Oral frailty is commonly observed and associated with cognitive function and decreased muscle strength in patients on maintenance hemodialysis: A retrospective observational study

Background Oral frailty is a new concept introduced in Japan in 2013. Our preliminary study showed that oral hypofunction was observed in more than half of patients undergoing maintenance hemodialysis (MHD). Therefore, we determined the exact prevalence of oral frailty in MHD patients and investigated the association between oral cavity function, findings obtained by comprehensive geriatric assessment, and motor features. Methods We initiated two-week hospitalization program for MHD patients to evaluate frailty including oral cavity functions. Along with a comprehensive geriatric assessment and evaluation of motor functions, seven items of oral cavity functions were assessed by a professional dentist to determine oral frailty. After determining the incidence of each item, the association between these factors was analyzed to explore the factors that affect oral frailty. Results Oral frailty was observed in 33 out of 50 patients (66%). Especially, tongue-lip motor functions were frequently impaired in this population. Oral cavity function scores, which increased as oral function deteriorated, negatively correlated with cognitive function (r = -0.349; p  = 0.0129) and grip strength (r = -0.364; p  = 0.00933). Conclusions Oral frailty was commonly observed in MHD patients. We are currently consider the exercise programs to improve tongue-lip motor function, enhance cognitive function through interprofessional cooperation, and strengthen the grip.