Associations of apathy and fatigue with physical capacity and daily physical activity in older adults with mild neurocognitive disorders

People with neurocognitive disorders often exhibit poorer mobility. In this context, factors that can alter physical functioning should be carefully addressed. This study aimed to examine the associations of apathy and fatigue characterized by difficulties in initiating activities with physical capacities and daily physical activity.

A 10 m walk test (10MWT), a Timed Up and Go test (TUG), a 6 min walk test (6MWT), and ambulatory actigraphy were performed among 56 older adults with mild neurocognitive disorders (age = 78.5 ± 5.6 years). Apathy and fatigue were measured using the Apathy Inventory and the Fatigue Severity Scale. Associations were tested using linear regressions.

Apathy was associated with the TUG (β = 0.35, p < 0.01), the 6MWT (β = − 0.34, p < 0.01), sedentary (β = 0.42, p < 0.01), and moderate- to vigorous-intensity activity (β = − 0.39, p < 0.01) after controlling for cognitive impairment. Fatigue was associated with all tests of physical capacity (10MWT, β = 0.43, TUG, β = 0.35, 6MWT, β = − 0.49, p < 0.01) and the moderate- to vigorous-intensity activity (β = − 0.40, p < 0.01).

Present results suggest that both apathy and fatigue are associated with changes in physical capacities and daily physical activity in older adult with mild neurocognitive disorders. Thus, they should be carefully assessed and treated, notably by putting in place strategies targeting physical functioning.

NCT04573712, 2020-10-06