelo tri-compartimental) permiten predecir la composición corporal de ratas machos wistar en una fase etárea de 84 a 112 días de edad.Introduction: Assessment of body composition is important as it allows splitting body weight in muscle weight, fat weight, bone weight and residual weight, both in humans and animals. Objectives: To validate somatic equations to predict a tri-compartment model of body composition (fat weight, fat free weight and residual weight) in male Wistar rats. Design: Descriptive transversal type study. Setting: Faculty of Biology, State University UNICAMP, Sao Paulo, Brazil. Biological material: Male Wistar rats. Methods: The study evaluated body weight (g) in 10 average age (X = 98.00 ± 10.40 days) male Wistar rats. They were sacrificed and splitting of fat weight (skin), fat free weight (muscle and bone) and residual weight (PR) (g) was done. Results were analyzed by arithmetic mean (X), standard deviation (SD) and Pearson product moment correlations (r) descriptive statistics. To predict components single and multiple regression statistics were applied, with weight body (g) and age (days) as independent variables. On the other hand, to verify agreement between in vitro method of dissection and regression equations Bland and Altman’s plotting were used. Main outcome measures: Somatic equations validation to predict rat’s corporal composition. Results: We observed high correlation coefficients (r) with body weight and age, which led to equations to allow prediction of the fat weight (PG=-31.6+(0.361*PT)-(0.345*age) (R2=0.73) and fat free weight (PLG=19.9+(0.453*PT)+(0.114*age) (R2=0.94). However, residual weight (PR) was obtained by mathematical deduction (PR = total weight -(PLG + PG)). Additionally, the Bland and Altman’s plotting allowed determining high concordance between the two procedures. Conclusion: Regression equations as doubly indirect method (three-compartment model) allow predicting 84 to 112 day-old male Wistar rats’ body composition

Crecimiento físico y estado nutricional de adolescentes escolares

Objectives: To determine physical growth parameters and to assess nutritional status of school adolescents. Design: Descriptive comparative study. Institution: Liceo Naval Admiral Lizardo Montero, Lima, Peru. Participants: Adolescents aged 12-15 years. Interventions: A non-probability selection of 501 school children of both sexes (251 men and 250 women) was done. Variables determined included weight and height. Mean, standard deviation, percentages, t-test for independent samples and paired (p &lt;0.05) and chi-square (p&lt;0.05) analysis were done. Main outcome measures: Variables of growth and nutritional status. Results: Compared to international references, there were no significant differences (p &lt;0.05) in weight and height by sex in adolescents. The nutritional status showed higher proportion of well nourished subjects (74.5% in men and 75.6% in women) compared with low birth weight (2% in men, 0.8% in women), overweight (16.3% in men and 20.4 in women) and obesity (7.2% in men and 3.2% in women). Conclusions: Physical growth pattern was similar to international reference values but the high prevalence of overweight in both sexes suggests a public health problem.Objetivos: Determinar los parámetros del crecimiento físico y valorar el estado nutricional de adolescentes escolares. Diseño: Descriptivo comparativo. Institución: Liceo Naval Contralmirante Lizardo Montero, Lima, Perú. Participantes: Adolescentes de 12 a 15 años. Intervenciones: De forma no-probabilística (accidental) se seleccionó 501 escolares de ambos sexos (251 hombres y 250 mujeres). Los escolares pertenecían al Liceo Naval Contralmirante Lizardo Montero de Lima. Se evaluó las variables de peso y estatura. Los datos fueron analizados a través de la media aritmética, desviación estándar, porcentajes, prueba t para muestras independientes y apareadas (p&lt;0,05) y chi cuadrado (p&lt;0,05). Principales medidas de resultados: Variables de crecimiento y estado nutricional. Resultados: No hubo diferencias significativas (p&lt;0,05) en peso y estatura en adolescentes de ambos sexos respecto a la referencia internacional. En el estado nutricional se observó mayor proporción de eutróficos (74,5% en hombres y 75,6% en mujeres), teniendo peso bajo 2% de los hombres y 0,8% de mujeres, sobrepeso 16,3% varones y 20,4 mujeres, y obesidad 7,2% hombres y 3,2% mujeres. Conclusiones: Los resultados sugieren similar patrón de crecimiento físico que la referencia internacional y elevados valores de prevalencia de sobrepeso en ambos sexos, lo cual sugiere un problema de salud pública

The use of World Health Organization growth curves in children and adolescents that live in regions of moderate altitude

OBJECTIVE: To determine the applicability of the World Health Organization growth curves in school children that live in areas of moderate altitude. METHODS: A cross-sectional study, using a stratified random sample of 955 children and adolescents aged 6 to 12 years-old (473 boys and 482 girls) attending public schools in the urban area of Arequipa (Peru). The evaluated variables included body mass (kg) and height (m) values and the body mass index. Z score and the t test for paired measurements were applied for statistical analysis. RESULTS: The boys had similar values of body mass when compared with the reference. However, girls showed higher values than the reference at ages six, seven, and ten years-old (p<0.001). For height and body mass index, differences (p<0.001) were noted between the reference and the school children living in areas of moderate altitude for all ages and genders, being the height lower than the reference and the body mass index higher than the reference. Z scores for the body mass index were: boys - 1.0 (six years-old), 0.69 (seven years-old), 0.50 (eight years-old), 1.20 (nine years-old), 0.75 (ten years-old), 0.41 (11 years-old) and 0.82 (12 years-old); girls - 0.36 (six years-old), 0.53 (seven and eight years-old), 0.48 (nine years-old), 0.89 (10 years-old), 0.55 (11 years-old), and 0.43 (12 years-old). CONCLUSIONS: The body mass index should not be applied to children and adolescents that live in regions of moderate altitude. The linear growth retardation presented by this population directly compromises the results of this index.OBJETIVO: Determinar a aplicabilidade do uso das curvas de crescimento da Organização Mundial da Saúde (OMS) em escolares que vivem em regiões de altitude moderada. MÉTODOS: Estudo transversal cuja população foi constituída por uma amostra probabilística estratificada com 955 crianças e adolescentes de seis a 12 anos, sendo 473 meninos e 482 meninas que frequentavam escolas públicas da área urbana da Região de Arequipa (Peru). As variáveis avaliadas envolveram medidas de massa corpórea (kg) e estatura (m) e índice de massa corporal. Para as comparações, utilizou-se o escore Z e o teste t para medidas pareadas. RESULTADOS: Os meninos apresentaram valores similares de massa corpórea quando comparados com a referência. No entanto, as meninas mostraram valores superiores à referência nas idades de seis, sete e dez anos (p<0,001). No caso da estatura e do índice de massa corporal, houve diferenças (p<0,001) entre a referência e os escolares de moderada altitude em todas as idades e em ambos os sexos, com estatura inferior à referência e, consequentemente, maior índice de massa corporal, sendo o escore Z para os meninos: 1,0 (seis anos), 0,69 (sete anos), 0,50 (oito anos), 1,20 (nove anos), 0,75 (dez anos) 0,41 (11 anos) e 0,82 (12 anos); para as meninas, 0,36 (seis anos), 0,53 (sete e oito anos), 0,48 (nove anos), 0,89 (dez anos), 0,55 (11 anos) e 0,43 (12 anos). CONCLUSÕES: O índice de massa corporal não deve ser aplicado a crianças e adolescentes de moderada altitude devido ao retardo no crescimento linear, o que compromete o resultado final deste índice.OBJETIVO: Determinar la aplicabilidad del uso de curvas de crecimiento de la Organización Mundial de la Salud en escolares que viven en regiones de altitud moderada. MÉTODOS: Estudio transversal, cuya población fue constituida por una muestra probabilística estratificada con 955 niños y adolescentes de seis a 12 años de edad, siendo 473 muchachos y 482 muchachas, que frecuentaban escuelas públicas de área urbana de la Región de Arequipa (Perú). Las variables evaluadas implicaron medidas de masa corporal (kg) y estatura (m) y el índice de masa corporal. Para las comparaciones, se utilizó el escore Z y la prueba t para medidas pareadas. RESULTADOS: Los muchachos presentaron valores similares de masa corporal cuando comparados con la referencia. Sin embargo, las muchachas mostraron valores superiores a la referencia en las edades de seis, siete y diez años (p<0,001). En el caso de la estatura y del índice de masa corporal, hubo diferencias (p<0,001) entre la referencia de los escolares de moderada altitud en todas las edades y en ambos sexos, con estatura inferior a la referencia y, como consecuencia, mayor índice de masa corporal, siendo el escore Z para los muchachos: 1,0 (seis años), 0,69 (siete años), 0,50 (ocho años), 1,20 (nueve años), 0,75 (diez años), 0,41 (11 años) y 0,82 (12 años) y, para las muchachas, 0,36 (seis años), 0,53 (siete y ocho años), 0,48 (nueve años), 0,89 (diez años), 0,55 (11 años) y 0,43 (12 años). CONCLUSIONES: El índice de masa corporal no debe ser aplicado a niños y adolescentes de moderada altitud debido al retraso en el crecimiento lineal, lo que compromete el resultado final de este índice.31432

Predictores de los Indicadores de adiposidad corporal por edad cronológica y biológica en niños y adolescentes que residen en el sur de Chile

Introduction: The aims of this study were to identify the skin folds that predict the indicators of body adiposity (Body Mass Index [BMI] and waist circumference [CC]), as well as to analyze if the indicators of body adiposity should be evaluated by chronological and/or biological age.Material and Methods: 131 children and adolescents (76 men and 55 women) were studied. The age range ranged between 6.0 and 14.9 years. Weight, standing height, sitting height, waist circumference were evaluated. The BMI and the peak growth rate years were calculated. The nutritional status categories were determined by BMI and CC according to the cut-off points of the CDC-2012.Results: The four folds used (tricipital, bicipital, suprailiac and calf) explained the BMI from 38 to 58% in men and women from 38 to 72%. The power of explanation for CC in men was 30 to 56% and in women from 27 to 53%. The chronological age explained the BMI and CC in men from 0.08 to 37% and in women from 15 to 17%. The biological age explained BMI and CC in men from 11 to 44% and in women from 21 to 24%.Conclusions: The suprailiac fold appears as the best predictor of BMI and CC in both sexes. The analysis of both indicators must be carried out by biological age rather than by chronological age.Introducción: Los objetivos del presente trabajo fueron identificar los pliegues cutáneos que predicen los indicadores de adiposidad corporal (Índice de Masa Corporal [IMC] y circunferencia de la cintura [CC]), así como analizar si los indicadores de adiposidad corporal deben ser evaluados por edad cronológica y/o biológica.Material y Métodos: Se estudió a 131 niños y adolescentes (76 hombres y 55 mujeres). El rango de edad osciló entre 6,0 hasta 14,9 años. Se evaluó el peso, estatura de pie, estatura sentada, circunferencia de la cintura. Se calculó el IMC y los años de pico de velocidad de crecimiento. Se determinaron las categorías del estado nutricional por IMC y CC de acuerdo a los puntos de corte del CDC-2012.Resultados: Los cuatro pliegues utilizados (tricipital, bicipital, suprailíaco y pantorrilla) explicaron el IMC desde 38 a 58% en hombres y en mujeres desde 38 a 72%. El poder de explicación para la CC en hombres fue de 30 a 56% y en mujeres desde 27 a 53%. La edad cronológica explicó el IMC y la CC en hombres desde 0,08 a 37% y en mujeres desde 15 a 17%. La edad biológica explicó el IMC y CC en hombres desde 11 a 44% y en mujeres desde 21 a 24%.Conclusiones: El pliegue suprailíaco se perfila como el mejor predictor del IMC y la CC en ambos sexos. El análisis de ambos indicadores debe ser efectuado por edad biológica antes que por edad cronológica

Modeling Time Dependent Behaviors of Polymeric Sandwich Composites at Various Environmental Conditions

Polymeric sandwich composites are appealing for lightweight structures that require high strength and stiffness such as parts of aircraft, marine vessels, civil infrastructures and wind turbine blades. In wind turbine blades, sandwich composites with polymeric foam or honeycomb core and fiber-reinforced polymer (FRP) skins are a promising solution to obtain sufficiently lightweight blades with high bending stiffness and strength. In naval structures, sandwich composites with foam core and fiber-reinforced composite skins are used to create a light, corrosion resistant and stiff structure. However, there are many challenging and unresolved scientific issues that engineers face in using sandwich composites in the above applications. Polymeric sandwich composites undergo complex loading histories in addition to constant exposure to hostile environments, i.e., temperature and humidity changes. Moreover, one of the characteristics of polymers is their prominent viscoelastic response when subjected to mechanical loading. The viscoelastic response of polymers becomes more pronounced at elevated temperatures and high humidity. Coupled mechanical loading and hostile environments cause the constituents of the sandwich structures to experience different time-dependent behavior and degradation, leading to complex failure mechanisms in sandwich composites. The aim of this study is to describe the performance of sandwich composites subjected to mechanical loading histories and various environmental conditions, by incorporating knowledge of the behavior in each constituent (skin, core, fiber-matrix constituents)