Apolipoprotein E genotype is associated with serum C-reactive protein but not abdominal aortic aneurysm

Abstract

Objective Apolipoprotein E ( ApoE) genotype has been associated with systemic inflammation and athero-thrombosis however the association with abdominal aortic aneurysm (AAA) has not been previously examined. We assessed the association between ApoE genotype with AAA presence and growth, and serum C-reactive protein (CRP). Methods Serum concentrations of CRP (in 1358 men) and 6 single nucleotide polymorphisms (SNPs) for ApoE (in 1711 men) were examined in subjects from the Health In Men Study. 640 men with small AAAs were followed by ultrasound surveillance for a mean of 4.1 years. Results There was no association between ApoE genotype and AAA presence. Men heterozygote for the ApoE p.Arg176Cys polymorphism had slower AAA growth, odds ratio for AAA progression ≥ median 0.41, 95% confidence intervals 0.21–0.80, p = 0.01. Men heterozygote for the ApoE g.50093756A > G polymorphism had slightly more rapid AAA growth, odds ratio for AAA progression ≥ median 1.48, 95% confidence intervals 1.02–2.14, p = 0.04. None of the ApoE SNPs were associated with AAA growth however taking into account multiple testing. Two SNPs in ApoE were associated with serum CRP under a co-dominant model, ApoE p.Cys130Arg (SNP ID rs429358), p = 0.00003 and ApoE g.50114786A > G (SNP ID rs4420638), p = 0.00013. Adjusting for other risk factors plus serum creatinine the ɛ4 allele was associated with lower serum CRP under a dominant model, coefficient 0.089, p = 0.002. Conclusion We found no consistent association between ApoE genotype and AAA. We confirmed an association between ApoE genotype and serum CRP.