Cystatin C-based estimated glomerular filtration rate and periodontitis

Accumulating evidence suggests that decreased kidney function characterised by low estimated glomerular filtration rate (eGFR) may be associated with periodontitis. Recent studies have suggested that the use of cystatin C strengthens the association between the eGFR and the risks of adverse outcomes in decreased kidney function. The aim of this cross-sectional study was to investigate the association of cystatin C-based eGFR (eGFRcys) and creatinine-based eGFR (eGFRcreat), the commonly used method to assess kidney function, with periodontitis in 502 Japanese women (average age, 68.6 years).

GFR was estimated from serum cystatin C and serum creatinine, respectively, using the Japanese equation for GFR. Participants were classified into five groups according to their eGFRcys and eGFRcreat values. Poisson regression models with robust error variance assessed the associations of eGFRcys and eGFRcreat with periodontitis. Tests for trends were performed by fitting the five-category eGFR variables in their continuous form to the regression models.

Participants with eGFRcys < 50 ml/min/1.73 m(2) were at significantly higher risk of periodontitis compared with the reference group (≥90 ml/min/1.73 m(2) ) (adjusted relative risk = 2.12, 95% confidence interval = 1.12 to 4.02). Additionally, there was a trend towards a higher risk of periodontitis among participants with lower eGFRcys values (p for trend in the multivariable model = 0.008). In contrast, eGFRcreat did not show a significant association with periodontitis.

The findings of this study of Japanese older women showed that eGFRcys had a stronger and more linear association with periodontitis than eGFRcreat.