Influence of Periodontal Disease on Changes of Glycated Hemoglobin Levels in Patients With Type 2 Diabetes Mellitus: A Retrospective Cohort Study

Background: Little evidence is available regarding the effects of long-term periodontal infection on diabetes mellitus (DM) control. The aim of this retrospective cohort study is to evaluate influence of periodontal status on changes of glycated hemoglobin (HbA1c) levels of patients with type 2 DM (DMt2). Methods: Eighty patients (mean age: 56.0-8.9 years) with DMt2 were included. Patients were non-smokers, aged >= 40 years, and using antidiabetic drugs. Demographics, health history, and HbA1c levels were retrieved from medical charts. Probing depth and clinical attachment loss (AL) were recorded. Results: Patients were examined at two time points within a mean interval of 38.6-6.6 months. Increase in HbA1c over time was statistically significant when severe periodontitis was diagnosed at baseline (2.32%, 95% confidence interval [CI]: 1.50% to 3.15%), in patients showing at least one tooth with >= 2 mm of AL progression (2.24%, 95% CI: 1.56% to 2.91%), in males (2.75%, 95% CI: 1.72% to 3.78%), and in those with HbA1c <6.5% at baseline (3.08%, 95% CI: 2.47% to 3.69%). After adjusting for baseline HbA1c, significant changes were still observed for severe periodontitis and progression of AL with increases of 0.85% and 0.9%, respectively. After adjusting for sex and HbA1c, AL progression was also statistically significant, with increases of 0.84%. Conclusions: Periodontitis progression was associated with increase in HbA1c in patients with DMt2. Identification of these risk factors suggests that periodontal treatment may improve glycemic control of patients with DMt2 by eliminating periodontal infection.