P774 Higher plasma cotinine is associated with an increased risk for later developing IBD, especially among users of combusted tobacco
L. Widbom*1, J. Schneede2, P. Karling3, J. Hultdin1
1Umeå University, Department of medical bioscienses, clinical chemistry, Umeå, Sweden, 2Umeå University, Department of pharmacology and clinical neuroscience, Umeå, Sweden, 3Umeå University, Department of public health and clinical medicine, Umeå, Sweden
Smoking has previously been associated with inflammatory bowel disease (IBD), but no study has reported on cotinine, an objective measure of tobacco use. We aimed to test the hypothesis that cotinine is higher among healthy subjects who later develop IBD compared with matched controls. Also to adjust for use of combusted vs. non-combusted tobacco.
We analysed plasma cotinine and lifestyle questionnaires including tobacco habits in 96 subjects who later developed IBD (70 Ulcerative colitis (UC) and 26 Crohn′s disease (CD)) and in sex and age-matched controls.
Patients who later developed IBD (median time to diagnosis 5.091 years) and UC had significant higher plasma cotinine levels compared with controls. Although plasma cotinine concentrations were higher in snuff users compared with smokers no increase in risk was seen for snuff users. In multi-variate analysis, higher log-cotinine was associated with higher risk for developing IBD (OR 1.338 (95% CI 1.099-1.630)). After stratifying for time to diagnosis, this confined to those with shorter time to diagnosis (OR 1.445 (1.087–1.920)). The findings were similar for UC but not for CD. For all IBD cases, snuff use was associated with a lower risk of developing IBD among subjects with shorter time to diagnosis in multi-variate analysis.
Cotinine, an objective method for measuring tobacco use, is associated with later developing IBD and UC. The findings among snuff users indicate that components of combusted tobacco other than nicotine are involved in the genesis of IBD in smokers.