Motoric cognitive risk syndrome as a predictive factor of cognitive impairment and dementia - A systematic review and...

Motoric cognitive risk syndrome (MCR) is defined as the presence of slow gait-speed and subjective cognitive decline in older individuals without mobility disability or dementia. While some studies suggest that MCR is a pre-dementia syndrome and may help predict the risk of cognitive impairment and dementia, not all studies concur. The objective of this study is to comprehensively summarize and synthesize evidence to assess the association between MCR and cognitive impairment and dementia.

Following a pre-specified protocol, two authors systematically searched PubMed, Embase, and The Cochrane Library from inception to 19 August 2024 for observational or randomized studies pertaining to the association between MCR and cognitive impairment and dementia. We favoured maximally adjusted hazards and odds ratios to determine the longitudinal and cross-sectional risk of cognitive impairment and dementia. We investigated for potential sources of heterogeneity and also conducted sensitivity and subgroup analyses by continent and the type of cognitive outcome. The quality of evidence was assessed using the Newcastle-Ottawa Scale (NOS) and the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) framework.

We included 20 studies comprising a combined cohort of 1206,782 participants, of which 17 studies were included in the quantitative analysis. The pooled analysis outlined that individuals with MCR exhibited 2.20-fold higher risk of cognitive impairment and dementia, compared to controls (RR=2.20; 95 %CI=1.91-2.53). These findings remained robust across all subgroup analyses, sensitivity analyses and assessments of publication bias.

MCR may be considered a predictive factor for long-term cognitive impairment and dementia. This should be taken into consideration when clinically evaluating the risk of cognitive impairment and dementia but further research is required to lend greater clarity to this association.