Blood pressure (BP) is a practical and useful measure of cardiovascular health in youth.
This study aims to examine the dose-response relationship between objectively measured PA and BP in children and adolescents.
The sample included 1170 youth aged 8-17 yr from the 2003/04 U.S. National Health and Nutrition Examination Survey. PA was measured using Actigraph accelerometers (Ft. Walton Beach, FL, USA) over 7 d.
Thresholds of 2000 and 3000 counts per minute were used to denote those minutes where the participants were engaged in total PA and moderate-to-vigorous intensity PA, respectively. BP was measured using standard procedures.
Systolic and diastolic BP values were adjusted for age, height, and sex.
Participants with adjusted BP values > or = 90th percentile were considered to have hypertension. Thirty-six fractional polynomial regression models were used to obtain the dose-response curve that best fit the relation between PA with systolic BP, diastolic BP, and hypertension.
Inverse dose-response relations were observed between total and moderate-to-vigorous PA with systolic and diastolic BP. The slopes of the curves were modest indicating a minimal influence of PA on mean BP values.
The likelihood of having hypertension decreased in a curvilinear manner with increasing minutes of PA. At 30 and 60 min.d of moderate-to-vigorous PA, the odd ratios (95% confidence intervals) for hypertension were 0.50 (0.28-0.64) and 0.38 (0.17-0.52), respectively, in comparison to no PA.
A modest dose-response relation was observed between PA and mean systolic and diastolic BP values. PA did, however, have a strong gradient effect on BP when predicting hypertensive values.
These results support the public health recommendation that children and youth accumulate at least 60 min of moderate-to-vigorous PA daily.
DOI - Medicine and science in sports and exercise (DOI)