JMIR Publications

ABSTRACT

Background:

Emerging research shows regular physical activity reduces cognitive decline risk, but most studies rely on self-reported measures, which are limited by recall bias, subjectivity, and a lack of continuous monitoring capability.

Objective:

This study aimed to explore passive physical activity measures as early indicators of cognitive impairment by examining their association with cognitive impairment incidence and neuropsychological (NP) test performance.

Methods:

We included participants from the Framingham Heart Study (FHS), a community-based cohort with longitudinal cognitive impairment surveillance. Participants wore an Actical accelerometer for at least 3 days, excluding bathing. Thirty physical activity measures were grouped into intensity-specific durations, step and cadence summaries, and peak cadence. Cox proportional hazard models were applied to assess their associations with incident cognitive impairment, adjusting for age, sex, education, and accelerometer wear time. Predictive performance for incident cognitive impairment was evaluated using time-dependent areas under the receiver operating characteristic curves (AUCs) generated by random survival forest models. Additionally, linear regression models were employed to investigate the relationships between these measures and 18 NP tests.

Results:

Among 1212 participants from the FHS Offspring cohort (mean age: 70±8 years; 53.7% women), 10 physical activity measures, including all peak cadence metrics, showed nominal significance with incident cognitive impairment. Models incorporating either peak 1 minute cadence or moderate to vigorous physical activity and total steps/day increased AUC for predicting cognitive impairment by 1.4-4.2%% at 8 years, compared to base models including age, sex, education, and accelerometer wear time. Peak 1 minute cadence and total steps/day also showed significantly positive associations with Trail Making Tests A and B.

Conclusions:

Our analysis highlighted significant associations between accelerometer-based physical activity and cognitive performance, emphasizing the role of moderate movement in supporting cognitive health.