The Relations Between Physical Activity Level, Executive Function, and White Matter Microstructure in Older Adults

Area of Science:

• Neuroscience
• Gerontology
• Public Health

Background:

• The global population of older adults is growing.
• Age-related cognitive decline is a significant concern.
• Understanding factors influencing cognitive health in aging is crucial.

Purpose of the Study:

• To investigate if white matter characteristics mediate the link between physical activity and executive function in healthy older adults.
• To explore the relationship between different measures of physical activity and cognitive performance.

Main Methods:

• Recruited 43 older adults (mean age 73) without cognitive impairment or neurological/psychiatric disorders.
• Assessed physical activity using accelerometry (average intensity, steps).
• Examined white matter integrity with diffusion tensor imaging and executive function with neuropsychological tests.

Main Results:

• Higher average daily steps were significantly associated with better executive function (P = .007).
• Moderate to vigorous physical activity did not show a significant association with executive function (P = .08).
• White matter metrics did not mediate the relationship between physical activity and executive function.

Conclusions:

• Daily step count, a measure of physical activity, is linked to executive function in older adults.
• Microstructural white matter characteristics may not be the sole mechanism explaining how physical activity influences cognitive function in aging.
• Further research is needed to identify the pathways through which physical activity benefits cognition in older age.