Improvement of glycated hemoglobin in Japanese subjects with type 2 diabetes by resolution of periodontal inflammation using adjunct topical antibiotics: Results from the Hiroshima Study

Aims: Periodontal treatment reduces glycated hemoglobin (HbA1) in subjects with type 2 diabetes, although effective strategy for different severities of periodontitis remains unclear. We hypothesized that resolution of periodontitis-induced inflammation by the therapy combined with antibiotics may have beneficial effects on the glycemic control of diabetes. Methods: A total of 523 subjects with type 2 diabetes were screened for periodontal disease. Of these, 160 subjects who visited dentists were divided into two groups according to high-sensitivity c-reactive protein (hsCRP) level: >500. ng/ml and <500. ng/ml. The group with hsCRP over 500. ng/ml was further sub-divided into two groups according to treatment strategy: topical application of antibiotics combined with conventional mechanical debridement (group A), and debridement alone (B). Subjects with hsCRP below 500. ng/ml were sub-divided similarly (C: combination therapy; D: debridement alone). hsCRP was measured after 1 month and changes of HbA1c after 3 months. These parameters were also measured in control subjects (N= 118) who did not visit dentists (E: initial hsCRP > 500. ng/ml; F: hsCRP < 500. ng/ml). Results: A multiple comparison by ANOVA revealed that only group A showed a significant reduction in HbA1c over time (P< 0.001). Multivariable analyses revealed elevated hsCRP and the combination treatment with antibiotics were two independent variables influencing the decrease of HbA1c over the study (P< 0.01 and P< 0.001, respectively). Conclusions: In subjects with type 2 diabetes and periodontitis-induced mild inflammation (hsCRP. > 500. ng/ml), treatment to reduce hsCRP using antibiotics is recommended.