Association between angiotensin-converting enzyme insertion/deletion polymorphisms and intracranial aneurysm susceptibility: A meta-analysis.

Various studies have evaluated the association between polymorphisms of angiotensin-converting enzyme (ACE) and intracranial aneurysm (IA) risk; however, the results remain inconsistent. The PubMed, Embase, and Wanfang Data databases were systematically searched until January 6th 2016. Case-control studies investigating the association between the ACE polymorphism and IA risk were included. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated with the fixed or random-effects model assuming allele, homozygote comparison of codominant, heterozygote comparison of codominant, dominant, and recessive models. Seven studies including 1,074 cases and 1,500 controls were included in the current meta-analysis. The results of the analysis indicated that the ACE polymorphism significantly increased IA risk in the allele, homozygote comparison of codominant and dominant models. According to the further stratified analysis by ethnicity, source of control and sample sizes, a significant association was identified between the ACE variant and IA risk in Asian individuals, hospital-based, or large (>300) subgroups in all of the genetic models, not including the recessive model. Furthermore, no significantly increased risk was indicated in Caucasian individuals, population-based, or small (<300) subgroups in the heterozygote comparison of codominant, dominant and recessive models. The available evidence indicates that the ACE polymorphism is associated with an increased risk of IA, particularly in Asian individuals. However, other factors may impact this association. Further large, well-designed multicenter studies are required to validate the findings from the present study.