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

Abstract

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.

Performance of 4 definitions of childhood elevated blood pressure in predicting subclinical cardiovascular outcomes in adulthood

“…Recently, the American Academy of Pediatrics updated the Fourth Report BP standards based on new evidence . However, the childhood BP standards established in one population may not be applicable to other populations as the distribution of BP values vary across different ethnic groups and geographic areas . Several country‐specific childhood BP standards have been established .…”

“…15,16 Several country-specific childhood BP standards have been established. [16][17][18][19] Using nationally representative data, standard BP percentiles by sex, age, and height for Chinese children aged 3-17 years have also been established. 19 For international comparisons of childhood elevated BP prevalence, Xi and colleagues 20 combined BP data from 7 countries to establish international childhood BP standards.…”

“…To reduce the long-term risk of CVD, it is still unclear whether the Chinese standards are more appropriate to identify Chinese children with elevated BP than other standards.Both the Fourth Report and updated US standards were established based on the US pediatric samples. Given the distribution of BP values varied across different ethnic groups and geographic areas,15,16 these 2 standards should be used with caution in the Chinese population. The Fourth Report or updated US standards may result in unpredictable bias when identifying childhood elevated BP in other countries.…”

One Step Further Toward a Targeted Screening Program

“…The more recent German and Iranian blood pressure reference data in childhood underline the necessity of establishing population-specific reference values, as well as defining a healthy population when developing reference values. 6,7 Second, the question is where to set the cutoff? The article by Hao et al 3 presents differences in prevalence increase over time depending on the trajectory group ranging from 42% hypertension in young adulthood in the high to 1.8% in the low blood pressure increase group, despite all participants being normotensive at the beginning of the study.…”

Identifying elevated blood pressure and hypertension in children and adolescents

“…In addition, assessing subtle changes in the cardiovascular system in children by noninvasive technologies should also be informative . Second, although harmonized, cross‐population standards may facilitate comparisons of results across populations, such standards may, to different degrees, misclassify BP status in different populations . It has been well documented that significant ethnic and geographic differences exist in BP levels, cardiovascular disease spectrum, and the association of childhood BP with adult cardiovascular risk .…”