Association between oral frailty and locomotive syndrome among community-dwelling older adults

BACKGROUND: The association between oral frailty and locomotor function, as well as the mechanisms underlying this relationship, remains unclear. This study aimed to examine the association between oral frailty and locomotive syndrome among community-dwelling older Japanese adults, exploring the roles of dietary intake and frequency of going outside in this association. METHODS: This study included 439 community-dwelling older adults (mean age: 77.7 years) who underwent health examinations in Miyagi and Akita prefectures, Japan. Oral frailty was assessed using the Oral Frailty Six-Item Scale, comprising four objective measures (number of remaining teeth, masticatory ability, oral diadochokinesis, and tongue pressure) and two subjective measures (self-reported masticatory performance and swallowing function). Locomotive syndrome, a domain of intrinsic capacity, was evaluated using the stand-up test, two-step test, and 25-item Geriatric Locomotive Function Scale. Covariates included age, sex, education, smoking status, alcohol consumption, handgrip strength, cognition, and comorbidities. RESULTS: Among the participants, 321 (73.1%) had locomotive syndrome, and 111 had oral frailty. Multivariate modified Poisson regression analysis showed that individuals with confirmed oral frailty had a significantly higher prevalence of locomotive syndrome than those without oral frailty (prevalence ratio, 1.21; 95% confidence interval, 1.10-1.34). Structural equation modeling showed a significant indirect effect of going outside on this association, whereas the dietary variety score did not mitigate this association. CONCLUSION: This cross-sectional study demonstrated a significant association between oral frailty and locomotive syndrome among community-dwelling older adults. Moreover, frequency of going outside may partially explain this association.