Do subjective cognitive complaints and slow gait speed increase the probability of progression to objective cognitive impairment? A systematic review and meta-analysis on motoric cognitive risk syndrome

Motoric cognitive risk (MCR) syndrome, characterized by the coexistence of subjective cognitive complaints (SCCs) and slow gait speed, has been identified as a potential risk factor for objective cognitive impairment and dementia. This research article performs a systematic review and meta-analysis to analyze cross-sectional and longitudinal associations between MCR syndrome and objective cognitive impairment. Cross-sectional and longitudinal studies in cognitively unimpaired adults with SCCs were included. The risk associated with progression to mild cognitive impairment (MCI) or dementia was estimated, also for longitudinal studies specifically. An additional meta-analysis was conducted to explore the association with SCCs and gait speed independently. Random-effects meta-analyses were conducted to estimate pooled effects with 95% confidence intervals and assess heterogeneity. Egger's test and Trim and Fill procedure were used to detect publication bias. The findings show a significant association between MCR syndrome in preclinical stages and objective cognitive impairment. Longitudinally, the risk of progression to MCI or dementia increased from 1.99 (95% CI, 1.61 to 2.45, p < .001) to 2.49 (95% CI, 1.85 to 3.34, p < .001). Additional meta-analyses conducted to separately analyze the effect of MCR components did not reveal any significant associations. Individuals with MCR showed an almost twofold higher risk of cognitive impairment compared with non-MCR participants, and this risk increases when based solely on longitudinal predictions. Individually, components of the MCR syndrome showed no significant associations. Our results supported that MCR syndrome at preclinical stages was associated with objective cognitive decline.