Oxidative stress links periodontal inflammation and renal function

Aims
Patients with chronic kidney disease (CKD) are also susceptible to periodontitis. The causal link between periodontitis and CKD may be mediated via systemic inflammation/oxidative stress. Using structural equation modelling (SEM), this cross‐sectional study aimed to explore the causal relationship between periodontal inflammation (PI) and renal function.

Materials and Methods
Baseline data on 770 patients with stage 3‐5 (pre‐dialysis) CKD from and ongoing cohort study was used. Detailed, bio‐clinical data on PI and renal function, as well as potential confounders and mediators of the relationship between the two, was collected. SEMs of increasing complexity were created to test the causal assumption that PI affects renal function and vice versa.

Results
SEM confirmed the assumption that PI and renal function are causally linked, mediated by systemic oxidative stress. The magnitude of this effect was such that a 10% increase in PI resulted in a 3.0% decrease in renal function and a 10% decrease in renal function resulted in a 25% increase in PI.

Conclusions
PI represents an occult source of oxidative stress in patients with CKD. Further clinical studies are needed to confirm whether periodontal therapy, as a non‐pharmacological approach to reducing systemic inflammatory/oxidative stress burden, can improve outcomes in CKD.