NOCTURNAL HOME VERSUS AMBULATORY BLOOD PRESSURE MONITORING IN CHILDREN AND ADOLESCENTS: ASSOCIATION WITH PRECLINICAL TARGET-ORGAN DAMAGE

Abstract

Abstract Objective: To evaluate the relationship between nighttime blood pressure (BP) assessed by home (HBP) or ambulatory (ABP) monitoring with preclinical damage in children and adolescents. 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) 7-day HBP monitoring during daytime (duplicate morning and evening measurements) and nighttime (3 nights, 3 readings/night) (Microlife WatchBP Home-N), and measurement of (iii) carotid intima-media thickness (cIMT) and carotid distensibility coefficient (cDC), (iv) carotid-femoral pulse wave velocity (PWV; Complior device), and (v) echocardiographic left ventricular mass index (LVMI). Results: 94 individuals were analyzed (mean age 13.2 ± 2.8 years, 54 males, BMI 24.8 ± 5.2 kg/m2, 18 with 24 h ABP > 95th centile). Daytime HBP was slightly lower than daytime ABP (difference -2.0 ± 6.4/-0.8 ± 5.0 mmHg, systolic/diastolic, p < 0.01/NS), whereas nighttime HBP was slightly higher than nighttime ABP (2.5 ± 7.1/2.1 ± 6.2 mmHg, p < 0.01/ < 0.01). There was a strong association between ABP and HBP (daytime r = 0.83/0.79 and nighttime 0.79/0.60, systolic/diastolic) (all p < 0.05). Nighttime systolic ABP and HBP were associated with all indices of target-organ damage (LVMI r = 0.36/0.30 for ABP/HBP; cIMT 0.47/0.49; cCD -0.31/-0.25; PWV 0.50/0.56 (p = NS for HBP-ABP comparisons). The agreement between nighttime HBP and ABP in identifying: (i) subjects with asleep ABP > 90th percentile was 73% (kappa 0.38, p < 0.01) and (ii) non-dippers 55% (kappa 0.16). Conclusions: These results suggest that in children and adolescents nocturnal HBP monitoring is feasible, is strongly correlated with nighttime ABP and gives similar correlations with preclinical target-organ damage. The agreement between these methods in identifying individuals with nocturnal hypertension is satisfactory, whereas for non-dippers it is moderate.