Blood pressure curve for children less than 10 years of age: Findings from the ewha birth and growth cohort study

Background: Routine blood pressure (BP) measurement is recommended to begin at 3 years of age, but there are no national BP reference values for Korean children less than 7 years of age. Therefore, we developed sex-, age-, and height-specific BP reference values for non-overweight children aged 3-9 years. Methods: We analyzed the data of416, 340, 321, 323, and 332 subjects aged 3, 5,7,8, and 9 years, respectively, who participated in the Ewha Birth and Growth Cohort Study. BP percentile curves were generated using generalized additive models for location, scale, and shape. Reference values for the 50th, 90th, and 95th percentiles of BP were determined according to sex, age, and height percentiles. Results: In both boys and girls, a gradual increase in systolic blood pressure (SBP) with age was more pronounced than that in diastolic blood pressure (DBP). In boys, the reference values for 90th percentile of SBP/DBP at median height for children aged 3 and 9 years were 105/69 and 118/70, respectively. In girls, the reference values corresponding to the above conditions were 105/69 and 116/70, respectively. Among children aged 7-9 years of median height, the 90th percentile of SBP in the current study was lower and that of DBP was similar to the national reference values of Korea. For children aged < 7 years of median height, the reference value for SBP, but not that for DBP, was similar to that developed in the European study. Conclusion: Although further research is needed, our findings could be used to help identify high BP in children less than 10 years of age.