Background: Hypertension is one of the most important risk factors in the etiology of cardiovascular and renal diseases both in children and adults. Due to the absence of a blood pressure (BP) normograph in children living in Tehran, this study was conducted in Autumn 2002 to determine the BP status in children 7-11 years old and its relationship with age, sex, height and weight.
Materials and Methods: This descriptive study was carried out on 1061 children (boys and girls). The age, sex, height, weight and systolic and diastolic BP were measured according to the standard procedures, then 50th, 75th, 90th and 95th percentiles of BP were tabulated.
Results: The data showed that systolic and diastolic BP increased by height and weight. Also, the 90th and 95th percentiles of systolic BP was equal in boys and girls aged 7 and 8 years however, it was higher in girls aged 9, 10 and 11 years. The diastolic BP at 90th and 95th percentile was equal in boys and girls aged 7, 8 and 9, but it was higher in girls aged 10 and 11 years. When BP percentile of American children was compared to the Iranians it was found that boys and girls living in Tehran had a lower systolic and diastolic BP than that of Americans.
Conclusion: These data show that, in addition to age and sex, other factors such as height, weight, race, nutrition, genetics and environment have influence on normal range of BP in children. Therefore, each society should have their own standard BP normograph for their populations. Similar studies with more samples are highly recommended.