Association between mobility limitations and cognitive decline in community-dwelling older adults: the English Longitudinal Study of Ageing.

Background and objectives: Mobility limitations has been linked to cognition. However, little is known about the relationship between mobility decline and cognitive decline. This study investigated the effect of mobility limitations and decline on cognitive decline in a population-based cohort of older adults.

Result design and methods: A population-based cohort of 9695 cognitively intact participants (mean age = 65.4 years, standard deviation [SD] = 10.4) was assessed. Mobility limitation scores ranging from 0-10 were assessed at baseline (wave 4) by using self-reporting difficulty in a set of 10 activities, and a higher score indicated worse mobility. A subset of 9250 participants underwent two mobility assessments at waves 3 and 4, and were categorized into normal mobility or mobility decline (defined as wave 4 - wave 3 > 1 SD of wave 3). Linear mixed models were used to assess the longitudinal contribution of mobility limitations and decline to cognitive decline.

Results: During a median follow-up period of 9.4 years (SD 1.8), the participants in the highest quartile of mobility scores displayed an accelerated cognitive decline (-0.191 SD/year, 95% CI = -0.223, -0.159) compared with those in the lowest quartile. Notably, individuals experiencing mobility decline exhibited a marked cognitive decline (-0.179 SD/year, 95% CI = -0.220, -0.139), potentially influenced by factors such as physical activity and depression.

Discussion and implications: Mobility limitations and decline significantly correlate with cognitive decline in older adults, highlighting that mobility-focused interventions in healthcare strategies to preserve cognition.