Periodontitis and the incidence of chronic obstructive pulmonary disease: A longitudinal study of an adult Japanese cohort.

Abstract

To examine the relationship between periodontitis as an independent effect of smoking and the development of chronic obstructive pulmonary disease (COPD) in Japanese people based on longitudinal data. We targeted 4745 people who underwent pulmonary function tests and dental check-ups at baseline and 8 years later. The Community Periodontal Index was used to assess periodontal status. A Cox proportional hazard model was used to examine the relationship between the incidence of COPD and periodontitis and smoking. To clarify the interaction between smoking and periodontitis, interaction analysis was performed. In a multivariable analysis, both periodontitis and heavy smoking had significant effects on COPD development. When periodontitis was analysed as a continuous value (number of sextants with periodontitis) and as a category (presence or absence of periodontitis) in the multivariable analyses after adjusting for smoking, pulmonary function and other variables, periodontitis had significantly higher hazard ratios (HRs) for the incidence of COPD; the HRs were 1.09 (1.01-1.17) and 1.48 (1.09-2.02), respectively. Interaction analysis showed no significant interaction between heavy smoking and periodontitis on COPD. These results suggest that periodontitis has no interaction with smoking but has an independent effect on developing COPD.