The relationship between weight gain and blood pressure in children and adolescents

Background: The aim of this study was to determine the relationship between the trajectories of weight gain and systolic blood pressure (SBP) in youth. Methods: Annual surveys of anthropometry, fitness, SBP, and its determinants (cardiac output, systemic vascular resistance, and arterial compliance) were conducted in youth (aged 5 to 19 years) in a school-based setting between 2004 and 2006. Children were stratified according to change in body mass index (BMI) over time. Results: Within the entire cohort (n = 2089), mean SBP (121 +/- 16 SD v 112 +/- 15 SD mm Hg; P < .01) and the prevalence of high blood pressure (48% v 18%, P < .01) were significantly higher and fitness levels were lower (P < .01) in obese children, relative to healthy-weight peers. After 2 years of follow-up, despite similar SBP and BMI at baseline, the average change in SBP was similar to 4.5-fold greater in children with the largest increase in BMI, relative to children who experienced minimal weight gain. This group also experienced a significantly greater increase in stroke volume (P < .05), while the change in heart rate, arterial compliance, and systemic vascular resistance was comparable with that of children who experienced minimal weight gain. Multiple linear regression analysis revealed that SBP increased 0.77 mm Hg for every kilogram of weight gain over a period of 2 years (P < .01). Conclusions: Overweight and disproportionate weight gain in children are associated with elevated SBP. These data support the need for interventions to prevent excessive weight gain and obesity in children and adolescents.