Physical Activity, but Not Body Mass Index Is Associated With Blood Pressure in Young Children.

Purpose: This study examined associations between physical activity (PA) and obesity with blood pressure (BP) in young children. Furthermore, a possible moderating effect of obesity status was examined.

Methods: A cross-sectional study was completed with 121 children (3.96 [1.14] y). BP, weight, and height were measured, and body mass index (BMI) was calculated. Z scores were calculated for BMI, systolic, and diastolic values. Accelerometry measured time spent in PA intensities. Correlations and regressions examined relationships among PA intensities, BMI z scores, and BP z scores and to determine if obesity status moderated these relationships.

Results: On average, the children spent 52 minutes per day in moderate-to-vigorous physical activity, 31% were considered overweight/obese, and 15% were considered hypertensive. After adjusting for confounders, participation in moderate, vigorous, and moderate-to-vigorous physical activity was related with lower systolic and diastolic BP z scores (P < .05). BMI z score was not related to BP values. Obesity status did not moderate the relationships between time spent in PA and BP.

Conclusions: Participation in PA, but not obesity, was related to lower BP levels in young children. The impact PA has on BP is the same regardless of obesity status. Thus, young children should be encouraged to be active in different intensities to benefit the cardiovascular system.