2026 Volume 43 Issue 3 Pages 241-244
We examined the cross–sectional and longitudinal associations of objectively measured lifestyle factors, such as physical activity, conversation, and sleep using wearable sensors, with cognitive function or positron emission tomography images. The cross–sectional analysis showed that number of walking steps, total sleep time, conversation time, and heart rate were associated with Mini–Mental State Examination (MMSE) scores. Moreover, MMSE scores increased with step count, plateauing at 7,791 steps, and sleep duration showed increasing MMSE scores within the range of 353 to 434 minutes, but decreased beyond 434 minutes. Conversation duration showed increasing MMSE scores within the range of 80 to 321 minutes, but decreased beyond 321 minutes. Shorter sleep duration was associated with greater brain amyloid burden, whereas longer sleep duration was associated with decreased cortical glucose metabolism. The longitudinal analysis showed that lower physical activity and poor sleep quality were associated with subsequent cognitive decline and lower sleep efficiency was associated with greater brain amyloid burden. Moreover, the number of daily walking steps showed a positive correlation with sleep efficiency and an inverse correlation with WASO, awakening time count, and naptime. Our results can help promote walking as an intervention for preventing sleep disturbances in community–dwelling older adults. Our cohort study suggests the importance of lifestyle improvements to delay cognitive decline.