Mechanisms of motoric cognitive risk—Hypotheses based on a systematic review and meta‐analysis of longitudinal cohort studies of older adults

We aimed to refine the hypothesis that motoric cognitive risk (MCR), a syndrome combining measured slow gait speed and self‐reported cognitive complaints, is prognostic of incident dementia and other major causes of morbidity in older age. We propose mechanisms on the relationship between motor and cognitive function and describe a roadmap to validate these hypotheses. We systematically searched major electronic databases from inception to August 2021 for original longitudinal cohort studies of adults aged ≥60 years that compared an MCR group to a non‐MCR group with any health outcome. Fifteen cohorts were combined by meta‐analysis. Participants with MCR were at an increased risk of cognitive impairment (adjusted hazard ratio [aHR] 1.76, 95% CI 1.49–2.08; I(2 )= 24.9%), dementia (aHR 2.12, 1.85–2.42; 33.1%), falls (adjusted Relative Risk 1.38, 1.15–1.66; 62.1%), and mortality (aHR 1.49, 1.16–1.91; 79.2%). The prognostic value of MCR is considerable and mechanisms underlying the syndrome are proposed.