Is rest-activity rhythm prospectively associated with all-cause mortality in older people regardless of sleep and physical activity level? The 'Como Vai?' Cohort study.

OBJECTIVE: This study aims to test the association of rest-activity rhythm (intradaily variability and interdaily stability) with all-cause mortality in an older adult cohort in Brazil. It also assesses whether the amount of time spent at each intensity level (i.e., physical activity and nocturnal sleep) interferes with this association. METHODS: This cohort study started in 2014 with older adults (≥60 years). We investigated deaths from all causes that occurred until April 2017. Rest-activity rhythm variables were obtained using accelerometry at baseline. Intradaily variability indicates higher rhythm fragmentation, while interdaily stability indicates higher rhythm stability. Cox proportional-hazard models were used to test the associations controlling for confounders. RESULTS: Among the 1451 older adults interviewed in 2014, 965 presented valid accelerometry data. During the follow-up period, 80 individuals died. After adjusting the analysis for sociodemographic, smoking, morbidity score, and number of medicines, an increase of one standard deviation in interdaily stability decreased 26% the risk of death. The adjustment for total sleep time and inactivity did not change this association. On the other hand, the association was no longer significant after adjusting for overall physical activity and moderate to vigorous physical activity. CONCLUSION: Rest-activity rhythm pattern was not associated with mortality when physical activity was considered, possibly because this pattern could be driven by regular exercise. Promoting physical activity remains a relevant strategy to improve population health.

Health inequalities in Brazilian adolescents: Measuring and mapping gaps in a cross-sectional school-based survey.

Background and Aims: This study aims to describe inequalities in health indicators according to gender, area of residence, and socioeconomic position among Brazilian adolescents. Methods: Cross-sectional study using data from a school-based survey carried out in Brazil in 2019. Twelve health outcomes were evaluated. Dimensions of inequality assessed were gender, area of residence, wealth and subnational region. Results: This study comprises a sample of 124,898 adolescents. The most prevalent outcome was physical inactivity (71.9%) followed by thinking life is worthless (52.6%) and bullying (51.8%). Gender inequalities were more marked for physical inactivity and thinking life is worthless with girls presenting a prevalence more than 20 p.p. higher than boys. In zero-dose HPV, however, the prevalence in girls was 17.7 p.p. lower than in boys. Area of residence and wealth inequalities were smaller than gender disparities. Context presented a relevant role in inequality with analysis stratified by states of the country, revealing high variability in estimates. Conclusions: We highlight the need for attention to disparities between subgroups of the adolescent population, especially for gender inequalities that were the most marked for this age group.

Objectively measured physical activity according to the periods of the day in the Pelotas Cohort / Medida objetiva de atividade física de acordo com períodos do dia em uma coorte de Pelotas

This study aims to describe objectively measured physical activity (PA) in different periods of the day in young adults according to sex, socioeconomic position and during weekdays and weekends. This is a cross-sectional analysis carried out with the participants of the 1993 Pelotas Birth Cohort at 22 years. PA was assessed by triaxial accelerometer. Descriptive analyses were performed presenting the time spent on light PA (LPA) and bouted moderate to vigorous PA (MVPA) in different periods of the day (morning - 6am to 11:59 am, afternoon ­ 12pm to 7:59 pm and night ­ 8pm to 11:59pm). The present study included 2,766 individuals (48.2% male and 51.8% female). LPA was higher among women, while bouted MVPA levels were higher among men. The median of PA was higher on weekdays compared to weekends for all intensities. The bouted MVPA medians in the morning and at night were zero minutes for all days and both sexes. The richest group presented a higher percentage of individuals with zero minutes. PA may vary according to different periods of the day and intensity. The absence of PA practice was markedly influenced by sex and socioeconomic position

Este estudo teve o objetivo de mensurar atividade física (AF) objetivamente em diferentes períodos do dia em adultos jovens de acordo com sexo, posição socioeconômica e dia de semana e final de semana. Esta é uma análise transversal conduzida com participantes da Coorte de Nascimentos de 1993 de Pelotas aos 22 anos. AF foi avaliada por um acelerômetro triaxial. Foram realizadas análises descritivas apresentando o tempo em AF leve (AFL) e moderada a vigorosa (AFMV ) em diferentes períodos do dia (manhã ­ 6h às 11:59h, tarde ­ 12h às 19:59h e noite ­ 20h às 0h). O presente estudo incluiu 2.766 individuos (48.2% homens e 51.8% mulheres). AFL foi maior entre as mulheres enquanto AFMV foi maior entre os homens. A mediana de AF foi maior nos dias de semana comparado aos dias de final de semana para qualquer intensidade. As medianas de AFMV pela manhã e noite foram zero minutos para todos os dias nos dois sexos. O grupo econômico mais alto apresentou maior percentual de individuos com zero minutos de AFMV. AF pode variar de acordo com diferentes períodos do dia e intensidades. A ausência de prática de AF foi marcadamente influenciada por sexo e posição socioeconômica