Smoking is Associated with an Increased Risk of Microscopic Colitis: Results From Two Large Prospective Cohort Studies of US Women

Abstract

In two large prospective cohort studies, we observed an association between current smoking and risk of microscopic colitis. Risk of microscopic colitis appeared to increase with higher pack-years and diminish following smoking cessation. Future studies focused on characterizing the biological mechanisms underlying these associations are warranted.

Dietary Gluten Intake and Risk of Microscopic Colitis Among US Women without Celiac Disease: A Prospective Cohort Study

“…We estimated that we would have an 80% power to detect a HR of at least 1.81 between the highest and lowest quintiles in a 2-tailed test. However, as previously reported in our cohort and consistent with prior studies (11, 28, 29), use of NSAIDs, PPIs, SSRIs, and smoking are strongly associated with risk of microscopic colitis, indicating that the contribution of gluten to the risk of microscopic colitis, if any, is minimal. Third, this study relied on self-reported questionnaires for assessing dietary gluten intake which may be subject to measurement errors.…”

“…In both cohorts, a diagnosis of microscopic colitis was self-reported initially and was subsequently confirmed by two gastroenterologists (K.E.B, and H.K.) (11). Since 1976 in NHS and 1989 in NHSII, participants reported diagnoses of inflammatory bowel diseases, including microscopic colitis, ulcerative colitis, and Crohn’s disease during biennial questionnaires.…”

Do Sex Hormones Cause, or Are They Only Associated With, Microscopic Colitis?

“…In a prior publication, the NHS reported a hazard ratio for tobacco smoking of 2.52 (1.59-4.00). 17 This result was similar to a previous odds ratio calculated for current tobacco use of 2.67 (1.38-5.17). 14 The similarity of these risk estimates from different studies again suggests but does not prove causality for MC.…”

European guidelines on microscopic colitis: United European Gastroenterology and European Microscopic Colitis Group statements and recommendations

“…LE: moderate; GR: NA; agreement: 100%, strong consensus Summary of evidence: the prevalence of current smoking in MC patients ranged from 15.3% to 40.7% (CC: 13.6-37.1%; LC: 13.2-26.0%) compared to 5.0-28.2% in non-MC control groups. 28,43,[73][74][75][76][77][78][79][80][81][82] In a recent meta-analysis, 83 current smokers had a significantly increased risk of MC compared with never smokers (odds ratio (OR) 2.99; 95% CI: 2.15-4.15). 83 Current smoking was more strongly associated with CC than LC (OR 5.5, 95% CI: 3.4-8.9; OR 2.96, 95% CI: 2.0-4.3, respectively).…”

“…[73][74][75][76]78,80,82 In two studies, current smokers developed MC more than one decade earlier than former or never smokers. 77,84 The majority of the studies showed no differences in terms of clinical presentation response to treatment, spontaneous remission rates and disease recurrence or need for maintenance treatment 73,75,77,78,81,[84][85][86][87][88][89] (see also Appendix D, supplementary material). Only in a post-hoc analysis of pooled data from two randomised controlled trials (RCTs) was current smoking associated with a decreased ability to achieve clinical remission with corticosteroid treatment (OR, 0.31; 95% CI: 0.10-0.98).…”