Association between Accelerometer-Measured Light-Intensity Physical Activity and Cognitive Function in Older Adults

Objectives: This study aimed to investigate whether accelerometer-measured light physical activity (LPA) is associated with cognitive function and whether engaging in ≥3 h/day of LPA can reduce the chance of cognitive impairment among a sample of older adults in Taiwan. Design: Cross-sectional study. Setting: An outpatient department in a medical center. Participants: Participants were community-dwelling older adults aged 65 years and older who were able to walk independently from September 2020 to March 2021. Measurements: A tri-axial accelerometer was used to measure LPA for 7 consecutive days, and the Mini-Mental State Examination (MMSE) scale was used to assess the chance of cognitive impairment. Multiple linear regression model and binary logistic regression model were performed to examine the association between LPA and MMSE scores. Results: 145 older Taiwanese adults (51.7% men; 81.2±6.8 years; 6.9% at chance of cognitive impairment) were included. After adjusting for moderate-to-vigorous physical activity (MVPA) and wear time, we found that there was a significant association between LPA and cognitive function (95% confidence interval [CI]: 0.64–1.65; P<0.001), and further found that those who engaged in LPA ≥3 h/ day were at reduced chance of cognitive impairment compared with people who engaged in LPA <3 h/day (odds ratio [OR]: 0.16; 95% CI: 0.03–0.80; P=0.025). Conclusion: This study demonstrated that engaging in LPA ≥3 h/day could be viewed as a protective factor for maintaining cognitive function in older adults. We recommend further longitudinal research to elucidate the association between intensity-specific LPA and cognitive function.