24-hour ambulatory blood pressure monitoring (ABPM) provides more accurate assessment of blood pressure (BP) in the patient’s common environment. The results of ABPM in the adult population have a much better correlation with end organ damage than casual blood pressure and seem to provide more sensitive data of the general prognosis in terms of morbidity and mortality. The objective of this study was to evaluate the ABPM in a setting close to a population study. 115 children and adolescents aged 8 - 20 years (82 boys and 33 girls) with repeatedly elevated conventional BP readings in 25 primary care physicians’ and pediatricians’ offices were included to participate in this study in the course of two years. Based on the results of the ABPM 51 subjects (44%) were labelled as white coat hypertension (WCH). Of 64 hypertensive subjects 7 (11%) were known to have a secondary cause of hypertension, the rest - 57 (89%) were assumed to suffer from essential hypertension. The nocturnal dipping of blood pressure was significantly lower in hypertensive subjects when compared with WCH (the difference of systolic dipping was 2.7% on average, p = 0.003; the difference of diastolic dipping was 2.5%; p = 0.04). 24-hours pulse pressure values were significantly higher in hypertensive subjects (59.6 ± 7.3 mm Hg) compared with WCH (53.3 ± 5.3 mm Hg); p < 10 -5 . The left ventricular measurements in hypertensive subjects were higher when compared with WCH (left ventricle posterior wall thickness 8.4 ± 1 mm in hypertensive vs. 8.0 ± 1.1 mm in WHC (p = 0.047) and left ventricular mass index 81.8 ± 13.8 g/m 2 vs. 74.3 ± 12 g/m 2 respectively; p = 0.003).

        Key words: ambulatory blood pressure monitoring (ABPM), white coat hypertension, children, hypertension,