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

Abstract

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.

Keywords: Alzheimer’s disease; estrogen receptor α gene; meta-analysis; polymorphism.

Figure 1.

Meta-analysis for AD risk depending on the rs9340799 polymorphism in the ESR-α gene. Forest plots of relationship between polymorphism of ESR-α gene rs9340799 and AD risk in codominant model after excluding articles that deviated from Hardy-Weinberg equilibrium (HWE) in controls and sensitivity analysis. White diamond denotes the pooled OR. Black squares indicate the OR in each study, with square sizes inversely proportional to the standard error of the OR. Horizontal lines represent 95% confidence intervals (CIs). AD indicates Alzheimer’s disease; ESR-α, estrogen receptor α; OR, odds ratio.

Figure 2.

Meta-analysis for AD risk depending on the rs2234693 polymorphism in the ESR-α gene. Forest plots of relationship between polymorphism of ESR-α gene rs2234693 and AD risk in recessive model after excluding articles that deviated from Hardy-Weinberg equilibrium (HWE) in controls and sensitivity analysis. White diamond denotes the pooled OR. Black squares indicate the OR in each study, with square sizes inversely proportional to the standard error of the OR. Horizontal lines represent 95% confidence intervals (CIs). AD indicates Alzheimer’s disease; ESR-α, estrogen receptor α; OR, odds ratio.