LOW-DENSITY-LIPOPROTEIN CHOLESTEROL APOLIPOPROTEIN B-100 RATIO - INTERACTION OF FAMILY HISTORY OF PREMATURE ATHEROSCLEROTIC CORONARY-ARTERYDISEASE WITH RACE AND GENDER IN 7 TO 11 YEAR OLDS

Background. In adults, a low density lipoprotein cholesterol (LDL-C)/a polipoprotein B-100 (ApoB) ratio is an indicator of ApoB-enriched smal l dense LDL, which is associated with premature coronary artery diseas e (CAD). Since this LDL subclass may be inherited, we investigated whe ther a low LDL-C/ApoB ratio was associated with a positive family hist ory of premature CAD in young children. Methods. Subjects were 66 chil dren aged 7 to 11 years who were recruited through a school-based fami ly history survey, flyers, and hospital newspaper advertisements. They were divided according to family history and assessed for fatness, bl ood pressure, lipids, lipoproteins, and apoproteins. Results. Family h istory interacted with gender such that girls with a positive family h istory had a lower LDL-C/ApoB ratio than girls with a negative family history, while the opposite was true in boys; ie, family history-posit ive boys had a higher ratio than family history-negative boys. The ass ociation of a low ratio with a positive family history was seen most c learly in white girls. Family history-positive whites had higher ApoB than family history-negative whites, whereas the pattern was reversed in the blacks. The LDL-C/ApoB ratio and ApoB were not related to other CAD risk factors such as fatness, blood pressure, or other lipids and lipoproteins. Conclusion. In young children, a low LDL-C/ApoB ratio a nd high ApoB levels were associated with a positive family history of CAD only in the white girls, suggesting that this group is at increase d risk of genetically mediated CAD.