The effect of the APOE4 genotype on physiological and cognitive health in randomised controlled trials with an exercise intervention: a systematic review and meta-analysis.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of randomized controlled trials
PubMed 39828710 · doi:10.1186/s13063-024-08696-4
What was done
Searches across MEDLINE, EMBASE, and PsycINFO identified randomized controlled trials evaluating the effect of exercise interventions on physical and cognitive health outcomes stratified by APOE4 genotype in participants with varied cognitive abilities. Quality and risk of bias assessments were conducted on included studies.
What was found
Nineteen studies met criteria for the systematic review, and 3 contained data suitable for meta-analysis. The abstract reports no numerical effect sizes or confidence intervals. Very low to moderate quality evidence showed mixed outcomes: APOE4 carriers had greater post-exercise improvements than non-carriers in certain cognitive (executive function, learning) and physical (relative telomere length) metrics, whereas non-carriers benefited more in other physical (serum BDNF, gait speed) and cognitive (global cognition, verbal memory) markers. Meta-analysis of 3 studies found very low quality evidence indicating no difference between APOE4 carriers and non-carriers on physical function outcomes.
Why it matters
Whether genetic risk for Alzheimer's disease alters responsiveness to lifestyle interventions remains unclear, and this review indicates that existing trial evidence is too sparse and methodologically limited to support genotype-specific exercise recommendations.
Limits
The abstract provides no numerical effect estimates, confidence intervals, or total participant sample sizes. Only 3 of 19 trials could be quantitatively pooled. Included trials had design and reporting weaknesses, including poor control of relative exercise intensity and incomplete statistical reporting.
Cited by
- context People with the APOE4 allele are significantly less likely to develop Alzheimer's disease if they exercise, with more intense exercise providing greater protection.