Chronic periodontitis and community-acquired pneumonia: a population-based cohort study

BACKGROUND: This study aimed to determine the association between chronic periodontitis (CP) and community-acquired pneumonia (CAP) according to CP severity in the Korean population based on the National Health Insurance Service database. METHODS: Data from the National Health Insurance Service-National Health Screening Cohort (NHIS-HEALS), conducted from 2002 to 2013, were analyzed. A total of 363,541 participants were enrolled in this retrospective cohort study. Data on socio-demographic characteristics and CAP-related variables were collected. Participants were divided into 4 groups according to CP severity. Cox proportional hazards regression was performed after adjusting for sociodemographic and related covariates. RESULTS: A total of 363,541 participants were included in the analysis. The number of CAP cases in the index period was 14,838 (4.1%). Among the 4 groups, the mean age was significantly higher in the severe CP group. The incidence rates of severe and non-severe CP were 5.68 and 4.99, respectively (per 10(3) person-years). The hazard ratio for CAP was not significant in any of the models regardless of the presence or absence of CP. On stratification analysis by sex, smoking and Charlson comorbidity index, there were no significant differences between CAP and CP in any of the models. CONCLUSION: The results of this study show that CP may not be a potential risk factor for CAP.