Abstract Objective: To evaluate the optimal schedule of nighttime blood pressure (BP) assessed by home monitoring (HBP) in children and adolescents in terms of agreement with nighttime ambulatory (ABP) and association with preclinical target-organ damage. Design and method: Apparently healthy children and adolescents (age 6–18 yeas) referred for elevated BP were subjected to (i) 24 h ABP monitoring (Microlife WatchBP O3), (ii) HBP monitoring during daytime (7 days, duplicate morning and evening measurements) and nighttime (3 nights, 3 hourly readings/night; Microlife WatchBP Home-N), (iii) carotid intima-media thickness (cIMT) measurement, (iv) carotid-femoral pulse wave velocity (PWV; Complior device; duplicate measurements), and (v) echocardiographic left ventricular mass index (LVMI). Results: 49 children and adolescents were analysed (mean age 13.4 ± 2.7 years, 25 males, BMI 24.3 ± 4.9 kg/m2, 14 with 24 h ABP > 95th percentile).). There was no difference in nighttime HBP between the 3 nights (1st 109.7 ± 10.9/60.8 ± 7.3 mmHg, systolic/diastolic; 2nd 109.1 ± 11.7/59.7 ± 8.6; 3rd 109.1 ± 11.5/60.4 ± 8.4, p = NS). By averaging an increasing number of nighttime systolic HBP readings, there was a consistent trend towards stronger association of nighttime HBP with nighttime ABP (correlation coefficients r increased from 0.65 to 0.81), and with target-organ damage (for LVMI r increased from 0.21 to 0.30; cIMT from 0.38 to 0.57; PWV from 0.60 to 0.69). No further improvement in the associations was observed by averaging more than 4 nighttime HBP readings. Conclusions: In line with findings in adults, in children and adolescents 2-night HBP schedule (6 readings) appears to be the minimum requirement for a reliable assessment of nighttime HBP, which gives reasonable association with ABP and preclinical organ damage.
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