Apolipoprotein E e4 Allele Is Associated with Subjective Cognitive Decline: A Meta-Analysis

Area of Science:

• Neurology
• Genetics
• Epidemiology

Background:

• Subjective Cognitive Decline (SCD) is a precursor to Alzheimer's disease.
• The Apolipoprotein E e4 (APOE e4) allele is a known genetic risk factor for Alzheimer's disease.

Purpose of the Study:

• To estimate the prevalence of the APOE e4 allele in individuals with SCD.
• To determine the association between APOE e4 and SCD through a meta-analysis.

Main Methods:

• A meta-analysis of 28 studies was conducted, including 6,044 individuals with SCD.
• Searched MEDLINE, EMBASE, and Cochrane Library databases.
• Stratified and meta-regression analyses were used to address heterogeneity.

Main Results:

• The APOE e4 allele showed a weak association with SCD (OR 1.12).
• The pooled prevalence of APOE e4 carriers among individuals with SCD was 32%.
• Age and northern European residency were identified as significant factors contributing to heterogeneity.

Conclusions:

• A weak association exists between APOE e4 and SCD.
• Age and geographic factors (northern European residency) are critical in understanding the heterogeneity of APOE e4 prevalence in SCD.