Association of the insertion/deletion gene polymorphism of the apolipoprotein B signal peptide with myocardial infarction

The Del allele of the apolipoprotein B (apoB) signal peptide (SP) insertion /deletion (Ins/Del) polymorphism has been shown to be associated with eleva ted plasma levels of apoB, cholesterol and low density lipoprotein. It was the aim of the present study to analyse the relation of this gene variation to the risk of coronary artery disease (CAD) and of myocardial infarction (MI) in a population of 2259 male Caucasians, whose coronary anatomy was de fined by means of coronary angiography. ApoB SP DelDel genotypes had signif icantly higher apoB plasma concentrations than InsIns homozygotes (P = 0.00 01) and InsDel heterozygotes (P = 0.002); however, the apoB plasma levels o f InsIns and InsDel genotypes were essentially the same (P = 0.54). Similar observations were made with respect to ApoB SP genotype-dependent choleste rol plasma concentrations. Since the apoB plasma level was not only associa ted with the apoB SP Ins/Del gene variation but also to the extent of coron ary artery disease (P < 0.0001), individuals with an InsIns genotype and wi thout CAD had the lowest and subjects with a DelDel genotype and triple ves sel disease the highest apoB plasma levels (P < 0.0001). An association of the apoB SP Ins/Del gene variation with CAD was not detected, neither in th e total population nor in low risk groups. In contrast, the gene variation was associated with MI (P < 0.05). An Odds ratio of 1.18 (95% CI, 1.01-1.39 ) associated with the Del allele was detected in the total sample (P < 0.02 ). In a subpopulation of individuals with low plasma triglyceride levels (< 154 mg/dl; mean value) and an DD genotype of the angiotensin I-converting e nzyme insertion/deletion gene polymorphism an Odds ratio of 2.01 (1.42-3.05 ) was calculated (P < 0.001). The present study presents evidence for a sta tistically significant difference in the development of MI between genotype classes of the apoB SP Ins/Del gene polymorphism. (C) 1998 Elsevier Scienc e Ireland Ltd. All rights reserved.