Activity behaviors in schoolchildren and subsequent 5-yr change in blood pressure.

Purpose: This study aimed to establish whether time spent in sport-related physical activities and sedentary behaviors (e.g., TV viewing, videogame usage, and homework) was prospectively associated with change in blood pressure (BP) for 5 yr.

Methods: Eight hundred and twenty-one students age 6 yr at baseline (397 girls and 424 boys) were examined from 2003-2004 to 2009-2011. Children completed detailed activity questionnaires. BP was measured using a standardized protocol.

Results: After adjusting for age, ethnicity, parental education, parental history of hypertension, baseline height, BP, body mass index (BMI), baseline time spent in corresponding activity behavior, and change in BMI, each hour per day spent in total screen time was associated with a 0.69 and 0.59 mm Hg increase in diastolic BP (P = 0.01) and mean arterial BP (P = 0.01), respectively. In boys, each hour per day spent in TV viewing was associated with a concurrent 1.42-mm Hg increase in diastolic BP (P = 0.04) during the 5 yr. Children engaging in low sport-related physical activities at baseline but who engaged in high levels of physical activity (≥ 60 min · d(-1)) at follow-up (n = 154) compared with those engaging in low sport-related physical activities at both examinations (n = 305) demonstrated significantly lower mean arterial BP, 7.26 versus 9.61 mm Hg (P = 0.04).

Conclusions: Time spent in physical activity and screen time could influence BP measures during childhood.