Periodontitis predicts elevated C-reactive protein levels in chronic kidney disease.

Based on the existing evidence supporting a state of chronic inflammation in chronic kidney disease (CKD), we hypothesized that periodontal infection may affect the systemic inflammatory status of a nationally representative CKD population as measured by serum C-reactive protein (CRP). We examined this hypothesis using the National Health and Nutrition Examination Survey 1988-1994 (NHANES III) dataset including 2303 individuals. We followed the American Academy of Periodontology (AAP)/Centers for Disease Control and Prevention (CDC) case definition for periodontitis. We used a cutoff point of 30% sites with (PD) ≥ 5 mm and (CAL) ≥ 4 mm to define generalized periodontitis cases. We estimated glomerular filtration rate based on cystatin C levels using the relevant equation. Urinary albumin-to-creatinine ratio was calculated in milligrams per gram with a cutoff point of 30 mg/g. CKD was defined based on eGFR < 60 mL/min/1.73 m(2) and albuminuria ≥ 30 mg/g. Periodontitis was found in 427 (12.3%) individuals. Of individuals with periodontitis, 41.8% had serum CRP higher than 0.3 mg/dL compared with 27.1% of non-periodontitis and 53.1% of edentulous individuals (p = 0.001 for all comparisons). When the extent of periodontitis was used as one of the independent variables, the parsimonious model showed a strong independent association between extent of periodontitis and serum CRP levels (OR = 2.0, CI95% = 1.2-3.6).