oral functional limitation and long-term frailty trajectories: a 6-year cohort study of community-dwelling older adults in Korea

Frailty is a dynamic and potentially reversible condition, yet limited evidence has examined whether oral functional limitation is associated not only with frailty onset but also with long-term frailty transitions. We analyzed 6-year prospective data (2016-2023) from 2731 community-dwelling adults aged 70-84 years in the Korean Frailty and Aging Cohort Study. Oral functional limitation was defined as self-reported difficulty in chewing or pronunciation. Frailty was assessed using Fried's physical phenotype. Incident frailty and longitudinal transitions between robust, pre-frail, and frail states were evaluated using Cox regression, landmark analysis for early oral function changes, and multi-state modeling. Participants with oral functional discomfort had a higher risk of incident frailty (adjusted HR 1.53, 95% confidence interval [CI] 1.19-1.98). Persistent oral functional discomfort during the first 2 years was associated with increased subsequent frailty risk (adjusted HR 1.42, 95% CI 1.02-2.13). Multi-state analyses showed that individuals with oral functional discomfort were more likely to progress from robust to pre-frail (HR 1.26, 95% CI 1.09-1.47) and from pre-frail to frail (HR 1.52, 95% CI 1.14-2.01), and less likely to recover from pre-frail to robust (HR 0.78, 95% CI 0.66-0.92). Transition probability curves consistently showed faster progression and reduced recovery among participants with oral functional discomfort. Oral functional limitation, assessed using brief self-reported measures, was associated with unfavorable long-term frailty trajectories characterized by accelerated progression and reduced recovery. Brief oral-function screening in primary care and community settings may serve as a scalable marker for identifying older adults at higher risk and supporting risk-informed frailty management.