P-70: Reproducibility of home and ambulatory blood pressure in children and adolescents

To evaluate the reproducibility of home blood pressure (HBP) in comparison to ambulatory (ABP) and clinic blood pressure (CBP) in children and adolescents. Fourteen subjects referred for elevated CBP were included (mean age 13.1±2.8 [SD] years, range 8 to 17, 8 boys). According to Task Force CBP criteria, 6 subjects were classified as hypertensives, 3 as borderline hypertensives and 5 as normotensives. CBP was measured in 2 visits, HBP on 5 days and ABP for 24 hours. A second session including all the above CBP, HBP and ABP measurements was performed after 8 weeks. The reproducibility of the CBP (average of 2nd visit of each session), HBP (average of days 2–5 of each session) and ABP (average 24-hour, awake and asleep) was quantified using test-retest correlations coefficients and the standard deviation of differences between repeated measurements. The reproducibility of HBP was superior to that of CBP. ABP appeared to provide the most reproducible values whereas aspects of the diurnal BP variation were poorly reproducible (Table). Test-Retest Corellation-Coefficient (systolic/diastolic) Standard Deviation of Differences (systolic/diastolic) Clinic BP 0.62/0.62 11.2/5.9 Home BP 0.73/0.65 7.1/4.1 24-hour ABP 0.89/0.79 5.4/3.6 Awake ABP 0.88/0.75 5.8/3.8 Asleep ABP 0.70/0.59 7.4/5.2 Awake-Asleep ABP difference 0.59/0.22 7.0/5.3 Awake:Asleep ABP ratio 0.49/0.18 0.07/0.11 These data suggest that home BP measurements are more reproducible than clinic BPs. However, ambulatory BP monitoring appears to provide the most reproducible blood pressure values. The nocturnal decline in ambulatory BP is poorly reproducible.