Background: Cigarette smoking is a significant risk factor for both chronic obstructive pulmonary disease (COPD) and periodontal disease. The goal of this study was to better understand the role of smoking in a possible relationship between periodontal disease and COPD.
Methods: The study population consisted of 7,625 participants in the Third National Health and Nutrition Examination Survey (NHANES III) during 1988-1994 who were aged 30 years or older when examined and who received a spirometric examination. The data analysis employed logistic regression models and accounted for the complex sampling design used in NHANES III.
Results: After adjustment for potential confounders, there was no statistically significant association between periodontal disease and COPD among former or non-smokers. Current smokers with > or = 4 mm mean loss of attachment had an odds ratio of 3.71 (95% confidence interval: 1.74, 7.89).
Conclusions: These results suggest that cigarette smoking may be a cofactor in the relationship between periodontal disease and chronic obstructive pulmonary disease. The key role played by smoking in the etiology of both periodontal disease and chronic obstructive pulmonary disease suggests that much of the observed increase in risk may actually reflect the exposure to smoking. Additional research into smoking-related effect modification is needed to clarify the role of periodontal disease in the etiology of smoking-related systemic diseases.