Periodontitis and the Incidence of Inflammatory Bowel Diseases: A Nationwide Population-Based Cohort Study

INTRODUCTION: Periodontitis and other oral health indicators are reportedly related to systemic inflammation. Our study aimed to investigate a possible association of oral health status (periodontitis and number of missing teeth) and oral hygiene behaviors (frequency of tooth brushing, dental visit, and dental scaling) with the risk of inflammatory bowel disease (IBD) incidence. METHODS: Using the Korean National Health Insurance Database, we conducted a nationwide, population-based cohort study involving participants from the 2003 national health screening program. We followed these individuals until December 2020 or the occurrence of censoring events. Crohn's disease (CD) and ulcerative colitis (UC) were defined by disease classification codes from the International Classification of Diseases-10 and national codes for rare intractable disease. The occurrence of IBD was analyzed using the Cox proportional hazard model, with propensity score matching performed to balance baseline characteristics between participants with and without periodontitis. RESULTS: Our analysis involved a total of 2,272,012 participants with a median follow-up period of 17.0 years. The incidence rates for CD and UC were 11.6 and 32.4 per 100,000 person-years, respectively. In multivariable analysis after propensity score matching, the presence of periodontitis was associated with an increased risk of both CD (adjusted hazard ratio [aHR] 1.32, 95% confidence interval [CI] 1.14-1.52, P < 0.001) and UC (aHR 1.21, 95% CI 1.10-1.32, P < 0.001). Conversely, frequent tooth brushing ≥3 times a day was associated with a reduced risk of CD (aHR 0.81, 95% CI 0.65-0.99, P = 0.049), but no significant association was observed with UC. DISCUSSION: Periodontitis may augment the risk of incidence for CD and UC. This association underscores the potential significance of periodontal health in the context of IBD, emphasizing the importance of comprehensive oral hygiene practices and potential preventive strategies to reduce the risk of CD and UC incidence.