Risk of inflammatory bowel disease in patients with chronic obstructive pulmonary disease: A nationwide, population-based study

BACKGROUND There is a growing evidence regarding an increased risk of inflammatory bowel disease (IBD) among patients with airway diseases. AIM To investigate the influence of chronic obstructive pulmonary disease (COPD) on the risk of IBD. METHODS A nationwide, population-based study was conducted using data from the National Health Insurance Service database. A total of 1303021 patients with COPD and 6515105 non-COPD controls were identified. The COPD group was divided into the severe and the mild COPD group according to diagnostic criteria. The risk of IBD in patients with COPD compared to controls was analyzed by Cox proportional hazard regression models. The cumulative incidences of IBD were compared between the groups. RESULTS The COPD group had higher incidences of IBD compared to non-COPD controls (incidence rate, 9.98 vs 7.18 per 100000 person-years, P < 0.001). The risk of IBD in the COPD group was increased by 1.38 (adjusted hazard ratio (HR); 95%CI: 1.25-1.52). The incidence rate of IBD was higher in the severe COPD group than in the mild COPD group (12.39 vs 9.77 per 100000 person-year, P < 0.001). The severity of COPD was associated with an increased risk of IBD (adjusted HR 1.70 in severe COPD, 95%CI: 1.27-2.21 and adjusted HR 1.35 in mild COPD, 95%CI: 1.22-1.49) CONCLUSION The incidences of IBD were significantly increased in COPD patients in South Korea and the risk of developing IBD also increased as the severity of COPD increased.