Meta-analysis of the association between polymorphisms of estrogen receptor α genes rs9340799 and rs2234693 and Alzheimer's disease: evidence from 23 articles

Objective: A meta-analysis was performed to better clarify the association between polymorphisms of estrogen receptor α genes rs9340799 and rs2234693 and risk of Alzheimer's disease (AD).

Methods: Pooled odds ratios (ORs) with 95% confidence intervals (CIs) from fixed and random effect models were calculated. Heterogeneity among studies was evaluated using the I(2). Meta-regression was used to explore the potential sources of between-study heterogeneity.

Results: A total of 23 studies about rs9340799 and 24 studies about rs2234693 were included in this meta-analysis. The combined evidence suggested that the x allele of rs9340799 had a significant protective effect on the risk of AD in codominant model (ORs = 0.893, 95%CIs = 0.822-0.970), especially for AD in Asia and sporadic AD (SAD). The p allele of rs2234693 was associated with decreased risk of AD in codominant model for patients with SAD. No publication bias was detected.

Conclusions: This meta-analysis suggested that x allele of rs9340799 might have a protective effect on the risk of AD in Asia and in patients with SAD. In addition, the p allele of rs2234693 might decrease the risk of patients with SAD.