Polymorphisms of apolipoprotein E and aneurysmal subarachnoid haemorrhage: A meta-analysis

Abstract

Subarachnoid haemorrhage (SAH) is characterised by bleeding in the subarachnoid space in the brain. There are various polymorphisms in genes which are associated with this disease. We performed a systematic meta- analysis to investigate the relationship of APOE polymorphism on aSAH. A comprehensive literature search was done in the Pubmed database, Science Direct, Cochrane library and Google Scholar. The OR and 95% CI were evaluated for the gene and aSAH association using fixed and random effect models. Publication bias was assessed using Begg's funnel plot and Egger's regression test. All statistical evaluations were done using the software Review Manager 5.0 and Comprehensive Meta Analysis v2.2.023. A total of 9 studies were assessed on APOE polymorphism (1100 Cases, 2732 Control). Meta analysis results showed significant association in ε2/ ε2 versus ε3/ε3, ε2 versus ε3 genetic models and ε2 allele frequency. In subgroup analysis statistically significant association was observed in Asians in the genetic models ε2/ ε2 versus ε3/ε3, ε2/ε3 versus ε3/ε3, ε2 versus ε3 and also in ε2 allele frequency. However, in Caucasian population only ε2/ε2 versus ε3/ε3 genetic model showed significant association between APOE and risk of aSAH. In this meta-analysis study, the ε2/ε2 genotype is associated with increased risk of aSAH.

Polymorphism and plasma levels of apolipoprotein E and the risk of aneurysmal subarachnoid hemorrhage in a Chinese population: a case-control study

“…In our present study, we found the distribution of ε2/ε3 genotype in aSAH was higher than the healthy controls, and allele frequencies of ApoE ε2 in aSAH was also higher than controls. Latter, using the multivariate logistic regression analysis, we found that ApoE ε2 allele was significantly increased compared to ε3 in aSAH (OR = 2.083, 95% CI = 1.045-4.153, P = 0.037), suggesting that ε2 allele is a risk factor for aSAH, which was consistent with the result of the previous meta-analysis [ 24 ] and the study of Liu et al [ 12 ].…”

“…A recently meta-analysis of 9 studies, which was mainly including Caucasian and Asian population, have showed that there was a significant association between APOE genotype and aSAH, and ε2 allele was a risk factor for aSAH [ 24 ]. In our present study, we found the distribution of ε2/ε3 genotype in aSAH was higher than the healthy controls, and allele frequencies of ApoE ε2 in aSAH was also higher than controls.…”

“…Alternatively, presence of the ε4 allele has been associated with poor outcomes after traumatic brain injury [ 23 ]. Recently, the association between the APOE polymorphism and risk of aSAH has been investigated in several studies among different populations, however, the conclusion from these studies were conflicting [ 13 , 24 , 25 ]. Furthermore, most of evidences were from Caucasian populations in Europe and USA, the direct evidence from Chinese Han population is relatively poor [ 26 ].…”

Apolipoprotein E polymorphism and the risk of aneurysmal subarachnoid hemorrhage in a South Indian population

“…A meta-analysis of nine case control studies found that in the Asian population, ε2/ε2 vs. ε3/ε3, ε2/ε3 vs. ε3/ε3, ε2 vs. ε3 and ε2 allele frequency were associated with the risk of aSAH. However, the study concluded that only the ε2/ε2 vs. ε3/ε3 genetic model was associated with the risk of aSAH in the Caucasian population [ 21 ].…”

“…The ε4 allele is associated with unfavorable outcomes after traumatic brain injury [ 17 , 18 ] and aSAH in the Chinese and Italian population [ 19 , 20 ]. We performed a meta-analysis that suggested that there is significant association with the risk of aSAH in ε2/ε2 vs. ε3/ε3, ε2/ ε3 vs. ε3/ε3 and ε2 vs. ε3 genetic models and ε2 allele frequency [ 21 ].…”