Background: Studies using ambulatory blood pressure (BP) monitoring have shown that in children and adolescents masked hypertension (MH) is not uncommon. This school-based study investigated the prevalence and the characteristics of MH diagnosed using home BP measurements.
Methods: A total of 765 subjects aged 6-18 years were assessed with office (two visits, six readings) and home BP measurements (3 days, 12 readings). Office hypertension was diagnosed using the US Task Force normalcy tables and home hypertension using the Arsakeion normalcy tables (> or = 95th percentile for both). White-coat hypertension (WCH) was defined as office hypertension but low home BP (<95th percentile) and MH as home hypertension but low office BP (<95th percentile).
Results: On the basis of office BP measurements of the first visit 3.3% of participants had MH, 5.9% WCH, and 2.7% hypertension compared to 4.2, 2.1, and 1.8%, respectively, when a two-visit-average BP was used (P < 0.001 vs. first visit). Subjects with MH or WCH did not differ from hypertensives or normotensives regarding age, gender, or height. However, weight, body mass index (BMI), waist and hip circumference, and office and home BP values fell in between those of normotensives and hypertensives. Prehypertension (office BP: 90-95th centile) and increased BMI were independent predictors of MH.
Conclusions: In children and adolescents MH detected by home BP monitoring is not uncommon and is associated with prehypertension and overweight. Repeated office measurements are essential for the precise diagnosis. MH and WCH in children appear to be intermediate phenotypes of hypertension.