Department of Internal Medicine, Liver Research Institute, Seoul National University College of Medicine, 101 Daehak-ro, Chongno-gu, Seoul, 03080, South Korea.
Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, 20, Eonju-ro 63-gil, Gangnam-gu, Seoul, 06229, South Korea.
J Gastroenterol. 2019 Oct;54(10):881-890. doi: 10.1007/s00535-019-01589-3. Epub 2019 May 15.
Former cigarette smokers are at risk of developing ulcerative colitis (UC). However, the impact of smoking behavior on the occurrence of UC according to the amount smoked remains elusive. We aimed to determine the relationship between smoking behavior and the risk of UC development.
We conducted a retrospective population-based cohort study using the National Health Insurance Service database in South Korea. From January 2009 to December 2012, 23,235,771 individuals over 18 years of age who underwent a national health examination were enrolled and followed until 2016. All study participants were divided into the following 3 groups: nonsmokers, former smokers, and current smokers. The primary endpoint was newly developed UC.
Compared with nonsmokers, the risk of UC development was significantly higher in former smokers [adjusted hazard ratio (aHR) 1.83; 95% confidence interval (CI) 1.73-1.95] but significantly lower in current smokers (aHR 0.92; 95% CI 0.87-0.98). Among current smokers, individuals who stopped smoking after the baseline evaluation had a significantly higher risk of UC development than those who continued to smoke (aHR 2.42; 95% CI 2.10-2.80). The risk of UC development among former smokers was significantly associated with smoking amount and duration. Among current smokers, however, the risk of UC development was not correlated with the cumulative lifetime smoking exposure. The preventive effect of current smoking on UC development was observed only in men (aHR 0.90; 95% CI 0.84-0.96).
Compared with nonsmokers, former smokers have a significantly higher risk of UC development that may be proportional to the cumulative smoking exposure.
曾经吸烟的人患溃疡性结肠炎（UC）的风险增加。然而，吸烟行为对 UC 发生的影响与吸烟量之间的关系仍不清楚。我们旨在确定吸烟行为与 UC 发病风险之间的关系。
我们使用韩国国家健康保险服务数据库进行了一项回顾性基于人群的队列研究。从 2009 年 1 月至 2012 年 12 月，纳入了 23235771 名年龄在 18 岁以上接受国家健康检查的个体，并随访至 2016 年。所有研究参与者分为以下 3 组：不吸烟者、曾经吸烟者和当前吸烟者。主要终点是新诊断的 UC。
与不吸烟者相比，曾经吸烟者 UC 发病风险显著升高（调整后的危险比[aHR]1.83；95%置信区间[CI]1.73-1.95），而当前吸烟者的风险显著降低（aHR 0.92；95% CI 0.87-0.98）。在当前吸烟者中，与继续吸烟者相比，基线评估后戒烟的个体 UC 发病风险显著升高（aHR 2.42；95% CI 2.10-2.80）。曾经吸烟者的 UC 发病风险与吸烟量和吸烟时间呈显著相关。然而，在当前吸烟者中，UC 发病风险与累积终生吸烟暴露量无关。当前吸烟对 UC 发病的预防作用仅在男性中观察到（aHR 0.90；95% CI 0.84-0.96）。
与不吸烟者相比，曾经吸烟者 UC 发病风险显著升高，且可能与累积吸烟暴露量成正比。
