Relationship between tongue pressure and back muscle strength in healthy elderly individuals

Background Aging is associated with a decrease in muscle mass and strength in swallowing muscles, as well as in whole-body muscles. A decrease in tongue pressure (TP) is related with whole-body function, and the trunk, including abdominal and back muscles, forms the core of the body. However, the direct relationship between TP and trunk muscle strength remains unclear. Aims To clarify the association between back muscle strength, an indicator of trunk muscle strength, and TP in healthy elderly individuals. Methods In all, 112 healthy community-dwelling individuals aged >= 60 years (men: 35, median age 74.0; women: 77, median age 69.0) were included. Body mass index (BMI), TP, and back muscle strength (BMS) were measured. Tooth loss pattern was evaluated by the Eichner classification. Participants were divided into two groups based on the median of the BMS and classified into three groups based on the Eichner index (Eichner A, B, and C). The effects of BMS and occlusal support on TP were analyzed. Results In the low BMS group, there was a significant difference in TP between the Eichner B and Eichner C (p = 0.017) groups. However, in the high BMS group, occlusal support did not affect TP. Moreover, the explanatory factors for TP were BMS (beta = 0.373, p = 0.001) and the Eichner index (beta = 0.190, p = 0.036). Conclusions TP was correlated more with BMS than aging and occlusal support in healthy elderly individuals. This study indicated that the clinical evaluation of the whole body is important when assessing oral and swallowing function.