Objective

Smoking has previously been associated with inflammatory bowel disease (IBD), but no study has reported on cotinine, an objective, biochemical measure of tobacco use. We aimed at testing the hypothesis that cotinine levels among healthy subjects are associated with an increased risk of developing IBD in later life.

Design

We analysed plasma cotinine and evaluated corresponding lifestyle questionnaires that included tobacco habits in subjects (n = 96) who later developed late-onset IBD (70 ulcerative colitis (UC) and 26 Crohn’s disease (CD)) and in sex and age-matched controls (n = 191).

Results

Patients who later developed IBD had significantly higher plasma cotinine levels compared to controls. In multivariable analysis, higher log-cotinine was associated with a higher risk of developing IBD (OR 1.34 (95% CI 1.01–1.63)). After stratifying for time to diagnosis, the association was only significant in subjects with shorter time (< 5.1 years) to diagnosis (OR 1.45 (1.09–1.92)). The findings were similar for UC- and CD-cases, but did not reach statistical significance in CD-cases. Although plasma cotinine concentrations were higher in snuff users compared to combusted tobacco users, no increase in the risk of IBD and lower risk of developing IBD among subjects with shorter time (< 5.1 years) to diagnosis was seen among snuff users.

Conclusions

Cotinine, a biomarker of tobacco use, is associated with increased risk of developing late-onset IBD in general, and UC in particular. No increased risk among snuff users indicates that other components in combusted tobacco than nicotine may be involved in the pathogenesis of IBD among smokers.

中文翻译：

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血浆可替宁水平升高与IBD发生风险增加有关，尤其是在燃烧烟草使用者中。

目的

吸烟以前曾与炎症性肠病（IBD）相关，但尚无关于可替宁的研究报告，可替宁是一种客观的生化指标，用于烟草使用。我们旨在检验以下假设：健康受试者中的可替宁水平与以后生活中发生IBD的风险增加有关。

设计

我们分析了血浆可替宁，并评估了相应的生活方式调查表，其中包括后来出现迟发性IBD（70溃疡性结肠炎（UC）和26克罗恩病（CD））以及性别和年龄匹配的对照组的吸烟习惯（n = 96） （n = 191）。

结果

后来患IBD的患者血浆可替宁水平明显高于对照组。在多变量分析中，较高的对数可卡因与发生IBD的风险较高（OR 1.34（95％CI 1.01-1.63））。在对诊断时间进行分层之后，这种关联仅在诊断时间较短（<5.1年）的受试者中才有意义（OR 1.45（1.09–1.92））。UC和CD病例的发现相似，但CD病例未达到统计学意义。尽管鼻烟使用者的血浆可替宁浓度高于吸烟者，但鼻烟使用者的诊断时间较短（<5.1年）的受试者中IBD的风险没有增加，IBD的风险也较低。

结论

可替宁，一种烟草使用的生物标志物，与罹患迟发性IBD（特别是UC）的风险增加有关。鼻烟使用者的患病风险没有增加，表明吸烟者除尼古丁以外的燃烧烟草中其他成分可能与吸烟者IBD的发病有关。