The significance of physical development on the blood pressure curve of children between 6 and 9 years of age and its relationship with familial aggregation.

Arterial blood pressure values of 3109 children between 6 and 9 years of age in the city of Rio de Janeiro were analysed according to low, medium and high socio-economic levels. At medium and high socio-economic levels, arterial pressures, weight and height were higher than those observed in children of a lower socio-economic level. Blood pressure was best correlated to body weight. The aggregation of arterial pressure, weight and height was compared between family members of children with percentiles below 50 and above 90. Systolic blood pressure and weight were significantly lower in family members with a percentile below 50. We conclude that there is a need for a long-term follow-up of these children and their families, in order to improve our knowledge of the mechanisms involved in the origin of arterial hypertension.