Cognition Mediates the Relationship Between Sensory Function and Gait Speed in Older Adults: Evidence from the English Longitudinal Study of Ageing

Abstract

Background/Objective:

Gait speed is an important indicator for assessing overall health status. Previous studies have reported the important role of sensory function in gait speed; however, the underlying mechanism is still unclear. This study aimed to examine whether cognition mediates the association of sensory function with gait speed among English older adults.

Methods:

Gait speed was assessed by “timed walking test”. Hearing was measured by using a hearing screening device. Vision was self-reported. Cognition was assessed by questionnaire. Baron and Kenny’s causal steps method and Sobel test were used to examine the mediating effect.

Results:

Among 4,197 participants aged 60 years and older, 13.5% had poor hearing and 12.6% had poor vision, 2.6% had both poor hearing and poor vision. Multiple linear regression models suggested that poor hearing (β= – 1.905, p < 0.001), poor vision (β= – 1.309, p = 0.004), and poor dual sensory function (β= – 2.442, p = 0.013) was associated with worse cognition. Cognition was correlated with gait speed (β= 0.004, p < 0.001). Poor hearing (β= – 0.072, p < 0.001), poor vision (β= – 0.031, p = 0.029), and poor dual sensory function (β= – 0.081, p = 0.011) was associated with slower gait speed. After introducing cognition into the models, regression coefficients between sensory function and gait speed decreased (β= – 0.066, p < 0.001 for hearing; β= – 0.027, p = 0.054 for vision; β= – 0.073, p = 0.020 for combined hearing and vision). Sobel test identified the significant mediating effect of cognition on the association between sensory function and gait speed.

Conclusion:

Cognition partially mediates the association between sensory function and gait speed. Efforts to maintain mobility performance in older adults should consider protecting both sensory function and cognition.