The Association of Periodontal Disease and Incident Type 2 Diabetes

Objectives: We tested the hypothesis that exposure to periodontal inflammation, using clinical exam evidence, predicts the subsequent occurrence of incident type 2 diabetes.
Methods: Incident diabetes was assessed with yearly telephone interviews and self-reports from study participants. Clinical assessments of periodontal inflammation were defined by two assessments: bleeding upon probing (BOP) and periodontal pockets(PD) (rounded down to the nearest mm) Using these two parameters, participants were classified into 5 categories-I) PD ≤3mm, BOP ≤10% , II) PD≤3mm, BOP >10mm, III) one or more sites with PD≥4mm, BOP≤10mm, IV) one or more sites with PD≥4mm, BOP>10% &<50, V) one or more sites with PD≥4mm, BOP≥50% . Bleeding upon probing parameters were divided into 3 groups.(Mild BOP<10% (reference category), Moderate BOP≥10-49% , Severe BOP≥50%). In multivariable analyses using the Cox proportional hazards model, we adjusted for sex, age, race, education level, smoking status, physical activity, total caloric intake, waist circumference, hypertension, previous cardiovascular disease, family history of diabetes, and HDL cholesterol levels.
Results: During 13.84 years of follow up, 1,967 individuals developed Type 2 diabetes of the total (n= 5,819) participants. The incidence of type 2 diabetes did not appear to increase monotonically across the 5 periodontal categories that measured both periodontal pockets and bleeding upon probing with statistical significance. However, a dose-response relationship with clinical inflammation and incident diabetes could be seen by using only bleeding upon probing as a measure for clinical inflammation. (Relative hazard ratio for Mild bleeding=1.0, Moderate bleeding-1.2 (95%CI:1.2-1.7) and severe bleeding=1.7 (95%CI:1.4-2.0).
Conclusions: This study supports the hypothesis that clinical periodontal inflammation increases the risk of incident diabetes several years later. An increase in bleeding upon probing appears to be longitudinally associated with the onset of incident diabetes. Since even minimal bleeding upon probing in this study was associated with future incident diabetes, a strong case is made to support patient education for prevention of periodontal disease to and study the effect of prevention of even mild periodontal inflammation on impaired glucose tolerance and diabetes.