[Tracking indices of the blood pressure in a longitudinal study in infants and adolescents].

OBJECTIVE

The objective of this study was to assess the degree of BP Tracking from childhood to adulthood and to evaluate whether high BP levels persist over time and progress to adult hypertension.

PATIENTS AND METHODS

Two hundred and twenty-two healthy schoolchildren living in the North of Portugal were assessed at 17 year intervals, starting in 1979 (cohort 1) aged 5 to 18 years, and again in 1996 (cohort 2). Tracking indices (Ti) were calculated as follows: Ti = (2x + y-z) /N/0.89, where x, y and z refer to the total number in the same, adjacent and remote trisections, respectively, and N = x + y + z. If Ti > 1 there is positive tracking.

RESULTS AND CONCLUSIONS

For systolic and diastolic blood pressure, all Ti were greater than 1.0. All individuals that remained in the 3rd tertil, 17 years later, weigh more and are more obese than those of the 1st tertil. 56.6% of the individuals that belong to the 3rd tertil are now hypertensive, which means that a significant percentage of the children with high blood pressure in the first survey will be hypertensive in the future.