Association of Oral Frailty with Physical Frailty and Malnutrition in Patients on Peritoneal Dialysis

Background: Oral frailty is a state between normal oral function and oral hypofunction. Oral frailty progresses to oral hypofunction and dysphagia, which leads to malnutrition, and then to physical frailty and sarcopenia. Oral frailty is reported to be associated with physical frailty and malnutrition in hemodialysis patients, but there have been no reports on peritoneal dialysis (PD) patients. Methods: This prospective cohort study investigated the associations of oral frailty with physical frailty, sarcopenia, and malnutrition in patients on PD. Patients were divided into an oral frailty group and a non-oral frailty group according to the Oral Frailty Index-8. Patients were assessed for physical frailty, sarcopenia, and malnutrition at baseline and 1 year later, and changes in each measure were compared between the two groups. Physical frailty was assessed using the Revised Japanese version of the Cardiovascular Health Study Criteria (Revised J-CHS) and the FRAIL scale. Sarcopenia was assessed using the diagnostic criteria reported by the Asian Working Group for Sarcopenia in 2019 (AWGS2019 criteria) and the Screening Tool for Sarcopenia Combined with Calf Circumference (SARC-CalF), skeletal muscle index (SMI), calf circumference (CC), grip strength, and gait speed. Nutritional status was assessed with the Short-Form Mini-Nutritional Assessment (MNA-SF), the Malnutrition Universal Screening Tool (MUST), the Global Leadership Initiative on Malnutrition (GLIM) criteria, weight, and body mass index (BMI). Results: Of the 58 eligible patients, 51 completed the study. The oral frailty group was significantly older and had slower gait speed, fewer teeth, higher intact parathyroid hormone, higher C-reactive protein, higher frequency of cardiovascular disease, and lower employment at baseline. The oral frailty group had significantly worse physical frailty (Revised J-CHS, p = 0.047; FRAIL scale, p = 0.012), sarcopenia (SMI, p = 0.018; CC, p = 0.002), and nutritional status (MNA-SF, p = 0.029; MUST, p = 0.005; GLIM criteria, p = 0.022; weight, p < 0.001; BMI, p < 0.001). However, there were no significant differences in the worsening of sarcopenia (AWGS2019 criteria, SARC-CalF, grip strength, and gait speed). Conclusions: Oral frailty in patients on PD was associated with the development and progression of physical frailty and malnutrition, and may be associated with the development and progression of sarcopenia.