Frailty and Risk of Incident Motoric Cognitive Risk Syndrome

Background: Frailty is highly prevalent among older adults, and associated with cognitive decline. Relationship between frailty and motoric cognitive risk syndrome (MCR), a pre-dementia syndrome characterized by the presence of subjective cognitive complaints and slow gait, is yet to be elucidated. Objective: To examine whether frailty increases the risk of developing incident MCR. Methods: We analyzed 641 adults, aged 65 and above, participating in the LonGenity study. Frailty was defined using a 41-point cumulative deficit frailty index (FI). MCR was diagnosed at baseline and annual follow-up visits using established criteria. Cox proportional hazard models were used to study the association of baseline frailty with incident MCR, and reported as hazard ratio (HR) with 95% confidence intervals (CI) adjusted for age, sex, and education. Results: At baseline, 70 participants (10·9%) had prevalent MCR. Of the remaining 571 non-MCR participants (mean age 75.0, 57.3% women), 70 developed incident MCR (median follow-up 2.6 years). Higher frailty scores at baseline were associated with an increased risk of incident MCR (HR for each 0.01 increase in the FI: 1.07; 95% CI 1.03-1.11; p=0.0002). The result was unchanged even after excluding mobility related or chronic illnesses items from the FI as well as accounting for reverse causation, competing risk of death, baseline cognitive status, social vulnerability, and excluding participants with mild cognitive impairment syndrome. Conclusions: Higher levels of frailty increase risk for developing MCR and suggest shared mechanisms. This association merits further study to identify strategies to prevent cognitive decline.