Estudio multi-céntrico SAYCARE, de evaluación del estado nutricional y estilos de vida en niños y adolescentes

Introduction: The main Energy Balance-Related Behaviors’ (EBRB) in children and adolescents are: sedentary behavior (eg. screen time: TV, video games and computer), sugary drinks intake, having breakfast and daily physical activities (eg. active commuting to school, physical activity during recess, participation in sports and recreational physical activity) 1, 2. To understand EBRB, researchers need information about the personal, familiar factors and environmental correlates of these behaviors3. The methods used to obtain these data must be reliable and validated in the study population, and able to compare different countries. Multicenter studies using standardized methods regarding lifestyle in children and adolescents appears to be the best strategy to compare countries, such as the Europeans4, 5. Developing methods in South America seem to maximize the quality of data collection, thus clarify the comprehension of these factors among countries. The aims are: (i) To develop and valid and reliable measurement methods to obtain information about EBRB physical activity sedentary behavior); and (ii) To assess the reliability and validity of these methods. Methods: This is a multicenter pilot study entitled South American Youth/Child cARdiovascular and Environment Study (acronym: SAYCARE Study), that was held in seven South American cities: São Paulo and Teresina (Brazil), Buenos Aires (Argentina), Santiago (Chile), Montevideo (Uruguay), Lima (Peru) and Medellin (Colombia). The study assess pre-school, primary school, and up to the third year of high school subjects (3 to 17 years), enrolled in both public and private schools of their respective cities. The sample size was calculated based on the experience of other multicenter projects, in which a feasibility pilot study was conducted previously, and the reliability and validity of the used method was evaluated4. The sample consists of 360 study subject in each age-range (pre-school, primary school and high school) from every research center. A total of and 2,520 subjects in total (50% of participants for each sex). The Research Ethics Committee of each city involved will approve this study. Questionnaires: Physical activity (PA): Children/adolescents were asked about PA (frequency, duration and intensity) in: recreation, transportation and also the activities during physical education classes in school (including its main determinants and barriers). Sedentary behavior (SB): structured questionnaire to assess how long children/adolescents usually spend in front of television, computer and video games, during week and weekends. The questionnaire for both behaviors were adapted from European multicenter studies4, 5. Accelerometers: The physical activity and sedentary time were also measured using accelerometers (Actigraph MTI, model GT1M, Manufacturing Technology Inc., Fort Walton Beach, FL, USA) during seven consecutive days (at least 3 days), with a minimum of 8 hours recording/ day. The time sampling interval (epoch) was set to 5 seconds. Devices will be fixed at the waist using an elastic belt.. In children, the cut-offs counts per minute (cpm) per epoch to define the PA intensity categories used were: sedentary= 0 to 25 cpm; moderate= 574 to 1,002 cpm per epoch; vigorous= ?1,003 cpm per epoch. In adolescents, sedentary time, moderate and vigorous PA were defined as: <100, 2000-3999 and 4000 cpm, respectively. For both methods (questionnaire and accelerometers) and following current PA guidelines, the subjects were classified as active when they accumulated at least 60 min/d of moderate-to-vigorous PA. The agreements between measurements were calculated by determining the kappa coefficients for categorical variables. Results: Currently, we evaluated 237 children and adolescents. Preliminary results have shown that, using the questionnaire; children and adolescents had an average of moderate to vigorous physical activity of 101 min/d, and sedentary behavior of 260.3 min/d. On the other hand, when measured by accelerometers, means were 151.7 min/d and 528.5/d, for PA and sedentary time, respectively. According to the current recommendation level for PA, 90.2% (by questionnaire) and 92.9% (by accelerometer) of adolescents were classified as physically active. The agreement between the questionnaire and the accelerometer for PA, as a categorical variable, was 85.8% (k = 0.46). Conclusions: We developed standardized questionnaires that have good reliability and validity for South American pediatric populations. References: 1. Worobey J. Physical activity in infancy: developmental aspects, measurement, and importance. Am J Clin Nutr. 2014;99(3):729S-733S. 2.de Moraes AC, Carvalho HB, Rey-López JP, Gracia-Marco L, Beghin L, Kafatos A, et al. Independent and combined effects of physical activity and sedentary behavior on blood pressure in adolescents: gender differences in two cross-sectional studies. PLoS One. 2013;8(5):e62006. 3.Fernández-Alvira JM, te Velde SJ, De Bourdeaudhuij I, Bere E, Manios Y, Kovacs E, et al. Parental education associations with children’s body composition: mediation effects of energy balance-related behaviors within the ENERGY-project. Int J Behav Nutr Phys Act. 2013;10:80. 4.Moreno LA, De Henauw S, González- Gross M, Kersting M, Molnár D, Gottrand F, et al. Design and implementation of the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study. Int J Obes (Lond). 2008;32 Suppl 5:S4-11. 5.van Stralen MM, te Velde SJ, Singh AS, De Bourdeaudhuij I, Martens MK, van der Sluis M, et al. EuropeaN Energy balance Research to prevent excessive weight Gain among Youth (ENERGY) project: Design and methodology of the ENERGY cross-sectional survey. BMC Public Health. 2011;11:65.