Baseline Mobility is Not Associated with Decline in Cognitive Function in Healthy Community-Dwelling Older Adults: Findings From The Irish Longitudinal Study on Ageing (TILDA)

Abstract

Objectives: Few studies examine the relationship between Timed Up-and-Go (TUG), a commonly used clinical test, and cognitive decline. This study examines whether TUG, usual gait speed (UGS), and dual-task gait speed (DTGS) predict decline in global cognition, executive function, processing speed, memory, and attention with follow- up of up to 5.9 years. Design: Longitudinal study. Setting: The Irish Longitudinal Study on Ageing (TILDA), a nationally representative cohort study. Participants: Community-dwelling adults aged ≥65 years, with Mini-Mental State Examination (MMSE) score ≥18 and no known history of memory impairment, dementia, Alzheimer’s disease or Parkinson’s disease were included (N = 2,250). Measurements: Participants com- pleted mobility tasks during the baseline health assessment and cognitive tasks during interviews conducted at 2 year intervals (waves 1, 2, and 3) and health assessments (waves 1 and 3). Linear and Poisson mixed effects regression models were used to examine longitudinal associations between mobility and each cognitive test, adjust- ing for sociodemographics and physical and mental health. Results: There was little evidence of an association between TUG, UGS, or DTGS with decline in cognitive func- tion after adjusting for confounders. Conclusions: These mobility tasks are not sensitive predictors of cognitive decline in this high-functioning, community-dwelling sample; nonetheless, limited decline in cognitive function was observed during follow-up.Further work with longer follow-up and/or analysis of more specific and comprehensive measures associated with gait is required. (Am J Geriatr Psychiatry 2018; 26:438–448)