Purpose: Although the association between oral health and physical frailty is well established, psychological frailty has not been investigated. Therefore, this prospective cohort study was conducted to examine the association between masticatory performance and psychological frailty in older community-dwelling Japanese individuals.
Methods: The participants included 498 older adults who completed baseline and 3- and 6-year follow-up surveys. The World Health Organization-5 (WHO-5) scale and the Japanese version of the Montreal Cognitive Assessment (MoCA-J) were used to evaluate the psychological frailty status of participants. Psychological frailty was defined as a WHO-5 score < 13 and a MoCA-J score < 23. Masticatory performance was evaluated using a scoring method for the test gummy jelly (score: 0-9). A mixed-effects ordinal logit model analysis was used to examine the influence of masticatory performance and number of teeth on the development of psychological frailty while adjusting for relevant factors such as educational level, financial status, living situation, area of residence, history of chronic diseases, and handgrip strength.
Results: A total of 311 participants (62.5%) exhibited psychological robustness at baseline. The rates of development of psychological frailty after 3 and 6 years were 4.2% and 4.5%, respectively. The longitudinal analysis revealed that masticatory performance at baseline was negatively associated with the prevalence of psychological frailty and pre-frailty at follow-up.
Conclusions: Decreased masticatory performance is associated with the development of psychological frailty in older community-dwelling people of Japanese descent.
Keywords: Masticatory performance; Older adults; Oral rehabilitation; Prospective cohort studies; Psychological frailty.