Objective and Subjective Measurements of Motor Function: Results from the HELIAD Study.

Background: Slow gait speed has recently emerged as a potential prodromal feature of cognitive decline and dementia. Besides objective measurements, subjective motor function (SMF) difficulties might be present prior to the manifestation of gait disorders.

Objectives: To examine the association of walking time and the presence of SMF with future cognitive decline in cognitively normal individuals.

Design: Longitudinal study.

Settings: Athens and Larissa, Greece.

Participants: 931 cognitively normal individuals over the age of 64 with longitudinal follow-up from the Hellenic Longitudinal Investigation of Aging and Diet (HELIAD).

Measurements: We used a simple chronometer for recording objective walking time (OWT) and SMF was assessed using a self-reported physical functioning questionnaire. Generalized estimating equations (GEE) models were deployed to explore the associations between baseline OWT and SMF difficulties and the rate of change of performance scores on individual cognitive domains over time. Models were adjusted for age, years of education and sex.

Results: Each additional second of OWT was associated with 1.1% of a standard deviation more decline per year in the composite z-score, 1.6% in the memory z-score, 1.1% in the executive z-score and 1.8% in the attention-speed z-score. The presence of SMF difficulties was not associated with differential rates of decline in any cognitive domain.

Conclusion: Gait speed can be indicative of future cognitive decline adding credence to the notion that gait speed might serve as a simple and easily accessible clinical tool to identify a larger pool of at risk individuals and improve the detection of prodromal dementia.