Correlates of lipoprotein(a) levels in a biracial cohort of young girls: The NHLBI Growth and Health Study

Elevated levels of lipoprotein(a) [Lp(a)] are associated with increased ris k for coronary heart disease (CHD). However, racial differences in both Lp( a) levels and their associated CHD risk are observed, with African American s having, on average, higher Lp(a) levels than US whites but not the expect ed increase in CHD risk. We determined Lp(a) levels and their correlates in a large cohort (n = 2379) of black and white girls, ages 9 to 10 years, at the baseline visit of a longitudinal study of obesity development, the Nat ional Heart, Lung, and Blood Institute Growth and Health Study. Lp(a) level s were available for 1269 girls. The median Lp(a) level in black girls was over S-fold higher than that in white girls. Associations were examined bet ween Lp(a) levels and low-density lipoprotein cholesterol (LDL-C), high-den sity lipoprotein cholesterol, apolipoprotein B, triglycerides, adiposity, p ubertal maturation stage, body fat patterning (triceps/truncal skinfold rat io), and dietary fat (Keys' score). In black girls multiple regression anal ysis identified LDL-C (P < .001) and adiposity (P = .08) as predictors of L p(a) levels. In white girls only LDL-C (P = .02) was associated with Lp(a). In conclusion, the level of Lp(a) was significantly higher in black girls. Our study also revealed a racial difference in correlates of Lp(a), such a s LDL-C and adiposity. Whether this racial difference is due to an underlyi ng biologic difference Or is merely a reflection of a greater statistical p ower to detect a relationship with the level, which was 2.5-fold higher in black girls than in white girls, needs further investigation.