Effects of exercise training on the cognitive function of older adults with different types of dementia: a systematic review and meta-analysis.

ABSTRACT

OBJECTIVES: To assess the effect of exercise training on the cognitive function of older adults living with different types of dementia, as well as potential moderators of exercise efficacy. DESIGN: Systematic review and meta-analysis. DATA SOURCES Cochrane Central, PsycINFO, Embase, Medline and CINAHL. ELIGIBILITY CRITERIA Peer-reviewed, randomised controlled trials, in English (1990-present), which examined the effects of exercise training on the cognitive function of older adults living with dementia. STUDY APPRAISAL AND SYNTHESIS: Risk of bias and study quality were assessed (Cochrane Risk of Bias Tool 2.0 and Physiotherapy Evidence Database Scale). We performed random-effects models using robust variance estimation and tested moderators using the approximate Hotelling-Zhang test. RESULTS: Twenty-eight studies (n=2158) were included in the qualitative review and 25 in the meta-analysis. For all-cause dementia, a small effect of exercise training on cognitive function was observed (g=0.19; 95% CI 0.05 to 0.33; p=0.009). Type of dementia and exercise training characteristics did not moderate the effects of exercise training on cognitive function (p>0.05). Adherence to the intervention moderated the cognitive outcome effect size such that greater mean adherence was associated with greater cognitive outcome effect sizes (b=0.02; SE=0.01; p=0.005). CONCLUSION: Exercise training showed small benefits for the cognitive function of older adults living with all-cause dementia. More research and standardised reporting of exercise training characteristics can strengthen the evidence for what works best for which types of dementia. PROSPERO REGISTRATION NUMBER CRD42020198716.