Bovha Hus K, et al. - Researchers compared the reliability of 48-hour ambulatory blood pressure monitoring (ABPM) to that of 24-hour monitoring in order to attenuate the influence of external factors on blood pressure (BP) in children. They performed 48-hour ABPM in 215 children with indications for ABPM. The study was conducted in 3 parts. Between the first 24 hours and the total 48 hours, they compared the values of systolic BP, diastolic BP and heart rate in the first part. They compared the same parameters between the first and second 24 hours in the second part. In the third part, they investigated if the variations in measurements between the first and second 24 hours had clinical importance and implied a change of diagnosis. Within certain limits, findings are indicative of a superior reliability of 48-hour ABPM vs 24-hour ABPM, where particularly the second 24 hours represent a duration of measurement that is recommended to be taken into account for this purpose. The possible influence of these findings on the diagnostics of arterial hypertension in children is suggested.