Distribution and correlates of lipoproteins and their subclasses in black and white young adults. The Bogalusa Heart Study.

Lipoprotein subclasses vary in CAD risk potential, but their distribution and correlates are not well documented in black and white young adults. A subsample of 449 (32%) young adults (67% white, 58% female) aged 20-37 years examined in the Bogalusa Heart Study had lipoprotein subclasses measured in terms of cholesterol by vertical spin density-gradient ultracentrifugation. LDL subclass pattern was characterized as either predominantly LDL(1) (large, buoyant), LDL(2) (intermediate) or LDL(3) (small, dense). Whites had significantly higher levels of VLDL, VLDL(3), and LDL and lower levels of HDL(2) and HDL(3) than blacks. White females had significantly higher levels of HDL(2) than white males. Visceral fatness, measured as waist circumference, and race were the major contributors to the explained variance (6-22%) of these lipoproteins, with adverse trends seen among whites and persons with large waist circumferences. Sex (males>females), waist circumference (positive), HDL(2) (negative), and HDL(3) (positive) were the predictor variables for the likelihood of having the LDL(3) pattern. When glucose and insulin were included in the multivariate analysis, insulin (positive), sex (males>females), HDL(2) (negative) and HDL(3) (positive) became significant predictors of LDL(3) pattern. Positive parental history of CAD was associated with LDL (P=0.009) in white males, and HDL(2) (P=0.008) and LDL(3) subclass pattern (P=0.038) in white females; whereas none in blacks. The observed correlates of lipoprotein subclasses and patterns need to be considered in estimating CAD risk in young adults.

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 reproducibility of K4 and K5 diastolic blood pressure measurements and the ability to predict adulthood values. STUDY DESIGN: The Bogalusa Heart Study is a long-term epidemiologic study of cardiovascular disease risk factors from birth to early adulthood conducted in the biracial (one third black, two thirds white) community of Bogalusa, Louisiana. Analyses included blood pressure measurements taken on 12,139 subjects during multiple cross-sectional screenings from 1973 to 1994; 20% (N = 2530) had measurements taken as a child, ages 4 to 18 years, and during adulthood, ages 19 to 32 years. Six resting blood pressure measurements were taken by trained observers with mercury sphygmomanometers at each screening with K1, K4, and K5 recorded. Variance components analysis was used to evaluate the reliability of K4 and K5. RESULTS: The total variance was larger for K5 (253 mm Hg2) than for K4 (109 mm Hg2) at age 5 years. Variance for both K4 and K5 decreased with age. The interobserver variability was larger for K5 (more than 50% vs 40%). Childhood K4 (vs childhood K5) 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 than K5 (1.57 vs 1.14 at age 11 to 13 years). CONCLUSION: During childhood K4 is a more reliable measure of diastolic blood pressure than K5. K4 diastolic blood pressure measured in childhood is a better predictor of adult hypertension.