Twenty-four hour blood pressure monitoring in healthy children.

Blood pressure and heart rate were measured every 20 min during the day and every 30 min during the night in 105 children (51 girls and 54 boys, aged 6-10 years) with a portable automated blood pressure monitor using an oscillometric principle of measurement. The monitor was well accepted by most of the children and the rate of invalid measurements was only 13%. Mean systolic and diastolic blood pressure was 114 +/- 7/72 +/- 5 by day and 99 +/- 7/56 +/- 6 by night. The corresponding heart rates were 93 +/- 8 and 72 +/- 9 beats/min. No significant differences were found between boys and girls. At night, systolic blood pressure dropped by 13% +/- 4%, the diastolic value by 22% +/- 7% and heart rate fell by 22% +/- 6%. Mean systolic and diastolic blood pressure measurements correlated positively with the subject's height, whereas no correlation was found with age.