Association of periodontitis with insulin resistance, β-cell function, and impaired fasting glucose before onset of diabetes.

Periodontitis and insulin resistance (IR) show bidirectional relationship. No studies have assessed the associations of periodontitis with IR, impaired β-cell function, and impaired fasting glucose (IFG) in the general population. We investigated these associations in a representative sample of the Korean population. The subjects were 8,248 males and 10,874 females, who were ≥ 20 years of age and participants in the third, fourth, and fifth Korea National Health and Nutritional Examination Surveys (2008-2010). Periodontitis was defined as community periodontal index (CPI) ≥ code 3 according to World Health Organization criteria. Homeostasis model assessments of IR and β-cell function (HOMA-IR and HOMA-β) were calculated. Participants with periodontitis showed a higher prevalence of diabetes than those without periodontitis. Among subjects without diabetes, after adjustment for confounding factors including age, gender, body mass index, systolic blood pressure, serum total cholesterol, smoking status, alcohol consumption, region, and regular exercise, a comparison of participants with periodontitis vs those without showed a significantly higher prevalence of IFG (28.5% vs. 17.7%, p<0.001) and lower HOMA-β (115.2 vs. 130.8, p<0.001). Periodontitis was identified as a risk factor for IFG (OR, 1.301; 95% CI, 1.193∼1.418; p<0.001). Conversely, participants with and without periodontitis had similar HOMA-IR. In conclusion, periodontitis showed an association with decreased β-cell function and increased prevalence of IFG before onset of diabetes as well as increased prevalence of diabetes in the Korean population. Future longitudinal studies are warranted to elucidate the shared pathophysiology between periodontal disease and diabetes mellitus.