In school-aged children 8-10 years old, blood pressure increases significantly with age and is strongly determined by weight and heart rate.
This paper describes the distribution of systolic and diastolic blood pressures in a homogeneous population of 1330 schoolchildren (81% of the eligible population) aged 8-10 years in Odense, Denmark. A single blood pressure measurement was made. No significant difference in mean blood pressure between the sexes could be demonstrated. A significant age-related increase in systolic blood pressure of 4.4 mmHg/year and in diastolic blood pressure of 3.4 mmHg/year was observed. Weight and the heart rate were important determinants of blood pressure level. Other positive determinants were age and triceps skinfold thickness. There was a significant association between diastolic blood pressure and sexual maturation, which seemed to depend on body weight.
Hansen et al. (Sun,) studied this question.