Association between asthma and sleep hours in Brazilian adolescents: ERICA

Abstract Objective To investigate the association between asthma and sleep duration in participants of the Study of Cardiovascular Risks in Adolescents. Materials and methods Cross-sectional, national, school-based study, involving adolescents aged 12-17 years. In the period between 2013−14, data from 59,442 participants were analyzed. Bivariate analysis between current asthma and short sleep duration, defined as < 7 h/night, was performed separately with the other variables analyzed: sex, age group, type of school, weight categories, and common mental disorders. Then, different generalized linear models with Poisson family and logarithmic link functions were used to assess the independence of potential confounding covariates associated with both asthma and short sleep duration in the previous analysis. Crude and adjusted prevalence ratios and respective 95% confidence intervals were calculated, and a value of p < 0.05 was considered significant for all analyses performed. Results Prevalence of current asthma was 13.4%, being significantly higher among students with short sleep duration (PR: 1.17; 95% CI: 1.01-1.35; p = 0.034). This remained significant even after adjusting for the other study covariates. Conclusion There was a positive association between the prevalence of current asthma and short sleep duration among Brazilian adolescents. Considering the high prevalence and morbidity of the disease in this age group, the promotion of sleep hygiene should be considered as a possible health strategy aimed at contributing to better control of asthma in this population.

Association between asthma and sleep hours in Brazilian adolescents: ERICA.

OBJECTIVE: To investigate the association between asthma and sleep duration in participants of the Study of Cardiovascular Risks in Adolescents. MATERIALS AND METHODS: Cross-sectional, national, school-based study, involving adolescents aged 12-17 years. In the period between 2013-14, data from 59,442 participants were analyzed. Bivariate analysis between current asthma and short sleep duration, defined as < 7 h/night, was performed separately with the other variables analyzed: sex, age group, type of school, weight categories, and common mental disorders. Then, different generalized linear models with Poisson family and logarithmic link functions were used to assess the independence of potential confounding covariates associated with both asthma and short sleep duration in the previous analysis. Crude and adjusted prevalence ratios and respective 95% confidence intervals were calculated, and a value of p < 0.05 was considered significant for all analyses performed. RESULTS: Prevalence of current asthma was 13.4%, being significantly higher among students with short sleep duration (PR: 1.17; 95% CI: 1.01-1.35; p = 0.034). This remained significant even after adjusting for the other study covariates. CONCLUSION: There was a positive association between the prevalence of current asthma and short sleep duration among Brazilian adolescents. Considering the high prevalence and morbidity of the disease in this age group, the promotion of sleep hygiene should be considered as a possible health strategy aimed at contributing to better control of asthma in this population.

[Quality analysis of self-reported information on sleep duration in schoolchildren in the Study of Cardiovascular Risk Factors in Adolescents (ERICA)]. / Análise da qualidade da informação autorreferida sobre duração do sono de escolares do Estudo de Riscos Cardiovasculares em Adolescentes (ERICA).

The study aimed to assess sleep behavior in adolescents 12 to 17 years of age participating in ERICA (Study of Cardiovascular Risk Factors in Adolescents), based on sociodemographic characteristics, school shift, and type of school, and to describe the correction of inconsistent sleep times in a nationally representative study in Brazil. Data were collected in 2013 and 2014. Four questions were asked on habitual time for sleeping and waking on weekdays and weekends, with 24 possible answers, one for each hour of the day. Analysis of inconsistencies considered the distribution of frequencies of answers as to sleeping and waking times, in addition to compatibility with the school shift. Sleep duration during the week and on weekends was obtained by the difference between sleeping and waking times, and differences of ≤ 4 or ≥ 14 hours were excluded. Mean total sleep duration in seven days was calculated by the formula (weekday sleep duration x 5 + weekend sleep duration x 2)/7. The following groups were created: original data (answers that did not require correction), corrected data (inconsistent, but amenable to correction), and excluded data (inconsistent, and for which there was no criterion for correction). Correction recovered inconsistent information for 5,988 adolescents, 8% of the 74,589 participants. A total of 7,937 (10.6%) answers were excluded. Adolescents whose information was corrected or excluded were younger, predominantly males, from public schools, and from the North of Brazil. Correction minimized losses and lent greater consistency to the data treatment. The study contributes to the improvement of data collection tools in observational studies, lending transparency to the way of dealing with inherent limitations in the data collection method.

Objetivou-se avaliar o comportamento do sono de adolescentes de 12 a 17 anos, participantes do ERICA (Estudo de Riscos Cardiovasculares em Adolescentes), estudo de representatividade nacional, segundo características sociodemográficas, turno e tipo de escola, e descrever a correção das horas inconsistentes. A coleta de dados ocorreu em 2013 e 2014. Foram feitas quatro perguntas sobre horas habituais de dormir e de acordar durante a semana e no final de semana, com 24 opções de respostas, uma para cada hora do dia. A análise das inconsistências considerou a distribuição de frequências das respostas quanto às horas habituais de dormir e de acordar, além da compatibilidade com o turno. A duração do sono durante a semana e final de semana foi obtida pela diferença entre horas habituais de dormir e de acordar e foi excluída se ≤ 4 ou ≥ 14 horas. A média de sono total da semana foi calculada pela fórmula: (duração do sono durante a semana x 5 + duração do sono no final de semana x 2)/7. Foram criados três grupos: dados originais (respostas que não necessitaram correções), dados corrigidos (inconsistentes, mas passíveis de correção) e dados excluídos (inconsistentes, para os quais não se tinha critério para correção). A correção recuperou informação inconsistente de 5.988 adolescentes (8%) dos 74.589 participantes. Foram excluídas 7.937 (10,6%) respostas. Os adolescentes cujas informações foram corrigidas ou excluídas são mais novos, do sexo masculino, de escolas públicas e da Região Norte. A correção minimizou perdas e conferiu maior consistência ao tratamento dos dados. O estudo contribui para o aprimoramento da construção de instrumentos de coleta de dados em estudos observacionais, tornando transparente a forma de lidar com as limitações inerentes ao método de coleta de dados.

El objetivo fue evaluar el comportamiento del sueño en adolescentes de 12 a 17 años, participantes en el ERICA (Estudio de Riesgos Cardiovasculares en Adolescentes), según características sociodemográficas, turnos y tipos de escuela, donde además se describe la corrección de las horas incompatibles en un estudio de nivel nacional en Brasil. La recogida de datos se realizó en 2013 y 2014. Se hicieron cuatro preguntas sobre las horas habituales de sueño y de despertarse durante la semana y el fin de semana, con 24 opciones de respuesta, una para cada hora del día. El análisis de las incompatibilidades consideró la distribución de frecuencias en las respuestas, respecto a las horas habituales de sueño y de despertarse, además de la compatibilidad con el turno. La duración del sueño durante la semana y fin de semana se obtuvo mediante la diferencia entre horas habituales de sueño y de despertarse y fue excluida si ≤ 4 ó ≥ 14 horas. La media de sueño total de la semana se calculó mediante la fórmula: (duración del sueño durante la semana x 5 + duración del sueño durante el fin de semana x 2)/7. Se crearon tres grupos: datos originales (respuestas que no necesitaron correcciones), datos corregidos (inconsistentes, pero plausibles de corrección) y datos excluidos (inconsistentes en los que no había criterio para la corrección). La corrección recuperó información inconsistente de 5.988 adolescentes (8%) de los 74.589 participantes. Se excluyeron 7.937 (10,6%) respuestas. Los adolescentes cuya información fue corregida o excluida son más jóvenes, sexo masculino, procedentes de escuelas públicas y de la región Norte. La corrección minimizó pérdidas y otorgó una mayor consistencia al tratamiento de los datos. El estudio contribuye al perfeccionamiento de la creación de instrumentos de recogida de datos en estudios observacionales, haciendo transparente la forma de enfrentarse a las limitaciones inherentes del método de recogida de datos.

Overview of meta-analysis on prevention and treatment of childhood obesity / Visão geral das meta-análises sobre prevenção e tratamento da obesidade infantil

Abstract Objectives: This study aimed to assess the quality of systematic reviews on prevention and non-pharmacological treatment of overweight and obesity in children and adolescents. Data source: A search was done in electronic databases (Medline via PubMed, Web of Science, Scopus, LILACS, the Cochrane Library, and Clinical Trials), including only systematic reviews with meta-analysis. Reviews were selected by two researchers, and a third one solved the divergences. PRISMA statement and checklist were followed. Summary of data: A total of 4574 records were retrieved, including 24 after selection. Six reviews were on obesity prevention, 17 on obesity treatment, and one on mixed interventions for prevention and treatment of obesity. The interventions were very heterogeneous and showed little or no effects on weight or body mass index. Mixed interventions that included dieting, exercise, actions to reduce sedentary behavior, and programs involving the school or families showed some short-term positive effects. Reviews that analyzed cardiovascular risk factors demonstrated significant improvements in the short-term. Conclusion: The systematic reviews of interventions to prevent or reduce obesity in children and adolescents generally showed little or no effects on weight or body mass index, although cardiovascular profile can be improved. Mixed interventions demonstrated better effects, but the long-term impact of obesity treatments of children and adolescents remains unclear.

Resumo Objetivos: Este estudo teve como objetivo avaliar a qualidade das revisões sistemáticas sobre prevenção e tratamento não farmacológico do sobrepeso e da obesidade em crianças e adolescentes. Fontes de dados: Foi realizada uma busca em bases de dados eletrônicas (Medline via Pubmed, Web of Science, Scopus, LILACS, The Cochrane Library e Ensaios Clínicos), incluindo apenas revisões sistemáticas com meta-análise. As revisões foram selecionadas por dois pesquisadores e um terceiro resolveu as divergências. A lista de recomendações do PRISMA foi seguida. Síntese dos dados: Foram identificados 4.574 publicações, e 24 foram incluídas após seleção. Seis publicações eram sobre prevenção da obesidade, 17 sobre tratamento da obesidade e 1 sobre intervenções mistas para prevenção e tratamento da obesidade. As intervenções eram muito heterogêneas e mostraram pouco ou nenhum efeito sobre o peso ou índice de massa corporal. Intervenções mistas que incluíam dieta, exercícios, ações para reduzir o comportamento sedentário e programas que envolviam a escola ou as famílias mostraram alguns efeitos positivos de curto prazo. Revisões que analisaram fatores de risco cardiovascular demonstraram melhoras significativas em curto prazo. Conclusão: As revisões sistemáticas de intervenções para prevenir ou reduzir a obesidade em crianças e adolescentes geralmente mostraram pouco ou nenhum efeito sobre o peso ou índice de massa corporal, embora o perfil cardiovascular possa ter melhorado. Intervenções mistas demonstraram melhores efeitos, mas o impacto em longo prazo dos tratamentos da obesidade de crianças e adolescentes ainda não está claro.

Overview of meta-analysis on prevention and treatment of childhood obesity.

OBJECTIVES: This study aimed to assess the quality of systematic reviews on prevention and non-pharmacological treatment of overweight and obesity in children and adolescents. DATA SOURCE: A search was done in electronic databases (Medline via PubMed, Web of Science, Scopus, LILACS, the Cochrane Library, and Clinical Trials), including only systematic reviews with meta-analysis. Reviews were selected by two researchers, and a third one solved the divergences. PRISMA statement and checklist were followed. SUMMARY OF DATA: A total of 4574 records were retrieved, including 24 after selection. Six reviews were on obesity prevention, 17 on obesity treatment, and one on mixed interventions for prevention and treatment of obesity. The interventions were very heterogeneous and showed little or no effects on weight or body mass index. Mixed interventions that included dieting, exercise, actions to reduce sedentary behavior, and programs involving the school or families showed some short-term positive effects. Reviews that analyzed cardiovascular risk factors demonstrated significant improvements in the short-term. CONCLUSION: The systematic reviews of interventions to prevent or reduce obesity in children and adolescents generally showed little or no effects on weight or body mass index, although cardiovascular profile can be improved. Mixed interventions demonstrated better effects, but the long-term impact of obesity treatments of children and adolescents remains unclear.

Análise da qualidade da informação autorreferida sobre duração do sono de escolares do Estudo de Riscos Cardiovasculares em Adolescentes (ERICA) / Quality analysis of self-reported information on sleep duration in schoolchildren in the Study of Cardiovascular Risk Factors in Adolescents (ERICA) / Análisis sobre calidad de los datos autoinformados sobre la duración del sueño en escolares del Estudio de Riesgos Cardiovasculares en Adolescentes (ERICA)

Resumo: Objetivou-se avaliar o comportamento do sono de adolescentes de 12 a 17 anos, participantes do ERICA (Estudo de Riscos Cardiovasculares em Adolescentes), estudo de representatividade nacional, segundo características sociodemográficas, turno e tipo de escola, e descrever a correção das horas inconsistentes. A coleta de dados ocorreu em 2013 e 2014. Foram feitas quatro perguntas sobre horas habituais de dormir e de acordar durante a semana e no final de semana, com 24 opções de respostas, uma para cada hora do dia. A análise das inconsistências considerou a distribuição de frequências das respostas quanto às horas habituais de dormir e de acordar, além da compatibilidade com o turno. A duração do sono durante a semana e final de semana foi obtida pela diferença entre horas habituais de dormir e de acordar e foi excluída se ≤ 4 ou ≥ 14 horas. A média de sono total da semana foi calculada pela fórmula: (duração do sono durante a semana x 5 + duração do sono no final de semana x 2)/7. Foram criados três grupos: dados originais (respostas que não necessitaram correções), dados corrigidos (inconsistentes, mas passíveis de correção) e dados excluídos (inconsistentes, para os quais não se tinha critério para correção). A correção recuperou informação inconsistente de 5.988 adolescentes (8%) dos 74.589 participantes. Foram excluídas 7.937 (10,6%) respostas. Os adolescentes cujas informações foram corrigidas ou excluídas são mais novos, do sexo masculino, de escolas públicas e da Região Norte. A correção minimizou perdas e conferiu maior consistência ao tratamento dos dados. O estudo contribui para o aprimoramento da construção de instrumentos de coleta de dados em estudos observacionais, tornando transparente a forma de lidar com as limitações inerentes ao método de coleta de dados.

Abstract: The study aimed to assess sleep behavior in adolescents 12 to 17 years of age participating in ERICA (Study of Cardiovascular Risk Factors in Adolescents), based on sociodemographic characteristics, school shift, and type of school, and to describe the correction of inconsistent sleep times in a nationally representative study in Brazil. Data were collected in 2013 and 2014. Four questions were asked on habitual time for sleeping and waking on weekdays and weekends, with 24 possible answers, one for each hour of the day. Analysis of inconsistencies considered the distribution of frequencies of answers as to sleeping and waking times, in addition to compatibility with the school shift. Sleep duration during the week and on weekends was obtained by the difference between sleeping and waking times, and differences of ≤ 4 or ≥ 14 hours were excluded. Mean total sleep duration in seven days was calculated by the formula (weekday sleep duration x 5 + weekend sleep duration x 2)/7. The following groups were created: original data (answers that did not require correction), corrected data (inconsistent, but amenable to correction), and excluded data (inconsistent, and for which there was no criterion for correction). Correction recovered inconsistent information for 5,988 adolescents, 8% of the 74,589 participants. A total of 7,937 (10.6%) answers were excluded. Adolescents whose information was corrected or excluded were younger, predominantly males, from public schools, and from the North of Brazil. Correction minimized losses and lent greater consistency to the data treatment. The study contributes to the improvement of data collection tools in observational studies, lending transparency to the way of dealing with inherent limitations in the data collection method.

Resumen: El objetivo fue evaluar el comportamiento del sueño en adolescentes de 12 a 17 años, participantes en el ERICA (Estudio de Riesgos Cardiovasculares en Adolescentes), según características sociodemográficas, turnos y tipos de escuela, donde además se describe la corrección de las horas incompatibles en un estudio de nivel nacional en Brasil. La recogida de datos se realizó en 2013 y 2014. Se hicieron cuatro preguntas sobre las horas habituales de sueño y de despertarse durante la semana y el fin de semana, con 24 opciones de respuesta, una para cada hora del día. El análisis de las incompatibilidades consideró la distribución de frecuencias en las respuestas, respecto a las horas habituales de sueño y de despertarse, además de la compatibilidad con el turno. La duración del sueño durante la semana y fin de semana se obtuvo mediante la diferencia entre horas habituales de sueño y de despertarse y fue excluida si ≤ 4 ó ≥ 14 horas. La media de sueño total de la semana se calculó mediante la fórmula: (duración del sueño durante la semana x 5 + duración del sueño durante el fin de semana x 2)/7. Se crearon tres grupos: datos originales (respuestas que no necesitaron correcciones), datos corregidos (inconsistentes, pero plausibles de corrección) y datos excluidos (inconsistentes en los que no había criterio para la corrección). La corrección recuperó información inconsistente de 5.988 adolescentes (8%) de los 74.589 participantes. Se excluyeron 7.937 (10,6%) respuestas. Los adolescentes cuya información fue corregida o excluida son más jóvenes, sexo masculino, procedentes de escuelas públicas y de la región Norte. La corrección minimizó pérdidas y otorgó una mayor consistencia al tratamiento de los datos. El estudio contribuye al perfeccionamiento de la creación de instrumentos de recogida de datos en estudios observacionales, haciendo transparente la forma de enfrentarse a las limitaciones inherentes del método de recogida de datos.

Self-reported nocturnal sleep duration and glycosylated hemoglobin A in the Study of Cardiovascular Risks in Adolescents (ERICA).

OBJECTIVE: At present, epidemiologic studies regarding the relationship between sleep duration and glucose metabolism in adolescents are scarce. The objective was to investigate the association between self-reported nocturnal sleep duration and glycosylated hemoglobin A in 12- to 17-year-old Brazilian adolescents. PATIENTS/METHODS: A school-based multicenter cross-sectional study was carried out in private and public schools from 273 municipalities with more than 100,000 inhabitants. The final sample comprised 24,923 adolescents. A self-administered questionnaire was used. Blood tests included glucose, insulin, glycosylated hemoglobin A and serum lipids. Age, sex, skin color, school type, body mass index (BMI), physical activity, and Brazilian regions were studied as possible effect modifiers and/or confounders using linear regression. RESULTS: A significant positive association was found between more than 12 h of nocturnal sleep and glycosylated hemoglobin A in two Brazilian regions: Southeast and South, even after adjustment for age, sex, skin color, and BMI (coefficients of 0.142 and 0.339, respectively). No association was found with nocturnal sleep duration <7 h. CONCLUSION: Notably, a significant positive relationship was found between more than 12 h of nocturnal sleep duration and glycosylated hemoglobin A in two Brazilian regions. The specific pubertal sleep curtailment can be a compensatory mechanism for dealing with the insulin resistance during adolescence. Those that escape from this regulatory strategy and sleep longer than the adequate duration, break down this balance and tend to damage their glucose metabolism. To our knowledge, this is the first large scale study, of the association between sleep duration and glucose metabolism in adolescents.

Challenges for conducting blood collection and biochemical analysis in a large multicenter school-based study with adolescents: lessons from ERICA in Brazil.

The Study of Cardiovascular Risk in Adolescents (ERICA) is a pioneering study that aimed to assess the prevalence of cardiovascular risk factors, including metabolic syndrome components in Brazilian adolescents. This study aims to describe the methodological aspects related to blood collection as well as to report pertaining results of the preparation, transport, storage, and exams in ERICA. Exams in ERICA were performed in a single laboratory and blood samples were collected in schools in a standardized manner. Logistics involved air transportation of samples to the reference laboratory with controlled temperature since sample collection. The serum was stored in local biorepositories in four centers to be used in future analyses. During the study, 284,247 exams were performed and rate of participation in exams was 56.2%, thus involving 40,732 adolescents. From the total, 92.6% of the samples reached the reference laboratory maintaining the temperature between 0-10°C. No clinical significant changes in results due to temperature changes were identified. External quality control recorded satisfactory results in 98.7% of the evaluations. Four biorepositories with samples of 7,785 adolescents were created. Thus, we can consider that the logistics adopted in ERICA was fairly successful and description of this as well as the difficulties experienced in Brazil can inform and facilitate the planning of future studies, especially in developing countries.

Comparison between self-reported sleep duration and actigraphy among adolescents: gender differences.

INTRODUCTION: There are only few agreement studies between subjective measures of sleep and actigraphy among adolescents. OBJECTIVE: To compare self-reported sleep and actigraphy in this age group, by studying gender differences and, using a new graphical approach, the survival agreement plot. METHODS: Thirty-seven subjects, aged 12 to 17 years, answered questions about nocturnal sleep duration and used actigraphy for seven days. The mean and median differences between the informed sleep and the recorded one, the intraclass correlation coefficient, the Bland-Altman plot and the survival-agreement plot were used. RESULTS: A mean difference of about one hour (SD = 2.1; median = 0.5; p < 0.01) was found between both strategies, which was higher among boys, 1.9 hours (SD = 2.8; median = 1.6; p < 0.05), than among girls, 0.5 hours (SD = 1.4; median = 0.3; p = 0.11). The graphical evaluation showed similar results, as well as the intraclass correlation coefficient: 0.06 (95%CI = -0.33 - 0.46; p = 0.489) for boys and 0.43 (95%CI = 0.12 - 0.83; p < 0.001) for girls. CONCLUSIONS: Our data are consistent with previous studies as to non-agreement between the two methods. These results are relevant because this is the first study of concordance between subjective measures of sleep and actigraphy among Brazilian adolescents, as far as we know. In addition, they reinforce the need of a careful use of nocturnal sleep measures among adolescents, mainly among boys.

Software to record 24-hour food recall: application in the Study of Cardiovascular Risks in Adolescents. / Programa para registro de recordatório alimentar de 24 horas: aplicação no Estudo de Riscos Cardiovasculares em Adolescentes.

INTRODUCTION: The Study of Cardiovascular Risk in Adolescents (ERICA) is a national multicenter study whose purpose is to describe the cardiovascular risk profile, including obesity, changes in lipid and glucose metabolism, and blood pressure, of about 75,000 Brazilian adolescents. OBJECTIVE: To describe the development of a tool for data collection of 24-hour food recall (REC24h) in ERICA and to report its performance in the pilot study. METHODS: The Multiple Pass Method was used for the development of the computer program that guides REC24h interview. REC24h-ERICA uses a database composed of 1,626 food items including preparation methods and units of predefined portion sizes. Food consumption data are obtained through interviews and entered directly into REC24h-ERICA, avoiding the use of paper. RESULTS: The pilot study included 1,367 adolescents, of which 1,047 (77%) responded to REC24h. The researchers did not report difficulties in program use, the average duration of interviews was 20 minutes and the interviewers inserted 50 new food items. CONCLUSION: The program developed was proven suitable for use in large-population studies, even in a country like Brazil, where there is great diversity in eating habits.

Cost of diseases related to alcohol consumption in the Brazilian Unified Health System.

OBJECTIVE: To estimate the direct costs associated to outpatient and hospital care of diseases related to alcohol consumption in the Brazilian Unified Health System. METHODS: Attributable populational risks were estimated for the selected diseases related to the use of 25 g/day or more of ethanol (risk consumption), considering a relative risk (RR) ≥ 1.20. The RR estimates were obtained from three meta-analysis. The risk consumption rates of the Brazilian population ≥ 18 years old were obtained by a national survey. Data from the Hospital Information System of SUS (HIS-SUS) were used to estimate the annual costs of the health system with the diseases included in the analysis. RESULTS: The total estimated costs for a year regarding diseases related to risk consumption were U$8,262,762 (US$4,413,670 and US$3,849,092, for outpatient and hospital care, respectively). CONCLUSIONS: Risk consumption of alcohol is an important economic and health problem, impacting significantly the health system and society.

Comparison between self-reported sleep duration and actigraphy among adolescents: gender differences / Comparação entre duração do sono autodeclarada e actigrafia entre adolescentes: diferenças de gênero

ABSTRACT: Introduction: There are only few agreement studies between subjective measures of sleep and actigraphy among adolescents. Objective: To compare self-reported sleep and actigraphy in this age group, by studying gender differences and, using a new graphical approach, the survival agreement plot. Methods: Thirty-seven subjects, aged 12 to 17 years, answered questions about nocturnal sleep duration and used actigraphy for seven days. The mean and median differences between the informed sleep and the recorded one, the intraclass correlation coefficient, the Bland-Altman plot and the survival-agreement plot were used. Results: A mean difference of about one hour (SD = 2.1; median = 0.5; p < 0.01) was found between both strategies, which was higher among boys, 1.9 hours (SD = 2.8; median = 1.6; p < 0.05), than among girls, 0.5 hours (SD = 1.4; median = 0.3; p = 0.11). The graphical evaluation showed similar results, as well as the intraclass correlation coefficient: 0.06 (95%CI = -0.33 - 0.46; p = 0.489) for boys and 0.43 (95%CI = 0.12 - 0.83; p < 0.001) for girls. Conclusions: Our data are consistent with previous studies as to non-agreement between the two methods. These results are relevant because this is the first study of concordance between subjective measures of sleep and actigraphy among Brazilian adolescents, as far as we know. In addition, they reinforce the need of a careful use of nocturnal sleep measures among adolescents, mainly among boys.

RESUMO: Introdução: Existem poucos estudos de concordância entre as medidas subjetivas de sono e a actigrafia entre adolescentes. Objetivo: Comparar o sono autodeclarado e a actigrafia neste grupo etário, estudando as diferenças quanto ao sexo e, usando uma nova abordagem gráfica, o gráfico de concordância e sobrevivência. Métodos: Trinta e sete indivíduos de 12 a 17 anos responderam a questões sobre a duração do sono noturno e usaram actigrafia por sete dias. As diferenças entre as médias e as medianas entre sono informado e a medida objetiva, o coeficiente de correlação intraclasse e os gráficos de Bland-Altman e de concordância e sobrevivência foram aplicados. Resultados: Uma diferença média de aproximadamente uma hora (DP = 2,1; mediana = 0,5; p < 0,01) foi encontrada entre ambas as estratégias, a qual foi maior entre os meninos, com 1,9 horas (DP = 2,8; mediana = 1,6; p < 0,05), do que entre as meninas, 0,5 horas (DP = 1,4; mediana = 0,3; p = 0,11). A avaliação gráfica mostrou resultados semelhantes, bem como o coeficiente de correlação intraclasse: 0,06 (IC95% = -0,33 - 0,46; p = 0,489) para os meninos e 0,43 (IC95% = 0,12 - 0,83; p < 0,001) para as meninas. Conclusões: Nossos dados são consistentes com prévios estudos em relação à não concordância entre os dois métodos. Esses resultados são relevantes porque este é o primeiro estudo de concordância entre medidas subjetivas de sono e actigrafia em adolescentes brasileiros, do nosso conhecimento. Além disso, eles reforçam a necessidade de um cuidadoso uso das medidas de sono noturno entre adolescentes, principalmente entre os meninos.

ERICA: use of screens and consumption of meals and snacks by Brazilian adolescents.

OBJECTIVE To describe the length of exposure to screens and the prevalence of consumption of meals and snacks by Brazilian adolescents in front of screens. METHODS We evaluated 74,589 12 to 17-year old adolescents from 1,247 schools in 124 Brazilian municipalities. A self-administered questionnaire was used. Its segment regarding nutrition contained questions about using TV, computers, and video game systems, having meals while watching TV, and consuming snacks in front of screens. Consumption of meals and snacks in front of screens was analyzed according to the following variables: geographical region, gender, age range, type of school (public or private), and school shift. The prevalences and their respective 95% confidence intervals were estimated under a complex sampling design. RESULTS A great deal of the adolescents (51.8% IC95% 50.7-53.0) [corrected] reported spending two or more hours a day in front of screens. That habit was more frequent among male adolescents, private school students, morning shift students, and students from Brazil's South region. More than half of the adolescents (56.6%, 95%CI 55.4-57.8) reported almost always or always having meals in front of TV, and 39.6% (95%CI 38.8-40.5) of them said they consumed snacks in front of screens exactly as often. Both situations were the most prevalent ones among the girls, who attended public schools and were from Brazil's Midwest region. CONCLUSIONS Length of exposure to screens and consumption of meals and snacks almost always or always in front of screens are high among Brazilian adolescents. It is necessary to develop strategies aiming to reduce the length of screen use, considering the media reality that children and adolescents have been experiencing from earlier and earlier ages. That context must therefore be analyzed in an indissociable way.

ERICA: prevalence of dyslipidemia in Brazilian adolescents.

OBJECTIVE To determine the distribution of total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides in Brazilian adolescents, as well as the prevalence of altered levels of such parameters. METHODS Data from the Study of Cardiovascular Risks in Adolescents (ERICA) were used. This is a country-wide, school-based cross-sectional study that evaluated 12 to 17-year old adolescents living in cities with over 100,000 inhabitants. The average and distribution of plasma levels of total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides were evaluated. Dyslipidemia was determined by levels of total cholesterol ≥ 170 mg/dl, LDL cholesterol ≥ 130 mg/dl, HDL cholesterol < 45 mg/dL, or triglycerides ≥ 130 mg/dl. The data were analyzed by gender, age, and regions in Brazil. RESULTS We evaluated 38,069 adolescents - 59.9% of females, and 54.2% between 15 and 17 years. The average values found were: total cholesterol = 148.1 mg/dl (95%CI 147.1-149.1), HDL cholesterol = 47.3 mg/dl (95%CI 46.7-47.9), LDL cholesterol = 85.3 mg/dl (95%CI 84.5-86.1), and triglycerides = 77.8 mg/dl (95%CI 76.5-79.2). The female adolescents had higher average levels of total cholesterol, LDL cholesterol, and HDL cholesterol, without differences in the levels of triglycerides. We did not observe any significant differences between the average values among 12 to 14 and 15- to 17-year old adolescents. The most prevalent lipid alterations were low HDL cholesterol (46.8% [95%CI 44.8-48.9]), hypercholesterolemia (20.1% [95%CI 19.0-21.3]), and hypertriglyceridemia (7.8% [95%CI 7.1-8.6]). High LDL cholesterol was found in 3.5% (95%CI 3.2-4.0) of the adolescents. Prevalence of low HDL cholesterol was higher in Brazil's North and Northeast regions. CONCLUSIONS A significant proportion of Brazilian adolescents has alterations in their plasma lipids. The high prevalence of low HDL cholesterol and hypertriglyceridemia, especially in Brazil's North and Northeast regions, must be analyzed in future studies, to support the creation of strategies for efficient interventions.

ERICA: prevalence of metabolic syndrome in Brazilian adolescents.

OBJECTIVE To determine the prevalence of metabolic syndrome and its components in Brazilian adolescents. METHODS We evaluated 37,504 adolescents who were participants in the Study of Cardiovascular Risks in Adolescents (ERICA), a cross-sectional, school-based, national study. The adolescents, aged from 12 to 17 years, lived in cities with populations greater than 100,000 inhabitants. The sample was stratified and clustered into schools and classes. The criteria set out by the International Diabetes Federation were used to define metabolic syndrome. Prevalences of metabolic syndrome were estimated according to sex, age group, school type and nutritional status. RESULTS Of the 37,504 adolescents who were evaluated: 50.2% were female; 54.3% were aged from 15 to 17 years, and 73.3% were from public schools. The prevalence of metabolic syndrome was 2.6% (95%CI 2.3-2.9), slightly higher in males and in those aged from 15 to 17 years in most macro-regions. The prevalence was the highest in residents from the South macro-region, in the younger female adolescents and in the older male adolescents. The prevalence was higher in public schools (2.8% [95%CI 2.4-3.2]), when compared with private schools (1.9% [95%CI 1.4-2.4]) and higher in obese adolescents when compared with nonobese ones. The most common combinations of components, referring to 3/4 of combinations, were: enlarged waist circumference (WC), low HDL-cholesterol (HDL-c) and high blood pressure; followed by enlarged WC, low HDL-c and high triglycerides; and enlarged WC, low HDL-c, high triglycerides and blood pressure. Low HDL was the second most frequent component, but the highest prevalence of metabolic syndrome (26.8%) was observed in the presence of high triglycerides. CONCLUSIONS ERICA is the first Brazilian nation-wide study to present the prevalence of metabolic syndrome and describe the role of its components. Despite the prevalence of Metabolic Syndrome being low, the high prevalences of some components and participation of others in the syndrome composition shows the importance of early diagnosis of this changes, even if not grouped within the metabolic syndrome.

ERICA: prevalence of healthy eating habits among Brazilian adolescents.

OBJECTIVE To describe the prevalence of eating habits considered healthy in adolescents according to sex, age, education level of the mother, school type, session of study, and geographic region. METHODS The assessed data come from the Study of Cardiovascular Risks in Adolescents (ERICA), a cross-sectional, national and school-based study. Adolescents of 1,247 schools of 124 Brazilian municipalities were evaluated using a self-administered questionnaire with a section on aspects related to eating behaviors. The following eating behaviors were considered healthy: consuming breakfast, drinking water, and having meals accompanied by parents or legal guardians. All prevalence estimates were presented proportionally, with their respective 95% confidence intervals. The Chi-square test was used to evaluate the differences in healthy eating habits prevalences according to other variables. The module survey of the Stata program version 13.0 was used to analyze complex data. RESULTS We evaluated 74,589 adolescents (72.9% of the eligible students). Of these, 55.2% were female, average age being 14.6 years (SD = 1.6). Among Brazilian adolescents, approximately half of them showed healthy eating habits when consuming breakfast, drinking five or more glasses of water a day, and having meals with parents or legal guardians. All analyzed healthy eating habits showed statistically significant differences by sex, age, type of school, session of study, or geographic region . CONCLUSIONS We suggest that specific actions of intersectoral approach are implemented for the dissemination of the benefits of healthy eating habits. Older female adolescents (15 to 17 years old) who studied in public schools, resided in the Southeast region, and whose mothers had lower education levels, should be the focus of these actions since they present lower frequencies concerning the evaluated healthy habits.

ERICA: prevalence of common mental disorders in Brazilian adolescents.

OBJECTIVE To describe the prevalence of common mental disorders in Brazilian adolescent students, according to geographical macro-regions, school type, sex, and age. METHODS We evaluated 74,589 adolescents who participated in the Cardiovascular Risk Study in Adolescents (ERICA), a cross-sectional, national, school-based study conducted in 2013-2014 in cities with more than 100,000 inhabitants. A self-administered questionnaire and an electronic data collector were employed. The presence of common mental disorders was assessed using the General Health Questionnaire (GHQ-12). We estimated prevalence and 95% confidence intervals of common mental disorders by sex, age, and school type, in Brazil and in the macro-regions, considering the sample design. RESULTS The prevalence of common mental disorders was of 30.0% (95%CI 29.2-30.8), being higher among girls (38.4%; 95%CI 37.1-39.7) when compared to boys (21.6%; 95%CI 20.5-22.8), and among adolescents who were from 15 to 17 years old (33.6%; 95%CI 32.2-35.0) compared to those aged between 12 and 14 years (26.7%; 95%CI 25.8-27.6). The prevalence of common mental disorders increased with age for both sexes, always higher in girls (ranging from 28.1% at 12 years to 44.1% at 17 years) than in boys (ranging from 18.5% at 12 years to 27.7% at 17 years). We did not observe any significant difference by macro-region or school type. Stratified analyses showed higher prevalence of common mental disorders among girls aged from 15 to 17 years of private schools in the North region (53.1; 95%CI 46.8-59.4). CONCLUSIONS The high prevalence of common mental disorders among adolescents and the fact that the symptoms are often vague mean these disorders are not so easily identified by school administrators or even by health services. The results of this study can help the proposition of more specific prevention and control measures, focused on highest risk subgroups.

ERICA: intake of macro and micronutrients of Brazilian adolescents.

OBJECTIVE To describe food and macronutrient intake profile and estimate the prevalence of inadequate micronutrient intake of Brazilian adolescents. METHODS Data from 71,791 adolescents aged from 12 to 17 years were evaluated in the 2013-2014 Brazilian Study of Cardiovascular Risks in Adolescents (ERICA). Food intake was estimated using 24-hour dietary recall (24-HDR). A second 24-HDR was collected in a subsample of the adolescents to estimate within-person variability and calculate the usual individual intake. The prevalence of food/food group intake reported by the adolescents was also estimated. For sodium, the prevalence of inadequate intake was estimated based on the Tolerable Upper Intake Level (UL). The Estimated Average Requirement (EAR) method used as cutoff was applied to estimate the prevalence of inadequate nutrient intake. All the analyses were stratified according to sex, age group and Brazilian macro-regions. All statistical analyses accounted for the sample weight and the complex sampling design. RESULTS Rice, beans and other legume, juice and fruit drinks, breads and meat were the most consumed foods among the adolescents. The average energy intake ranged from 2,036 kcal (girls aged from 12 to 13 years) to 2,582 kcal (boy aged from14 to 17 years). Saturated fat and free sugar intake were above the maximum limit recommended (< 10.0%). Vitamins A and E, and calcium were the micronutrients with the highest prevalence of inadequate intake (> 50.0%). Sodium intake was above the UL for more than 80.0% of the adolescents. CONCLUSIONS The diets of Brazilian adolescents were characterized by the intake of traditional Brazilian food, such as rice and beans, as well as by high intake of sugar through sweetened beverages and processed foods. This food pattern was associated with an excessive intake of sodium, saturated fatty acids and free sugar.

Response rate in the Study of Cardiovascular Risks in Adolescents - ERICA.

OBJECTIVE To describe the response rate and characteristics of people who either took part or not in from the Study of Cardiovascular Risks in Adolescents (ERICA) , according to information subsets. METHODS ERICA is a school-based, nation-wide investigation with a representative sample of 12 to 17-year-old adolescents attending public or private schools in municipalities with over 100,000 inhabitants in Brazil. Response rate of eligible subjects were calculated according to macro-regions, sex, age, and type of school (public or private). We also calculated the percentages of replacement schools in comparison with the ones originally selected as per the sample design, according to the types of schools in the macro-regions. The subjects and non-subjects were compared according to sex, age, and average body mass indices (kg/m2). RESULTS We had 102,327 eligible adolescents enrolled in the groups drawn. The highest percentage of complete information was obtained for the subset of the questionnaire (72.9%). Complete information regarding anthropometric measurements and the ones from the questionnaire were obtained for 72.0% of the adolescents, and the combination of these data with the 24-hour dietary recall were obtained for 70.3% of the adolescents. Complete information from the questionnaire plus biochemical blood evaluation data were obtained for 52.5% of the morning session adolescents (selected for blood tests). The response percentage in private schools was higher than the one in public schools for most of the combination of information. The ratio of older and male adolescents non-participants was higher than the ratio among participants. CONCLUSIONS The response rate for non-invasive procedures was high. The response rate for blood collection - an invasive procedure that requires a 12-hour fasting period and the informed consent form from legal guardians - was lower. The response rate observed in public schools was lower than in the private ones, and that may reflect lower school frequency of registered students.

ERICA: prevalences of hypertension and obesity in Brazilian adolescents.

OBJECTIVE To estimate the prevalence of arterial hypertension and obesity and the population attributable fraction of hypertension that is due to obesity in Brazilian adolescents. METHODS Data from participants in the Brazilian Study of Cardiovascular Risks in Adolescents (ERICA), which was the first national school-based, cross-section study performed in Brazil were evaluated. The sample was divided into 32 geographical strata and clusters from 32 schools and classes, with regional and national representation. Obesity was classified using the body mass index according to age and sex. Arterial hypertension was defined when the average systolic or diastolic blood pressure was greater than or equal to the 95th percentile of the reference curve. Prevalences and 95% confidence intervals (95%CI) of arterial hypertension and obesity, both on a national basis and in the macro-regions of Brazil, were estimated by sex and age group, as were the fractions of hypertension attributable to obesity in the population. RESULTS We evaluated 73,399 students, 55.4% female, with an average age of 14.7 years (SD = 1.6). The prevalence of hypertension was 9.6% (95%CI 9.0-10.3); with the lowest being in the North, 8.4% (95%CI 7.7-9.2) and Northeast regions, 8.4% (95%CI 7.6-9.2), and the highest being in the South, 12.5% (95%CI 11.0-14.2). The prevalence of obesity was 8.4% (95%CI 7.9-8.9), which was lower in the North region and higher in the South region. The prevalences of arterial hypertension and obesity were higher in males. Obese adolescents presented a higher prevalence of hypertension, 28.4% (95%CI 25.5-31.2), than overweight adolescents, 15.4% (95%CI 17.0-13.8), or eutrophic adolescents, 6.3% (95%CI 5.6-7.0). The fraction of hypertension attributable to obesity was 17.8%. CONCLUSIONS ERICA was the first nationally representative Brazilian study providing prevalence estimates of hypertension in adolescents. Regional and sex differences were observed. The study indicates that the control of obesity would lower the prevalence of hypertension among Brazilian adolescents by 1/5.