Background: The aim of this study was to explore the circadian blood pressure (BP) rhythm using ambulatory BP monitoring (ABPM) in normotensive children with a family history of essential hypertension.

Methods: Group 1 consisted of children with hypertensive mothers and/or fathers (n = 20), Group 2 consisted of children with hypertensive grandparents (n = 20), and Group 3 consisted of children with normotensive parents (n = 20). All participating children underwent a 24-h ABPM and echocardiography.

Results: Significantly higher systolic burden was found in children with hypertensive parents (p < 0.05) and grandparents (p < 0.05) compared to controls. Ambulatory BP measurements had a higher daytime systolic BP in Group 1 compared to controls (p < 0.05). While left ven­tricular (LV) posterior wall thickness was similar in Group 1 and Group 2, it was significantly higher in both of these groups compared to the controls. The LV mass index (LVMI) was signifi­cantly higher in Group 1 than in controls (p < 0.05). However, diastolic BP was significantly higher in dippers compared to non-dippers (p < 0.05). LV posterior wall thickness, interven­tricular septum thickness and LVMI were significantly higher among non-dippers compared to dippers (p < 0.05). In children with a family history of hypertension, a positive correlation between nocturnal systolic BP and LVMI was found, and increasing nocturnal BP values were associated with increasing LVMI (p < 0.01).

Conclusions: In children with a family history of hypertension, target-organ damage may precede the clinical detection of hypertension, and in those with a nocturnal non-dipper status, a more marked effect on LVMI may occur.