The Study of Cardiovascular Risk in Adolescents--ERICA: rationale, design and sample characteristics of a national survey examining cardiovascular risk factor profile in Brazilian adolescents.

BACKGROUND: The Study of Cardiovascular Risk in Adolescents (Portuguese acronym, "ERICA") is a multicenter, school-based country-wide cross-sectional study funded by the Brazilian Ministry of Health, which aims at estimating the prevalence of cardiovascular risk factors, including those included in the definition of the metabolic syndrome, in a random sample of adolescents aged 12 to 17 years in Brazilian cities with more than 100,000 inhabitants. Approximately 85,000 students were assessed in public and private schools. Brazil is a continental country with a heterogeneous population of 190 million living in its five main geographic regions (North, Northeast, Midwest, South and Southeast). ERICA is a pioneering study that will assess the prevalence rates of cardiovascular risk factors in Brazilian adolescents using a sample with national and regional representativeness. This paper describes the rationale, design and procedures of ERICA. METHODS/DESIGN: Participants answered a self-administered questionnaire using an electronic device, in order to obtain information on demographic and lifestyle characteristics, including physical activity, smoking, alcohol intake, sleeping hours, common mental disorders and reproductive and oral health. Dietary intake was assessed using a 24-hour dietary recall. Anthropometric measures (weight, height and waist circumference) and blood pressure were also be measured. Blood was collected from a subsample of approximately 44,000 adolescents for measurements of fasting glucose, total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides, glycated hemoglobin and fasting insulin. DISCUSSION: The study findings will be instrumental to the development of public policies aiming at the prevention of obesity, atherosclerotic diseases and diabetes in an adolescent population.

ERICA: leisure-time physical inactivity in Brazilian adolescents.

OBJECTIVE To evaluate the prevalence of leisure-time physical inactivity in Brazilian adolescents and their association with geographical and sociodemographic variables. METHODS The sample was composed by 74,589 adolescents participating in the Study of Cardiovascular Risks in Adolescents (ERICA). This cross-sectional study of school basis with national scope involved adolescents aged from 12 to 17 years in Brazilian cities with more than 100 thousand inhabitants. The prevalence of leisure-time physical inactivity was categorized according to the volume of weekly practice (< 300; 0 min). The prevalences were estimated for the total sample and by sex. Poisson regression models were used to assess associated factors. RESULTS The prevalence of leisure-time physical inactivity was 54.3% (95%CI 53.4-55.2), and higher for the female sex (70.7%, 95%CI 69.5-71.9) compared to the male (38.0%, 95%CI 36.7-39.4). More than a quarter of adolescents (26.5%, 95%CI 25.8-27.3) reported not practicing physical activity in the leisure time, a condition more prevalent for girls (39.8%, 95%CI 38.8-40.9) than boys (13.4%, 95%CI 12.4-14.4). For girls, the variables that were associated with physical inactivity were: reside in the Northeast (RP = 1.13, 95%CI 1.08-1.19), Southeast (RP = 1.16, 95%CI 1.11-1.22) and South (RP = 1.12, 95%CI 1.06-1.18); have 16-17 years (RP = 1.06, 95%CI 1.12-1.15); and belong to the lower economic class (RP = 1.33, 95%CI 1.20-1.48). The same factors, except reside in the Southeast and South, were also associated with not practicing physical activity in the leisure time for the same group. In males, as well as the region, being older (p < 0.001) and declaring to be indigenous (RP = 0.37, 95%CI 0.19-0.73) were also associated with not practicing physical activities in the leisure time. CONCLUSIONS The prevalence of leisure-time physical inactivity in Brazilian adolescents is high. It presents regional variations and is associated with age and low socioeconomic status. Special attention should be given to girls and to those who do not engage in any physical activity during the leisure time, so that they can adopt a more active lifestyle.

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.

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.

Efeito agudo da corrida aeróbica na pressão arterial em jovens adultos normotensos / Acute effects of aerobic running on blood pressure in young normotens adults

RESUMO O objetivo do presente estudo foi investigar o efeito hipotensivo induzido pela corrida aeróbica em jovens adultos. Trinta e um indivíduos (18 mulheres e 13 homens) foram submetidos a uma avaliação antropométrica e o protocolo de corrida proposto em uma esteira ergométrica durante 40 min entre 60 a 70% da frequência cardíaca de reserva. Realizaram-se medidas da pressão arterial sistólica (PAS) e pressão arterial diastólica (PAD) que posteriormente foram comparados antes e ao final do protocolo de corrida através do teste t de Student para as variáveis dependentes. Todos os testes foram assumidos com α = 0,05. Em comparação com a PAS antes (127,1 ± 11,5 mmHg) e após (119,9 ± 10,2 mmHg) a corrida, os resultados obtidos evidenciaram uma diminuição da pressão arterial sistólica, o qual resultou uma diferença média de -7,2 ± 6,2 mmHg, demonstrando uma diferença significativa (p = 0,00001). Entretanto, na PAD antes (73,6 ± 8,6 mmHg) e após (72,5 ± 7,8 mmHg) não demonstrou uma diferença significativa (p = 0,36) como efeito agudo na diminuição após a corrida. Portanto, conclui-se que a corrida em moderada intensidade e longa duração pode ser auxiliado no tratamento não farmacológico da hipertensão arterial e como melhoria na saúde cardiovascular.

ABSTRACT The aim of the present study was to investigate the acute effects of blood pressure induced by moderate intensity aerobic exercise in young adults. Thirty-one individuals (18 women and 13 men) were submitted an anthropometric evaluation and a 40-min running protocol between 60% and 70% of the reserve heart rate. Hemodynamic measurements, systolic blood pressure (SBP) and diastolic blood pressure (DBP) were carried out before and after the running protocol through Student's t-test for the dependent variables. All tests assumed α = 0.05. Significant differences were recorded between SBP before (127.1 ± 11.5 mmHg) and after (119.9 ± 10.2 mmHg) the running protocol. The results showed a decrease in systolic blood pressure, which resulted in a mean difference of -7.2 ± 6.2 mmHg, demonstrating a significant difference (p = 0.00001). However, in the DBP before (73.6 ± 8.6 mmHg) and after (72.5 ± 7.8 mmHg) no showing a significant difference (p = 0.36) as an acute effect on the decrease the running protocol. In conclusion, that moderate intensity and long duration running exercise can be aided in the non-pharmacological treatment of arterial hypertension and as an improvement in cardiovascular health.

ERICA: leisure-time physical inactivity in Brazilian adolescents / ERICA: inatividade física no lazer em adolescentes brasileiros

ABSTRACT OBJECTIVE To evaluate the prevalence of leisure-time physical inactivity in Brazilian adolescents and their association with geographical and sociodemographic variables. METHODS The sample was composed by 74,589 adolescents participating in the Study of Cardiovascular Risks in Adolescents (ERICA). This cross-sectional study of school basis with national scope involved adolescents aged from 12 to 17 years in Brazilian cities with more than 100 thousand inhabitants. The prevalence of leisure-time physical inactivity was categorized according to the volume of weekly practice (< 300; 0 min). The prevalences were estimated for the total sample and by sex. Poisson regression models were used to assess associated factors. RESULTS The prevalence of leisure-time physical inactivity was 54.3% (95%CI 53.4-55.2), and higher for the female sex (70.7%, 95%CI 69.5-71.9) compared to the male (38.0%, 95%CI 36.7-39.4). More than a quarter of adolescents (26.5%, 95%CI 25.8-27.3) reported not practicing physical activity in the leisure time, a condition more prevalent for girls (39.8%, 95%CI 38.8-40.9) than boys (13.4%, 95%CI 12.4-14.4). For girls, the variables that were associated with physical inactivity were: reside in the Northeast (RP = 1.13, 95%CI 1.08-1.19), Southeast (RP = 1.16, 95%CI 1.11-1.22) and South (RP = 1.12, 95%CI 1.06-1.18); have 16-17 years (RP = 1.06, 95%CI 1.12-1.15); and belong to the lower economic class (RP = 1.33, 95%CI 1.20-1.48). The same factors, except reside in the Southeast and South, were also associated with not practicing physical activity in the leisure time for the same group. In males, as well as the region, being older (p < 0.001) and declaring to be indigenous (RP = 0.37, 95%CI 0.19-0.73) were also associated with not practicing physical activities in the leisure time. CONCLUSIONS The prevalence of leisure-time physical inactivity in Brazilian adolescents is high. It presents regional variations and is associated with age and low socioeconomic status. Special attention should be given to girls and to those who do not engage in any physical activity during the leisure time, so that they can adopt a more active lifestyle.

RESUMO OBJETIVO Avaliar a prevalência de inatividade física no lazer em adolescentes brasileiros e sua associação com variáveis geográficas e sociodemográficas. MÉTODOS A amostra foi composta por 74.589 adolescentes participantes do Estudo de Riscos Cardiovasculares em Adolescentes (ERICA). Esse estudo transversal de base escolar com abrangência nacional envolveu adolescentes brasileiros de 12 a 17 anos de municípios com mais de 100 mil habitantes. A prevalência de inatividade física no lazer foi categorizada de acordo com o volume de prática semanal (< 300; zero min). As prevalências foram estimadas para o total da amostra analisada e por sexo. Modelos de regressão de Poisson foram utilizados para avaliar fatores associados. RESULTADOS A prevalência de inatividade física no lazer foi de 54,3% (IC95% 53,4-55,2), superior no sexo feminino (70,7%, IC95% 69,5-71,9) comparado ao masculino (38,0%, IC95% 36,7-39,4). Mais de um quarto dos adolescentes (26,5%, IC95% 25,8-27,3) referiram não praticar atividade física no lazer, condição mais prevalente no sexo feminino (39,8%, IC95% 38,8-40,9) que no masculino (13,4%, IC95% 12,4-14,4). Para o sexo feminino, as variáveis que se associaram à inatividade física foram: residir nas regiões Nordeste (RP = 1,13, IC95% 1,08-1,19), Sudeste (RP = 1,16, IC95% 1,11-1,22) e Sul (RP = 1,12, IC95% 1,06-1,18); ter 16-17 anos (RP = 1,12, IC95% 1,06-1,15); e pertencer à classe econômica mais baixa (RP = 1,33, IC95% 1,20-1,48). Os mesmos fatores, exceto residir no Sudeste e Sul, também associaram-se com não praticar atividade física no lazer no mesmo grupo. No sexo masculino, além da região, ser mais velho (p < 0,001) e declarar-se indígena (RP = 0,37, IC95% 0,19-0,73) associaram-se à prevalência de não praticar atividade física no lazer. CONCLUSÕES A prevalência de inatividade física no lazer em adolescentes brasileiros é elevada, apresenta variações regionais e está associada à idade e ao baixo nível socioeconômico. Especial atenção deve ser dada às meninas e aos que não praticam nenhuma atividade física no lazer, a fim de que estes possam adotar estilo de vida mais ativo.

Associação entre excesso de peso e atividade física em adolescentes brasileiros: análise segundo características sociodemográficas e geográficas / Association between overweight and physical activity in Brazilian adolescents: analysis according to sociodemographic and geographic characteristics

Introdução: O excesso de peso aumentou rapidamente em nível mundial, inclusive entre adolescentes de países alta renda. No Brasil, evidências indicam que um a cada quatro adolescentes escolares apresenta excesso de peso, com variação regional significativa. A prática insuficiente de atividade física é apontada como um dos principais determinantes do aumento do excesso de peso e representa um comportamento passível de modificação. Os padrões de atividade física entre adolescentes também diferem entre as macrorregiões brasileiras e associam-se ao baixo nível socioeconômico. A associação entre excesso de peso e atividade física apresenta diferenças sociodemográficas e geográficas importantes, sendo conhecimento imprescindível para a proposição de políticas públicas e programas de prevenção do excesso de peso. Objetivo geral: Avaliar associação entre excesso de peso e atividade física em adolescentes brasileiros segundo características sociodemográficas e geográficas. Método: Utilizaram-se dados do Estudo de Riscos Cardiovasculares em Adolescentes (ERICA), estudo multicêntrico, transversal, de base escolar e de representatividade nacional. A amostra incluiu 73.624 adolescentes de 12 a 17 anos, selecionados de 1247 escolas das 27 capitais e de cinco conjuntos de municípios com mais de 100 mil habitantes de cada uma das cinco macrorregiões do País. Os dados foram coletados de fevereiro de 2013 a novembro de 2014. A variável dependente excesso de peso foi avaliada pelo Índice de Massa Corporal (IMC), como variável contínua e categórica, que incluiu sobrepeso (1< z-score 2) e obesidade (z-score >2), classificados de acordo com sexo e idade, conforme pela Organização Mundial de Saúde. Atividade física foi avaliada por questionário subjetivo, como variável contínua (minutos de atividade física/semana) e categórica, classificada em três níveis: ativos (300 minutos/semana), insuficientemente ativos (1-299 minutos/semana) e inativos (sem prática de atividade física). Realizou-se análise descritiva univariada e múltipla para as variáveis de interesse, em modelos de regressão linear (IMC e minutos de atividade física/semana) e múltipla (excesso de peso e categorias de atividade física). Foram estimadas prevalências e intervalos de confiança de 95% (IC95%) do excesso de peso por categorias de atividade física, segundo características sociodemográficas e geográficas. Associação entre excesso de peso, como variável dicotômica e categorias de atividade física, foi analisada também por meio de modelos de análise multinível logística, considerando nível 1 (indivíduo), nível 2 (capital de Estado) e nível 3 (macrorregião), com intercepto e declive aleatórios (efeito da atividade física), ambos para capitais de Estado e macrorregião. Foram executados modelos brutos (apenas com o nível de atividade física como variável independente) e modelos ajustados a classe econômica, sexo, faixa etária e cor de pele. Os efeitos fixos da atividade física e das variáveis ajustadas foram apresentados em Odds Ratio (OR) e respectivos IC95%. Os modelos multinível foram realizados com o package Ime4 disponível para o R, sendo todas as análises realizadas com o package survey. O nível de significância de todos os testes foi de 5%. O ERICA obteve aprovação dos Comitês de Ética em Pesquisa das 27 instituições participantes de cada uma das unidades da federação brasileira. Resultados: Constataram-se associação positiva entre IMC e níveis de atividade física, com aumento de 0,012kg/m2 de IMC para cada 60 minutos de atividade física; e associação entre excesso de peso e categorias de atividade física no modelo bruto, com maior chance de excesso de peso em adolescentes insuficientemente ativos (OR=1,10; IC95%:1,05-1,16) e ativos (OR=1,14; IC95%:1,08-1,20) em relação aos adolescentes inativos, mas, o efeito da atividade física no excesso de peso deixou de ser significativo quando o modelo foi ajustado para classe econômica, sexo, faixa etária e cor de pele (p=0,894; p=0,481). Essa associação foi igualmente observada nas análises separadas para sobrepeso e obesidade. As análises no modelo multinível mostraram efeito negativo da atividade física sobre o excesso de peso nas macrorregiões com maiores prevalências de excesso de peso e efeito positivo nas regiões com menores prevalências, sendo esses efeitos observados tanto nos adolescentes insuficientemente ativos quanto nos ativos. Nas capitais de Estado, o efeito da atividade física no excesso de peso manteve-se significativo apenas para os adolescentes insuficientemente ativos. Resultado similar foi obtido na análise para sobrepeso, porém com significância também nas macrorregiões. Para os obesos, no nível das capitais, verificou-se efeito contrário da atividade física nos adolescentes insuficientemente ativos (efeito positivo nas capitais com maiores prevalências de excesso de peso e efeito negativo nas capitais com menores prevalências de excesso de peso), porém o mesmo não foi observado nos adolescentes ativos. Conclusão: Os resultados mostram que, nos adolescentes, quanto maior o tempo de atividade física praticada, maior o IMC. Entretanto, a associação entre excesso de peso e categorias de atividade física no nível individual não se sustenta na análise ajustada, evidenciando a importância de classe econômica, sexo, faixa etária e cor de pele. Quando a análise é realizada para o nível das capitais de Estado e macrorregiões, as associações passam a apresentar efeitos positivos ou negativos, a depender das prevalências de excesso de peso acima ou abaixo da média nacional. Sugerem-se estudos que avaliem atividade física com métodos objetivos e que a massa muscular e a de gordura sejam consideradas na avaliação do excesso de peso em adolescentes. Contudo, as elevadas prevalências de excesso de peso e de adolescentes insuficientemente ativos/inativos evidenciam a urgência de políticas públicas, pois comportamentos adquiridos nessa fase tendem a se manter na vida adulta, com importantes consequências para a saúde futura.

Introduction: Overweight increased rapidly in the worldwide, including among adolescents from high income countries. In Brazil, evidence indicates that one in four school adolescents are overweight, with regional variation. Insufficient practice of physical activity has been pointed out as one of the main reasons for increase of the excess of weight and represents a behavior susceptible of modification. Patterns of physical activity among adolescents also differ between Brazilian macro-regions and are associated with low socioeconomic status. Association between overweight and physical activity presents important sociodemographic and geographical differences, essential knowledge for the proposal of public policies and programs for the prevention of overweight among adolescents. Objective: To evaluate the association between overweight and physical activity in Brazilian adolescents according to sociodemographic and geographic characteristics. Methods: We analized data from Study of Cardiovascular Risks in Adolescents among adolescents (acronum - ERICA), a multicenter, cross-sectional study carried out in national representative school-based study. 73,624 Brazilian adolescents (12-17years) were selected from 1247 schools from 27 states capitals and five sets o municipalities with than 100 thousand inhabitants from each of the five macro-regions of the country. Data were collected from February 2013 to November 2014. Excess weight dependent variable was evaluated by Body Mass Index (BMI), as a continuous and categorical variable and define from the cut points proposed by the WHO for the BMI for age, according to gender (z-score> 1 and 2) and obesity (z-score> 2). Physical activity was assessed by subjective questionnaire, as a continuous variable (minutes of physical activity / week) and categorical, classified into three levels: active (300 minutes / week), insufficiently active (1-299 minutes / week) and inactive Practice of physical activity). Univariate and multiple descriptive analysis were performed for the variables of interest, in linear regression models (BMI and minutes of physical activity / week) and multiple (overweight and physical activity categories). The prevalence and confidence intervals of 95% (95% CI) of excess weight were estimated by categories of physical activity, according to sociodemographic and geographic characteristics. Prevalence and confidence intervals of 95% (95% CI) of excess weight were estimated by categories of physical activity, according to sociodemographic and geographic characteristics. Association between excess weight, as a dichotomous variable and physical activity categories was also analyzed through multilevel logistic analysis models, considering level 1 (individual), level 2 (state capital) and level 3 (macro-region), with intercept and Slope (effect of physical activity), both for state capitals and macro-region. Rude models (only with the level of physical activity as an independent variable) and models adjusted to economic class, gender, age group and skin color were executed. The fixed effects of physical activity and adjusted variables were presented in Odds Ratio (OR) and respective 95% CI. Multilevel models were performed with the package Ime4 available for the R, and all analyzes were performed with the package survey. Significance level of all tests was 5%. ERICA obtained approval from the Research Ethics Committees of the 27 participating institutions of each of the units of the Brazilian federation. Results: Positive association was observed between BMI and physical activity level, with an increase of 0.012kg/m2 BMI for every 60 minute of physical activity. Association between excess weight and physical activity was also observed in the crude model: insufficiently active (OR = 1.10, 95% CI: 1.05-1.16) and active adolescents (OR = 1.14, 95% CI: 1.08-1.20) were more likely to be overweight relate to inactive adolescents. However, effect of physical activity on excess weight was no longer significant when the model was adjusted for economic class, sex, age, and skin color (p = 0.894, p = 0.481). This association was also observed in the separate analyzes for overweight and obesity. Analyzes in the multilevel model showed a negative effect of physical activity on excess weight in the macro-regions with higher prevalences of excess weight and positive effect in regions with lower prevalences, and these effects were observed in both active and active adolescents. In state capitals, the effect of physical activity on excess weight remained significant only for underactive adolescents. Similar result was obtained in the analysis for overweight, but with significance also in the macro-regions. For the obese, at the capital level, there was an opposite effect of physical activity on the underactive adolescents (positive effect on capitals with higher prevalences of overweight and negative effect on capitals with lower prevalence of overweight), but the same was not observed in active adolescents. Conclusion: Results show that in the adolescents, the greater the minutes of physical activity practiced, the greater the BMI. However, the association between excess weight and categories of physical activity at the individual level is not supported by the adjusted analysis, showing the importance of economic class, sex, age group and skin color. When the analysis is carried out for state capitals and macro-regions, associations have positive or negative effects, depending on the prevalence of excess weight above or below the national average. We suggest studies that evaluate physical activity with objective methods and that muscle and fat mass be considered in the evaluation of overweight in adolescents. However, high prevalence of excess weight and insufficiently active / inactive adolescents evidences the urgency of public policies, since behaviors acquired during this phase tend to remain in adult life, with important consequences for future health.