Is physical activity associated with resting heart rate in boys and girls? A representative study controlled for confounders / A atividade física está associada à frequência cardíaca de repouso em meninos e meninas? Estudo representativo controlado para fatores de confusão

Abstract Objective: Investigate the relationship between different domains of physical activity and resting heart rate (RHR) in boys and girls. Method: The sample included 1011 adolescents, aged between 10 and 17 years. RHR was measured by a heart rate monitor and physical activity was assessed in total and in three different domains (school, occupational, and sports practice) by a questionnaire. Anthropometry was directly obtained for body mass index and central fat. Ethnicity, sedentary behavior, and smoking habits were self-reported and used to adjust the analysis, through hierarchical linear regression. Results: Total physical activity was associated with low RHR in boys (β = −0.52; 95% CI: −0.92, −0.12) and girls (β = −0.67; 95% CI: −1.07, −0.28). Although sporting physical activities were associated with low RHR in both boys (β = −0.58; 95% CI: −1.05, −0.11) and girls (β = −0.87; 95% CI: −1.34, −0.39), occupational physical activity was related to low RHR only in boys (β = −1.56; 95% CI: −2.99, −0.14). Conclusion: The practice of physical activity in the sport practice domain and total physical activity were related to low RHR in both sexes, while occupational physical activities were associated with RHR only in boys.

Resumo Objetivo Investigar a relação entre diferentes domínios de atividade física e frequência cardíaca de repouso (FCRep) em meninos e meninas. Método A amostra incluiu 1.011 adolescentes, entre 10 e 17 anos. A FCRep foi medida por um monitor de frequência cardíaca e a atividade física foi avaliada no total e em três diferentes domínios (escolar, ocupacional e prática esportiva) através de um questionário. A antropometria foi obtida diretamente para o índice de massa corporal e gordura central. Etnia, comportamento sedentário e tabagismo foram autorrelatados e usados para ajustar a análise, através da regressão linear hierárquica. Resultados A atividade física total foi associada à baixa FCRep nos meninos (β = −0,52; IC95% −0,92; −0,12) e meninas (β = −0,67; IC95% −1,07; −0,28). Embora as atividades físicas esportivas estivessem associadas à baixa FCRep em ambos, meninos (β = −0,58; IC95% −1,05, −0,11) e meninas (β = −0,87; IC95% −1,34, −0,39), a atividade física ocupacional estava relacionada à baixa FCRep apenas em meninos (β = −1,56; IC95% −2,99; −0,14). Conclusão A prática de atividade física no domínio da prática esportiva e a atividade física total foram relacionadas à baixa FCRep em ambos os sexos, enquanto as atividades físicas ocupacionais foram associadas à FCRep apenas em meninos.

Sedentary behavior is more related with cardiovascular parameters in normal weight than overweight adolescents.

This study analyzed the relationship between sedentary behavior and cardiovascular parameters in normal weight and overweight adolescents. The sample included 449 boys and 555 girls with mean age of 13 years from public schools, which were divided into five geographical regions, with data collections performed in one selected school from each region. Sedentary behavior was assessed by screen time on TV, computer, videogame and cell phone/tablet, with good reliability in adolescents. Physical activity was assessed by Baecke's questionnaire, validated for adolescents. Measures of body weight, height and waist circumference were collected. Adolescents were classified as overweight or normal weight by cut-off points of body mass index for age and sex. Cardiovascular parameters were evaluated by oscillometric device and heart rate by specific monitor. Computer use was positively related to systolic blood pressure (SBP) (ß = 0.35; 95%CI = 0.07-0.62) and diastolic blood pressure (DBP) (ß = 0.25; 95%CI = 0.05-0.44) in normal weight but not in overweight adolescents. Similar results were observed for cell phone/tablet in SBP (ß = 0.46; 95%CI = 0.20-0.72) and DBP (ß = 0.36; 95%CI = 0.18-0.54), only for normal weight. The cluster of screen time was related to SBP in normal weight (ß = 0.44; 95%CI = 0.03-0.84) and overweight (ß = 0.60; 95%CI = 0.01-1.19). Screen time in computer and cell phone/tablet was more related to cardiovascular parameters in normal weight than overweight adolescents.

Is physical activity associated with resting heart rate in boys and girls? A representative study controlled for confounders.

OBJECTIVE: Investigate the relationship between different domains of physical activity and resting heart rate (RHR) in boys and girls. METHOD: The sample included 1011 adolescents, aged between 10 and 17 years. RHR was measured by a heart rate monitor and physical activity was assessed in total and in three different domains (school, occupational, and sports practice) by a questionnaire. Anthropometry was directly obtained for body mass index and central fat. Ethnicity, sedentary behavior, and smoking habits were self-reported and used to adjust the analysis, through hierarchical linear regression. RESULTS: Total physical activity was associated with low RHR in boys (ß=-0.52; 95% CI: -0.92, -0.12) and girls (ß=-0.67; 95% CI: -1.07, -0.28). Although sporting physical activities were associated with low RHR in both boys (ß=-0.58; 95% CI: -1.05, -0.11) and girls (ß=-0.87; 95% CI: -1.34, -0.39), occupational physical activity was related to low RHR only in boys (ß=-1.56; 95% CI: -2.99, -0.14). CONCLUSION: The practice of physical activity in the sport practice domain and total physical activity were related to low RHR in both sexes, while occupational physical activities were associated with RHR only in boys.

Screen time by different devices in adolescents: association with physical inactivity domains and eating habits.

BACKGROUND: Sedentary behaviors in adolescents are associated with using screen devices, analyzed as the total daily time in television viewing, using the computer and video game. However, an independent and clustered analysis of devices allows greater understanding of associations with physical inactivity domains and eating habits in adolescents. METHODS: Sample of adolescents aged 10-17 years (N.=1011) from public and private schools, randomly selected. The use of screen devices was measured by hours per week spent in each device: TV, computer, videogames and mobile phone/tablet. Physical inactivity domains (school, leisure and sports), eating habits (weekly food consumption frequency) and socioeconomic status were assessed by questionnaire. RESULTS: The prevalence of high use of mobile phone/tablet was 70% among adolescents, 63% showed high use of TV or computer and 24% reported high use of videogames. High use of videogames was greater among boys and high use of mobile phone/tablet was higher among girls. Significant associations of high use of TV (OR=1.43, 95% CI: 1.04-1.99), computer (OR=1.44, 95% CI: 1.03-2.02), videogames (OR=1.65, 95% CI: 1.13-2.69) and consumption of snacks were observed. High use of computer was associated with fried foods consumption (OR=1.32, 95% CI: 1.01-1.75) and physical inactivity (OR=1.41, 95% CI: 1.03-1.95). Mobile phone was associated with consumption of sweets (OR=1.33, 95% CI: 1.00-1.80). Cluster using screen devices showed associations with high consumption of snacks, fried foods and sweets, even after controlling for confounding variables. CONCLUSIONS: The high use of screen devices was associated with high consumption of snacks, fried foods, sweets and physical inactivity in adolescents.

Obesidade abdominal: prevalência, fatores sociodemográficos e de estilo de vida associados em adolescentes / Abdominal obesity: prevalence, sociodemographic and lifestyle-associated factors in adolescents

INTRODUCTION: Among human development stages, adolescence comprises the period in which intense somatic and behavioural changes occur¹. In this period of life, the presence of detrimental health habits can be consolidated until and into adulthood, and can be a precursor for higher risk of mortality and chronic diseases. OBJECTIVE: The aim of this study was to determine the prevalence of abdominal obesity and its associated factors among adolescents, independent of confounders. METHODS: A sample of 14-17-year-old individuals (n = 1.231), who were students from Londrina/PR - Brazil public schools, was studied. A questionnaire about physical activity, sedentary behaviour and socioeconomic conditions was applied. Anthropometry was composed of body weight (kg), height (m), body mass index (BMI = kg/m²) and waist circumference (cm). The association of abdominal obesity and independent variables was assessed using the chi-square test and the magnitude of associations was verified using Binary Logistic Regression in an unadjusted model and adjusted for confounders (gender, age, socioeconomic status, physical activity and sedentary behaviour). The confidence interval and statistical significance were set at 95% and 5%, respectively, using SPSS v15.0. RESULTS: The abdominal obesity prevalence was 17.5% (CI = 15.4%-19.6%), and was higher in boys than in girls. Adolescents with abdominal obesity had higher values of body weight, height, body mass index and sedentary behaviour compared to eutrophic individuals. Being male increased the risk of abdominal obesity by 36% in adolescents. This risk was two times higher in those with high levels of sedentary behaviour. CONCLUSION: Abdominal obesity was significantly associated with gender and high levels of sedentary behaviour, regardless of confounding factors. Lifestyle habits are important modifiable risk factors that can effectively contribute to the reduction of obesity from an early age.

OBJETIVO: Verificar a prevalência de obesidade abdominal e fatores associados em adolescentes brasileiros, independentemente de fatores de confusão. MÉTODO: Amostra composta por adolescentes de 14 a 17 anos (n = 1.231), alunos de escolas públicas de Londrina/PR-Brasil. Um questionário sobre o nível de atividade física, comportamento sedentário e condições socioeconômicas foi aplicado. A antropometria foi composta por peso corporal (kg), estatura (m), índice de massa corporal (IMC = kg/m²) e circunferência de cintura (cm). A associação entre obesidade abdominal e as variáveis independentes foi verificada pelo teste qui-quadrado e a magnitude das associações verificada por Regressão Logística Binária no modelo não-ajustado e ajustado por confundidores (sexo, idade, nível socioeconômico, atividade física e comportamento sedentário). O intervalo de confiança e a significância estatística foram fixados em 95% e 5%, respectivamente, por meio da utilização do programa estatístico SPSS v15.0. RESULTADOS: A prevalência de obesidade abdominal foi de 17,5% (IC = 15,4%-19,6%) em adolescentes brasileiros, sendo maior em meninos do que em meninas. Indivíduos com obesidade abdominal apresentaram maiores valores de peso corporal, estatura, índice de massa corporal e comportamento sedentário do que indivíduos eutróficos. Ser do sexo masculino elevou em 50% o risco de adolescentes apresentarem obesidade abdominal. Esse risco foi duas vezes maior nos que tiveram elevado comportamento sedentário. CONCLUSÃO: Obesidade abdominal foi associada significativamente ao sexo e ao elevado comportamento sedentário, independentemente de fatores de confusão. Hábitos de vida são importantes fatores de risco modificáveis que podem contribuir efetivamente na redução da obesidade desde idades precoces.