Introduction
The association between physical activity (PA) and resting blood pressure (BP) is poorly understood in adolescents (Kelley, Kelley, & Tran, 2003), since several variables such as body composition, maturation level or sex, which interfere with, must be analyzed (Muntner, He, Cutler, Wildman, & Whelton, 2004). Therefore, the aim of this study was to explore the association of PA, body composition, blood pressure, and maturation in adolescent boys and girls.
Methods: Two hundred and nine (n=114 boys, n=95 girls) healthy adolescents (15.6±1.6 years, 21.9±4.3 BMI) were volunteers. A PA score was estimated by Physical Activity Questionnaire (PAQ-A). BMI, waist circumference (WC) and fat mass percent (%FM) were assessed by anthropometric measurements as adiposity markers. Tanner’s maturation stages were evaluated and systolic and diastolic blood pressure (SBP and DBP) were measured by OMRON sphygmomanometer. SBP and DBP indexes (SBPI and DBPI) were calculated as mmHg/height (cm). Spearman rank order correlations were used to explore associations between variables after control to maturation.
Results: All the relationships between parameters showed a positive correlation. There were significant associations between BP variables and BMI (SBP r=0.202, P<0.01; DBP r=0.305, P<0.001), and WC (SBP r=0.197, P<0.01; DBP r=0.295, P<0.001). PA score was only related with body composition variables either girls or boys. Also, there were significant correlations between %FM and BP variables (SBP r=0.332, P <0.01; DBP r=0.330, P<0.01; DBPI r=0.308, P <0.01) in girls but not in boys.
Discussion: Our data confirm the relationship between BP and body composition variables as WC and BMI (Rosa, Fonseca, Oigman, & Mesquita, 2006). Nevertheless, we could not find any association between PA and BP. The recently developed SBPI and DBPI were not better associated with any variable than simple BP. These results should be considered carefully since measuring physical activity by objective methods could have changed the conclusions. So, other studies have reported a negative association between PA measured by accelerometry and BP (Hearst, Sirard, Lytle, Dengel, & Berrigan, 2012; Kelley, Kelley, & Tran, 2003). Further prospective studies using accelerometry or larger samples must be need in order to explore deeply the impact of PA on BP in adolescents.
References
Hearst, M. O., Sirard, J. R., Lytle, L., Dengel, D. R., & Berrigan, D. (2012). J Phys Act Health, 9(1), 78-85.
Kelley, G. A., Kelley, K. S., & Tran, Z. V. (2003). Prev Cardiol, 6(1), 8-16.
Muntner, P., He, J., Cutler, J. A., Wildman, R. P., & Whelton, P. K. (2004). JAMA, 291(17), 2107-2113.
Rosa, M. L., Fonseca, V. M., Oigman, G., & Mesquita, E. T. (2006). Arq Bras Cardiol, 87(1), 46-53.