Aim: In this ultra-aged society with an increasing number of the elderly requiring care in Japan, the prevention of long-term nursing care is one of the crucial issues. The concept of “frailty”, which is defined as losses of physiologic reserve that increase the risk of disability, has attracted steep increase of interest among researchers and clinicians. In Japan, the concept of “oral frailty”, associated with the decline of oral function, has also been proposed. The aim of this study was to investigate the relationship between oral frailty and physical frailty by using covariance structure analysis in a cross-sectional study.
Materials and Methods: A total of 225 subjects were enrolled after informed consent. For evaluating oral frailty, occlusal force and moisture of oral mucosa was measured. Grip strength and walking speed was measured for assessing physical frailty. For statistical analysis, decision tree analysis and covariance structure analysis were performed. The study was approved by the Ethics Committee of the Tokushima University Hospital (No. 2404).
Results: Occlusal force was selected as the variable by the decision tree analysis in first layer for grip strength. Grip strength, occlusal force and moisture of oral mucosa were selected for walking speed. In a covariance structure analysis, a more appropriate model indicates that the causal relationship of oral frailty toward physical frailty was chosen compared to that by the inverse relationship between them.
Conclusion: The causal relationship of oral frailty to physical frailty and significance of occlusal force for oral and physical frailty were suggested.