Effect of physical exercise on cognitive function in older adults’ carriers versus noncarriers of apolipoprotein E4: systematic review and meta-analysis

The presence of apolipoprotein (Apo) E4 is a genetic risk factor in cog-nitive impairment. Physical exercise contributes to slowing cognitive impairment in older adults, but little is known about the influence of ex-ercise on ApoE4 carriers and noncarriers. The objective of systematic review is to study the role of physical exercise in older adults’ ApoE4 carriers and noncarriers. A systematic literature search was carried out in five international databases: PubMed, Web of Science, PeDro, Scopus, and SPORTDiscus. A total of nine randomized controlled trials were included with a sample size of 2,025 subjects (901 ApoE4 carriers). The exercise reported a significant improvement on cognitive perfor-mance in older adults’ ApoE4 noncarriers (standardized mean differ-ence [SMD]=0.653; 95% confidence interval [CI], 0.29–1.00; chi2=35.36; degrees of freedom [df ]=7; P