Are Periodontitis and Diabetes interacting on all-cause or cardiovascular Mortality?

Objectives: Currently, the evidence on the association between periodontitis and mortality (both all-cause and cardiovascular) is inconsistent. In addition, interaction with diabetes has rarely been addressed. We investigated whether periodontal disease is associated with mortality and if this effect was modified by diabetes.
Methods: We used data prospectively collected within the population-based study of Health in Pomerania (SHIP) which was conducted in northeastern Germany with baseline examinations conducted from 1997-2001. The final sample comprised 3352 subjects with periodontal examinations, aged 20-81 years. In 11 years of mean follow-up time, 274 deaths occurred, 89 of which were of cardiovascular reasons. Periodontitis was measured using mean CAL (clinical attachment level), extent CAL ≥ 3mm and periodontitis score. Periodontitis score is calculated as the average of standardized scores of mean CAL, extent CAL ≥ 3mm and number of missing teeth. Cox proportional hazards regression models were run to evaluate the relationship between different periodontal measures, diabetes and mortality, adjusting for age, gender, school education, income, physical activity, BMI, smoking and oral health behavior.
Results: Mean CAL (HR =1.09; 1.02-1.16), extent CAL ≥ 3mm (HR=1.01; 1.001-1.013), number of teeth (HR=0.98; 0.96- 0.99) and periodontitis score (HR= 1.36; 1.09- 1.68) were linearly associated with all-cause mortality. For cardiovascular mortality analysis, after exclusion of subjects with prevalent cardiovascular diseases (heart surgery, myocardial infarction or stroke), HRs were significant for mean CAL (HR= 1.14; 1.00-1.31) and periodontitis score (HR=1.62; 1.02-2.56). We did not find any association between remaining periodontal definitions and cardiovascular mortality. For none of the periodontal measures, multiplicative interaction with diabetes was not found.
Conclusions: This study confirmed an association between periodontal disease and all-cause or cardiovascular mortality. We did not find an effect modification by diabetes on mortality suggesting that there might not be an increased mortality risk for subjects having both periodontitis and diabetes in this population.