Meta-Analysis of the Relationship between the APOE Gene and the Onset of Parkinson’s Disease Dementia

Purpose. To clarify the relationship between certain genotypes or alleles of the APOE gene and the onset risk of Parkinson’s disease dementia (PDD). Methods. The PubMed, Cochrane, Embase, CBM, CNKI, and Wanfang databases were searched to identify all case-control studies and cohort studies published before October 30, 2017, that investigated the association between the APOE gene and the onset of PDD. Manual information retrieval was also performed. All studies that met the quality requirements were included in a meta-analysis performed using RevMan 5.3 software. Results. The meta-analysis included 17 studies, with a total of 820 patients in the PDD group and 1,922 in the non-PDD group. The influence of the APOE gene on PDD onset was analyzed from three aspects: five genotypes vs. e3/3, e2