Relation of Cholesterol to Apolipoprotein B in Low Density Lipoproteins of Children

Cholesterol and apolipoprotein (apo) B contents and their relationship within serum low density llpoprotein (LOL) were examined In 2018 children, ages 8 to 17 years, from a blraclal community. The levels of LDL cholesterol and LDL apo B showed significant race-related differences (blacks>whltes) in both boys and girls and gender-related differences (glrts>boys) In white children. These LDL measures associated Inversely and significantly with both age and Tanner stage, more so in boys than In girls. The black-white differences In LDL measures persisted after adjusting for the covarlates (sexual maturation, age, adiposity, oral contraceptive use, cigarette smoking, and alcohol use). The distribution of LDL cholesterol for a given range of LDL apo B varied considerably, despite a strong correlation (r =0.91) between these variables, Indicating that measuring LDL cholesterol alone does not accurately reflect LDL concentration. The ratio of cholesterol to apo B In LDL ranged from 1.01 (5th percentlle) to 1.42 (95th percentlle) among the four race-gender groups, suggesting marked InterlndMdual variation In composition. That this ratio was significantly elevated In black children Indicates the occurrence of relatively larger, less dense, and cholesterol-enriched LDL particles In blacks. Significant Independent associations were noted between LDL cholesterol/apo B ratios and the levels of serum total cholesterol (positive) and trlglycerldes (negative), suggesting the Influence of pool size of different lipoproteins on LDL composition. These observations may help identify a subgroup of children with apo B-enriched LDL particles who are potentially at risk for coronary artery disease. (Arteriosclerosis 9:493-500, July/August 1989)