Optimal nighttime blood pressure monitoring schedule using home monitors in children and adolescents: association with ambulatory blood pressure and preclinical target-organ damage.

Nighttime blood pressure assessed by home monitors (HBP) appears to be a feasible and reliable alternative to ambulatory blood pressure (ABP) monitoring in adults. This study evaluated the optimal schedule for nighttime HBP monitoring in children and adolescents in terms of its agreement with nighttime ABP and association with preclinical target organ damage (TOD). Individuals aged 6-18 years referred for elevated blood pressure were evaluated with ABP (24 h) and HBP monitoring (daytime: 7 days, duplicate morning and evening measurements; night-time: 3 nights, 3 automated asleep measurements at 1-hour interval/night), as well as with determination of left ventricular mass index (LVMI), carotid intima-media thickness (cIMT) and carotid-femoral pulse wave velocity (PWV). Forty-nine children with all 9 nighttime HBP measurements (3 nights) were analyzed [mean age 13.4 ± 2.7 (SD) years, males 51%]. By averaging an increasing number of nighttime systolic HBP readings, there was a consistent trend towards stronger association with nighttime ABP (correlation coefficients r increased from 0.65 to 0.81), and with TOD indices (for LVMI r increased from 0.21 to 0.30; cIMT from 0.38 to 0.57; PWV from 0.60 to 0.69). However, no further improvement in these associations was observed by averaging more than 4 nighttime readings. The diagnostic agreement between the 2 methods in detecting nocturnal hypertension was progressively improved by averaging more nighttime HBP readings, and reached a plateau at 4 measurements. Four nighttime home BP measurements, performed during at least 2 nights appear to be the minimum requirement for a reliable assessment of nighttime HBP in children and adolescents, regarding its agreement with ABP and association with TOD. HBP monitoring in children and adolescents constitutes an alluring alternative to ABP monitoring concerning nighttime BP measurements since it provides reasonable agreement with ABP measurements and similar association with target organ damage indices. The optimal nighttime HBP schedule requires at least 4 nighttime home BP measurements, performed during at least 2 nights, which is in line with similar studies in adults.