Cross-Sectional Study of Periodontal Care and Glycosylated Hemoglobin in an Insured Population

OBJECTIVE: Compare GHb among people with diabetes who have and have not received periodontal care. RESEARCH DESIGN AND METHODS: This cross-sectional study linked 5 years of electronic medical record and dental insurance data for dually insured patients with diabetes, ages 40–70 years (n = 5,103). We assessed the association between annual mean GHb (%) and periodontal care (a proxy for periodontitis) defined using claim codes. Among patients who received periodontal care, we assessed the association between GHb and periodontal treatment intensity. We determined associations using linear regression adjusted for potential confounders and tested for effect modification by age, sex, insulin use, diabetes severity, BMI, and smoking. RESULTS: Mean GHb was 7.66%; 38% of participants received periodontal care during the 5 years. After multivariate adjustment, patients who received periodontal care had a GHb level 0.08 percentage points higher than patients who did not (P = 0.02). In stratified analyses, the association was present for women (0.18 percentage points higher GHb with periodontal care, P < 0.001) but not significant for men (0.008 percentage points lower, P = 0.86). In patients who received periodontal care, those with one, and with two or more, surgical treatments had GHb 0.25 (P = 0.04) and 0.36 (P = 0.002) percentage points lower, respectively, than patients without periodontal surgeries. CONCLUSIONS: This population-based cross-sectional study showed small associations between periodontal care (a proxy for periodontitis) and higher GHb. Well-controlled longitudinal studies or clinical trials are needed to evaluate causality and temporal trends. Sub-analyses suggest that further investigation of this association among women, and by intensity of periodontal treatment, may be of interest.