Background: Smoking and diabetes are well-known risk factors for periodontitis. The aims of this study are to examine whether these factors are associated with periodontitis in representative samples of Koreans and to estimate the interaction impact of smoking and diabetes on periodontitis in this population.
Methods: The Korean National Oral Health Survey (KNOHS) 2006 collected nationally representative samples of oral epidemiologic data. A community periodontal index (CPI) of 3 to 4 and a CPI value of 0 to 2 were classified as periodontitis and non-periodontitis, respectively. A total of 4,118 participants from KNOHS 2006 were interviewed on smoking and diabetes. Periodontitis was the outcome variable. Smoking and diabetes were the major explanatory variables. The confounders consisted of age, sex, education, occupation, monthly income, and residential area. Logistic regression analyses were used to evaluate the associations of smoking and diabetes with periodontitis after adjustment for confounders.
Results: The overall prevalence of periodontitis, current smoking, and self-reported diabetes in Korean adults was 10.1%, 25.9%, and 4.5%, respectively. Associations of smoking and diabetes with periodontitis were : current smokers, odds ratio (OR) = 1.40, 95% confidence interval (CI) = 1.02 to 1.90; and diabetes, OR = 1.21, 95% CI = 0.82 to 1.77. The association between diabetes and periodontitis was not significant and there were no synergistic interactions of smoking and diabetes on periodontitis.
Conclusions: The results suggest that smoking has a significant impact on the periodontal health of Korean adults, but the combined effect of smoking and diabetes had no significant impact.