Changing relationship between home and office blood pressure with increasing age in children: the Arsakeion School study

BACKGROUND: Home blood pressure (HBP) monitoring is being used in children. However, there is no information on the relationship between HBP and office measurements (Office BP (OBP)) in this population. METHODS: This school-based study investigated the effect of age on the difference between HBP and OBP in 765 healthy subjects aged 6-18 years (mean age 12 +/- 3 (SD years)). HBP (3 days, 12 readings) and OBP (2 visits, 6 readings) were measured using electronic devices validated in children (Omron 705IT). RESULTS: Average OBP was slightly lower than HBP by 0.6+/- 7.0 mm Hg (95% confidence intervals (CI) 0.1, 1.1, P=0.01) systolic and 1+/- 6 mm Hg (95% CI 0.7, 1.6, P<0.0001) diastolic, whereas pulse rate was higher in the office by 7+/- 10 beats/min (95% CI 6.2, 7.6, P<0.0001). Age was significantly correlated with the OBP-HBP difference (r = 0.13/0.24 for systolic/diastolic, P< 0.001). In the younger children (6-12 years), both diastolic and systolic HBP were higher than OBP, whereas pulse rate was higher in the office. In older children and adolescents, the BP difference was eliminated whereas the pulse rate difference was reduced but remained significant. These changes with age were similar in boys and girls. CONCLUSIONS: In the pediatric population OBP appears to be higher than HBP. This difference is reduced with advancing age and eliminated after the age of 12 years. These data should be taken into account in the assessment of HBP in children and adolescents.