Risk factors associated with ulcerative colitis: A multidimensional case-control study from Tianjin, China

Abstract

Background and study aims Although ulcerative colitis (UC) incidence is increasing in China, there are few reports on risk factors. We conducted a case‒control study in Tianjin, China, to assess potential risk factors for the development, extent and severity of UC. Methods 361 UC patients and 1444 controls with similar social backgrounds were screened by detailed questionnaires and corresponding endoscopic findings in Tianjin's colorectal cancer screening program from 2012 to 2020. Basic demographic characteristics were compared using the chi-square test, and multivariate analysis was conducted by conditional logistic regression models. Results Multivariate analysis showed the risk factors for UC were male sex (OR = 1.83, 95% Cl: 1.27-2.63) and history of mucus and blood in stool (OR = 3.25 95% Cl: 2.24 4.68). For lesion extent and lesion severity, men and patients with history of mucus and blood in stool were more likely to have larger and more severe UC lesions. Advanced age, BMI≥25, current smoking status, regular exercise, a history of first-degree relatives with bowel cancer, and a history of chronic constipation were indicated as protective factors for UC. Conclusions Our study demonstrates that different environmental factors influence different clinical pathways in the initiation and progression of UC. Avoidance of environmental variables associated with disease risk leads to better clinical outcomes.