Association between apolipoprotein E gene polymorphism and mild cognitive impairment: a meta-analysis

Area of Science:

• Genetics
• Neurology
• Epidemiology

Background:

• The apolipoprotein E (ApoE) gene is implicated in lipid transport and has been linked to neurodegenerative diseases.
• Previous studies on the association between ApoE gene polymorphism and mild cognitive impairment (MCI) have yielded conflicting results.

Purpose of the Study:

• To conduct a comprehensive meta-analysis to clarify the association between ApoE gene polymorphism and MCI susceptibility.
• To pool data from multiple case-control studies to achieve a more robust statistical estimation.

Main Methods:

• Systematic literature search of electronic databases (PubMed, Wanfang, CNKI, VIP, EMBASE) for relevant case-control studies.
• Inclusion of 18 studies comprising 2,004 cases and 3,705 controls.
• Meta-analysis performed using various genetic models to assess risk and protective associations.

Main Results:

• The ApoE ε4 allele was significantly associated with an increased risk of MCI in the overall population (e.g., ε4 vs ε3: OR=2.38, 95% CI: 2.11-2.68).
• The ApoE ε2/ε3 genotype showed a slight protective effect against MCI (OR=0.80, 95% CI: 0.66-0.97).
• Similar associations were observed in stratified analyses, including the Chinese population.

Conclusions:

• The ApoE ε4 allele is a significant risk factor for developing MCI.
• The ApoE ε2/ε3 genotype may confer a protective effect against MCI, warranting further investigation.