[Blood pressure in the child and the adolescent. Effect of age, sex, height, weight and heart rate].

6,391 school children in the department of Seine-Saint-Denis were studied to determine the normal limits of blood pressure, its variations with age and sex, and its correlations with height, weight and heart rate. Blood pressure has a nearly perfect Gaussian distribution. Average blood pressures increase linearly with age according to sex. Boys have higher systolic blood pressures after the age of 14 and higher diastolic blood pressures after the age of 16. The estimated incidence of hypertension was 3,1% systolic hypertension and 2.2% diastolic hypertension. There was a very close relationship between systolic and diastolic blood pressure. Average systolic and diastolic blood pressures increased very significantly with height and weight, in both sex. Heart rate decreased with age. The average blood pressure was not related to heart rate. Blood pressure charts, related to age, sex, height and weight, allow follow-up of arterial blood pressure as children grow up and may lead to a better understanding of the mechanism of hypertension.