Lower-limb physical function is associated with executive function in frail older adults.

Area of Science:

• Gerontology
• Neuroscience
• Physiology

Background:

• Frailty, an accumulation of health deficits, impacts multiple physiological systems in older adults.
• Physical function is linked to executive function, but frailty's role in this association is unclear.

Purpose of the Study:

• To investigate if frailty intensifies the relationship between physical performance and executive function in older adults.
• To explore the association between cerebral oxygenation and these factors.

Main Methods:

• Sixty older adults were categorized into non-frail and very-mild+frailty groups based on a 34-item frailty index.
• Physical function was assessed using the 6-minute walk test (6MWT), 30-second chair stand test (30CST), grip strength (HGT), and 8-foot up-and-go test (8FUGT).
• Executive function was measured via a computerized Stroop task, and prefrontal cortex oxygenation was assessed using functional-near-infrared spectroscopy (fNIRS).

Main Results:

• Non-frail individuals demonstrated better performance on 6MWT, 30CST, and 8FUGT compared to the very-mild+frailty group.
• In the very-mild+frailty group, better 6MWT and 30CST performance correlated with faster executive function (inhibition and switching).
• Prefrontal cortex oxygenation was higher in non-frail participants during a switching task, but did not mediate the physical function-executive function link.

Conclusions:

• The association between lower-limb physical performance and executive function is more pronounced in older adults with accumulated health deficits (frailty).
• Frailty may exacerbate the impact of physical decline on cognitive function, particularly executive functions like inhibition and switching.