Association Between Polymorphisms and Risk of Alzheimer's Disease and Parkinson's Disease: A Meta-Analysis Based on 5,315 Individuals.

A number of studies have reported that aldehyde dehydrogenase-2 () polymorphisms maybe associated with the risk of Alzheimer's disease (AD) and Parkinson's disease (PD). However, the results of such studies are inconsistent. We therefore conducted a meta-analysis to clarify the association between polymorphisms and the risk of AD and PD. Five online databases were searched and the relevant studies were reviewed from inception through May 10, 2018. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated in each genetic model of the general population and various subgroups. Furthermore, we simultaneously performed heterogeneity, cumulative, sensitivity, and publication bias analyses. Overall, nine case-control studies involving 5,315 subjects were included in this meta-analysis. Potential associations were found between the rs671 G>A polymorphism and the risk of AD (A vs. G: OR = 1.46, 95%CI = 1.01-2.11, = 0.05, = 84.2%; AA vs. GG: OR = 2.22, 95%CI = 1.03-4.77, = 0.04, = 79.2%; AA vs. GG+GA: OR = 1.94, 95%CI = 1.03-3.64, =0.04, = 71.1%). In addition, some similar results were observed in other subgroups. Moreover, no significant association between polymorphisms and PD risk. In conclusion, our meta-analysis indicated that the rs671 G>A polymorphism plays an important role in AD development.