Relationship Between Blood Test Results and Oral Function Tests in Individuals Undergoing Regular Physical Examinations

Background: There is growing interest in the relationship between oral function and lifestyle-related diseases. Objectives: This study aimed to investigate the associations between the results of oral function tests and those of blood tests for lipid abnormalities, glucose metabolism and kidney function. Methods: A total of 118 individuals aged ≥ 50 years (80 men and 38 women) who had undergone health check-ups at our hospital in 2021 and 2023 were examined. Based on the fasting blood glucose (GLU), HbA1c, high-density lipoproteins (HDL), low-density lipoproteins (LDL), urea nitrogen (BUN) and estimated glomerular filtration rate (eGFR) values obtained from the health check-up results; the subjects were divided into two groups: those with test values outside the reference range in 2021 and/or 2023 and those with test values within the reference range. The results of seven oral function tests were compared between the groups using the Mann–Whitney U test. p < 0.05 was considered significant. Results: The group with GLU and HbA1c values outside the reference ranges had significantly lower numbers of remaining teeth (RTN) and oral diadochokinesis (OD) values compared to the group within the reference range. The groups with HDL and LDL values outside the standard ranges had a significantly higher tongue coat index (TCI) and significantly lower OD. Significant differences in TCI and OD/ta/ /ka/ were observed between BUN groups within and outside the reference range. Likewise, significant differences in TCI, RTN and OD/ta/ /ka/ were observed between eGFR groups within and outside the reference range. Conclusions: Subjects with blood test values outside the reference range exhibited a decline in oral function, indicating that a decline in oral function might increase the risk of lifestyle-related diseases and facilitate the progression of frailty.