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> or =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> or =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 varepsilon4 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.