The impact of frailty and its changes on the development of motoric cognitive risk syndrome in middle-aged and older adults.

BACKGROUND: Previous research links frailty to cognitive decline, but the relationship between frailty and motoric cognitive risk syndrome (MCR), a dementia precursor, is underexplored. METHODS: This study used CHARLS data with 3388 participants aged ≥45. Data from 2011 to 2012, 2013, and 2015 were analyzed to examine the relationship between frailty index (FI), total FI, and changes in FI (△FI) with MCR risk. Nine machine learning models were built using baseline FI to predict MCR risk, and changes in frailty status over time were assessed for their impact on MCR risk. RESULTS: By follow-up end, 127 participants (3.74%) developed MCR. Higher baseline FI, total FI, and △FI were associated with increased MCR risk. Restricted cubic splines (RCS) showed a linear relationship between FI and MCR risk (p > 0.05). Trend regression analysis confirmed a significant upward trend in MCR risk (P < 0.05), with odds ratios of 1.434 (1.195, 1.721), 1.766 (1.450, 2.151), and 1.278 (1.081, 1.511) for different FI categories. Logistic regression and GBDT models had AUC > 0.6, indicating baseline FI showed modest predictive performance associated with MCR. Participants transitioning from robust to frail/pre-frail showed higher MCR prevalence, while those regaining robustness from frailty showed lower MCR prevalence. Remaining pre-frail or improving to robust status also associated with reduced MCR occurrence compared to progressing from pre-frailty to frailty. CONCLUSION: This study highlights the crucial associations of frailty with MCR. Early detection and intervention in frailty might be promising targets for mitigating MCR development and potentially linked to dementia prevention.