Determinants of rise in blood pressure in normotensive children.

Thirty-nine initially normotensive children (25 girls) with a large increase in systolic blood pressure (SBP) over a period of 7 years were compared with 78 children with a small increase, matched for age and gender. They were selected from a random sample of 596 Dutch children who were examined at an initial examination and 4 weeks later, and at yearly intervals thereafter. Body weight, height and Quetelet index at baseline were similar in children with a large rise in SBP and those with a small rise. Children with a large increase had a larger weight gain during follow-up than those with a small rise. Parental blood pressure (BP) and parental history of diabetes mellitus and cardiovascular diseases did not differ between the study groups. Cardiovascular reactivity as assessed by a cold-pressor test at baseline did not differ between the study groups, nor did urinary sodium excretion during follow-up. Total tobacco consumption was larger in those with a small increase. Children with a large rise in SBP experienced a larger fall in SBP from the initial to the 4-week examination. The individual variability of BP over the whole observation period did not differ between the study groups. These observations suggest that a fall in BP after a short follow-up period may be indicative of high BP in the years to come.