Population-Based Case Control Study of Seroprevalence of Mycobacterium paratuberculosis in Patients with Crohn's Disease and Ulcerative Colitis

ObjectiveTo determine whether occupational exposure to silica dust causes an increased risk of developing Crohn’s disease (CD) and ulcerative colitis (UC).DesignCase–control study of CD (K50) and UC (K51) from 2007 through 2016. Controls were matched to cases (2:1) based on age, sex and county at the time of diagnosis. A job exposure matrix was used to estimate the occupational silica exposure of all cases and controls.SettingMedical and occupational data from the National Outpatient Register were used to implement a case–control analysis, while the two controls used for each case were selected from the National Register of the Total Population.ParticipantsAll men and women aged 20–65 years old who were diagnosed with CD (K50) and UC (K51) during the years of study were included and assigned two controls, resulting in 58 136 cases and 116 272 controls.Main outcomesSilica dust exposure correlates with an increased risk of developing UC in men and CD in women.ResultsThe prevalence of UC was significantly higher in the group exposed to silica dust (OR 1.13, 95% CI 1.06 to 1.21) than in controls, particularly in individuals with over 5 years exposure. When stratified by sex, a significantly increased OR was detected for men (OR 1.33, 95% CI 1.05 to 1.22). This trend was also consistent with longer exposure times. The prevalence of UC was not increased in exposed women. The prevalence of CD was significantly increased among exposed women (OR 1.29, 95% CI 1.01 to 1.65), but not for exposed men.ConclusionsSilica dust exposure correlates with an increased risk of developing UC, especially in men, and the risk seems to increase with the duration and degree of exposure. Conversely, silica dust exposure correlates positively with the risk of developing CD in women.

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Appendicectomy, childhood hygiene, Helicobacter pylori status, and risk of inflammatory bowel disease: a case control study

Gut ◽

10.1136/gut.43.4.494 ◽

1998 ◽

Vol 43 (4) ◽

pp. 494-498 ◽

Cited By ~ 130

Author(s):

A E Duggan ◽

I Usmani ◽

K R Neal ◽

R F A Logan

Keyword(s):

Ulcerative Colitis ◽

Crohn’S Disease ◽

Crohn's Disease ◽

Case Control Study ◽

Case Control ◽

Hot Water ◽

Inverse Association ◽

Inflammatory Bowel ◽

H Pylori ◽

Control Study

Aims—To examine the relation between inflammatory bowel disease and appendicectomy, childhood domestic hygiene, andHelicobacter pylori infection.Methods—Case control study involving 213 patients with ulcerative colitis, 110 with Crohn’s disease, and 337 controls having elective surgery.Results—Nine patients with ulcerative colitis (4.5%) reported a previous appendicectomy compared with 57 controls (19%) (odds ratio (OR) 0.20, 95% confidence interval (CI) 0.1–0.4, p<0.0001). The inverse association was unaffected by excluding operations performed after the age of onset of ulcerative colitis and was stronger for appendicectomy performed before age 20 (OR 0.14). No association with appendicectomy was found for Crohn’s disease and no associations with tonsillectomy for either disease. The availability of a fixed hot water supply in early childhood (before age 11) was associated with Crohn’s disease (OR for hot water not always versus always available 0.56, 95% CI 0.3–0.9, p=0.02) but not with ulcerative colitis. No other aspect of domestic hygiene before or after age 11 was associated with either Crohn’s disease or ulcerative colitis. Although H pylori seroprevalence was positively associated with overcrowding (p<0.001) and the absence of running hot water in childhood it was not associated with the presence of either Crohn’s disease or ulcerative colitis. H pyloriseroprevalence was no lower in patients who had been exposed to sulphasalazine than in controls or those not exposed.Conclusions—Our findings confirm the strong inverse association between previous appendicectomy and the development of ulcerative colitis and suggest that the protective effect is greater for appendicectomy performed in childhood.

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