The Risk Of The APOE Gene In The Onset Of Parkinson’s Disease Dementia:a Meta-analysis

Objectives: Parkinson’s disease dementia has become a major factor affecting the quality of life in patients with Parkinson’s disease,early detection and timely prevention can delay the progress of dementia,improve patient quality of life and reduce social burden.We found that APOE gene may be associated with the risk of dementia in Parkinson’s disease.The occurrence of some genotypes or alleles may indicate the increased risk of dementia in patients with Parkinson’s disease.If this conclusion is confirmed,we can use APOE gene to predict the risk of Parkinson’s disease dementia,for timely tracking and prevention of high-risk persons,in order to prevent the onset of dementia and delay the progress of it.There are a lot of studies on the risk of APOE gene in the onset of dementia in Parkinson’s disease.However,due to the differences in research design,statistical methods and sample size,the scholars have not come to an agreement with the conclusions in this field.We need an objective and quantitative synthesis to clear if APOE gene is the risk factor for Parkinson’s disease dementia.Methods: In this paper,we use the method of Meta-analysis method to objectively and quantitatively analyze the related research literature: Comprehensive and systematic search of Pubmed,Cochrane,Embase,CBM,CNKI,Wanfang database,All case-control and cohort studies before October 30,2017 of “The risk of the APOE gene in the onset of Parkinson’s disease dementia” were collected.The inclusion / exclusion criteria were rigorously established.Two researchers independently extracted the data and assessed the quality using the Newcastle-Ottawa Scale(NOS)standard.Meta-analysis was performed on Rev Man 5.3 software.Odds ratio(OR)and 95% confidence interval(CI)were used as evaluation criteria to calculate the risk association between different genotypes and gene carriers.Heterogeneity,sensitivity and bias analysis were conducted,and the heterogeneity results decided on whether to perform subgroup analysis.Results: In this paper,we included a total of 17 articles,including 820 cases of experimental group(Parkinson’s disease dementia group)and 1922 cases of control group(Parkinson’s disease non-dementia group).We analyzed the APOE gene risk of Parkinson’s disease dementia from three aspects.First,the two genotypes of ε3 / 4 and ε4 / 4 may be the risk factors for Parkinson’s disease dementia(OR and 95% confidence intervals were 1.47 [1.14,1.89],2.93 [1.20,7.14]),However,due to the limitations of the original data,we need more large samples to further prove.Second,There was no significant difference in the distribution of ε2 + vs.ε3 / 3 [OR: 1.35,95% CI:(0.97,1.87),P = 0.07].The risk of dementia with ε4 + in Parkinson’s disease patients was 1.61 times than that in Parkinson’s disease patients with ε3 / 3 [OR: 1.61,95% CI:(1.24,2.08),P = 0.0003].Third,we found that there is no risk or protective effect of ε2 + gene.Therefore,we divided the population into ε4 + and ε4-and found that the risk of dementia of ε4 + in patients with Parkinson’s disease was 1.72 times that of ε4-[OR:1.72,95% CI:(1.41,2.10),P<0.00001].We conducted a subgroup analysis according to different regions and found that ε4 + in all regions was a risk factor for dementia in Parkinson’s disease.The Meta-analysis sensitivity analysis was stable and no publication bias was found.Conclusion: ε2 + in APOE genotype is not a risk factor for dementia in Parkinson’s disease,nor is protective factor,ε4 + is a risk factor for dementia in Parkinson’s disease.This conclusion applies in Asia,Europe and the Americas respectively.For a single APOE genotype,ε3 / 4,ε4 / 4 may be risk factors for Parkinson’s disease dementia,but more large sample size needs further validation.