Objectives: We aimed to establish community-based normal reference values of 24-h ambulatory blood pressure monitoring (ABPM) for Chinese children and adolescents. Furthermore, we investigated how excluding overweight children affects BP percentiles and compared them with German references.
Methods: In this territory-wide cross-sectional prospective cohort study, 1445 Hong Kong Chinese children and adolescents aged 8-17 years with body height between 119 and 185 cm were recruited. Their ABPM assessment was performed using validated arm oscillometric recorders (A&D TM-2430) and complied with American Heart Association's recommendations. The reference tables were constructed using the LMS method to normalize skewed distribution of ABP data to sex and age or height.
Results: The ambulatory BP was higher among boys and the difference between boys and girls progressively widened with age. An increasing trend in daytime and night-time SBP and DBP with age and height was observed in both sexes. The age-specific and sex-specific 95th percentiles from nonoverweight children (n=1147; 79%) were lower than the whole cohort by up to 2.5 and 1 mmHg for SBP and DBP, respectively. In comparison, our overall and nonoverweight reference standards were generally higher than corresponding German references.
Conclusion: The study provides ambulatory BP standards for Chinese children, with sex-related age-specific and height-specific percentiles. Further longitudinal studies are required for investigating its clinical utility in Chinese.