Blood pressure tracking in children and adolescents

High blood pressure is a major risk factor for cardiovascular disease. Blood pressure tracking could help to identify individuals with potential hypertension. Therefore, we have asked whether or not tracking was of predictive value for the development of hypertension in early life. Blood pressure was routinely measured in 13,261 children and adolescents in outpatient clinics as well as during hospitalization. In one analysis, 568 individuals with elevated and normotensive blood pressure values were evaluated after 2, 4, and 6 years of follow-up. In a second analysis, 2,157 individuals with normotensive blood pressure were examined in a paired t test. The follow-up analysis showed a significant tracking effect. However, the Pearson correlation coefficients of the systolic and diastolic blood pressure standard deviation scores (SDS) decreased over time. Upon the follow-up after 6 years, 35.6 % of the children and adolescents with elevated blood pressure values remained in the elevated range group. Of the children within the normotensive blood pressure range, 80.4 % remained normotensive after 6 years. Children with normotensive blood pressure showed a stronger tracking than those who had had one hypertensive blood pressure reading. Children with higher body mass index (BMI) at follow-up changed blood pressure SDS track from initially normal to higher blood pressure values. Blood pressure tracking in children and adolescents is moderate. We conclude that the predictive power of a single hypertensive blood pressure measurement during a single visit is rather small, and thus repetitive measurements across several consecutive visits are necessary.