Dataset Information

Does physical activity prevent cognitive decline and dementia?: A systematic review and meta-analysis of longitudinal studies.

ABSTRACT:

Background

By 2050, it has been estimated that approximately one-fifth of the population will be made up of older adults (aged ?60 years). Old age often comes with cognitive decline and dementia. Physical activity may prevent cognitive decline and dementia.

Methods

We reviewed and synthesised prospective studies into physical activity and cognitive decline, and physical activity and dementia, published until January 2014. Forty-seven cohorts, derived from two previous systematic reviews and an updated database search, were used in the meta-analyses. Included participants were aged ?40 years, in good health and/or randomly selected from the community. Studies were assessed for methodological quality.

Results

Twenty-one cohorts on physical activity and cognitive decline and twenty-six cohorts on physical activity and dementia were included. Meta-analysis, using the quality-effects model, suggests that participants with higher levels of physical activity, when compared to those with lower levels, are at reduced risk of cognitive decline, RR 0.65, 95% CI 0.55-0.76, and dementia, RR 0.86, 95% CI 0.76-0.97. Sensitivity analyses revealed a more conservative estimate of the impact of physical activity on cognitive decline and dementia for high quality studies, studies reporting effect sizes as ORs, greater number of adjustments (?10), and longer follow-up time (?10 years). When one heavily weighted study was excluded, physical activity was associated with an 18% reduction in the risk of dementia (RR 0.82; 0.73-0.91).

Conclusions

Longitudinal observational studies show an association between higher levels of physical activity and a reduced risk of cognitive decline and dementia. A case can be made for a causal interpretation. Future research should use objective measures of physical activity, adjust for the full range of confounders and have adequate follow-up length. Ideally, randomised controlled trials will be conducted. Regardless of any effect on cognition, physical activity should be encouraged, as it has been shown to be beneficial on numerous levels.

SUBMITTER: Blondell SJ

PROVIDER: S-EPMC4064273 | biostudies-literature | 2014 May

REPOSITORIES: biostudies-literature

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Publications

Does physical activity prevent cognitive decline and dementia?: A systematic review and meta-analysis of longitudinal studies.

Blondell Sarah J SJ Hammersley-Mather Rachel R Veerman J Lennert JL

BMC public health 20140527

<h4>Background</h4>By 2050, it has been estimated that approximately one-fifth of the population will be made up of older adults (aged ≥60 years). Old age often comes with cognitive decline and dementia. Physical activity may prevent cognitive decline and dementia.<h4>Methods</h4>We reviewed and synthesised prospective studies into physical activity and cognitive decline, and physical activity and dementia, published until January 2014. Forty-seven cohorts, derived from two previous systematic r ...[more]

PMID: 24885250

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Project description:BackgroundFrailty is a multidimensional syndrome that increases an individual's vulnerability for developing adverse health outcomes, which include dementia. It might serve as a promising target for dementia prevention. However, there are currently no studies summarizing the association between multi-concept frailty and the risk of cognitive disorders. This study aims to summarize the evidence of associations between multi-concept frailty and cognitive disorders based on longitudinal studies.MethodsScopus, The Cochrane Library, PsycINFO, CINAHL, PubMed, and EMBASE databases were searched from inception to January 2, 2022. Longitudinal studies, which explored the association of frailty with incident risk of cognitive decline or dementia, were included. The multivariable-adjusted effect estimates were pooled by random-effects models. The evidence credibility was depicted according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) method.ResultsA total of 30 longitudinal studies were included. Four types of frailty concepts were involved, including physical, cognitive, social, and biopsychosocial frailty. The meta-analysis comprised 20 studies of 252,571 older adults (mean age: 64.1-80.4 years), among whom 7,388 participants developed cognitive decline or dementia. Physical frailty was associated with higher risk of developing cognitive disorders [pooled relative risk (pRR) = 1.52, 95% confidence interval (CI): 1.28-1.80, I 2 = 21.2%, pRR = 1.62 for cognitive decline, 95% CI: 1.07-2.45, I 2 = 40.2%, pRR = 1.37 for all-cause dementia (ACD), 95% CI: 1.13-1.66, I 2 = 0.0%]. Cognitive frailty (pRR = 2.90, 95% CI: 1.28-6.55, I 2 = 78.1%) and pre-frailty (pRR = 4.24, 95% CI: 2.74-6.56, I 2 = 30.2%) were linked to higher risk of ACD. Biopsychosocial frailty could predict a 41% (pRR = 1.41, 95% CI: 1.17-1.71) elevated risk of cognitive decline or dementia [pRR = 1.53 (95% CI: 1.19-1.96) for ACD and 1.11 (95% CI: 1.05-1.17) for Alzheimer's disease (AD)]. In the systematic review, social frailty was associated with a 53% higher risk of AD. Preventing frailty could avoid a maximum of 9.9% cognitive disorders globally. The overall evidence strength is rated as low-to-moderate. Inconsistency and imprecision are major sources of bias.ConclusionFrailty in late life is a promising risk factor for cognitive disorders. Frail elderly should be monitored for their cognitive dynamics and initiate early prevention of dementia.Systematic review registrationwww.ClinicalTrials.gov, identifier CRD4202127 3434.

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Dataset Information

Does physical activity prevent cognitive decline and dementia?: A systematic review and meta-analysis of longitudinal studies.

Background

Methods

Results

Conclusions

Publications

Does physical activity prevent cognitive decline and dementia?: A systematic review and meta-analysis of longitudinal studies.

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