ApoB gene SpIns/Del, XbaI polymorphisms and myocardial infarction: a meta-analysis of 7169 participants

Background Apolipoprotein B (ApoB) gene signal peptide insertion/deletion (SpIns/Del, I/D) and XbaI polymorphisms have been associated with susceptibility to myocardial infarction (MI). However, the results of studies on this association are still controversial. Objective and methods This study explored reports published from 1986 to 2008 regarding the association of ApoB gene SpIns/Del and XbaI polymorphisms with MI. A meta-analysis including 7169 participants from 19 individual studies was performed. The pooled odds ratios (ORs) and their corresponding 95% confidence intervals (95% CIs) were evaluated by fixed-effect or random-effect models. Results A significant relationship between ApoB SpIns/Del gene polymorphism and MI was found under allelic (OR: 1.270, 95% CI: 1.090-1.480, P=0.002), recessive (OR: 1.360, 95% CI: 1.130-1.630, P=0.0009), dominant (OR: 1.091, 95% CI: 1.037-1.146, P=0.001), homozygous (OR: 1.610, 95% CI: 1.330-1.950, P<0.00001) and heterozygous (OR: 1.081, 95% CI: 1.020-1.146, P=0.009) genetic models. A marginal relationship between ApoB XbaI polymorphism and MI was found under a dominant genetic model (OR: 1.083, 95% CI: 1.004-1.168, P=0.039). No significant association was detected under other genetic models (P>0.05). However, in the non-European subgroup analysis, increased MI risk emerged under all genetic models (P<0.05). Conclusion ApoB SpIns/Del gene polymorphism was positively associated with increased MI risk. D allele and DD genotype carriers might be predisposed to MI susceptibility. The ApoB XbaI gene polymorphism locus had a significant positive association with increased MI risk only in the non-European population. T allele and TT genotype carriers might be susceptible to MI in the non-European population. On the contrary, the ApoB gene XbaI restriction fragment length polymorphism was not associated with increased MI risk in the entire population, particularly in the European population.