286 Gait speed—a useful addition to dementia risk prediction in midlife? Results from ENBIND

Abstract

Abstract Background Midlife Type 2 Diabetes (T2DM) is associated with a two-fold increased risk of dementia in later life. The utility of spatiotemporal gait characteristics to identify those with midlife T2DM at greatest risk of later cognitive decline has not been assessed. This may aid in selecting-out those at greatest risk for preventative brain-health interventions. Methods ENBIND is a longitudinal study of cognitively-healthy individuals with midlife T2DM (free from microvascular/macrovascular complications) and healthy controls. At baseline, gait speed was measured across three tasks (usual gait speed, maximal gait speed and cognitive dual-task—whilst reciting alternate letters of the alphabet). Domain-specific neuropsychological performance was assessed using the Montreal Cognitive Assessment (MoCA) and a custom CANTAB battery with identical assessments repeated at a 4-year interval. Linear regression was used to analyse results with adjustment for important clinical confounders. Results 30 individuals (aged 55.5 ± 9 years; 50% female) were followed up, of whom three-quarters (n = 23, 76.7%) had midlife T2DM. Individuals with midlife T2DM did not experience greater cognitive decline over 4 years. Slower ‘usual’ gait speed (but not dual-task or maximal speed) at baseline was associated with greater likelihood of incident errors on the MoCA at 4 years, which persisted on controlling for T2DM status, age, sex and baseline cognition (B: -0.22 [95% Confidence Interval: −0.41, −0.03, p = 0.03]). Slower maximal (B: −3.07, −6.06, −0.08, p = 0.04) and cognitive dual-task (B:-1.98, −3.61, −0.17, p = 0.03) speed were both associated with significantly poorer delayed memory performance after 4 years. Conclusion In middle-aged individuals with known dementia risk factors, gait speed may be a useful adjunct to identify those at greatest risk of longitudinal cognitive decline. Whilst usual gait speed was associated with a decline in global cognition, fast and dual task gait speed were associated with longitudinal decline in delayed memory performance.