Blood pressure tables for Chinese adolescents: justification for incorporation of important influencing factors of height, age and sex in the tables

BACKGROUND: Elevated blood pressure (BP) in childhood was a predictor of hypertension in adulthood and contributes to the current epidemic of cardiovascular disease. It is necessary to identify abnormal BP in children and adolescents with accurate BP tables based on several crucial factors. The purpose of this study was to identify the important influencing factors of BP of Chinese adolescents. METHODS: BP, height, and body weight were assessed in 32221 normal-weight Chinese adolescents aged 12–17 years. An equal number of 6815 subjects from boys and girls were individually matched by height and age to assess the independent effect of sex on BP; and an equal number of 1422 subjects from each of the age groups (12, 13, 14, 15, 16 and 17 years) were individually matched by sex and height to estimate the independent effect of age on BP. Height of each sex and age was divided into eight height groups - ~5(th), ~10(th), ~25(th), ~50(th), ~75(th), ~90(th), ~95(th), and 95(th) ~ percentiles- and the Spearman’s correlation between height percentiles and BP was used to examine the independent effect of height on BP. RESULTS: Boys had higher systolic BP (SBP) and diastolic BP (DBP) than girls after controlling for age and height. BP increased with age after controlling for sex and height. In each age group, both SBP and DBP increased alongside increasing height in boys and girls. CONCLUSIONS: Sex, age and height are all independent determinants for BP levels in Chinese adolescents. It is essential to incorporate these three factors for the establishment of the BP reference tables.