The association between trypsin-like protease activity in the oral cavity and kidney function in Japanese workers

Aim: To evaluate the association between trypsin-like protease (TLP) activity in the oral cavity as an indicator of periodontal health status and kidney function in Japanese workers.Materials and Methods: This cross-sectional study included 1117 Japanese workers (mean age = 43.8 years). Tongue-swab TLP activity was quantified as a* value (the redness intensity of the matrix disc of the TLP activity assessment kit; a larger value indicates more intense enzymatic activity in the samples and poorer periodontal health status). Kidney function was assessed using the estimated glomerular filtration rate (eGFR; a lower value indicates poorer kidney function). We performed ordinal logistic regression analyses to assess the association of the a* value with three eGFR categories: >= 90, 60-89 and <60 mL/min/1.73 m(2).Results: The prevalence for each eGFR category was as follows: >= 90 (31.6%), 60-89 (63.8%) and <60 mL/min/1.73 m(2) (4.6%). After adjusting for potential confounders, the a* value was found to be significantly associated with reduced kidney function. The multivariable-adjusted odds ratio (95% confidence interval) for reduced kidney function was 1.12 (1.02-1.22) per unit increase in the a* value.Conclusions: Higher TLP activity was associated with reduced kidney function in Japanese workers.