Blood pressure in a school-age population. Distribution, correlations, and prevalence of elevated values.

Distribution of blood pressure values, prevalence of levels potentially predictive of hypertension in adulthood, and correlations with othe variables were studied in a sample of 2,809 children (1,392 boys and 1,417 girls) 6 to 15 years of age in Caracas, Venezuela. The mean values of systolic and diastolic blood pressures increased steadily with age in both sexes and were significantly higher in girls. The prevalence of high blood pressure readings was 10.2%-7.0% in boys and 13.3% in girls, a significant differnce. It was significantly higher in obese (7.6%) than in nonobese (3.8%) children. No significant differences in blood pressures were found among 1,580 mestizo, white, and black children. Partial correlation studies showed a determinant influence of weight in the correlation of blood pressure with height; the correlation with weight remained high after removal of the influence of height and age. At repeat examination 12 to 18 months later, 36% of the children who had a high blood pressure reading continued to have high values. Fifty-eight percent of them had one or both parents or one or more siblings (or both) who had hypertension.