Twenty-four-hour ambulatory blood pressure monitoring in young children.

Twenty-four-hour ambulatory blood pressure monitoring (ABPM) has many advantages for the diagnosis and follow-up of hypertension at all ages. This technique has so far not been documented as applicable to the very young. We studied the feasibility of ABPM in 61 healthy children and in 40 patients with renal diseases and/or hypertension, aged less than 6 years. A satisfactory ABPM profile (recording time = 24 h and > 30 good recordings) was obtained in 77% of the healthy children. The mean number of good blood pressure (BP) measurements per 24 h increased with age from 46 (3-4 years) to 58 (6 years). The mean (+/- SD) systolic and diastolic BPs of healthy 3- to 6-year-old children (n = 47) were 110 +/- 5/67 +/- 5 mmHg during the day-time and 100 +/- 5/58 +/- 5 mmHg at night. In addition to the nocturnal decrease in BP, ABPM detected a second, day-time dip in BP during bed rest after lunch. Ninety percent of patients with renal disease and/or hypertension had successful ABPM recordings for 24 h, with an age-dependent increase in the mean number of reliable readings from 34 (< 2 years) to 48 (4 years). In 5 of 10 children with hypertensive results obtained by casual BP measurements, elevated BP was not confirmed by ABPM. We conclude that ABPM is a useful tool for the diagnosis and evaluation of hypertension in children under 6 years of age.