The apolipoprotein B signal peptide insertion/deletion polymorphism is not associated with myocardial infarction in Norway

The three-amino acid insertion/deletion (I/D) polymorphism in the apoB signal peptide (27 amino acid versus 24 amino acid signal peptide) was evaluated as a possible risk factor for myocardial infarction (MI) in a case-control study population comprising 238 MI survivors and 547 controls. In controls, homozygotes for the deletion allele (DD) had the highest mean levels of both total cholesterol and low density lipoprotein (LDL) cholesterol (LDLC), the homozygotes for the insertion allele (II) had the lowest mean values, while the heterozygotes (ID) had intermediate mean levels (p < 0.05). In MI survivors, the trend was similar, but only differences in mean LDLC levels were statistically significant (p < 0.05). No differences in genotype frequencies were detected between cases and controls in univariate analysis or in multivariate logistic regression analysis. Despite the results from the lipid analyses, we conclude that the I/D polymorphism in the apoB signal peptide is unlikely to be of major importance for MI risk in relatively young Norwegians.