Exercise Interventions for Cognitive and Functional Outcomes in Dementia: A Systematic Review and Meta-Analysis...

Area of Science:

• Gerontology
• Neuroscience
• Exercise Science

Background:

• Exercise is a non-pharmacological approach for cognitive and functional support in older adults with dementia.
• Existing literature shows heterogeneous effects, with time-based dose markers potentially insufficient to explain trial variability.

Purpose of the Study:

• To systematically review and meta-analyze randomized controlled trials on exercise interventions for older adults with dementia.
• To assess if linear dose indicators explain heterogeneity in intervention effects on cognitive, functional, or behavioral outcomes.

Main Methods:

• Systematic review and meta-analysis following PRISMA 2020 guidelines.
• Inclusion of randomized controlled trials evaluating structured exercise in older adults with dementia.
• Random-effects meta-analysis and meta-regression to analyze pooled effects and dose-response relationships.

Main Results:

• Twenty-two studies were analyzed, revealing small, statistically significant improvements in fixed-effects models but not in random-effects models.
• Moderate between-study heterogeneity was observed (I² = 51.757%).
• Linear dose indicators did not significantly explain heterogeneity, indicating residual variability.

Conclusions:

• Current evidence shows limited and heterogeneous effects of exercise on cognition and function in older adults with dementia.
• A consistent linear dose-response relationship is not supported.
• Exercise strategy effectiveness likely depends on feasibility and supervision quality, emphasizing context-specific approaches over strict dose-dependency.