The "Motoric Cognitive Risk" Syndrome in the Quebec Population: Results From the NuAge Study - Sub-study: The Biological Underpinnings of Motoric Cognitive Risk Syndrome: a Multicenter Study

The overall objective of the proposal is to examine the epidemiology of the newly reported "motoric cognitive risk" (MCR) syndrome, which is a pre-dementia syndrome combining subjective cognitive complaint (i.e.; memory complaint) with objective slow gait speed, in the Quebec elderly population.

Cognition and locomotion are two human abilities controlled by the brain. Their decline is highly prevalent with physiological and pathological aging, and is greater than the simple sum of their respective prevalence, suggesting a complex age-related interplay between cognition and locomotion. Both declines in cognition and locomotion are associated, furthermore the temporal nature of their association has been unclear for a long time. Recently, a systematic review and meta-analysis has provided evidence that poor gait performance predicts dementia and, in particular, has demonstrated that MCR syndrome is a pre-dementia syndrome, suggesting that low gait performance is the first symptom of dementia. The uniqueness of MCR syndrome is that it does not rely on a complex evaluation or laboratory investigations. Indeed, this syndrome combined subjective cognitive complaint and objective slow gait speed, and is easy to apply in population-based settings.

Prevalence and incidence of MCR syndrome, as well as its association with incidence of cognitive decline and impairment, have never been reported in Canada. Nutrition as a determinant of successful aging: The Quebec longitudinal Study (the NuAge study) is a Quebec population-based observational cohort study performed in healthy older community-dwellers adults which provides a unique opportunity to: 1) obtain reliable estimates of MCR syndrome prevalence and incidence, 2) determine the distribution of clinical and biological (blood biomarkers and genetic) characteristics associated with MCR syndrome, 3) examine the association of MCR syndrome and its biological characteristics with cognitive decline and incidence of cognitive impairment in the Quebec elderly population.