Apolipoprotein A-I and B levels in adolescents; a trial to define subjects at risk for coronary heart disease.

The normal levels of apolipoprotein A-I and B (apo A-I, apo B) were determined in 220 male and 340 female 16-19-year-old adolescents. In addition to these apolipoproteins, total and high density lipoprotein cholesterol (total-C HDL-C) were analysed in an attempt to define subjects at high risk for coronary heart disease (CHD). The normal levels were for boys: apo A-I 0.96 +/- 0.13 g/l, apo B 0.64 +/- 0.14 g/l; for girls: apo A-I 1.04 +/- 0.18 g/l, apo B 0.65 +/- 0.14 g/l; for girls taking combined oral contraceptives: apo A-I 1.14 +/- 0.22 g/l, apo B 0.72 +/- 0.16 g/l. Subjects with the following high-risk profiles were selected for further follow-up: 1. Total-C and apo B greater than or equal to 95th percentile; 2. Total-C or apo B greater than or equal to 95th and HDL-C or apo A-I less than or equal to 5th percentile. Seven adolescents had the combination of high total-C and apo B. None had any of the other combinations. One girl had lipid, apolipoprotein levels and a family history indicating familial hypercholesterolemia (f.h.). Another two adolescents were suspected of having f.h. while one girl might have abnormal levels secondary to oral combined contraceptives. The study suggests that the analyses of apolipoproteins, especially apo B, are of value to trace adolescents at risk for future CHD.