Physical Activity and Blood Pressure in 11 Year Old Children

Abstract

Cardiovascular disease (CVD) is the leading cause of adult death in Western societies. The pathological processes associated with its development are initiated early in life; for example, elevated blood pressure (BP) can be seen in childhood, and has been shown to track into adulthood. There is a well-established relationship between physical activity (PA) and BP in adults, but few studies have investigated this in children, using an objective measure of PA. PURPOSE: To establish whether there is an association between objectively measured PA and BP in children. METHODS: Children aged 11 to 12 were recruited from a large birth cohort- the Avon Longitudinal Study of Parents and Children, and asked to wear a uniaxial accelerometer for seven days. Accelerometer counts per minute (cpm) and minutes per day spent in moderate to vigorous physical activity (MVPA) were derived, and children included if they had data for at least 10 hours on at least three days. The means of two BP readings taken using an automatic BP monitor were calculated. Data on a number of possible confounders were also available. RESULTS: Analyses were based on 5505 children. Associations between PA and BP after minimal and full adjustment for possible confounders are shown below:TableaAdjusted for age, gender (N=5505) bAdjusted for age, gender, BP measurement factors, social factors, maternal factors, current size, birthweight, gestation, puberty (N=2675). When cpm and MVPA were entered into models simultaneously, associations with cpm remained similar, while those with MVPA were reduced. CONCLUSIONS: Increases in PA at age 11 were associated with small reductions in BP, and the amount was more important than the intensity of activity.