Motoric cognitive risk syndrome and incident dementia in older adults from the Québec NuAge cohort

Background The co-occurrence of slow walking speed and subjective cognitive complaint (SCC) in non-demented individuals defines motoric cognitive risk syndrome (MCR), which is a pre-dementia stage. There is no information on the association between MCR and incident dementia in Québec’s older population. Objective The study aims to examine the association of MCR and its individual components (i.e. SCC and slow walking speed) with incident dementia in community-dwelling older adults living in the province of Québec (Canada). Design Québec older people population-based observational cohort study with 3 years of follow-up. Setting Community dwellings. Subjects A subset of participants (n = 1,098) in ‘Nutrition as a determinant of successful aging: The Québec longitudinal study’ (NuAge). Methods At baseline, participants with MCR were identified. Incident dementia was measured at annual follow-up visits using the Modified Mini-Mental State (≤79/100) test and Instrumental Activity Daily Living scale (≤6/8) score values. Results The prevalence of MCR was 4.2% at baseline and the overall incidence of dementia was 3.6%. MCR (Hazard Ratio (HR) = 5.18, with 95% confidence interval (CI) = [2.43–11.03] and P ≤ 0.001) and SCC alone (HR = 2.54, with 95% CI = [1.33–4.85] and P = 0.005) were associated with incident dementia, but slow walking speed was not (HR = 0.81, with 95%CI = [0.25–2.63] and P = 0.736). Conclusions MCR and SCC are associated with incident dementia in NuAge study participants.