Longitudinal Assessment of Blood Pressure in School-Aged Children: A 3-Year Follow-Up Study.

The purpose of this study was to assess the prevalence of abnormal blood pressure in a population of school children during a 3-year follow-up period and its relationship with obesity. Anthropometric and blood pressure data were collected from a population of Italian school children during three consecutive years. During each year blood pressure measurements were repeated three times, at intervals of 1 week. A total of 564 school-children [311 boys; mean (SD) age 8.8 ± 1.4 years] were recruited. During each year, systolic and diastolic blood pressure decreased from visit 1 to visit 3 (p < 0.001). This was associated with a decline in the percentage of prehypertension/hypertension from visit 1 to visit 3. An abnormal blood pressure value in at least one study visit was found in 8.8-17 % of children, whereas the prevalence of hypertension at all three study visits was between 5.2 and 7.8 %, and that of prehypertension at all three visits was between 2.8 and 3.8 %. High blood pressure was more frequent in obese children. In this population of school children the percentage of prehypertension/hypertension remarkably varied when based on one versus three annual assessments, thus emphasizing the importance of repeated measurement before making a diagnosis of abnormal blood pressure. Adiposity was confirmed to be a determinant of high blood pressure.