Periodontitis as the risk factor of chronic kidney disease: Mediation analysis

AIM: To determine sequences and magnitude of causality among periodontitis, diabetes and chronic kidney disease (CKD) by mediation analysis. METHODS: Ten‐year‐data were retrieved from the Electric Generation Authority of Thailand (EGAT) study. A cohort of 2,635 subjects was identified with no CKD at baseline. The interested outcome was CKD incidence defined as glomerular filtration rate <60 ml/min/1.73 m(2). The percentage of proximal sites with clinical attachment loss ≥5 mm was used to represent periodontitis. Mediation analysis with 1,000‐replication bootstrapping was applied to two causal diagrams, diagram A (Periodontitis → Diabetes → CKD) and diagram B (Diabetes → Periodontitis → CKD). RESULTS: The cumulative incidence of CKD was 10.3 cases per 100 persons during 10‐year period. In diagram A, each increasing percentage of proximal sites with severe periodontitis increased the adjusted odds ratio of CKD 1.010 (95% CI: 1.005, 1.015) and 1.007 (95% CI: 1.004, 1.013), by direct and indirect effect through diabetes, respectively. In diagram B, diabetes increased the odds of CKD twofold, with 6.5% of this effect mediated via periodontitis. CONCLUSIONS: Periodontitis had significant direct effect, and indirect effect through diabetes, on the incidence of CKD. Awareness about systemic morbidities from periodontitis should be emphasized.