Blood pressure percentiles by age and height for children and adolescents in Tehran, Iran.

To construct reference percentiles for blood pressure (BP) by sex, age and height for the first time in Iran, we used data on 16 972 healthy children, aged 1 month to 18 years, collected during 2000-2010 in Tehran. BP in this population rose steadily with age and height following a very similar trend in both genders up to the age of 14. Systolic BP (SBP) rise was more prominent in younger ages, and after puberty (15-18 years) was greater in boys compared with girls, while the rise in diastolic BP (DBP) was slightly higher in girls. Iranian norms, compared with 'Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents' (US-4th-Report) and the 'German BP Percentiles by Age and Height for Children and Adolescents' (KiGGS), showed a similar pattern of differences for both genders. For example, for Tehrani boys up to 6 years old whose heights were equal to 50th percentile of stature-for-age as well as length-for-age growth charts, the differences in 95th percentile for SBPs compared with the US-4th-report varied from 2-21 mm Hg while compared with KiGGS, maximum of differences was 9 mm Hg. For boys 7-15 years of age, ours were slightly higher than both. For ages of 16 and 17 years, we yielded figures lower than US-4th-report (2 mm Hg) but higher than KiGGS (3 mm Hg). Iranian 95th percentile for DBPs was lower than US-4th-report and KiGGS (1-11 mm Hg). Considering the differences with US-4th-report and KiGSS standards, the references presented in this study should rather be applied in Iranian population.