Smoking Experience before Adulthood Is Associated with an Increased Risk of Developing Ulcerative Colitis in Adult Ex-Smokers

• Published in: Yonsei medical journal 2025, 66(1), , pp.9-15
• Main Authors: Jun, Yu Kyung, Kim, Bongseong, Choi, Yonghoon, Shin, Cheol Min, Park, Young Soo, Kim, Nayoung, Lee, Dong Ho, Han, Kyungdo, Yoon, Hyuk
• Format: Article
• Language: English
• Subjects: Adult; Age of Onset; Colitis, Ulcerative - epidemiology; Colitis, Ulcerative - etiology; Crohn Disease - epidemiology; Crohn Disease - etiology; Ex-Smokers - statistics & numerical data; Female; Humans; Male; Original; Proportional Hazards Models; Republic of Korea - epidemiology; Risk Factors; Smoking - adverse effects; Smoking - epidemiology; Young Adult; 의학일반
• ISSN: 0513-5796; 1976-2437; 1976-2437
• DOI: 10.3349/ymj.2023.0612

Smoking may have a protective role in developing ulcerative colitis (UC) but have the opposite effect on Crohn's disease (CD). This study aimed to determine the risk of developing inflammatory bowel disease (IBD) according to smoking status and onset age of smoking. We collected data on the smoking experiences of participants aged 20-39 years who underwent biannual examinations provided by the Korean National Health Screening Program from 2009 to 2012. IBD diagnosis was identified using the National Health Insurance Service. The risk of IBD according to smoking status and onset age of smoking was analyzed after adjusting for major clinical variables. During a median 10.59-year follow-up, the risk of UC in ex-smokers was significantly higher than that in non-smokers, and the earlier ex-smokers started smoking, the higher risk of UC [ex-smokers whose onset age of smoking was