Measurements of adiposity and high blood pressure among children and adolescents living in Belo Horizonte.

OBJECTIVE To verify an association, if it exists, between obesity and blood pressure raised beyond the 90th percentile in children and adolescents, and to determine the measure of adiposity that best correlates with blood pressure in these subjects. DESIGN Cross-sectional study. SETTING A school-based study in Belo Horizonte, Brazil. PARTICIPANTS We selected randomly 1,403 students, aged from 6 to 18 years, from 545,046 students attending 521 public and private schools. Those selected completed the study. MAIN MEASURES OF OUTCOME: We recorded the weight, height, skin fold in the triceps, subscapular, and suprailiac areas, waist and hip circumference, body-mass index, and resting systolic and diastolic blood pressures using a mercury sphygmomanometer. RESULTS In univariate analyses, body mass index greater or lesser than 85th percentile, measurements of skin thickness in the subscapular and suprailiac areas, and the sum of all measurements of skinfold thickness, were associated with both systolic and diastolic measurements of blood pressure. After multivariate analyses that adjusted for all measurements of adiposity except itself, and age, race, and socioeconomic state, we found that the increased body mass index was associated with a 3.6-fold increased frequency of elevated systolic measurements of blood pressure, with 95% confidence intervals from 2.2 to 5.8, and a 2.7-fold increased frequency of elevated measurements of diastolic blood pressure, with 95% confidence intervals from 1.9 to 4.0. CONCLUSIONS Body-mass index serves as a better predictor of elevated blood pressure among children than do local measurements of adiposity.