Objectives: To determine whether the use of an ambulatory blood pressure monitor (ABPM) is feasible and gives accurate readings in children, and to provide data on normal daily blood pressures (BPs) and BP patterns in children.
Design: Cohort.
Subjects: Ninety-nine healthy fifth-grade students.
Interventions: Students wore an ABPM for 24 hours while recording their activities in diaries. Before and after the study period, each subject had three BPs simultaneously measured with the ABPM and a mercury manometer to assess the accuracy of the ABPM. An activity scale was retrospectively applied to diary entries to help explain the variety of BP patterns noted during data analysis.
Results: Systolic BPs obtained with the ABPM at the beginning and end of the study were slightly higher than those obtained with a mercury manometer; diastolic BPs were virtually identical. A circadian pattern of BPs was noted: mean systolic and diastolic BPs were higher during the day than at night. The BP patterns ranged from "hypoactive" (little baseline variation) to "hyperactive" (wide fluctuations with spikes to elevated BP ranges) during various activities. In general, higher BPs were noted at times of increased activity or emotional levels.
Conclusions: Ambulatory BP monitoring was well tolerated, and measurements were reproducible and accurate. The variety of BP measurements noted at different activity levels indicate that a child's activity should be considered during data analysis. As further experience is gained, the ABPM should prove helpful in diagnosis and management of hypertension in children.