Serum Vitamin D Levels Mediate the Association Between Physical Activity and Blood Pressure in Adolescents.

Individuals with low levels of vitamin D are associated with cardiovascular risks, such as elevated blood pressure (BP), and are; therefore, more likely to develop hypertension. Patients with vitamin D deficiency may face an increased risk of cardiovascular events. In this study, a multicenter, cross-sectional, and school-based investigation was conducted as part of the ERICA project. The sample comprised 1152 adolescents aged 12-17 years from 4 Brazilian cities. Anthropometric variables, BP measurements, and hydroxyvitamin D concentrations were assessed. A 2-level linear regression was fitted to examine the relationship between each level of BP and independent variables. Our findings indicate that movement behaviors were not associated with BP levels, with the exception of sleep time, which demonstrated a positive association. However, after adjustment, this association was found to be nonsignificant. Our study's mediation analysis revealed that vitamin D mediates up to 12.9% of the association between physical activity and systolic BP. Vitamin D is inversely associated with BP in adolescents. In addition to mediating the physical activity and systolic BP association, engaging in physical activity, particularly outdoors, can provide a dual benefit for adolescents by increasing serum vitamin D levels and assisting in the control of BP levels.

Assessment of the validity of a sedentary behavior questionnaire among university students from low-income regions / Evaluación de la validez de un cuestionario de comportamiento sedentario en estudiantes universitarios de regiones de escasos recursos

Introduction: to reduce the prevalence of overweight and obesity, lifestyle interventions, particularly in nutritional education programs, should be prioritized among university students. Monitoring sedentary behavior is an important step toward preventing and controlling obesity. Therefore, we assessed the reliability and validity of an online questionnaire on sedentary behavior among university students from low-income regions. Methods: this cross-sectional methodological feasibility study evaluated the psychometric properties of the South American Youth/Child Cardiovascular and Environmental (SAYCARE) questionnaire. We administered this questionnaire in an online format to 195 and 117 university students (aged between 17 and 53 years) to assess its validity and reliability, respectively. The questionnaire measures the daily time spent watching TV, playing electronic games, using a computer, studying and passive commuting on weekdays and weekends. The questionnaire involved two stages (Q1 and Q2) separated by an interval of 2 weeks. Reliability was assessed using Spearman’s correlation analysis. The structural validity of the construct was evaluated by exploratory factor analysis. Results: all variables showed acceptable reliability (Spearman’s rho > 0.30 and p < 0.05). Regarding construct structural validity, the exploratory factor analysis identified 4 factors (variance explained: 71.4 %) and did not exclude any items. Conclusion: the online SAYCARE questionnaire exhibited acceptable reliability and structural validity for assessing sedentary behavior among university students from low-income regions.(AU)

ntroducción: para reducir la prevalencia del sobrepeso y la obesidad, las intervenciones en el estilo de vida, particularmente en los programasde educación nutricional, deben priorizarse entre los estudiantes universitarios. Por lo tanto, monitorear el comportamiento sedentario es unpaso importante para prevenir y controlar la obesidad. Nuestro objetivo fue investigar la confiabilidad y validez de un cuestionario online sobrecomportamiento sedentario entre estudiantes universitarios de regiones de escasos recursos.Métodos: este estudio transversal de factibilidad metodológica evaluó las propiedades psicométricas del cuestionario South American Youth/Child Cardiovascular and Environmental (SAYCARE). Administramos este cuestionario en formato online a 195 y 117 estudiantes universitarios(de entre 17 y 53 años) para evaluar su validez y confiabilidad, respectivamente. El cuestionario midió el tiempo diario del estudiante viendotelevisión, jugando a juegos electrónicos, usando una computadora, estudiando y viajando pasivamente entre semana y fines de semana. Elcuestionario fue respondido en dos etapas (Q1 y Q2), con un intervalo de 2 semanas. La fiabilidad se evaluó mediante el coeficiente de correlaciónde Spearman. La validez estructural del constructo se evaluó mediante análisis factorial exploratorio.Resultados: todas las variables mostraron una confiabilidad aceptable (rho de Spearman > 0,30 y p < 0,05). En la validez estructural delconstructo, el análisis factorial exploratorio encontró 4 factores (varianza explicada del 71,4 %) y ningún ítem fue excluido.Conclusión: el cuestionario SAYCARE, en formato online, exhibió una confiabilidad y validez estructural aceptables para evaluar el comportamientosedentario entre estudiantes universitarios de regiones de escasos recursos.(AU)

Are sleep time and quality associated with inflammation in children and adolescents? A systematic review.

Sleep restriction in children can trigger the development of problems such as impaired cognition, behavioral problems, cardiovascular problems, and obesity. In addition, the inflammatory profile of children can also be influenced by sleep restriction. The aimed to review and analyze the association between time and sleep quality with inflammatory biomarkers in children and adolescents. Three electronic databases (MEDLINE, Web of Science and Scopus) were searched from August 30, 2022. The search strategy used the following descriptors: children and adolescents; sleep, and inflammatory profile. This review protocol is registered in the PROSPERO database (CRD42020188969). We obtained 2.724 results of articles with potentially relevant titles. Sixteen percent of the articles were excluded because they were duplicates, 84.3% were excluded after reading the title, and 0.9% were studied from systematic reviews or textbooks (0.9%). Accelerometers are the most commonly used method for the objective measurement of sleep time, while the PSQI questionnaire is the most commonly used subjective method to measure sleep quality. The results indicated an inconsistent association between sleep time and CRP in the literature. Sixty percent of studies used the Pittsburgh Sleep Quality Index (PSQI) for subjective assessment of sleep quality and possible sleep disorders. However, only one retrieved study showed significant association between sleep quality and CRP. Thus, sleep time does not present significant association with inflammatory biomarkers; whereas, poor sleep quality shows positive association with CRP with a lower magnitude.

Association Between Sleep Time and Pro- and Anti-Inflammatory Biomarkers Is Mediated by Abdominal Obesity Among Adolescents.

OBJECTIVES: Movement behaviors and abdominal obesity are associated with higher inflammatory biomarkers. However, the role of waist circumference as a mediating factor is still unknown. Thus, our aims were to (1) test the associations between 24-hour movement behavior variables (physical activity, sedentary behavior, and sleep), abdominal obesity, and pro- and anti-inflammatory biomarkers; and (2) investigate whether abdominal obesity had a mediating effect between the investigated associations. METHODS: This multicenter cross-sectional study included 3591 adolescents (aged 12-17 y) from 4 Brazilian cities. Waist circumference (in centimeters; at half the distance between the iliac crest and at the lower costal margin), 24-hour movement behaviors (validated questionnaire), high-sensitive C-reactive protein, and adiponectin (serum plasma) were evaluated. We used multiple mediation regression models (95% confidence interval) to determine if waist circumference mediated the association between 24-hour movement behaviors and pro- and anti-inflammatory biomarkers. RESULTS: The results revealed that screen time and moderate to vigorous physical activity were not associated with pro- or anti-inflammatory biomarkers. However, sleep duration (in hours per day) was negatively associated with pro- (C-reactive protein, ß = -0.08; 95% confidence interval, -0.38 to -0.02) and anti- (adiponectin, ß = -0.31; 95% confidence interval, -2.13 to -0.12) inflammatory biomarkers. Our results also showed that waist circumference mediated the association between sleep duration and high-sensitive C-reactive protein (2.7%), and adiponectin (2.8%). CONCLUSION: Sleep duration was inversely associated with pro- and anti-inflammatory biomarkers, and these relations were mediated by abdominal obesity. Therefore, adolescents having healthy sleep can have implications for reducing waist circumference and inflammatory indicators.

Psychometric properties of the online Satisfaction with Life Scale in university students from a low-income region.

PURPOSE: To test the feasibility, reliability, and validity of the Satisfaction with Life Scale (SWLS) in an online format in university students from a low-income region. METHODS: This was a psychometric study, involving a study of reliability (n = 117) and validity (n = 195) in university students from a region with a Gini index of 0.56. The scale was applied at two time points with an interval of 2 weeks. This scale measures satisfaction with life based on five statements and responses ranging from 1 to 7 (strongly disagree to strongly agree). We conducted the reliability assessment using temporal stability and internal consistency and construct validity assessment by internal structure solution. RESULTS: All SWLS items showed acceptable (rho > 0.30) and significant (p < 0.05) temporal stability and acceptable internal consistency (alpha > 0.70). In construct validity (internal structure), we identified a factor with an explained variance of 59.0% in the exploratory factor analysis. Additionally, in the confirmatory factor analysis, we identified a one-factor structure solution for SWLS with an acceptable model fitting (chi-square/degrees of freedom [X2/df] = 6.53; Tucker-Lewis Index [TLI] = 0.991; Comparative Fit Index [CFI] = 0.996; root mean square error of approximation [RMSEA] = 0.040; standardized root mean-squared residual [SRMR] = 0.026). CONCLUSION: The Satisfaction with Life Scale, in the online format, is a reliable and valid tool for university students in a low-income context.

Assessment of the validity of a sedentary behavior questionnaire among university students from low-income regions.

Introduction: Introduction: to reduce the prevalence of overweight and obesity, lifestyle interventions, particularly in nutritional education programs, should be prioritized among university students. Monitoring sedentary behavior is an important step toward preventing and controlling obesity. Therefore, we assessed the reliability and validity of an online questionnaire on sedentary behavior among university students from low-income regions. Methods: this cross-sectional methodological feasibility study evaluated the psychometric properties of the South American Youth/Child Cardiovascular and Environmental (SAYCARE) questionnaire. We administered this questionnaire in an online format to 195 and 117 university students (aged between 17 and 53 years) to assess its validity and reliability, respectively. The questionnaire measures the daily time spent watching TV, playing electronic games, using a computer, studying and passive commuting on weekdays and weekends. The questionnaire involved two stages (Q1 and Q2) separated by an interval of 2 weeks. Reliability was assessed using Spearman's correlation analysis. The structural validity of the construct was evaluated by exploratory factor analysis. Results: all variables showed acceptable reliability (Spearman's rho > 0.30 and p < 0.05). Regarding construct structural validity, the exploratory factor analysis identified 4 factors (variance explained: 71.4 %) and did not exclude any items. Conclusion: the online SAYCARE questionnaire exhibited acceptable reliability and structural validity for assessing sedentary behavior among university students from low-income regions.

Introducción: Introducción: para reducir la prevalencia del sobrepeso y la obesidad, las intervenciones en el estilo de vida, particularmente en los programas de educación nutricional, deben priorizarse entre los estudiantes universitarios. Por lo tanto, monitorear el comportamiento sedentario es un paso importante para prevenir y controlar la obesidad. Nuestro objetivo fue investigar la confiabilidad y validez de un cuestionario online sobre comportamiento sedentario entre estudiantes universitarios de regiones de escasos recursos. Métodos: este estudio transversal de factibilidad metodológica evaluó las propiedades psicométricas del cuestionario South American Youth/Child Cardiovascular and Environmental (SAYCARE). Administramos este cuestionario en formato online a 195 y 117 estudiantes universitarios (de entre 17 y 53 años) para evaluar su validez y confiabilidad, respectivamente. El cuestionario midió el tiempo diario del estudiante viendo televisión, jugando a juegos electrónicos, usando una computadora, estudiando y viajando pasivamente entre semana y fines de semana. El cuestionario fue respondido en dos etapas (Q1 y Q2), con un intervalo de 2 semanas. La fiabilidad se evaluó mediante el coeficiente de correlación de Spearman. La validez estructural del constructo se evaluó mediante análisis factorial exploratorio. Resultados: todas las variables mostraron una confiabilidad aceptable (rho de Spearman > 0,30 y p < 0,05). En la validez estructural del constructo, el análisis factorial exploratorio encontró 4 factores (varianza explicada del 71,4 %) y ningún ítem fue excluido. Conclusión: el cuestionario SAYCARE, en formato online, exhibió una confiabilidad y validez estructural aceptables para evaluar el comportamiento sedentario entre estudiantes universitarios de regiones de escasos recursos.

Psychometric properties of the online Satisfaction with Life Scale in university students from a low-income region

Purpose: To test the feasibility, reliability, and validity of the Satisfaction with Life Scale (SWLS) in an online format in university students from a low-income region. Methods: This was a psychometric study, involving a study of reliability (n = 117) and validity (n = 195) in university students from a region with a Gini index of 0.56. The scale was applied at two time points with an interval of 2 weeks. This scale measures satisfaction with life based on five statements and responses ranging from 1 to 7 (strongly disagree to strongly agree). We conducted the reliability assessment using temporal stability and internal consistency and construct validity assessment by internal structure solution. Results: All SWLS items showed acceptable (rho > 0.30) and significant (p < 0.05) temporal stability and acceptable internal consistency (alpha > 0.70). In construct validity (internal structure), we identified a factor with an explained variance of 59.0% in the exploratory factor analysis. Additionally, in the confirmatory factor analysis, we identified a one-factor structure solution for SWLS with an acceptable model fitting (chi-square/degrees of freedom [X2/df] = 6.53; Tucker-Lewis Index [TLI] = 0.991; Comparative Fit Index [CFI] = 0.996; root mean square error of approximation [RMSEA] = 0.040; standardized root mean-squared residual [SRMR] = 0.026). Conclusion: The Satisfaction with Life Scale, in the online format, is a reliable and valid tool for university students in a low-income context.

Validity and Reliability of Questionnaires That Assess Barriers and Facilitators of Sedentary Behavior in the Pediatric Population: A Systematic Review.

We systematically reviewed the literature about the validity and reliability of barriers and facilitators of sedentary behavior questionnaires for children and adolescents, considering accelerometers as the reference method. We included studies that assessed the agreement between the barriers and facilitators of sedentary behavior through a questionnaire and an objective measure (e.g., accelerometry). We searched four electronic databases (MEDLINE/PubMed, CINAHL, Web of Science, and SCOPUS): these databases were searched for records from inception to 5 March 2021, and updated to November 2022. The search strategy used the following descriptors: children and adolescents; barriers or facilitators; questionnaires; accelerometers; and validation or reliability coefficient. Studies identified in the search were selected independently by two reviewers. The inclusion criteria were: (i) population of children and adolescents, (ii) original studies, (iii) subjective and objective measurement methods, (iv) studies that report validity or reliability, and (v) population without specific diseases. Seven studies were eligible for our review. The main exclusion reasons were studies that did not report validity or reliability coefficients (56.6%) and non-original studies (14.5%). The participants' ages in the primary studies ranged from 2 to 18 years. Cronbach's alpha coefficient was the most reported reliability assessment among the eligible articles, while Pearson and Spearman's coefficients were prevalent for validity. The reliability of self-report questionnaires for assessing sedentary behavior ranged from r = 0.3 to 1.0. The validity of the accelerometers ranged from r = -0.1 to 0.9. Family environment was the main factor associated with sedentary behavior. Our findings suggest that questionnaires assessing the barriers and facilitators of sedentary behavior are weak to moderate. PROSPERO Registration (CRD42021233945).

Psychometric Properties of the Online International Physical Activity Questionnaire in College Students.

INTRODUCTION: Due to the restrictions imposed to control the COVID-19 pandemic, there has been an increase in studies based on online surveys. However, there are important concerns about the validity and generalizability of results from online surveys. Thus, we aimed to test the reliability and validity of the online version of the International Physical Activity Questionnaire short form (IPAQ-SF) among college students from low-income regions. METHODS: This was a methodological feasibility study with a random stratified sample from a college located in the state of Maranhão in the city of Imperatriz (Brazil). The sample consisted of 195 college students (at least 17 years of age) to evaluate the validity and 117 students to evaluate the reliability. All data were collected in a self-reported online format (via Google Forms) twice, with an interval of 2 weeks. We used Spearman's correlation analysis for the reliability study. Additionally, we applied exploratory and confirmatory factor analysis to evaluate the structural validity. RESULTS: The questionnaire showed acceptable (rho > 0.30) and significant (p < 0.05) reliability, except for the question about the duration of sitting time on a weekend day. When assessing the construct validity (exploratory analysis), we identified a single factor that explained 88.8% of the variance. The 1-factor model showed acceptable model fit (SRMR = 0.039; CFI = 0.96; TLI = 0.90) in confirmatory analysis. CONCLUSIONS: The online version of the IPAQ-SF has acceptable reliability among college students from low-income regions and maintains the structure of the construct regarding to physical activity.

Longitudinal Associations of Physical Activity Patterns and the Environment: An 18-Year Follow-Up to the MESA Study.

Introduction: Cross-sectional association between the neighborhood-built environment and physical activity (PA) has been demonstrated previously, indicating the importance of neighborhood perception characteristics such as walkability, safety, and the connectivity of streets on PA levels. Our study aimed to assess the longitudinal data from participants of the Multi-Ethnic Study of Atherosclerosis (MESA) to evaluate the potential relationship between perceived environment and PA patterns. Methods: We analyzed data from a subset of participants (n = 3097) with available PA data who participated in a prospective cohort conducted from 2000 to 2018. The exposure variables were the perceived aspects of the neighborhood environment and the perception of safety, and the outcome was patterns of PA. Patterns were defined as categories reflecting meeting versus not meeting PA guidelines over time. We created the following categories: adopters (individuals who did not meet guidelines at baseline but met guidelines at Exam 6), relapsers (individuals who met guidelines at baseline but did not meet guidelines at Exam 6), maintainers (individuals who met guidelines both at baseline and Exam 6), and insufficiently active (individuals who did not meet guidelines at either baseline or Exam 6). The maintainers' group was considered the reference category. We estimated the relative risk to assess the magnitude effect of the association between environmental perceptions and the outcome. Results: Individuals who reported that lack of parks and playgrounds was "not a problem" in their neighborhood had a 2.3-times higher risk of decreasing their physical activity (i.e., the "relapser" category) compared to maintainers. After full adjustment, perceiving poor sidewalks as "somewhat a serious problem" was associated with a 64% lower risk of becoming an adopter than a maintainer. When compared to those who perceive the neighborhood as "very safe", perception of the neighborhood as "safe" to "not at all safe" (ratings 3, 4, and 5, respectively, on the perceived safety scale) was significantly associated with being classified in the adopter category. Conclusions: As the first longitudinal study of the association of perceived environment and physical activity within the MESA cohort, we conclude that a few aspects are longitudinally associated with being physically active among adults.

24 h movement behavior and metabolic syndrome study protocol: A prospective cohort study on lifestyle and risk of developing metabolic syndrome in undergraduate students from low-income regions during a pandemic.

Introduction: Obesity and its comorbidities are increasingly prevalent in Latin America, with a more rapid growth in individuals with lower income. The composition of movement behaviors within a 24 h period may have important implications for obesity, metabolic and mental health in cross-sectional data. However, a longitudinal study is needed to confirm the findings from the primarily cross-sectional evidence. The COVID-19 pandemic has been associated with cardiometabolic outcomes and has impeded healthy behavior. Objectives: The first objective is to evaluate the time elapsed since the diagnosis of not meeting 24 h movement guidelines and the potential subsequent onset of metabolic syndrome in undergraduate students from low-income regions within 4 years of follow up. The second objective is to test the association between 24 h movement, mental wellbeing, eating behaviors, and abdominal obesity in the period of this pandemic. Methods: The 24 h movement behavior and metabolic syndrome (24 h-MESYN) study is a multicentre cohort study that will include participants from two Brazilian cities within the 2022-2025 period to asses the first objective, and also a nested case-control study at the baseline will be carried out to evaluate the second objective. Previously, we conducted a feasibility study in the academic year of 2021 to assessing the psychometric properties of subjective tools, refine our study protocol, and adjust the epidemiological conditions of the cohort's subsequent phases (like as prevalence of exposure of interest, sampling process, and study adherence). Statistical tests as Cohen's kappa agreement; factorial analysis; logistic, Poisson and linear regression; and Kaplan-Meier analysis will be performed, in accordance with the objectives.

Reliability and validity of the dutch eating behavior questionnaire in an online format for university students from low-income regions in a pandemic context: A 24†hour MESYN study.

Objective: To test the reliability and validity of the Dutch Eating Behavior Questionnaire (DEBQ) in an online format in university students from low-income regions. Methods: We applied the questionnaire to a sample of 195 and 117 university students from a low-income region (Gini index of 0.56) to study validity and reliability, respectively. The DEBQ consists of 33 items on eating behavior in three dimensions/factors: emotional eating, restrained eating and external eating. The questionnaire was administered twice at 2-week intervals. We tested the reliability via temporal stability and internal consistency and construct validity via exploratory and confirmatory factor analysis. Results: For reliability, we identified an acceptable Spearman correlation coefficient (rho > 0.30 and p < 0.05) and Cronbach's alpha (α ≥ 0.70) for all DEBQ items. In the exploratory analysis, we identified 6 factors representing a mix of original and additional factors, with an explained variance of 69.1%. In the confirmatory analysis with structural equation modeling, we observed better global model adjustment for the 6-factor model with the Tucker-Lewis index and comparative fit index closer to one, as well as root mean square error of approximation closer to zero than the original (3-factor) model. Using generalized structural equation modeling, we also observed a better fit in latent class modeling for the 6-factor model (AIC: 16990.67; BIC. 17874.38) than for the 3-factor model (AIC: 17904.09; BIC: 18342.67). Conclusion: The online format of the DEBQ has acceptable reliability and validity for measuring eating behavior in university students from low-income regions.

Individualised prognosis for risk of developing abdominal obesity in the paediatric population.

AIMS: To develop and validate risk scores for predicting abdominal obesity in South American children and adolescents based on extrinsic and intrinsic variables. METHODS: Children (n = 358) and adolescents (n = 369) from seven South American cities from the South American Youth Cardiovascular and Environmental (SAYCARE) Study. The primary outcome was abdominal obesity. Potential predictors were based on sociodemographic, maternal, environmental, and behavioural factors and nutritional status. In multilevel logistic models, associated variables were tested to build the scores, which were internally validated. RESULTS: We identified 120 children and 98 adolescents who were abdominally obese. We found at least five variables associated with the outcome in children with unacceptable predictive capacity. However, in adolescents, we found that biological sex, age, maternal body mass index (BMI), active commuting by bike, soft drink consumption (for risk score A), and weight (for score B) can predict abdominal obesity. Both scores, A and B, showed acceptable performance in the ROC curve [areas under curve: 0.70 (95% CI: 0.56-0.82) and 0.95 (95% CI: 0.89-1.00), respectively]. CONCLUSION: The SAYCARE risk scores present accurate, individualised estimates for identifying adolescents who are at risk of developing abdominal obesity. However, these have not been externally validated.

Psychometric properties of 4-item questionnaire for sleep habits and time in a South American paediatric population.

OBJECTIVES: To assess the psychometric properties of 4-item questionnaire about sleep habits and time in South American children (3-10 years) and adolescents (11-18 years). MATERIAL AND METHODS: We evaluated 459 participants from seven South American cities. Two items from week and weekend days wake up time and bedtime were asked twice, with a 2-week interval. We calculated time spent in bed (subtracting wake up time from bedtime). Participants also answered the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) sleep time questionnaire. RESULTS: The questionnaire showed acceptable temporal stability in children and adolescents on total days (rho≥0.30; p<0.05). For total days, the questionnaire presented acceptable convergent validity only in children (rho from 0.48 to 0.62; p≤0.01) compared with the HELENA questionnaire. CONCLUSION: The 4-item questionnaire is a reliable and valid tool for children; however, its validity is not consistent in adolescents for sleep habits and time.

Food consumption of branched chain amino acids and insulin resistance: A systematic review of observational studies in humans.

This review systematically investigated observational studies in humans that evaluated the dietary intake of branched-chain amino acids (BCAA) and its association with insulin resistance. A search implemented through the electronic databases of PubMed, Scopus, and Web of Science. The evaluation of insulin resistance or the risk of developing insulin resistance in humans were the variables of interest in the search for articles. After using the selection criteria, three studies included in this review. The Food Frequency Questionnaire (FFQ) was the instrument used to evaluate the diet in all of the selected studies. Overall, 1940 studies identified and three thoroughly reviewed. We found only one study with positive effects of BCAA on insulin resistance; the other two reviewed studies did not demonstrate positive effects of the dietary intake of BCAA, individually or the sum of three amino acids on variables of interest. In this sense, the associations between BCAA and insulin resistance are inconsistent, potentially due to other longitudinal outcomes.

Reliability and validity of a sedentary behavior questionnaire for South American pediatric population: SAYCARE study.

BACKGROUND: Multicenter studies from Europe and the United States have developed specifically standardized questionnaires for assessing and comparing sedentary behavior, but they cannot be directly applied for South American countries. The aim of this study was to assess the reliability and validity of the South American Youth Cardiovascular and Environmental (SAYCARE) sedentary behavior questionnaire. METHODS: Children and adolescents from seven South American cities were involved in the test-retest reliability (children: n = 55; adolescents: n = 106) and concurrent validity (children: n = 93; adolescents: n = 94) studies. The SAYCARE sedentary behavior questionnaire was administered twice with two-week interval and the behaviors were parent-reported for children and self-reported for adolescents. Questions included time spent watching television, using a computer, playing console games, passive playing (only in children) and studying (only in adolescents) over the past week. Accelerometer was used for at least 3 days, including at least one weekend day. We compared values of sedentary time, using accelerometers, by quartiles of reported sedentary behavior time and their sum. RESULTS: The reliability of sedentary behavior time was moderate for children (rho ≥0.45 and k ≥ 0.40) and adolescents (rho ≥0.30). Comparisons between the questionnaire and accelerometer showed a low overall agreement, with the questionnaire systematically underreporting sedentary time in children (at least, - 332.6 ± 138.5 min/day) and adolescents (at least, - 399.7 ± 105.0 min/day). CONCLUSION: The SAYCARE sedentary behavior questionnaire has acceptable reliability in children and adolescents. However, the findings of current study indicate that SAYCARE questionnaire is not surrogate of total sedentary time.

Impact of methodological approaches in the agreement between subjective and objective methods for assessing screen time and sedentary behavior in pediatric population: a systematic review / Impacto de las decisiones metodológicas en la concordancia entre métodos subjetivos y objetivos para valorar el tiempo de comportamiento sedentario en la población pediátrica: una revisión sistemática

Introduction: sedentary behavior is an important target for health promotion. In this systematic review, we aimed to provide evidence to support decisions about measurement approach choices for subjectively assessing sedentary behavior in pediatric population, adopting objective methods as the reference. Methods: in this systematic review with meta-analysis, published studies were retrieved from electronic databases: Medline (PubMed), Web of Science, Embase, SPORTDiscus, BioMed Central and SCOPUS. We considered studies evaluating sedentary behavior agreement through questionnaire and/or diary in comparison with an objective measure. A total of six inclusion criteria were used. We synthesized the data using correlation coefficients (r) as an indicator of agreement estimates. The review protocol is registered in the PROSPERO database (CRD42014015138). Results: a total of 14 studies met the inclusion criteria with ages ranging from 3 to 17.5 years and provided 17 agreement analyses. Thirteen of these agreement analyses (76.5%) reported correlation coefficients. We found two major groups of sedentary activities: screen time (47.1%) and sedentary behaviors (52.9%). The pooled agreement between questionnaires and accelerometers for assessing self-reported screen time was negative (r = -0.15; CI 95%: -0.17 to -0.13). Conversely, when the sedentary behavior was assessed by questionnaires and accelerometers, the pooled agreement was positive for parent-reporting (r = 0.09; CI 95%: 0.04 to 0.13) and self-reporting (r = 0.43; CI 95%: 0.40 to 0.47) in children and adolescents, respectively. Conclusion: questionnaires have positive agreement with accelerometers for assessing sedentary behavior, whereas the agreement is negative for assessing screen time. Self-reported questionnaires are recommended methods to measure sedentary behavior in adolescents

Introducción: el comportamiento sedentario es un objetivo importante para la promoción de la salud. En esta revisión sistemática, nuestro objetivo fue proporcionar evidencia para apoyar las decisiones sobre las opciones metodológicas acerca de los instrumentos para medición subjetiva del comportamiento sedentario en la población pediátrica, adoptando métodos objetivos como referencia. Métodos: en esta revisión sistemática con metaanálisis, fueron recuperados estudios publicados en las bases de datos electrónicas Medline (PubMed), Web of Science, Embase, SPORTDiscus, BioMed Central y SCOPUS. Consideramos estudios que evalúan el acuerdo de comportamiento sedentario a través del cuestionario y/o diario en comparación con una medida objetiva. Se utilizaron un total de seis criterios de inclusión. Sintetizamos los datos utilizando coeficientes de correlación (r) como un indicador de las estimaciones de la concordancia. El protocolo de revisión está registrado en la base de datos PROSPERO (CRD42014015138). Resultados: un total de 14 estudios cumplieron los criterios de inclusión con edades comprendidas entre 3 y 17,5 años y proporcionaron 17 análisis de concordancia. Trece de estos análisis de concordancia (76,5%) informaron coeficientes de correlación. Encontramos dos grupos principales de actividades sedentarias: tiempo de pantalla (47,1%) y comportamiento sedentario (52,9%). La concordancia entre cuestionarios y acelerómetros para evaluar el tiempo de pantalla autorreportado fue negativa (r = -0,15; IC 95%: -0,17 a -0,13). Sin embargo, cuando se evaluó el comportamiento sedentario mediante cuestionarios y acelerómetros, el acuerdo fue positivo para el reporte de los padres (r = 0,09; IC 95%: 0,04 a 0,13) y el reporte (r = 0,43; IC 95%: 0,40 a 0.47) de niños y adolescentes, respectivamente. Conclusión: los cuestionarios tienen un acuerdo positivo con los acelerómetros para evaluar el comportamiento sedentario, mientras que el acuerdo es negativo para evaluar el tiempo de pantalla. Los cuestionarios autorreportados son métodos recomendados para medir el comportamiento sedentario en adolescentes

Impact of methodological approaches in the agreement between subjective and objective methods for assessing screen time and sedentary behavior in pediatric population: a systematic review.

INTRODUCTION: Introduction: sedentary behavior is an important target for health promotion. In this systematic review, we aimed to provide evidence to support decisions about measurement approach choices for subjectively assessing sedentary behavior in pediatric population, adopting objective methods as the reference. Methods: in this systematic review with meta-analysis, published studies were retrieved from electronic databases: Medline (PubMed), Web of Science, Embase, SPORTDiscus, BioMed Central and SCOPUS. We considered studies evaluating sedentary behavior agreement through questionnaire and/or diary in comparison with an objective measure. A total of six inclusion criteria were used. We synthesized the data using correlation coefficients (r) as an indicator of agreement estimates. The review protocol is registered in the PROSPERO database (CRD42014015138). Results: a total of 14 studies met the inclusion criteria with ages ranging from 3 to 17.5 years and provided 17 agreement analyses. Thirteen of these agreement analyses (76.5%) reported correlation coefficients. We found two major groups of sedentary activities: screen time (47.1%) and sedentary behaviors (52.9%). The pooled agreement between questionnaires and accelerometers for assessing self-reported screen time was negative (r = -0.15; CI 95%: -0.17 to -0.13). Conversely, when the sedentary behavior was assessed by questionnaires and accelerometers, the pooled agreement was positive for parent-reporting (r = 0.09; CI 95%: 0.04 to 0.13) and self-reporting (r = 0.43; CI 95%: 0.40 to 0.47) in children and adolescents, respectively. Conclusion: questionnaires have positive agreement with accelerometers for assessing sedentary behavior, whereas the agreement is negative for assessing screen time. Self-reported questionnaires are recommended methods to measure sedentary behavior in adolescents.

INTRODUCCIÓN: Introducción: el comportamiento sedentario es un objetivo importante para la promoción de la salud. En esta revisión sistemática, nuestro objetivo fue proporcionar evidencia para apoyar las decisiones sobre las opciones metodológicas acerca de los instrumentos para medición subjetiva del comportamiento sedentario en la población pediátrica, adoptando métodos objetivos como referencia. Métodos: en esta revisión sistemática con metaanálisis, fueron recuperados estudios publicados en las bases de datos electrónicas Medline (PubMed), Web of Science, Embase, SPORTDiscus, BioMed Central y SCOPUS. Consideramos estudios que evalúan el acuerdo de comportamiento sedentario a través del cuestionario y/o diario en comparación con una medida objetiva. Se utilizaron un total de seis criterios de inclusión. Sintetizamos los datos utilizando coeficientes de correlación (r) como un indicador de las estimaciones de la concordancia. El protocolo de revisión está registrado en la base de datos PROSPERO (CRD42014015138). Resultados: un total de 14 estudios cumplieron los criterios de inclusión con edades comprendidas entre 3 y 17,5 años y proporcionaron 17 análisis de concordancia. Trece de estos análisis de concordancia (76,5%) informaron coeficientes de correlación. Encontramos dos grupos principales de actividades sedentarias: tiempo de pantalla (47,1%) y comportamiento sedentario (52,9%). La concordancia entre cuestionarios y acelerómetros para evaluar el tiempo de pantalla autorreportado fue negativa (r = -0,15; IC 95%: -0,17 a -0,13). Sin embargo, cuando se evaluó el comportamiento sedentario mediante cuestionarios y acelerómetros, el acuerdo fue positivo para el reporte de los padres (r = 0,09; IC 95%: 0,04 a 0,13) y el reporte (r = 0,43; IC 95%: 0,40 a 0.47) de niños y adolescentes, respectivamente. Conclusión: los cuestionarios tienen un acuerdo positivo con los acelerómetros para evaluar el comportamiento sedentario, mientras que el acuerdo es negativo para evaluar el tiempo de pantalla. Los cuestionarios autorreportados son métodos recomendados para medir el comportamiento sedentario en adolescentes.

What is the Validity of Questionnaires Assessing Fruit and Vegetable Consumption in Children when Compared with Blood Biomarkers? A Meta-Analysis.

Fruit and vegetable consumption has been associated with improved health outcomes in children. As an extensive number of questionnaires are currently used to assess fruit and vegetable consumption, we performed a systematic review of the criterion validity of questionnaires used to estimate fruit and vegetable consumption in children, considering blood biomarkers as the reference method. Five electronic databases (MEDLINE, CINAHL, Scopus, PsycINFO, Web of Science) were searched from database inception to 23 July 2018. The search strategy used the following sets of descriptors: children; fruits and vegetables; dietary questionnaires; blood biomarkers; and validation coefficient. The search terms were adapted for use with other databases in combination with database-specific filters. Potentially eligible articles were selected independently by two reviewers, separately, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Two articles meeting the inclusion criteria were included. The main reason for study exclusion was the sample age range, which included adolescents. The pooled correlation coefficient was 0.32 (95% confidence interval: 0.24⁻0.40).This review provided insights into assessment methods of fruit and vegetable consumption in children. Although further studies are required, questionnaires for assessing fruit and vegetable consumption have fair criterion validity in children.

Associations between REV-ERBα, sleep duration and body mass index in European adolescents.

BACKGROUND/OBJECTIVE: Although the REV-ERBα is considered an important regulator of both clock function and metabolism, its relationship with sleep duration and obesity is less clear. The objective of this study was to examine the association between the REV-ERBα clock gene and two outcomes - sleep duration and body mass index (BMI) - in European adolescents. METHODS: A sample of 831 adolescents (392 boys) aged 11.5-18.8 years from 10 European centers was used. The independent variables were REV-ERBα rs2071427 and rs2071570 SNPs, and their respective haplotypes. The outcomes were sleep duration and BMI. RESULTS: In girls, no significant association were found between rs2071427 or rs2071570 and the studied outcomes (p ≥ 0.43). In boys, however, significant associations were found between rs2071570 and sleep duration (ß: -0.32 h/day for T minor allele carriers; p = 0.0017), and rs2071427 and BMI (ß: +0.72 kg/m2 for A minor allele carriers; p = 0.016). In the haplotype analysis, the TA haplotype (carrying the two minor alleles) was associated with both lower sleep duration (Δ = -0.38 h/day; p = 0.05) and higher BMI (Δ = +1.41 kg/m2; p = 0.018) in boys, when compared with the common CC haplotype. CONCLUSIONS: The REV-ERBα rs2071427 and rs2071570 were associated with both sleep duration and BMI in boys. These findings confirmed the relevance of the REV-ERBα gene in human obesity, primarily in males, and also suggested that it has a potential role in affecting sleep duration.