Número de passos para discriminar pressão arterial elevada em jovens: quantos são o suficiente?

Abstract

The relationship between physical activity and blood pressure (BP) in children and adolescents has been extensively studied. However, step count cut-off points that discriminate high BP in the pediatric population are still uncertain. Thus, this study aimed to determine how many steps per day are enough to discriminate high BP in children and adolescents. Cross-sectional study involving 1,044 schoolchildren (456 boys) aged 6 to 17 years from the city of Amargosa, Bahia, Brazil. Blood pressure was measured and a high BP was defined as a systolic or diastolic value ≥ 95th percentile according to sex, age and height. The number of daily steps was estimated with a pedometer. Receiver operating curves were constructed and the area under the curve, sensitivity, specificity and 95% confidence interval (CI) were calculated, with analyzes separated by sex. The prevalence of high BP was 27.8%. Step count was a predictor of high BP in both boys (accuracy = 0.55; 95%CI: 0.51-0.60) and girls (accuracy = 0.58; 95%CI: 0.54-0.62). The cut-off points with the best balance between sensitivity and specificity were 14,228 steps for boys and 10,796 for girls. Pedometer-de-termined daily step count was a predictor of high BP in the children and adolescents studied. In practical terms, the use of 14,000 and 11,000 steps per day is recommended to discriminate high BP in young boys and girls, respectively. These findings could be useful to support actions designed to cope with high BP in childhood and adolescence.