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Hopkins-Rosseel D1, de Jager H1, May S1
1Queen's University, School of Rehabilitation Therapy, Faculty of Health Sciences, Kingston, Ontario, Canada
Background: In 2015, an estimated 47 million people worldwide suffered from dementia, with this number expected to triple by 2050. It is projected that 43% of people living with dementia will need a high level of care, with worldwide annual care costs at $156 billion. Current pharmacological interventions are costly and focused primarily on symptom management. Therefore, the development of effective strategies to delay the onset, or deflect the course, of dementia-related diseases are crucial for individuals and health-care systems. With current pharmacological interventions being costly and focused on symptom management, attention must shift towards preventative and cost effective interventions such as exercise.
Purpose: To undertake a systematic review of the literature to investigate the role of exercise in cognitive impairment prevention and management, including the evidence for any dose-response relationships between exercise and cognition.
Methods: Medline, CINAHL, EMBASE, and Cochrane databases were searched using the terms “dementia”, “exercise”, and “cognition”. Articles were included if they addressed exercise in adults over 40 years of age and any of 'mild cognitive impairment', Alzheimer's disease, Lewy Body Dementia, and/or vascular dementia . Articles were excluded if they used cognitive training interventions or the dementias were secondary to primary disorders (e.g. stroke). Two independent evaluators extracted the data including research question, participant group characteristics, study methodology, study findings, authors' conclusions and any evaluation of exercise dosage on cognitive impairment. Any discrepancies in the selection of papers or analysis of the findings were resolved by the third author. The quality of each paper was appraised using the Oxford Centre for Evidence-Based Medicine(OCEBM) Levels of Evidence, 2011, or the Joanna Briggs Institute Critical Appraisal Checklist for Systematic Reviews (2016). The PRISMA-P statement and checklist were applied to ensure a vigorous preparation and reporting of our review protocol.
Results: Of 325 studies resulting from the search, 36 met the inclusion criteria, with the majority attaining an OCEBM rating of 1b or higher(n=20). Despite a wide array of exercise interventions (mode/frequency/intensity/duration), and evaluating levels of dementia with numerous neuropsychiatric tools, the majority(n=35) provided evidence of a positive effect of exercise on cognition, with the remaining study reporting a maintenance of cognitive status. The improvements reported included global cognitive function, visual and verbal memory, and executive function. All studies also reported positive changes in function and/or exercise capacity. Although the studies with intervention groups performing different volumes of exercise demonstrated correlations with cognitive change, no definitive association was seen across studies.
Conclusion(s): There is convincing evidence that exercise is an effective intervention in the mitigation of dementia. A definitive conclusion regarding the prevention of dementias, or of any dose-response relationships between exercise and dementia, remain elusive. Future research should be directed towards prospective RCTs with consistent emphases on dose-response relationships and exercise as a unimodal intervention.
Implications: Physiotherapists can have an expeditious, significant and cost-effective impact on individuals' quality of life through the advocacy for, and applications of, exercise prescription in the mitigation of dementia. This is especially true given our scope in exercise prescription in diverse populations.
Keywords: Dementia, Exercise, Cognition
Funding acknowledgements: This was an unfunded project.
Purpose: To undertake a systematic review of the literature to investigate the role of exercise in cognitive impairment prevention and management, including the evidence for any dose-response relationships between exercise and cognition.
Methods: Medline, CINAHL, EMBASE, and Cochrane databases were searched using the terms “dementia”, “exercise”, and “cognition”. Articles were included if they addressed exercise in adults over 40 years of age and any of 'mild cognitive impairment', Alzheimer's disease, Lewy Body Dementia, and/or vascular dementia . Articles were excluded if they used cognitive training interventions or the dementias were secondary to primary disorders (e.g. stroke). Two independent evaluators extracted the data including research question, participant group characteristics, study methodology, study findings, authors' conclusions and any evaluation of exercise dosage on cognitive impairment. Any discrepancies in the selection of papers or analysis of the findings were resolved by the third author. The quality of each paper was appraised using the Oxford Centre for Evidence-Based Medicine(OCEBM) Levels of Evidence, 2011, or the Joanna Briggs Institute Critical Appraisal Checklist for Systematic Reviews (2016). The PRISMA-P statement and checklist were applied to ensure a vigorous preparation and reporting of our review protocol.
Results: Of 325 studies resulting from the search, 36 met the inclusion criteria, with the majority attaining an OCEBM rating of 1b or higher(n=20). Despite a wide array of exercise interventions (mode/frequency/intensity/duration), and evaluating levels of dementia with numerous neuropsychiatric tools, the majority(n=35) provided evidence of a positive effect of exercise on cognition, with the remaining study reporting a maintenance of cognitive status. The improvements reported included global cognitive function, visual and verbal memory, and executive function. All studies also reported positive changes in function and/or exercise capacity. Although the studies with intervention groups performing different volumes of exercise demonstrated correlations with cognitive change, no definitive association was seen across studies.
Conclusion(s): There is convincing evidence that exercise is an effective intervention in the mitigation of dementia. A definitive conclusion regarding the prevention of dementias, or of any dose-response relationships between exercise and dementia, remain elusive. Future research should be directed towards prospective RCTs with consistent emphases on dose-response relationships and exercise as a unimodal intervention.
Implications: Physiotherapists can have an expeditious, significant and cost-effective impact on individuals' quality of life through the advocacy for, and applications of, exercise prescription in the mitigation of dementia. This is especially true given our scope in exercise prescription in diverse populations.
Keywords: Dementia, Exercise, Cognition
Funding acknowledgements: This was an unfunded project.
Topic: Cardiorespiratory; Non-communicable diseases (NCDs) & risk factors; Intellectual disability
Ethics approval required: No
Institution: Queen's University
Ethics committee: Health Sciences Research Ethics Board
Reason not required: Ethics approval of the Queen’s University Health Sciences Research Ethics Board does not require approval if the work is a systematic review of the literature.
All authors, affiliations and abstracts have been published as submitted.
