Effects of physical exercise on the cognition of older adults with frailty syndrome: A systematic review and meta-analysis of randomized trials.

OBJECTIVES: To analyze the effects of physical exercise on the cognition of community-dwelling older adults with frailty syndrome, through randomized clinical trials. DATA SOURCES: Articles published until March 2020 were searched in the databases Science Direct, Scopus, Web of Science, PubMed, Lilacs, Cochrane, IEEE, EMBASE, and SciELO. Search terms included frailty, aged, exercise, rehabilitation, and cognition. For the Portuguese language, equivalent terms were used. STUDY SELECTION: Only randomized clinical trials that used physical exercise as an intervention method in community-dwelling older adults (≥ 60y.) with frailty syndrome, and which performed cognitive assessments before and after the intervention were included. DATA EXTRACTION: Two authors performed data extraction using predefined data fields. The risk of bias of the six included studies was assessed using the PEDro scale. DATA SYNTHESIS: In total, 4501 studies were found. After the selection process, 6 studies were included in the systematic review and 4 studies in the meta-analysis, all with a low risk of bias. The studies included 655 community-dwelling older adults with frailty syndrome. The types of intervention varied, with multicomponent physical exercise being the most frequent. The cognitive assessments were diverse, and the Mini-mental State Examination, Trail Making Test forms A and B, and Digit Span test were the most frequently applied. A meta-analysis was performed with Global Cognition and Trail Making Test forms A and B. The data from the meta-analysis showed that physical exercise improves Global Cognition (Mean Difference = 2.26; 95% CI, 0.42 - 4.09; P = 0.02) and mental flexibility (Trail Making Test B) (Mean Difference = -30.45; 95% CI; - 47.72 - -13.19; P = 0.0005).
CONCLUSION: Interventions with physical exercise promote benefits in global cognition and mental flexibility of older adults with frailty syndrome.