BLOOD-PRESSURE LEVELS IN SCHOOL-AGE JAPANESE CHILDREN - THE HISAYAMA STUDY

Blood pressure (BP) measurements were obtained on a total of 6325 chil dren (3294 boys and 3031 girls), aged 6-14 years, in Hisayama, Japan. All BPs were recorded in a sitting position by trained observers in a standardised manner. Standard mercury sphygmomanometers were used with commercially available cuffs, selected according to the arm circumfer ence. Cuff size no. 3 (bladder width 9 cm, length 23 cm) was the one m ost commonly selected in 84% of elementary schoolers aged 6-11 years a nd in 35% of junior high schoolers aged 12-14 years. Mean systolic BPs (SBPs) increased from 89 mmHg at age 6 years to 108 mmHg at 14 years (a 21% increase) for boys and from 88 mmHg to 102 mmHg (a 16% increase ) for girls. Diastolic BP (DBPs, Korotkoff phase IV, KIV) increased fr om ages 6 to 14 years to the same degree, from 58 mmHg to 72 mmHg (a 2 4% increase) for boys and from 58 mmHg to 70 mmHg (a 21% increase) for girls. The increase in DBP (Korotkoff phase V, KV) was greater, from 48 mmHg to 63 mmHg (a 30% increase) for boys and from 48 mmHg to 61 mm Hg (a 28% increase) for girls. The increase in mean SBP for adolescent boys was greater compared with that of girls; however, separation of age-specific values by sex was not observed for mean DBP (KIV) and DBP (KV). The cross-sectional relation between age and mean SBP levels wa s not linear.