Pre-Dementia Stages and Incident Dementia in the NuAge Study.

BACKGROUND Motoric cognitive risk syndrome (MCR) and mild cognitive impairment (MCI) are two pre-dementia stages with an overlap, which may influence the risk for dementia. OBJECTIVE The study aims to examine the association of MCR, MCI, and their combination with incident dementia in Quebec community-dwelling older adults. METHODS 1,063 older adults (i.e., ≥65) were selected from a population-based observational cohort study known as the "Nutrition as a determinant of successful aging: The Quebec longitudinal study" (NuAge). Participants were separated into four groups at the baseline assessment: those without MCR and MCI (i.e., cognitively healthy individual; CHI), those with MCR alone, those with MCI alone, and those with MCR plus MCI. Incident dementia was recorded at each annual visit during a 3-year follow-up. RESULTS The prevalence of CHI was 87.2%, MCR 3.0%, MCI 8.8%, and MCR plus MCI 0.9%. The overall incidence of dementia was 2.4% and was significantly associated with MCR alone (Odd Ratio (OR) = 5.00 with 95% Confidence interval (CI) = [1.01;24.59] and p = 0.049), MCI alone (OR = 6.04 with 95% CI = [2.36;15.47] and p≤0.001), and the combination of MCR and MCI (OR = 25.75 with 95% CI = [5.32;124.66] and p≤0.001). CONCLUSION Combining MCR and MCI increased the risk for incident dementia. These results also demonstrated that this combination is a better predictor of dementia than MCI or MCR alone.