The role of APOE ε4 in modulating the relationship between non-genetic risk factors and dementia: a system review and meta-analysis.
Level 3 - non-randomized controlled study
Systematic review and meta-analysis of observational longitudinal cohort studies.
PubMed 41083880 · doi:10.1007/s00415-025-13434-0
What was done
Authors conducted a systematic review and meta-analysis of population-based longitudinal studies published up to June 2023 examining associations between risk factors and all-cause dementia or Alzheimer's disease stratified by APOE ε4 carrier status. Subgroup analyses and meta-regression were performed to test for stratification effects and effect modification by APOE ε4.
What was found
A total of 170 studies evaluating 173 risk factors were included, with 48 factors analyzed quantitatively. Meta-regression confirmed statistically significant effect modification by APOE ε4 status for nine risk factors. Stronger associations in APOE ε4 carriers were observed for nonsteroidal anti-inflammatory drugs, statins, frequent drinking, and high systolic blood pressure. Stronger associations in noncarriers were observed for light-to-moderate alcohol consumption, female sex, physical activity, diabetes (which increased Alzheimer's disease risk only in noncarriers), and loneliness. Nine additional factors showed differential subgroup patterns that were not statistically significant in meta-regression (vitamin E intake, heart failure, serum neurofilament light chain, serum testosterone, agitation, air NO2 concentration, ever smoking, current smoking, and head injury). Specific numerical risk estimates and confidence intervals were not reported in the abstract.
Why it matters
This synthesis indicates that APOE ε4 genotype modulates the influence of modifiable lifestyle, cardiovascular, and environmental risk factors on dementia, supporting the potential utility of genotype-tailored prevention strategies.
Limits
The abstract reports no numerical effect sizes (e.g., hazard ratios, odds ratios) or confidence intervals, nor the total number of human participants across studies. Findings are derived from observational longitudinal cohorts, precluding direct causal inference and leaving open the possibility of residual confounding.
Cited by
- supports Moderate alcohol consumption is associated with a reduced risk of dementia specifically in individuals who do not carry the APOE4 allele.