Plasma lipoprotein(a) levels in familial defective ApoB

Aims: Elevated lipoprotein(a) (Lp[a]) is a risk factor for coronary artery disease. Its concentrations depend on genetic and nongenetic factors, and vary considerably. Familial ligand-defective ApoB (FDB) characterized by the R3500Q mutation in the ApoB gene, has been controversially associated with elevated lipoprotein(a) levels. We report on the relation of Lp(a) and FDB in the largest existing population study. Materials & methods: Lipoprotein(a) levels in 100 FDB patients are compared with 2207 control patients. In addition, a subgroup of relatives of FDB patients was analyzed. Results: FDB patients had significantly higher lipoprotein(a), 18 mg/dl compared with 8 mg/dl for non-FDB patients. When plasma triglycerides, LDL, age and sex were taken into account there was no association between FDB and lipoprotein(a). In FDB families the defective ApoB 3500 mutation had no significant influence on Lp(a) levels. Conclusion: After correcting for the above factors there is no association of Familial defective ApoB and Lp(a).