Effect of Isometric Tongue Lifting Exercise on Oral Function, Physical Function, and Body Composition in Community-Dwelling Older Individuals: A Pilot Study

Introduction: It is known that oral frailty is one of the risk factors for physical frailty. Therefore, early detection, appropriate treatment, and prevention of oral frailty are really important. Tongue lifting exercise has been identified as a well-known method for improving decreased tongue pressure, one of the factors for oral frailty. However, few reports have investigated how tongue-strengthening exercises affect physical function and body composition. The aim of this study was to investigate the effects of isometric tongue lifting exercises on oral function, physical function, and body composition. Methods: Participants were 49 elderly people aged 68-79 years, who had previously participated in the "Itoshima Frail Study." Participants performed isometric tongue lift exercises for 3 months. Oral function (tongue pressure and oral diadocokinesis), physical function (grip strength, open-eyed one-leg standing, sit-to-stand motion time, 5-m gait speed, and 3-m Timed up and go [TUG]), and body composition were measured at baseline and post-intervention, and the extent of changes in each item was statistically analyzed. Furthermore, participants were divided into physical frailty/pre-frailty and robust groups based on the Japanese version of the frail scale proposed by [BMC Geriatr. 2015 Apr;15:36] and were compared in terms of the extent of changes in each item baseline and the post-intervention. Results: After the intervention, oral function increased significantly together with a significant improvement in physical function, open-eyed one-leg standing time, sit-to-stand motion, and 3-m TUG. For body composition, visceral fat level and basal metabolic rate decreased significantly. Although no significant change in body composition was observed in the physical frailty/pre-frailty group after the intervention, significant improvements in several items were observed in the robust group. Conclusion: Isometric tongue lifting exercise can effectively improve oral function. Furthermore, it might affect physical function and body composition.