Background: This study aimed to explore the levels of circulating
inflammatory factors CRP, IL-6, IL-10 and TNF- based on the literature
review. This study also examined the influence of single nucleotide polymorphism
(SNP) sites on the susceptibility of abdominal aortic aneurysm (AAA) using
meta-analysis and intended to provide additional information on pathogenesis of
AAA research. Methods: Electronic databases including PubMed and Web of
Science were systemically searched to collect
the information on AAA, inflammatory factors such as CRP, IL-6, IL-10,
TNF- and the SNP sites for data extraction. Altogether six SNPs in four
genes (rs3091244, CRP; rs1800947, CRP; rs1205, CRP; rs1800795, IL-6; rs1800896,
IL-10; and rs1800629, TNF) were assessed. Results: This study enrolled
altogether 41 relevant investigations involving 9,007 AAA patients to carry out
meta-analysis. According to pooled analysis, circulating CRP and IL-6 levels were
shown to be related to the AAA, while plasma IL-10 and TNF- levels were
not associated with AAA. The circulating CRP level standard mean difference (SMD)
was 0.30 (95% confidence interval (CI): 0.17–0.43), the IL-6 level SMD was 0.34
(95% CI: 0.20–0.49), the IL-10 level SMD was –0.01 (95% CI: –0.09–0.06),
and the TNF- level SMD was 0.09 (95% CI: 0.00–0.19). Similarly, the
odds ratio (OR) of rs3091244 (CRP) under the recessive gene model was 1.70 (95%
CI: 1.13–2.57). In addition, individuals with A and T mutant genes at locus
rs3091244 might have a higher tendency of AAA susceptibility than those with C
allele. Consecutively, the OR was 0.91 (95% CI: 0.51–0.97) for rs1800795 (IL-6)
locus in the allele model, and individuals with G mutant gene at locus rs1800795
(IL-6) might be less susceptible to AAA than those with C allele. Meanwhile, the
rs1800896 (IL-10) locus had a positive association under the five statistical
models, and individuals with A mutant gene at locus rs1800896 might have a higher
susceptibility to AAA than those with G allele. Nevertheless, the rs1800947
(CRP), rs1205 (CRP), and rs1800629 (TNF) loci did not have positive correlation
under the five statistical models, with no statistical significance. The results
indicate that the gene polymorphisms at rs1800629, rs1800947, and rs1205 loci
were not related to the AAA susceptibility. Conclusions: Gene
polymorphisms in certain known inflammatory mediators related to AAA
susceptibility might serve as potential predictive biomarkers for clinical
applications. Moreover, SNP of inflammatory mediators relevant to abdominal
aortic aneurysmal formation and progression need extensive investigations to
confirm these results.