Repeated ambulatory blood pressure monitoring in adolescents with mild hypertension

The reproducibility of serial measurements of ambulatory blood pressure monitoring (ABPM) has not been well explored in children. We performed 24-h ABPM in 59 subjects (38 boys) aged 8–19 years with repeatedly elevated casual blood pressure (BP). According to the results of ABPM, the individuals were divided into a hypertensive group (mean 24-h systolic or diastolic BP >95th percentile for height, n=28) and a normotensive group (n=31). No antihypertensive agents were given. Both groups were reexamined after 1 year. In the hypertensive group, systolic and diastolic BP dropped significantly by an average of 2.1–4.5 mmHg when measured either during the daytime or over 24 h, but not at nighttime. In the normotensive group, only small BP changes were observed except for a significant increase in systolic BP at night. At the repeat examination after 1 year, 54% of the originally hypertensive subjects were defined as normotensive and 23% of the originally normotensive subjects as hypertensive. The study indicates that a single ABPM measurement is not sufficient for definitive classification of young individuals into hypertensives or normotensives.