Maturation level in adolescents: effects on body composition and physical activity changes

Background and aims: Longitudinal studies help move researchers closer to understanding determinants and mediators of maturation, physical activity (PA) and adiposity. The aim of this study was to longitudinally explore the influence of maturation on PA and adiposity changes in adolescents. Methods: Eighty healthy adolescents (42 girls and 38 boys) were followed over three academic years. A PA score was estimated using the Physical Activity Questionnaire (PAQ-A). Fat mass percentage (FMP) was assessed by anthropometric measurements. Sexual maturity was estimated by percentage of predicted adult stature and adolescents were classified into three changes groups: C0, change from on time to late maturation; C1, no change; C2, change from late/on time to on time/early maturation. A stepwise linear regression was conducted in order to estimate the predictors of PA and FMP changes. Results: An interaction between PA and maturation was statically significant (P<0.05). A non-significant trend was observed between three stages of change with a progressive reduction of FMP across the three stages of change in maturation level (C0 = 0.2752.70%; C1= -1.4901.10%; C2= -6.4172.57%; pairwise comparisons: C0 - C2 = 6.69%, P=0.081 and C1-C2 = 4.93%, P=0.080). Conclusions: Our results suggest that body composition changes observed during adolescence are not driven by changes in PA. PA alteration patterns were influenced by sex but not by maturation.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Supported by the Spanish Ministry of Education, Culture and Sport (AP2010-0583); the Spanish Ministry of Economy and Competitiveness (DEP2011-30565

Teaching Style in Physical Education and Changes of Daily Physical Activity after One Academic Year in Adolescents: GEOS Study

Increased Moderate-Vigorous physical activity (MVPA) and reduced sedentary time (ST) are key factors for a healthy lifestyle during childhood and adolescence. Studies have suggested that schools may be effective resources to promote healthy habits (Sallis, McKenzie et al. 2012). Therefore, in PE, is important to assess how teachers use strategies and provide students tools to engage in PA with the purpose of reduce the risk of sedentary behavior and contribute to promotion MVPA habits for a healthy lifestyle (Lonsdale, C. et al., 2013). Many factors may be involved in the successful PE class to promote healthy out-school behaviors, as teaching styles (TS), learning styles, learning time, motivation and so on (Mosston, M. 1966). Regarding TS, there is a lack of knowledge about influence of the teaching style (TS) in the promotion of daily MVPA. It was our aim to observe the differences of total daily PA dimensions between two groups of adolescents who were taught during a whole academic year using reproducing (RK) or producing knowledge (PK) TSs.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Reference values of total and regional skeletal muscle mass in children and adolescents

Introduction: The acquisition of skeletal muscle mass (SMM) during childhood and adolescence must be a main concern to ensure healthy growth and improved motor development. Moreover, peak SMM increment must happen during youth, which would determine adulthood health and performance. Although some indicators of SMM have been using for assessment of nutrition status since the seventies like upper arm circumference or arm areas there is insuffi cient SMM data throughout childhood and adolescence to establish references norms. The first aim of this study, therefore, was to analyze trends of fat free mass (FFM) and regional and total SMM. The second objective was to compare trends between SMM and FFM by age and gender. Method: Cross-sectional data of 1103 healthy volunteers were analyzed (13.3 ± 2.5 yrs, BMI=20.1 ± 3.4 kg/m2; 323 girls and 780 boys). They were recruited from local primary schools, high-schools and local sport clubs. Anthropometry in accordance with ISAK guidelines was used to measure: triceps, thigh and calf skinfolds, and arm, thigh and calf circumferences were assessed by a caliper and tape respectively. Regional muscle areas were calculated from the corrected limb circumferences. FFM was estimated by anthropometric-derived equation. Validated age-specifi c models were applied to obtain SMM based on anthropometric variables (Poortmans’ (0.000) while FFM showed 688.7 (P>0.000). Sex interaction was found. Conclusions: Our fi ndings show that there is a diff erence between boys and girls in the relationship between total SMM and age. Regional muscle areas from the upper limbs don’t develop in linear fashion with age in contrast to development in the lower extremity areas. These results suggest that upper and lower muscle areas growth is diff erent in terms of timing. Longitudinal studies are required to confirm these results.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Análisis fraccionado de la actividad física desarrollada en escolares

Se ha destacado la importancia de la actividad física (AF) con escolares. Los estudios indican que hay que realizar al menos 60 minutos de actividad física a intensidad desde moderada a vigorosa (AFMV) para garantizar la salud. El presente estudio transversal pretende, por un lado, conocer los niveles generales de AF de la población escolar y el grado de cumplimiento de las recomendaciones de salud; y, por otro lado, estudiar de manera fraccionada la AF en diferentes actividades durante la semana, para determinar su contribución a la AFMV a nivel diario (min/día), como el por hora (min/hora). Se seleccionaron 136 escolares españoles entre 8 y 19 años, empleándose acelerómetros GT3X para evaluar su nivel de actividad física durante una semana. En general, se observó un nivel bajo de AFMV (51,7 min/día) y cumplimiento de las recomendaciones (34,6%). A pesar de ello, aparecieron actividades escolares de corta duración, que proporcionaron una contribución elevada de AFMV/hora, fundamentalmente en Primaria respecto a Secundaria (9.66 vs. 5.75 min AFMV /hora; p < .001 para la educación física y 10.75 vs. 4.65 min AFMV/hora; p < .001 durante el Recreo). Estos resultados podrían ser relevantes para futuros estudios de intervención, así como para el establecimiento de estrategias y políticas de promoción de la AF en la población escolar.Several papers have focused on the importance of physical activity (PA) with school-aged subjects. These papers underline the importance of accruing 60-minutes of moderate to vigorous intensity physical activity (MVPA) to ensure a proper health status. The objectives of this paper are two: to describe general patterns of PA levels among school-aged subjects and the prevalence of meeting PA guidelines; and, secondly, to fractionally analyze the contribution of different activities performed during the week to daily MVPA (min/day), such as the MVPA per hour (min/hour). A hundred and thirty-six Spanish students aged 8 to 19 years were selected; they wore a GT3X accelerometer in order to measure their weekly PA. Most children displayed a low level of PA (51.7 min/day), and low compliance with PA health guidelines (34.6%). Despite these low levels, short duration schoolbased activities were found to provide a great amount of MVPA per hour, especially among Primary school subjects compared to Secondary (9.66 vs. 5.75 min MVPA /hour; p < .001 for physical education classes and 10.75 vs. 4.65 min MVPA /hour; p < .001 during recess). This fact could be essential for future intervention studies, and to establish strategies and PA promotion policies for school-aged subjects.Tem sido destacada a importância da actividade física em crianças. Os estudos indicam que se devem realizar pelo menos 60 minutos de actividade física de intensidade modera da ou vigorosa (AFMV) para se obterem benefícios para a saúde. O presente estudo transversal pretende, por um lado, conhecer os níveis gerais de AF da população escolar e o grau de cumprimento das recomendações de saúde; e, por outro lado, estudar de maneira fraccionada a AF em diferentes actividades durante a semana, para determinar a sua contribuição para a AFMV a nível diário (min/dia), como por hora (min/hora). Foram selecionados 136 estudantes espanhóis com idades compreendidas entre os 8 e os 19 anos, utilizando-se acelerómetros GT3X para avaliar o seu nível de actividade física durante uma semana. Em geral, verificou-se um nível baixo de AFMV (51.7 min/dia) e de cumprimento das recomendações (34.6%). Apesar destes resultados, verificaram-se actividades escolares de curta duração, que proporcionaram uma contribuição elevada de AFMV/hora, fundamentalmente no Ensino Primário comparativamente com o Secundário (9.66 vs. 5.75 min AFMV /hora; p < .001 para a educação física e 10.75 vs. 4.65 min AFMV/hora; p < .001 durante o Intervalo). Estes resultados podem ser relevantes para futuros estudos de intervenção, assim como para o delineamento de estratégias e políticas de promoção de AF na população escolar

TBW Assessment by Deuterium Dilution in Spanish Adolescents

Congreso para especialistas en Nutrición, Actividad Física y Composición CorporalINTRODUCTION: Total body water (TBW) assessment is a cornerstone in order to validate equations to estimate body composition components as fat mass and fat free mass. Deuterium dilution technique (D2DT) is considered the gold standard method to assess TBW, however in Spain there are not any reference data using D2DT. The knowledge of specific references for Spanish population must be a goal for the biological studies of Spanish people. OBJECTIVE: It was our aim to assess TBW using the D2DT in a sample of Spanish adolescents. METHODS: 224 specimens of urine from 150 adolescents (113 girls and 111 boys) were taken to analyze. A dose of 0.1 grams of 2D2O per Kg of body weight was administrated; afterwards it was followed by 4-hours stabilization period. The isotope (deuterium oxide (D2O)) dilution method was used to measure TBW with an isotope-ratio mass-spectrometer. Averages by sex and Tanner stages were calculated for %TBW and TBW. General lineal model were used to analyze differences and interactions between groups. RESULTS: %TBW was significantly different between boys and girls (58.98_5.59% vs 55.5_4.28%, P0.05). CONCLUSIONS: This study has been the first in Spain, which have measured TBW in vivo using D2DT. These data can be useful to validate new methods and equations from bioimpedance analysis to estimate TBW.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Coca-Col

A New Approach to Express Regional Adiposity and Its Association with Blood Lipids, Inflammation and Insulin Resistance Markers

Regional adiposity is classically related with inflammation, insulin resistance (IR) and an altered blood lipid profile. Traditionally, central adiposity expressed as a ratio (%FM) = fat mass/total mass of the region is the variable most used in research. However, this ratio does not account for total bodily fat mass (TFM). So, a great accumulation in a region, where lean mass is more important than fat, could be more associated with risk factors than other with less absolute fat (kg) but higher percentage (in instance abdomen). PURPOSE: To analyse the associations between the ratio (RW) = regional fat mass (kg) / TFM (kg) and blood lilid profile, IR and inflammation. METHODS: Sixty-two pre-menopausal and healthy women were recruited for this study (age, 39.6 ±7.2 years; BMI, 29.2 ±4.2 kg.m-2; total %TFM, 42.0 ±5.9%). Weight and height were measured to the nearest 0.1 kg and 0.1 cm respectively, and body composition was estimated with dual energy x-ray aborptiometry. RWF were calculated for trunk (RWT), lower limbs (RWLL) and upper limbs (RWUL). Insulin, glycaemia and insulin sensitivity (HOMA) were the IR markers. C-reactive protein (CRP) and Tumour Necrosis Factor (TNF-α) were the inflammation variables. Total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL) and triglycerides (TG) were also measured. Partial correlations adjusted to TFM between RW and blood markers were carried out. RESULTS: Significant correlations were found between RWUL and HOMA (r=0.276, P<0.05), TG (r=0.292, P<0.05) and insulin (r=0.271, P<0.05). RWT was also correlated with blood lipids: TG (r=0.278, P<0.05) and LDL (r=-0.318, P<0.05). Finally, RWLL was the ratio with more number of associations: HOMA (r=-0.274, P<0.05), TG (r=-0.342, P<0.01), LDL (r=0.317, P<0.05) and insulin (r=-0.253, P<0.05). Abdominal and trunk %FM were only correlated with HOMA (r=0.380, P<0.01) and LDL (r=0.264, P<0.05) respectively. CONCLUSION: In our sample, regional fat mass contribution (RW) for whole body FM showed more associations with blood markers than classical ratios (regional %FM). These findings highlighted RW ratios were well correlated with inflammatory and IR risk factors, which in turn could be useful to express positive or negative results in future studies. This issue requires further investigation.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Longitudinal differences of physical activity and adiposity in adolescents: a 2-year follow-up

It is commonly believed that boys are more physically active than girls, which could affect body composition changes during adolescence. One major point not always considered or controlled is the maturational differences between boys and girls of similar chronological age. So, it remains to be determined the importance of physical activity (PA) behaviors adjusted by sex and maturation on body composition modifications. This study complement the published results by evaluating the effects of gender, sexual maturation level on PA and body composition changes. PURPOSE: To explore PA and adiposity alterations in Spanish students during adolescence. METHODS: Sixty-eight healthy adolescents were followed-up during 2-year (32 girls and 36 boys). A PA score was estimated by Physical Activity Questionnaire (PAQ-A). Adiposity was assessed by anthropometric measurements, BMI and fat mass percent (FMP) were calculated using classical equation, and waist circumference (WC) as abdominal adiposity marker. Tanner’s maturation stages were evaluated. Three assessments were performed: September 2011, 2012 and 2013 (S1, S2, and S3, respectively). Repeated measures were carried out between three moments for all variables and adjusted by maturation level and sex. RESULTS: Significant differences for FMP were found between S1 and S2 (22.30±8.22 vs. 21.15±7.73, P<0.05); a significant interaction with sex was observed (P<0.05), but not for maturation. Regarding PA, S2 was significantly higher than S3 (2.68±0.68 vs. 2.23±0.72, P<0.001). An interaction between PA and maturation was statically significant (P<0.05). CONCLUSION: The main finding of this follow-up was a reduction in PA after S2 period without changes in adiposity. In opposite, a reduction of FMP was only significant between S1 and S2, while PA was not modified. Our results suggest that body composition and PA changes observed during adolescence are not parallel. Moreover, the interaction analysis highlighted that maturation affect PA behavior, but not sex.This work was supported by the Spanish Ministry of Education, Culture and Sport (AP2010-0583), Spanish Ministry of Economy and Competitiveness (DEP2011-30565) and Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Construct validity of the physical activity questionnaire for adolescents (paq-a): maximal oxygen uptake

Introduction: The Physical Activity Questionnaire for adolescents (PAQ-A) is a cost-effective tool to assess physical activity (PA) patterns during adolescence and it has been widely used in research and field settings. Convergent validity of PAQ-A has been confirmed in several countries (Bervoets et al., 2014; Janz, Lutuchy, Wenthe, & Levy, 2008; Martinez-Gomez et al., 2009). However, the construct validity has often been overlooked. Therefore, the aim of this study was to analyze the construct validity of PAQ-A, using maximal oxygen uptake as criterion. Methods: One hundred and seventy-eight (n=99 boys, n=79 girls) adolescents (14.2±1.9 years, 21.1±4.1 BMI) participated in this study. A PA score was estimated by PAQ-A and additionally a sport history was recorded. BMI, waist circumference (WC) and fat mass percent (FMP) were assessed by anthropometric measurements as adiposity markers. Aerobic fitness (VO2Max) was assessed by a progressive continuous test (Chester Step Test). Associations between PA-score and criterions were analyzed by Spearman correlations; a one-way ANOVA was conducted to detect differences between each item level from the PAQ-A; independent sample t tests were used to compare values between boys and girls, and athletes and non-athletes. Results: The results showed moderate significant positive correlations between VO2Max and the PAQ-C for total score (rho = 0.28, P<0.01) and items 5, 6, 7 and 8 (rho = 0.24; rho = 0.25; rho = 0.22; rho = 0.25, all P<0.05; respectively). Adolescents who were enrolled in competitive and organized sport practice had higher scores on the questionnaire (2.8 vs 2.5 average score) as well as higher VO2Max values (37.4 vs 34.2 ml/kg/min). Discussion: Our data confirm the PAQ-A had acceptable construct validity when using VO2Max as criterion. Moreover, our results suggest that information from some items could be more related with some health markers than others. References: Bervoets, L., Van Noten, C., Van Roosbroeck, S., Hansen, D., Van Hoorenbeeck, K., Verheyen, E., . . . Vankerckhoven, V. (2014). Reliability and Validity of the Dutch Physical Activity Questionnaires for Children (PAQ-C) and Adolescents (PAQ-A). Arch Public Health, 72(1), 47. doi: 10.1186/2049-3258-72-47 Janz, K. F., Lutuchy, E. M., Wenthe, P., & Levy, S. M. (2008). Measuring activity in children and adolescents using self-report: PAQ-C and PAQ-A. Medicine and Science in Sports and Exercise, 40(4), 767-772. doi: 10.1249/MSS.0b013e3181620ed1 Martinez-Gomez, D., Martinez-de-Haro, V., Pozo, T., Welk, G. J., Villagra, A., Calle, M. E., . . . Veiga, O. L. (2009). [Reliability and validity of the PAQ-A questionnaire to assess physical activity in Spanish adolescents]. Rev Esp Salud Publica, 83(3), 427-439. Contact: [email protected] This work was supported by the Spanish Ministry of Education, Culture and Sport (AP2010-0583), Spanish Ministry of Economy and Competitiveness (DEP2011-30565) and the University of Málaga (Campus of International Excellence Andalucía Tech).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Associations of physical activity with blood pressure, body composition and maturation level in adolescents: the GEOS Study

Introduction The association between physical activity (PA) and resting blood pressure (BP) is poorly understood in adolescents (Kelley, Kelley, & Tran, 2003), since several variables such as body composition, maturation level or sex, which interfere with, must be analyzed (Muntner, He, Cutler, Wildman, & Whelton, 2004). Therefore, the aim of this study was to explore the association of PA, body composition, blood pressure, and maturation in adolescent boys and girls. Methods: Two hundred and nine (n=114 boys, n=95 girls) healthy adolescents (15.6±1.6 years, 21.9±4.3 BMI) were volunteers. A PA score was estimated by Physical Activity Questionnaire (PAQ-A). BMI, waist circumference (WC) and fat mass percent (%FM) were assessed by anthropometric measurements as adiposity markers. Tanner’s maturation stages were evaluated and systolic and diastolic blood pressure (SBP and DBP) were measured by OMRON sphygmomanometer. SBP and DBP indexes (SBPI and DBPI) were calculated as mmHg/height (cm). Spearman rank order correlations were used to explore associations between variables after control to maturation. Results: All the relationships between parameters showed a positive correlation. There were significant associations between BP variables and BMI (SBP r=0.202, P<0.01; DBP r=0.305, P<0.001), and WC (SBP r=0.197, P<0.01; DBP r=0.295, P<0.001). PA score was only related with body composition variables either girls or boys. Also, there were significant correlations between %FM and BP variables (SBP r=0.332, P <0.01; DBP r=0.330, P<0.01; DBPI r=0.308, P <0.01) in girls but not in boys. Discussion: Our data confirm the relationship between BP and body composition variables as WC and BMI (Rosa, Fonseca, Oigman, & Mesquita, 2006). Nevertheless, we could not find any association between PA and BP. The recently developed SBPI and DBPI were not better associated with any variable than simple BP. These results should be considered carefully since measuring physical activity by objective methods could have changed the conclusions. So, other studies have reported a negative association between PA measured by accelerometry and BP (Hearst, Sirard, Lytle, Dengel, & Berrigan, 2012; Kelley, Kelley, & Tran, 2003). Further prospective studies using accelerometry or larger samples must be need in order to explore deeply the impact of PA on BP in adolescents. References Hearst, M. O., Sirard, J. R., Lytle, L., Dengel, D. R., & Berrigan, D. (2012). J Phys Act Health, 9(1), 78-85. Kelley, G. A., Kelley, K. S., & Tran, Z. V. (2003). Prev Cardiol, 6(1), 8-16. Muntner, P., He, J., Cutler, J. A., Wildman, R. P., & Whelton, P. K. (2004). JAMA, 291(17), 2107-2113. Rosa, M. L., Fonseca, V. M., Oigman, G., & Mesquita, E. T. (2006). Arq Bras Cardiol, 87(1), 46-53.This work was supported by the Spanish Ministry of Education, Culture and Sport (AP2010-0583), Spanish Ministry of Economy and Competitiveness (DEP2011-30565) and Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Estimation of internal abdominal fat from anthropometry measurements in children

Introduction: Internal abdominal fat (IAF) measured by dual energy X-ray absorptiometry (DXA) has been proposed as subrogate of visceral adipose tissue, which is a cornerstone measurement for screening of metabolic syndrome1,2. However, measuring IAF is time-consuming, expensive and impractical for field studies with children. Since 1990, anthropometric models have been developed to estimate IAF in adults, but no models exist for children. Because of the high prevalence of childhood obesity, the assessment of IAF is a major factor in the evaluation metabolic risk. Therefore, the aim of this study was to develop an anthropometry-based model to estimate IAF in children. Methods: Forty-one (n=24 boys, n=17 girls) healthy Caucasian children (age 11.4±0.6 years, BMI 20.1±3.9 Kg/m2) were volunteers. Anthropometric measurements (waist and hip circumferences, abdominal sagittal diameter and skinfolds) were taken in accordance with ISAK guidelines. Total body and IAF (dependent variable) body composition were measured by DXA. Stepwise regression analysis was carried out to obtain the fittest variables and beta coefficients in order to develop the equation that predicts IAF with a high squared R and a low standard error of estimation. Results: The best-correlated variables with IAF were BMI, waist circumference, calf and subscapular skinfolds (r=0.900; r=0.946; r=0.901; r=0.900; respectively, all P<0.001). The best model for estimating the IAF included waist circumference and subscapular skinfold (R2=0.93 SEE=115.43; P<0.001). The estimated model was IAF (g) = -1332.89 + (18.515*WC) + (773.39*SubSKF). Conclusion: We developed a model, which accurately predict IAF in children, affording a practical tool to quantify this variable without expensive techniques such as DXA. However, external cross-validation must be performed in order to confirm the model validity. Additionally, construct validity should be carried out to determine the applicability of this measurement in children. References: 1. Hill AM, La_Forgia J, Coates AM, Buckley JD, Howe PR. Estimating abdominal adipose tissue with DXA and anthropometry. Obesity. 2007 Feb;15(2):504-10. 2. Kaul S, Rothney MP, Peters DM, Wacker WK, Davis CE, Shapiro MD, et al. Dual-energy X-ray absorptiometry for quantification of visceral fat. Obesity. 2012 Jun; 20(6):1313-8.This work was supported by the Spanish Ministry of Education, Culture and Sport (AP2010-0583), Spanish Ministry of Economy and Competitiveness (DEP2011-30565) and University of Málaga. Campus of International Excellence Andalucía Tec