Sensorimotor function as an early marker of cognitive decline and alzheimer's biomarker burden.

Early identification of markers of cognitive decline in cognitively normal older adults is essential for dementia prevention strategies. Sensorimotor measures, such as gait speed, grip strength, and reaction time, may provide sensitive indicators of current and future impairment. This study examined associations between baseline sensorimotor function and cognitive decline in cognitively normal older adults. In this prospective cohort, 246 cognitively normal older adults from the DRIVES Project completed baseline assessments of grip strength, gait speed, simple reaction time, and the Preclinical Alzheimer Cognitive Composite (PACC). Participants were followed for a mean of 4 years. Linear mixed-effects models adjusted for demographics, APOE ε4 status, and neighborhood deprivation. Cross-sectional analyses evaluated the associations between sensorimotor measures and cerebrospinal fluid (CSF) biomarkers of amyloid, tau, and plasma neurofilament light chain (NfL). Participants (mean age: 74.9 ± 5.17 years; 48.8% female) had a mean baseline PACC score of 1.06 ± 0.50. Cross-sectionally, slower gait speed was associated with higher CSF tau/Aβ42 ratio (p = 0.027), CSF tTau/Aβ42 ratio (p = 0.009), and plasma NfL (p = 0.024). A slower reaction time was associated with lower baseline PACC scores (p = 0.028). Longitudinally, low grip strength (p = 0.002) and slow gait speed (p < 0.001) were predictive of lower cognitive performance, with slow gait speed also predicting a faster decline (p = 0.015). Sensorimotor function measures are associated with current and future cognitive performance, supporting their role in early identification of older adults at risk for cognitive decline.