Prediction of fat-free mass from body surface area in young basketball players.

BACKGROUND: Fat Free Mass (FFM) is an important and essential indicator in various sports populations, since greater muscle and bone mass generates greater strength, endurance and speed in athletes. OBJECTIVE: The purpose of the study was to validate Body Surface Area (BSA) as an anthropometric indicator to estimate FFM in young basketball players. METHODS: A descriptive cross-sectional study was carried out in 105 male basketball players of the Brazilian Basketball Confederation of Sao Paulo (Campinas), Brazil. The age range was 11 to 15 years. Weight and height were evaluated. BSA, body mass index (BMI) and maturity status (MS) were calculated. Total body scanning was performed by dual X-ray absorptiometry (DXA). The components were extracted: Fat mass (FM), Fat free mass (FFM), percentage of fat mass (%FM) and bone mass (BM). The data were analyzed using the correlation coefficient of concordance (CCC) in terms of precision and accuracy. RESULTS: Three regression equations were generated: equation 1 had age and body weight as predictors [FFM= -30.059+(2.926*age)+(0.625*Weight)] (R2 = 92%, precision = 0.96 and accuracy = 0.99), equation 2 used age and BSA [FFM=-45.719+(1.934*age)+(39.388*BSA)] (R2 = 94%, precision = 0.97 and accuracy = 0.99) and equation 3 was based on APHV and BSA [FFM=-15.284+(1.765*APHV)+(37.610*(BSA)] (R2 = 94%, precision = 0.96 and accuracy = 0.99). CONCLUSIONS: The results suggest the use of anthropometric equation using decimal age and BSA to estimate FFM in young basketball players. This new method developed can be used to design, evaluate and control training programs and monitor the weight status of athletes.

Household food insecurity among child and adolescent athletics practitioners: A cross-sectional, descriptive, and exploratory study.

OBJECTIVE: The aim of the study was to explore the prevalence of food insecurity among child and adolescent athletics practitioners and to investigate factors associated with exercise performance, dietary habits, body composition, sleep, and socioeconomic status based on food security status. METHODS: This was a cross-sectional, descriptive, and exploratory study conducted in Campinas, São Paulo, Brazil, between June and July 2023. The convenience sample included children and adolescents (7-17 y old) of both sexes. We evaluated exercise performance, household food insecurity (HFI), dietary-related parameters, and other body composition, lifestyle, and social-related variables. Exercise performance was assessed using the counter movement jump (CMJ), squat jump (SJ), horizontal long jump (HLJ), 50-m sprint test (50-m ST) and throwing strength test (TST). The assessment of HFI was conducted using the food insecurity experience scale (FIES). Comparisons and associations were investigated based on food security status. RESULTS: The total sample size was comprised of 138 children (n = 42; 30.4%) and adolescents (n = 96; 69.6%). We found an association between food security status and sex (X2(138,1) = 4.42; P = 0.036). SJ was higher in the food security group than in the HFI group (t(117) = 2.112; P = 0.037; ES = 0.39). Sleep- and dietary-related factors did not differ between the groups. CONCLUSIONS: In summary, the prevalence of HFI among child and adolescent athletics participants was approximately 40%. Regarding exercise performance, SJ was better in the food security group than in the HFI group. Concerning dietary-related data, the HFI group had a lower number of meals per day than the food security group, and other dietary data did not differ between the groups. Body composition and sleep-related parameters were similar between the groups.

Body surface area is a predictor of maturity status in school children and adolescents.

BACKGROUND: Generally, Body surface area (BSA) changes significantly during growth and maturation. These increases portend a possible relationship between body size as determined by BSA with maturational status in children and adolescents. OBJECTIVE: To determine the relationship between maturity status (MS) obtained by non-invasive anthropometric methods and body surface area (BSA) in children and adolescents of both sexes in a regional population of Chile. Additionally, we sought to verify the type of linear or nonlinear relationship between MS and BSA in both sexes. METHODS: A descriptive (cross-sectional) study was designed in 950 children and adolescents of both sexes (539 males and 411 females). The age range ranged from 6.0 to 17.9 years. Anthropometric measurements were evaluated: body weight, standing height, sitting height. MS was assessed by means of two non-invasive anthropometric techniques. Both techniques predict peak years of growth velocity (APHV) through a regression equation for each sex. BSA (m2) was estimated by means of the Haycock equation. RESULTS: The R2 in the linear model is relatively lower (R2 = 0.80 to 0.89 in males and 0.74 to 0.66 in females) in relation to the nonlinear quadratic model (R2 = 0.81 in males and 0.76 to 0.69). The quadratic nonlinear quadratic model reflected an adequate fit (RMSE) for the data set, being in men (RMSE = 1.080 and 1.125), while in women (RMSE = 1.779 and 1.479). CONCLUSION: BSA is positively associated with MS determined by two non-invasive methods in Chilean children and adolescents: The nonlinear quadratic model was a better fit to the data distribution. The results suggest the use of BSA as a possible predictor of maturity status in Chilean youth.

Aptitud física en jóvenes futbolistas y no-futbolistas por edadcronológica y estado de madurez chilenos / Physical fitness in young Chilean soccer and non-football players by chronological age and maturity stage

Introducción: Durante el periodo de la adolescencia se producen cambios en el cuerpo, siendo importante identificar las diferencias individuales de madurez entre los adolescentes. En el caso de los futbolistas, esto puede generar diferencias en su rendimiento deportivo. Objetivo: Comparar el desempeño físico de jóvenes futbolistas vs escolares (no futbolistas) según edad cronológica y estado de madurez. Metodología: Se efectuó un estudio de tipo descriptivo-comparativo en 139 jóvenes (62 futbolistas con 16,38±1,30 años y 77 escolares con 16,35±1,45años). La selección de la muestra fue de tipo no probabilística por conveniencia. El rango de edad fue entre 14 a 18 años de edad. Se evaluó el peso, la estatura, velocidad 20 metros, salto horizontal (SH), y la prueba de aptitud aeróbica de Leger. Se calculó el índice de masa corporal (IMC), los años de pico de velocidad de crecimiento (APVC), y el VO2max absoluto y relativo. Resultados: Los jóvenes futbolistas presentaron mayor VO2max absoluto y relativo en comparación con sus similares escolares, tanto por edad cronológica y estado de madurez. Hubo correlación positiva significativa (p<0.05) entre la edad y los APVC con el VO2max absoluto y salto horizontal, y negativa con la velocidad de 20 metros. No hubo correlación entre la edad y APVC con el VO2máx relativo (edad y VO2máx, r= 0.10, p=0.023 y APVC y VO2máx, r= 0.07, p= 0.036). Conclusión: Los jóvenes futbolistas presentaron un mejor VO2max absoluto y relativo, SH y velocidad 20m en relación a los no-futbolistas, tanto por edad cronológica y estado de madurez, aunque, el desempeño físico se observa mejor por estado de madurez, especialmente en el VO2max y en el SH. Estos resultados sugieren que los profesionales del futbol deben considerar el control del estado de madurez como una alternativa para categorizar a los futbolistas cuando se evalúa y trabaja el desempeño físico.(AU)

Introduction: During the adolescent period, changes ingrowth and body composition occur, and it is important toidentify individual differences in maturity among adolescents. In the case of soccer players, they may show better physicalfitness than their non-football players.Objective: To compare the physical fitness of young soccer players vs non-football players, according to chronologicalage and maturity status.Methodology: A descriptive-comparative study was carriedout in 139 young people (62 soccer players aged 16.38±1.30years and 77 schoolchildren aged 16.35±1.45 years). Thesample selection was non-probabilistic by convenience. Theage range ranged from 14 to 18 years old. Weight, height,speed 20 meters, horizontal jump (SH), and Leger’s aerobicfitness test were evaluated. Body mass index (BMI), peak years of growth velocity (APVC), and absolute and relativeVO2max were calculated.Results: Young soccer players presented higher absoluteand relative VO2max compared to their similar non-footballplayers, both by chronological age and maturity status. Therewas significant positive correlation (p<0.05) between age andAPVC with absolute VO2max and horizontal jump, and negative with 20-meter speed. There was no correlation betweenage and APVC with relative VO2max (age and VO2max, r=0.10, p=0.023 and APVC and VO2max, r= 0.07, p= 0.036).Conclusion: Young soccer players presented better absolute and relative VO2max, SH and 20m speed in relation tonon-football players, both by chronological age and maturitystatus, although, physical performance is better observed bymaturity status, especially in VO2max and SH. These resultssuggest that professionals working in grassroots soccershould consider the control of maturity status as an alternative to categorize soccer players when evaluating and workingon physical performance.(AU)

Fat-free mass and maturity status are determinants of physical fitness performance in schoolchildren and adolescents

Abstract Objectives: The objective of the study was to verify whether (FFM), maturity status (MS) and chronological age (CA) are determinants of physical fitness performance, and to analyze FFM and physical performance aligned by CA and MS in children and adolescents. Methods: A descriptive correlational study was carried out in 863 schoolchildren. Weight, height, and waist circumference (WC) were evaluated. Body mass index (BMI), FFM, fat mass (FM), MS (Age at peak height velocity, APHV) were calculated. The physical tests of velocity 20 m, agility 5 m × 10rep, and horizontal jump (HJ) were evaluated. Results: The APHV was estimated in boys at 14.0 ± 0.36APHV and in girls at 11.96 ± 0.49APHV. The relationships between CA and APHV with FFM was r = 0.80 in boys and r = 0.44 to 0.45 in girls. The relationships between FFM and physical tests in boys were [HJ (r = 0.70), agility 5m × 10rep (r = -0.68), velocity (r = -0.61)] and in girls [HJ (r = 0.42), agility 5m × 10rep (r = -0.52), velocity (r = -0.20)]. The differences in FFM and physical fitness tests were more pronounced when aligned by APHV than by CA. Conclusion: It was verified that both FFM, CA, and APHV are determinants of physical fitness performance. In addition, the APHV should be introduced in physical education as a means of ranking physical performance among schoolchildren.

Fat-free mass and maturity status are determinants of physical fitness performance in schoolchildren and adolescents.

OBJECTIVES: The objective of the study was to verify whether (FFM), maturity status (MS) and chronological age (CA) are determinants of physical fitness performance, and to analyze FFM and physical performance aligned by CA and MS in children and adolescents. METHODS: A descriptive correlational study was carried out in 863 schoolchildren. Weight, height, and waist circumference (WC) were evaluated. Body mass index (BMI), FFM, fat mass (FM), MS (Age at peak height velocity, APHV) were calculated. The physical tests of velocity 20 m, agility 5 m x 10rep, and horizontal jump (HJ) were evaluated. RESULTS: The APHV was estimated in boys at 14.0 ± 0.36APHV and in girls at 11.96 ± 0.49APHV. The relationships between CA and APHV with FFM was r = 0.80 in boys and r = 0.44 to 0.45 in girls. The relationships between FFM and physical tests in boys were [HJ (r = 0.70), agility 5m x 10rep (r = -0.68), velocity (r = -0.61)] and in girls [HJ (r = 0.42), agility 5m x 10rep (r = -0.52), velocity (r = -0.20)]. The differences in FFM and physical fitness tests were more pronounced when aligned by APHV than by CA. CONCLUSION: It was verified that both FFM, CA, and APHV are determinants of physical fitness performance. In addition, the APHV should be introduced in physical education as a means of ranking physical performance among schoolchildren.

[Development of anthropometric equations for predicting total body fat percentage in Chilean children and adolescents]. / Desarrollo de ecuaciones antropométricas para predecir el porcentaje de grasa corporal total en niños y adolescentes chilenos.

Introduction: Introduction: studying the percentage of body fat (%BF) in children and adolescents is very relevant, since a high level of body fat in childhood and adolescence represents overweight and obesity. Objective: to identify the anthropometric indicators related to %BF and to validate regression equations to predict %BF in children and adolescents using dual-energy X-ray absorptiometry (DXA) as a reference method. Methods: a descriptive study (cross-sectional) was designed in 1126 schoolchildren (588 males and 538 females) from the Maule region (Chile). The age range ranged from 6.0 to 17.9 years. Weight, height, two skinfolds (tricipital and subscapular and waist circumference (WC) were evaluated. Body mass index (BMI), triponderal mass index (TMI), waist height index (WHtR) were calculated. Body fat percentage (%BF) was assessed by DXA scanning. Results: the relationships between Σ (Tricipital + Subscapular), TMI and WHtR with %BF (DXA) ranged from R2 = 52 % to 54 % in men, and from R2 = 41 % to 49 % in women. The equations generated for men were: %BF = 9.775 + [(0.415 * (Tr + SE)] + (35.084 * WHtR) - (0.828 * age), R2 = 70 %, and %BF = 20.720 + [(0.492 * (Tr + SE)] + (0.354 * TMI) - (0.923 * age), R2 = 68 %], and for women: %BF = 8.608 + [(0.291 * (Tr + SE)] + (38.893 * WHtR) - (0.176 * age), R2 = 60 %, and %BF = 16.087 + [(0.306 * (Tr + SE)] + (0.818 * TMI) - (0.300 * age), R2 = 59 %. Conclusion: this study showed that the sum of tricipital and subscapular skinfolds, IP and WHtR are adequate predictors of %BF. These indicators allowed the development of two regression equations acceptable in terms of precision and accuracy to predict %BF in children and adolescents of both sexes.

Introducción: Introducción: estudiar el porcentaje de grasa corporal (%GC) en niños y adolescentes es muy relevante, puesto que un elevado nivel de grasa corporal en la infancia y la adolescencia representa sobrepeso y obesidad. Objetivo: identificar los indicadores antropométricos que se relacionan con el %GC y validar ecuaciones de regresión para predecir el %GC de niños y adolescentes a partir del uso de la absorciometría de rayos X de doble energía (DXA) como método de referencia. Métodos: se diseñó un estudio descriptivo (transversal) en 1126 escolares (588 hombres y 538 mujeres) de la región del Maule (Chile). El rango de edad oscila desde los 6,0 hasta los 17,9 años. Se evaluaron el peso, la estatura, dos pliegues cutáneos (tricipital y subescapular) y la circunferencia de la cintura (CC). Se calcularon el índice de masa corporal (IMC), el índice ponderal (IP) y el índice cintura-estatura (ICE). Se evaluó el porcentaje de grasa corporal (%GC) por medio del escaneo DXA. Resultados: las relaciones entre Σ (Tricipital + Subescapular), IP e ICE con el %GC (DXA) fueron de R2 = 52-54 % en hombres y R2 = 41-49 % en mujeres. Las ecuaciones generadas para los hombres fueron: %GC = 9,775 + [(0,415 * (Tr + SE)] + (35,084 * ICE) - (0,828 * edad), R2 = 70 %, y %GC = 20,720 + [(0,492 * (Tr + SE)] + (0,354 * IP) - (0,923 * edad), R2 = 68 %; y para mujeres: %GC = 8,608 + [(0,291 * (Tr + SE)] + (38,893 * ICE) - (0,176 * edad), R2 = 60 %, y %GC = 16,087 + [(0,306 * (Tr + SE)] + (0,818 * IP) - (0,300 * edad), R2 = 59 %. Conclusión: este estudio demostró que la sumatoria de los pliegues cutáneos tricipital y subescapular, el IP y el ICE son adecuados predictores del %GC. Estos indicadores permitieron desarrollar dos ecuaciones de regresión aceptables en términos de precisión y exactitud para predecir el %GC en niños y adolescentes de ambos sexos.

[Physical fitness in children and adolescents categorized by fat mass level]. / Aptitud física en niños y adolescentes categorizados por nivel de masa grasa.

Physical fitness is one of the important health markers as a predictor of cardiovascular disease mor bidity and mortality. OBJECTIVES: To evaluate the relationship between fat mass with anthropome tric indicators and, secondly, to compare the performance of physical fitness among children and adolescents categorized with adequate and excess fat mass. SUBJECTS AND METHOD: A descriptive cross-sectional study was conducted with 863 schoolchildren aged 6 to 17.9 years. Weight, height, and waist circumference were measured. physical fitness [speed (20m), agility (10x5m), and ho rizontal jump] was evaluated. Fat mass was calculated by anthropometric equation, body mass index, ponderal index, and waist to height ratio. Data were grouped into 6 age groups. RESULTS: Children of both sexes categorized as having adequate levels of fat mass had lower values of body mass index, ponderal index, and waist to height ratio than children with high levels of fat mass. In physical fitness, children with adequate fat mass were better than the ones with elevated fat mass. In girls with adequate fat mass, better results were observed in horizontal jump and agility during adolescence. There were no differences in the speed test. CONCLUSION: Fat mass can be considered as a valuable tool for determining excess body fat and categorizing children and adolescents with adequate and excess fat mass. In addition, having acceptable levels of fat mass may contribute to better physical fitness in boys in horizontal jump, agility, and speed and, in girls, only in horizontal jump and agility.

Correlation between body composition data obtained by DXA and skinfold predictive protocols in sprinters / Correlação entre dados de composição corporal obtidos pelo DXA e protocolos preditivos de dobras cutâneas em velocistas

Abstract The aim of this study was to describe the correlation between body composition data obtained through DXA and through skinfolds strategy, with some of their respective formulas, in sprinters. The sample consisted of 15 male sprinters (23.81 years ± 3.11; 70.06 Kg ± 4.38; and 179.13 CM ± 5.16) all high performance runners of speed and barriers events (100m, 200m, 400m, 110m with barriers and 400m with barriers). The athletes were submitted to DXA evaluation procedure and to skinfolds collection (triceps, biceps, subscapular, supra iliac, abdominal, medial thigh and calf) and the results were calculated through four distinct equations: Slaughter, Faulkner, Lázari and Boileau. The respective DXA correlations (0.60; 0.81; 0.23 and 0.48) and the equations predicted by skinfold strategy were calculated using Pearson correlation. Among the equations used, Faulkner's was the one presenting highest correlation value when compared to DXA protocol, although all of them aimed to estimate values for BF%.

Resumo O objetivo deste estudo foi descrever a correlação entre dados de composição corporal obtidos através de DEXA, e pela estratégia de dobras cutâneas, com algumas de suas respectivas fórmulas, em velocistas. A amostra foi composta por 15 velocistas do sexo masculino (23,81 anos ± 3,11; 70,06 Kg ± 4,38; e 179,13 cm ± 5,16) todos corredores de alto desempenho das provas de velocidade e barreiras (100m, 200m, 400m, 110m com barreiras e 400m com barreiras). Os atletas foram submetidos ao procedimento de avaliação do DEXA e a coleta de dobras cutâneas (tricipital, bicipital, subescapular, supra ilíaca, abdominal, coxa medial e panturrilha) e os resultados calculados através de quatros distintas equações Slaughter, Faulkner, Lázari e Boileau. As respectivas correlações (0,60; 0,81; 0,23 e 0,48) de DEXA e as equações previstas pela estratégia de dobras cutâneas foram calculadas através da correlação de Pearson. Dentre as equações utilizadas, a de Faulkner foi a que apresentou maior valor de correlação quando comparada ao protocolo do DEXA, apesar de todas terem por objetivo estimar valores para o %G.

Densidad mineral ósea en adultos: Una revisión sistemática sobre las técnicas de medición / Evaluation of Bone Mineral Density in Older Adults by DXA: A Systematic Review

Fundamentos: Conforme avanza la edad, el sistema esquelético sufre modificaciones estructurales, que afectan la masa muscular (sarcopenia) y masa ósea (osteopenia), por lo que debe ser evaluado periódicamente. El objetivo fue identificar las regiones anatómicas que más se utilizan en la evaluación de la Densidad Mineral Ósea (DMO) en adultos mayores (AM) a través de la absorciometría de rayos X dual energía(DXA), controlando la realización de actividad física. Métodos: Se efectuó un estudio de revisión sistemática, utilizando las bases de datos de PUB MED y SCOPUS. Las palabras claves para la búsqueda de información fueron: aging, elderly, bone mineral density, physical activity, bone health. Se consideró el periodo de años 2016-2020. Resultados: Fueron identificados 12 estudios primarios; 9 estudios reportaron el uso de Columna Lumbar(CL) y Cuello Femoral (CF) para evaluar la DMO como puntos referenciales, además 5 estudios que han utilizado el Cuerpo Total (CT) y CF. En cuanto al control de la Actividad Física (AF), 7 han utilizado acelerómetros y 5 cuestionarios de auto-reporte. Conclusiones: Se demostró que la absorciometría de rayos X dual (DXA) es muy utilizada para evaluar la DMO en AM, cuyos puntos anatómicos preferidos por los estudios son la CL y CF. (AU)

Background: As age progresses, the skeletal system undergoes structural modifications, which affect musclemass (sarcopenia) and bone mass (osteopenia), so it must be evaluated periodically. The objective was to identify the anatomical regions that are most used in the evaluation of Bone Mineral Density (BMD) in older adults (AM) through dual energy x-ray absorptiometry (DXA), controlling the performance of physical activity. Methods: A systematic review study was conducted, using the PUB MED and SCOPUS databases. The keywords for the information search were: aging, elderly, bone mineral density, physical activity, bone health. The period of years 2016-2020 was considered. Results: 12 primary studies were identified; 9 studies reported the use of Lumbar Spine (LS) and Femoral Neck (FC) to assess BMD as reference points, in addition to 5 studies that have used Total Body (TC) and CF. As for the control of Physical Activity (PA), 7 have used accelerometers and 5 self-report questionnaires. Conclusions: It was demonstrated that dual X-ray absorptiometry (DXA) is widely used to evaluate BMD inAM, whose anatomical points preferred by the studies are CL and CF. (AU)

Estimación de la masa grasa por medio de indicadores antropométricos en jóvenes con síndrome de Down / Estimation of fat mass by anthropometric indicators in young people with Down syndrome

Introducción: la evaluación de la composición corporal es relevante y útil para diseñar intervenciones de estilos de vida saludables y estrategias nutricionales.Objetivos: verificar las relaciones existentes entre los indicadores de adiposidad y la masa grasa (MG), y validar ecuaciones que permitan predecir la MG en jóvenes con síndrome de Down (SD).Métodos: se efectuó un estudio transversal en 48 jóvenes con SD (24 hombres y 24 mujeres). Se evaluaron el peso, la estatura, la circunferencia de la cintura (CC) y la circunferencia de la cadera (CCa). Se calcularon el índice de masa corporal (IMC), el índice de adiposidad corporal (IAC), el índice cintura-cadera (ICC) y el índice cintura-estatura (ICE). Se evaluó la MG mediante absorciometría de rayos X de doble energía (DXA). Resultados: la edad de los hombres era de 19,3 ± 3,0 años y la de las mujeres de 18,9 ± 1,9 años; el peso era de 73,6 ± 14,3 kg en los hombres y de 75,8 ± 20,3 kg en las mujeres; finalmente, la estatura de los hombres era de 168,9 ± 6,5 cm y la de las mujeres de 156,3 ± 6,2 cm. En los hombres, las correlaciones entre la MG (DXA) y los parámetros IMC, CC, CCa, ICE, IAC e ICE oscilaron entre r = 0,01 y r = 0,89; en las mujeres, entre r = 0,10 y r = 0,97. Las correlaciones más altas se observaron con el IMC y la CC en ambos sexos (hombres, r = 0,78 a 0,92 y mujeres, r = 0,83 a 0,97). Se generaron ecuaciones de regresión para estimar la MG en los hombres (R2 = 84 %) y en las mujeres (R2 = 96 %). Se calcularon los percentiles de MG según la DXA y con cada ecuación. Conclusiones:hubo correlaciones positivas significativas del IMC y la CC con la MG. Estos indicadores fueron determinantes para desarrollar ecuaciones que estiman la MG de los jóvenes con SD. Los resultados sugieren su uso y aplicación para evaluar, clasificar y monitorizar los niveles de adiposidad corporal en contextos clínicos y epidemiológicos. (AU)

Introduction: the assessment of body composition is relevant and useful for designing interventions for healthy lifestyles and nutritional strategies. Objective: our goal was to verify the relationships between adiposity indicators with fat mass (FM), and to validate equations that allow predicting FM in young people with Down syndrome (SD). Methods: a cross-sectional study was carried out in 48 young people with DS (24 men and 24 women). Weight, height, waist circumference (WC), and hip circumference (HC) were evaluated. Body mass index (BMI), body adiposity index (BAI), waist-to-hip index (WHI), and waist-to-height index (WHtR) were calculated. FM was evaluated by dual energy X-ray absorptiometry (DXA). Results: age in men was 19.3 ± 3.0 years, and in women it was 18.9 ± 1.9 years; weight was 73.6 ± 14.3 kg in men and 75.8 ± 20.3 kg in women, and height in men was 168.9 ± 6.5 cm, and in women it was 156.3 ± 6.2 cm. In males the correlations between FM (DXA) with BMI, WC, HC, WHtR, BAI and WHtR ranged from r = 0.01 to r = 0.89, and in females from r = 0.10 to r = 0.97. The highest correlations were observed with BMI and WC in both sexes (males r = 0.78 to 0.92, and females r = 0.83 to 0.97). Regression equations were generated to estimate FM in males (R2 = 84 %) and in females (R2 = 96 %). Percentiles were calculated for MG per DXA and for each equation. Conclusions: there were significant positive correlations between BMI and WC with FM. These indicators were decisive for developing equations that estimate FM in young people with DS. The results suggest its potential use and application to evaluate, classify and monitor body fat levels in clinical and epidemiological contexts. (AU)

[Estimation of fat mass by anthropometric indicators in young people with Down syndrome]. / Estimación de la masa grasa por medio de indicadores antropométricos en jóvenes con síndrome de Down.

INTRODUCTION: Introduction: the assessment of body composition is relevant and useful for designing interventions for healthy lifestyles and nutritional strategies. Objective: our goal was to verify the relationships between adiposity indicators with fat mass (FM), and to validate equations that allow predicting FM in young people with Down syndrome (SD). Methods: a cross-sectional study was carried out in 48 young people with DS (24 men and 24 women). Weight, height, waist circumference (WC), and hip circumference (HC) were evaluated. Body mass index (BMI), body adiposity index (BAI), waist-to-hip index (WHI), and waist-to-height index (WHtR) were calculated. FM was evaluated by dual energy X-ray absorptiometry (DXA). Results: age in men was 19.3 ± 3.0 years, and in women it was 18.9 ± 1.9 years; weight was 73.6 ± 14.3 kg in men and 75.8 ± 20.3 kg in women, and height in men was 168.9 ± 6.5 cm, and in women it was 156.3 ± 6.2 cm. In males the correlations between FM (DXA) with BMI, WC, HC, WHtR, BAI and WHtR ranged from r = 0.01 to r = 0.89, and in females from r = 0.10 to r = 0.97. The highest correlations were observed with BMI and WC in both sexes (males r = 0.78 to 0.92, and females r = 0.83 to 0.97). Regression equations were generated to estimate FM in males (R2 = 84 %) and in females (R2 = 96 %). Percentiles were calculated for MG per DXA and for each equation. Conclusions: there were significant positive correlations between BMI and WC with FM. These indicators were decisive for developing equations that estimate FM in young people with DS. The results suggest its potential use and application to evaluate, classify and monitor body fat levels in clinical and epidemiological contexts.

INTRODUCCIÓN: Introducción: la evaluación de la composición corporal es relevante y útil para diseñar intervenciones de estilos de vida saludables y estrategias nutricionales. Objetivos: verificar las relaciones existentes entre los indicadores de adiposidad y la masa grasa (MG), y validar ecuaciones que permitan predecir la MG en jóvenes con síndrome de Down (SD). Métodos: se efectuó un estudio transversal en 48 jóvenes con SD (24 hombres y 24 mujeres). Se evaluaron el peso, la estatura, la circunferencia de la cintura (CC) y la circunferencia de la cadera (CCa). Se calcularon el índice de masa corporal (IMC), el índice de adiposidad corporal (IAC), el índice cintura-cadera (ICC) y el índice cintura-estatura (ICE). Se evaluó la MG mediante absorciometría de rayos X de doble energía (DXA). Resultados: la edad de los hombres era de 19,3 ± 3,0 años y la de las mujeres de 18,9 ± 1,9 años; el peso era de 73,6 ± 14,3 kg en los hombres y de 75,8 ± 20,3 kg en las mujeres; finalmente, la estatura de los hombres era de 168,9 ± 6,5 cm y la de las mujeres de 156,3 ± 6,2 cm. En los hombres, las correlaciones entre la MG (DXA) y los parámetros IMC, CC, CCa, ICE, IAC e ICE oscilaron entre r = 0,01 y r = 0,89; en las mujeres, entre r = 0,10 y r = 0,97. Las correlaciones más altas se observaron con el IMC y la CC en ambos sexos (hombres, r = 0,78 a 0,92 y mujeres, r = 0,83 a 0,97). Se generaron ecuaciones de regresión para estimar la MG en los hombres (R2 = 84 %) y en las mujeres (R2 = 96 %). Se calcularon los percentiles de MG según la DXA y con cada ecuación. Conclusiones: hubo correlaciones positivas significativas del IMC y la CC con la MG. Estos indicadores fueron determinantes para desarrollar ecuaciones que estiman la MG de los jóvenes con SD. Los resultados sugieren su uso y aplicación para evaluar, clasificar y monitorizar los niveles de adiposidad corporal en contextos clínicos y epidemiológicos.

Comparison of Anthropometric Indicators That Assess Nutritional Status From Infancy to Old Age and Proposal of Percentiles for a Regional Sample of Chile.

Objectives: Anthropometric variables are used to evaluate health, dietary status, disease risks, and changes in body composition. The purpose of this study was to compare weight, height, and Body Mass Index (BMI) with American references from the National Center for Health Statistics (NCHS-2012), using BMI and Tri-Ponderal Mass Index (TMI) to propose percentiles for evaluating nutritional status of children, adolescents, and adults, ages 5-80 years old. Methods: A descriptive cross-sectional study was conducted in 15,436 (8,070 males and 7,366 females) children, youths and adults in the Maule region (Chile). The age range ranged from 5.0 to ~80 years of age. Weight and height were assessed. Body mass index BMI and tri-ponderal mass index (TMI) were calculated. The LMS method was used to generate percentiles. Results: The results illustrated that children were heavier and had more BMI during childhood compared to the NCHS references. During adolescence, reference values were greater until approximately ages 70-79. For height, children were relatively similar to those of the NCHS references, but during adolescence, differences became evident. Adolescence until approximately age 80, the population showed lower values for height. Percentiles were calculated using BMI and TMI by age range and sex. Differences occurred between the American NCHS references and the population with regard to the anthropometric variables of weight, height, and in BMI. Conclusion: Discrepancies with the American NCHS reference were verified in the anthropometric variables of weight, height and BMI. Reference percentiles of BMI and TMI were developed for the evaluation of the nutritional status of the regional population of Maule (Chile). Its use is suggested in clinical and epidemiological contexts.

Relación entre aptitud aeróbica con indicadores de adiposidad corporal en adolescentes de ambos sexos / Aptitud aeróbica con indicadores de adiposidad corporal en adolescentes

Introducción: La aptitud aeróbica es considerada como un indicador de salud que se relaciona con la adiposidad corporal. La dieta, nivel de actividad física, sedentarismo y la salud psicológica podrían influir en esa relación. Objetivo: Relacionar la aptitud aeróbica con cinco indicadores de adiposidad corporal en adolescentes de ambos sexos. Material y Métodos: Se efectuó un estudio descriptivo de corte transversal en 200 adolescentes de 14 a 17 años de edad (140 hombres y 60 mujeres). La selección de la muestra fue no-probabilística (cuotas). Se evaluó las mediadas antropométricas (peso, estatura, circunferencia de la cintura), se calculó los índices de adiposidad (Índice de masa corporal, índice ponderal, índice cintura-estatura y masa grasa). Se evaluó la aptitud aeróbica por medio de la prueba de indirecta de campo ida y vuelta de 20m (L/min-1 y ml/kg-1/min-1). La clasificación se efectuó a partir del Vo2max relativo según edad y sexo: Muy bajo (p80). Resultados: En hombres se observó diferencias significativas entre las categorías de aptitud aeróbica muy alto y alto vs muy baja y baja en todos los indicadores de adiposidad corporal (p<0,05). En mujeres las diferencias fueron significativas entre la capacidad aeróbica muy alta con baja y muy baja (p<0,05), y capacidad aeróbica alta vs muy baja (p<0,05). Las asociaciones fueron negativas en cinco indicadores de adiposidad en hombres (IMC, IP, CC ICE y MG, R2= 16 a 19%) y en cuatro indicadores de adiposidad en las mujeres (IMC, IP, CC e ICE, R2= 16 a 21%). Conclusión: Se demostró relación negativa entre la aptitud aeróbica (VO2máx) y los indicadores antropométricos de adiposidad corporal, además los adolescentes clasificados con elevados niveles de consumo máximo de oxígeno reflejaron adecuados valores de adiposidad corporal. (AU)

Introduction: Aerobic fitness is considered a healthindicator that is related to body fat. Diet, level of physicalactivity, sedentariness and psychological health could influencethis relationship. Objective: To relate aerobic fitness with five indicators ofbody fat in adolescents of both sexes. Material and Methods: A cross-sectional descriptive studywas carried out on 200 adolescents between 14 and 17 yearsof age (140 males and 60 females). The selection of the samplewas non-probabilistic (quotas). Anthropometric measurementswere evaluated (weight, height, waist circumference), adiposityindexes were calculated (body mass index, weight index, waist-height index, and fat mass). Aerobic fitness was evaluated bymeans of the 20m shuttle run test (L/min-1 and mL·kg-1·min-1).The classification was made from the relative VO2max accordingto age and sex: Very low (p80). Results: In men, significant differences were observedbetween the categories of very high and high vs. very low andlow aerobic fitness in all indicators of body fat (p<0.05). Inwomen the differences were significant between very highaerobic capacity with low and very low (p<0.05), and high vsvery low aerobic capacity (p<0.05). The associations werenegative in five indicators of adiposity in men (BMI, PI, WC,WHIR and FM, R2= 16 to 19%) and in four indicators ofadiposity in women (BMI, PI, WC and WHIR, R2= 16 to 21%). Conclusion: It was demonstrated negative relationbetween aerobic aptitude (VO2max) and anthropometricindicators of body adiposity, besides, adolescents classifiedwith high levels of maximum oxygen consumption reflectedlow values of body adiposity. (AU)

Evaluación de los trastornos del sueño y propuesta de percentiles para los adolescentes / Assessment of sleep disorders and proposed percentiles for adolescents

Objetivos. Los objetivos del estudio fueron los siguientes: a) construir un instrumento válido y confiable que evaluara, por autoinforme, los trastornos del sueño en adolescentes escolares chilenos y b) desarrollar valores percentílicos según la edad y el sexo. Metodología. Se efectuó un estudio de tipo descriptivo de corte transversal en 2310 adolescentes escolares de la Región del Maule, Chile. Se construyó el autoinforme de trastornos del sueño considerando cinco categorías (duración, alteraciones, problemas en la respiración, fatiga y uso de estimulantes). Se validó por medio del análisis factorial confirmatorio. La fiabilidad se evaluó por la consistencia interna. Se crearon percentiles a través del método LMS (L: asimetría, M: mediana y S: coeficiente de variación). Resultados. Las preguntas 3, 9 y 12 presentaron saturaciones inferiores a 0,40, y las demás preguntas reflejaron saturaciones superiores a 0,41. El valor de adecuación Kaiser-Meyer-Olkin fue 0,749 y la prueba de esfericidad de X2= 4790,09; el porcentaje de la varianza explicó el 62,1 %. El alfa de Cronbach mostró valores entre 0,71 y 0,76. Conclusión. El autoinforme desarrollado para medir los trastornos del sueño en los adolescentes puede ser aplicado de forma válida y confiable en programas de ciencias de la salud, de la educación y del deporte. Se sugiere el uso de percentiles para identificar los patrones normales y/o trastornos del sueño por edad y género.

Objectives. The objectives of this study included: a) to develop a valid and reliable self-reporting instrument to assess sleep disorders among Chilean adolescent students and b) to develop percentiles for age and sex. Methodology. This was a descriptive, crosssectional study in 2310 adolescent students conducted in the Maule Region, Chile. The sleep disorder self-report was developed considering five categories: duration, alterations, breathing problems, fatigue, and stimulant use. The instrument was validated using a confirmatory factor analysis. Reliability was assessed based on internal consistency. Percentiles were developed using the LMS method (L: lambda, asymmetry; M: mu, median; S: sigma, coefficient of variation). Results. Questions 3, 9, and 12 showed saturation values below 0.40, while the rest had saturation values above 0.41. The Kaiser-Meyer-Olkin measure of adequacy was 0.749 and the test of sphericity X2 was 4790.09; the percentage of variance accounted for 62.1%. Cronbach's alpha ranged between 0.71 and 0.76. Conclusion. The self-report developed to measure sleep disorders in adolescents is valid and reliable for its use in health, education, and sports science programs. Percentiles should be used to identify normal patterns and/or sleep disorders by sex and age.

Assessment of sleep disorders and proposed percentiles for adolescents. / Evaluación de los trastornos del sueño y propuesta de percentiles para los adolescentes.

OBJECTIVES: The objectives of this study included: a) to develop a valid and reliable self-reporting instrument to assess sleep disorders among Chilean adolescent students and b) to develop percentiles for age and sex. METHODOLOGY: This was a descriptive, crosssectional study in 2310 adolescent students conducted in the Maule Region, Chile. The sleep disorder self-report was developed considering five categories: duration, alterations, breathing problems, fatigue, and stimulant use. The instrument was validated using a confirmatory factor analysis. Reliability was assessed based on internal consistency. Percentiles were developed using the LMS method (L: lambda, asymmetry; M: mu, median; S: sigma, coefficient of variation). RESULTS: Questions 3, 9, and 12 showed saturation values below 0.40, while the rest had saturation values above 0.41. The Kaiser-Meyer-Olkin measure of adequacy was 0.749 and the test of sphericity X2 was 4790.09; the percentage of variance accounted for 62.1 %. Cronbach's alpha ranged between 0.71 and 0.76. CONCLUSION: The self-report developed to measure sleep disorders in adolescents is valid and reliable for its use in health, education, and sports science programs. Percentiles should be used to identify normal patterns and/or sleep disorders by sex and age.

Objetivos. Los objetivos del estudio fueron los siguientes: a) construir un instrumento válido y confiable que evaluara, por autoinforme, los trastornos del sueño en adolescentes escolares chilenos y b) desarrollar valores percentílicos según la edad y el sexo. Metodología. Se efectuó un estudio de tipo descriptivo de corte transversal en 2310 adolescentes escolares de la Región del Maule, Chile. Se construyó el autoinforme de trastornos del sueño considerando cinco categorías (duración, alteraciones, problemas en la respiración, fatiga y uso de estimulantes). Se validó por medio del análisis factorial confirmatorio. La fiabilidad se evaluó por la consistencia interna. Se crearon percentiles a través del método LMS (L: asimetría, M: mediana y S: coeficiente de variación). Resultados. Las preguntas 3, 9 y 12 presentaron saturaciones inferiores a 0,40, y las demás preguntas reflejaron saturaciones superiores a 0,41. El valor de adecuación Kaiser-Meyer-Olkin fue 0,749 y la prueba de esfericidad de X2= 4790,09; el porcentaje de la varianza explicó el 62,1 %. El alfa de Cronbach mostró valores entre 0,71 y 0,76. Conclusión. El autoinforme desarrollado para medir los trastornos del sueño en los adolescentes puede ser aplicado de forma válida y confiable en programas de ciencias de la salud, de la educación y del deporte. Se sugiere el uso de percentiles para identificar los patrones normales y/o trastornos del sueño por edad y género.

Validez, confiabilidad y percentiles para valorar el auto-concepto físico de jóvenes universitarios de Perú / Validity, reliability and percentiles to assess the physical self-concept of young university students in Peru

Fundamentos: Verificar la validez y confiabilidad de la escala de auto-concepto físico (ACF) y proponer referencias por medio de percentiles. Métodos: Se estudió 1.937 jóvenes universitarios (1.064 hombres y 873 mujeres) de la ciudad de Puno, Perú. Se evaluó el peso y estatura y se calculó el índice de Masa Corporal (IMC) de los universitarios. Se utilizó la técnica de la encuesta aplicando una escala de ACF de 30 preguntas. La validación se efectuó por medio de Análisis Factorial Confirmatorio (A-FC). La confiabilidad de verificó por medio de Alpha de Cronbach. Se generaron percentiles por medio del método LMS. Resultados: El A-FC arrojó saturaciones superiores a 0,41 para 29 preguntas. En el modelo generado con 29 preguntas, el porcentaje de explicación de la varianza fue del 42%, el KMO fue de 0,911 (X2= 15578.883, gl= 435, p<0,001). El alpha de Cronbach mostró valores superiores a 0,75. Los percentiles propuestos permiten categorizar el ACF en tres niveles: p85 (alto ACF).Conclusiones: La escala de ACF es válida y confiable para jóvenes universitarios. Los percentiles son una alternativa para identificar, clasificar y categorizar los niveles de ACF

Background: To verify the validity and reliability of the physical self-concept scale (CFA) and to propose references by means of percentiles. Methods: 1937 university students(1064 men and 873 women) from the city of Puno, Peru, were studied. The weight and height were evaluated and the Body Mass Index (BMI) was calculated. The survey technique was used applying an ACF scale of 30 questions. Validation was carried out through Confirmatory Factor Analysis (CF-A). The reliability of verified by means of Alpha de Cronbach. Percentiles were generated by means of the LMS method. Results: The CF-A showed saturations higher than 0.41 for 29 questions. In the model generated with 29 questions, the percentage explanation of the variance was 42%, the KMO was 0.911 (X2 = 15578.883, gl = 435, p <0.001). Cronbach's alpha showed values above 0.75. The proposed percentiles allow categorizing the ACF into three levels: p85 (high ACF). Conclusions: The ACF scale is valid and reliable for university students. The percentiles are an alternative to identify, classify and categorize the ACF levels

Parámetros del crecimiento físico de niños que viven a moderada altitud / Parameters of physical growth of children living at moderate altitude

El desarrollo del crecimiento físico depende del bagaje genético, nutricional, nivel socio-económico, enfermedades, influencias ambientales, tendencia secular, actividad física y el nivel de altitud. Objetivo: Determinar los parámetros del crecimiento físico de niños que viven a moderada altitud en función del género y en relación a los patrones referenciales del CDC y NHANAS-USA. Material y métodos: Fueron seleccionados 795 niños de condición socioeconómica media de manera probabilística (estratificado), siendo 394 varones y 401 damas de escuelas públicas del área urbana de la ciudad de Arequipa-Perú (2320 msnm). Se evaluaron las variables antropométricas peso corporal (kg), estatura (m), pliegue tricipital (mm) y circunferencia del brazo relajado (cm). Resultados: Se encontró valores similares en el peso corporal (p>0,005) y valores inferiores en estatura (p<0,005) en niños de ambos géneros en relación con la referencia del CDC. En el pliegue tricipital, se observó valores relativamente similares en ambos géneros, al comparar con la referencia del National Health and Nutrition Examination Survey (NHANES)-USA. Los valores de la circunferencia del brazo según percentiles fue menor en ambos géneros en comparación con la referencia NHANES-USA. Conclusiones: Los resultados sugieren atraso en el crecimiento lineal que podría estar relacionada con la altitud y con una pobre reserva de proteína observada en la circunferencia del brazo.

The development of physical growth depends on genetic background, nutritional, socioeconomic conditions, environmental, secular trend, physical activity and level of altitude. Objective: To determine the parameters of physical growth of children living at moderate altitude according gender and compared with reference patterns CDC and NHANAS-USA. Methods: We selected 795 children from socio-economic status mean, by probabilistic sampling (stratified); 394 males and 401 women from public school of urban area of Arequipa city, Peru (2320msnm). We evaluated body weight (kg), height (m), triceps skinfold (mm) and relaxed arm circumference (cm). Results: We found similar values of body weight (p> 0.005) and lower values of stature (p <0.005) in both genders when compared with CDC reference. In the triceps skinfold, there was similar values in both genders when compared with the reference National Health and Nutrition Examination Survey (NHANES)-USA. Values of arm circumference was lower in both gender in comparison with reference NHANES-USA. Conclusions: The results suggest delay in linear growth may be related to altitude and with poor reserves of protein observed in arm circumference.