Tracking of blood pressure from childhood to adolescence in a Greek cohort

Background: Studies have reported tracking of blood pressure (BP) from childhood to adulthood but with inconsistent results mainly due to methodological and ethnic differences. We aimed to examine BP tracking during a 7-year period in a Greek cohort. Methods: This is a longitudinal school-based study conducted during 1990-96 in Athens, Greece. Children underwent BP and anthropometric measurements on two to three visits annually (averaged to annual values) for 7 years. Results: A total of 166 children with complete yearly follow-up data for the examined period were included (mean baseline age 9 +/- 1.7 years, range: 5-12 years, 89 boys). At baseline, the prevalence of pre- and hypertension was 22.9 and 24.1% respectively and at the end of the follow-up 24.1% (P = NS vs. baseline) and 13.3% (P = 0.02 vs. baseline) respectively. Systolic/diastolic BP tracking correlation coefficients between 1990 and 1996 were 0.38 (P < 0.001)/0.20 (P = 0.06) for boys and 0.30 (P = 0.007)/0.22 (P = 0.06) for girls. Among children with baseline BP epsilon 90th centile (systolic and/or diastolic), 44% remained in the same BP range after 7 years. In stepwise multiple regression analysis, baseline systolic BP, male gender, baseline body mass index (BMI) and change in BMI from baseline to the end of the follow-up (delta BMI) were significant predictors of systolic BP levels at the end of the follow-up. Baseline diastolic BP, baseline BMI and delta BMI were significant predictors of diastolic BP at the end of the follow-up. Conclusions: These data suggest that the risk of developing high BP during adolescence can be predicted by BP and BMI at childhood.