PREDICTION OF ADULT HYPERTENSION BY K4 AND K5 DIASTOLIC BLOOD-PRESSURE IN CHILDREN - THE BOGALUSA HEART-STUDY

Objective: The objective of this study was to examine the reproducibil ity of K4 and K5 diastolic blood pressure measurements and the ability to predict adulthood values. Study design: The Bogalusa Heart Study i s a long-term epidemiologic study of cardiovascular disease risk facto rs from birth to early adulthood conducted in the biracial (one third black, two thirds white) community of Bogalusa, Louisiana. Analyses in cluded blood pressure measurements taken on 12,139 subjects during mul tiple cross-sectional screenings from 1973 to 1994; 20% (N = 2530) had measurements taken as a child, ages 4 to 18 years, and during adultho od, ages 19 to 32 Sears. Six resting blood pressure measurements were taken by trained observers with mercury sphygmomanometers at each scre ening with K1, K4, and K5 recorded. Variance components analysis was u sed to evaluate the reliability of K4 and K5. Results: The total varia nce was larger for K5 (253 mm Hg-2) than for K4 (109 mm Hg-2) at age 5 years. Variance for both K4 and K5 decreased with age. The interobser ver variability was larger for K5 (more than 50% vs 40%). Childhood K4 (vs childhood Kj) was better correlated with adult K1 and K5 (0.28 vs 0.11 for K1; 0.33 vs 0.25 for K5 at age 11 to 13 years). K4 was also shown to have a higher odds ratio for predicting adult hypertension th an K5 (1.57 vs 1.14 at age 11 to 13 years). Conclusion: During childho od K4 is a more reliable measure of diastolic blood pressure than K5. K4 diastolic blood pressure measured in childhood is a better predicto r of adult hypertension.