Risk of cancer in patients with bile acid diarrhoea: a Danish nationwide matched cohort study.

OBJECTIVE: Bile acid diarrhoea is a common cause of chronic diarrhoea. Increased levels of potentially carcinogenic bile acids in faeces, theoretically, may increase the risk of colorectal cancer in particular, but the long-term disease course is unknown. We aimed to investigate the overall and site-specific cancer risk in bile acid diarrhoea. DESIGN: Adult patients with bile acid diarrhoea were identified using nationwide Danish registries from 2003 to 2020 by a diagnostic gold-standard 75-selenium tauroselcholic acid procedure followed within 6 months by sequestrant prescription. The risk of overall and site-specific cancers in cases with bile acid diarrhoea was compared with sex, age and comorbidity-adjusted matched controls. A competing risk model estimated cumulative incidence functions and cause-specific HRs. RESULTS: We identified 2260 patients with bile acid diarrhoea with a mean follow-up of 5.5 years (SD 4.2). The overall cancer risk was increased by an HR of 1.32 (95% CI 1.12 to 1.54). The risk of site-specific cancer was increased in 3 of 10 cancer groups: haematological, HR 2.41 (1.36 to 4.02); skin, HR 1.33 (1.01 to 1.71); and male genital cancers, HR 1.85 (1.11 to 2.92). No increased risk of colorectal cancer was detected in patients with bile acid diarrhoea, HR 0.73 (0.34 to 1.63). CONCLUSIONS: Bile acid diarrhoea was associated with an increased overall risk of cancer, especially haematological cancers, but the risk of colorectal cancer was not increased. The lack of a diagnostic code for bile acid diarrhoea and potential residual confounding are limitations, and the findings should be replicated in other cohorts.

Tumor Necrosis Factor Inhibitors in Inflammatory Bowel Disease and Risk of Immune Mediated Inflammatory Diseases.

BACKGROUND & AIMS: Tumor necrosis factor inhibitors (anti-TNF) are effective therapies for several immune-mediated inflammatory diseases (IMIDs). However, case reports have identified the paradoxical occurrence of IMIDs in patients treated with anti-TNF. We studied the risk of rheumatoid arthritis, psoriasis, and hidradenitis suppurativa after the initiation of anti-TNF therapy for inflammatory bowel disease (IBD). METHODS: We conducted 2 nationwide cohort studies comprising all patients with IBD in Denmark (2005-2018) and France (2008-2018). We obtained individual-level information on exposure to anti-TNF, diagnoses of IMIDs including rheumatoid arthritis, psoriasis, and hidradenitis suppurativa, and potential confounders from healthcare registers in the respective countries. We used Cox models to estimate hazard ratios (HRs) for the association between anti-TNF exposure and IMIDs and then pooled the estimates from the 2 cohorts. To test the robustness of our results, we performed an active comparator analysis of anti-TNF monotherapy vs azathioprine monotherapy. RESULTS: The Danish and French cohorts comprised 18,258 and 88,786 subjects with IBD, respectively, contributing a total of 516,055 person-years of follow-up. Anti-TNF was associated with an increased risk of rheumatoid arthritis, psoriasis, and hidradenitis suppurativa in both the Danish (HR, 1.66; 95% confidence interval [CI], 1.34-2.07) and the French cohort (HR, 1.78; 95% CI, 1.63-1.94), with a pooled HR of 1.76 (95% CI, 1.63-1.91). Anti-TNF was also associated with an increased risk of the outcomes when compared with azathioprine (pooled HR, 2.94; 95% CI, 2.33-3.70). CONCLUSIONS: In 2 nationwide cohorts of IBD patients, anti-TNF therapy was associated with an increased risk of rheumatoid arthritis, psoriasis, and hidradenitis suppurativa.

Autoimmune diseases in microscopic colitis: A Danish nationwide case-control study.

BACKGROUND: The association between autoimmune diseases and microscopic colitis remains uncertain. AIMS: To describe the association between autoimmune diseases and microscopic colitis by using a matched case-control design based on nationwide registry data. METHODS: All adult Danish patients with a diagnosis of microscopic colitis from 2001 to 2018 were identified from nationwide registries. Odds of autoimmune diseases were compared between cases with microscopic colitis and sex- and age-matched controls from the background population in a 1:10 ratio and evaluated by logistic regression calculating odds ratios (OR) with 95% confidence intervals (CI) adjusted for comorbidity. Analyses were stratified according to sex, age and the subtypes of lymphocytic and collagenous colitis. RESULTS: We identified 15 597 cases with microscopic colitis and matched to 155 910 controls. In total, 3491 (22%) of patients with microscopic colitis had concomitant autoimmune disease compared to 16 521 (11%) of controls (OR, 2.46; 95% CI, 2.36-2.56). Adjusting for comorbidities reduced the OR to 2.09 (95% CI, 2.01-2.19). Analyses showed increased ORs with 16 different autoimmune diseases, particularly of gastrointestinal and endocrine origin, and connective tissue disorders. The highest ORs were for coeliac disease (OR = 10.15; 95% CI, 8.20-12.6), Crohn's disease (OR = 2.47; 95% CI, 2.10-2.91) and ulcerative colitis (OR = 6.73; 95% CI, 6.20-7.30). In stratified analyses younger age at diagnosis and collagenous colitis were associated with higher odds. CONCLUSION: Using nationwide registry data, microscopic colitis was associated with a wide range of autoimmune diseases, especially of gastrointestinal origin. The results suggest an autoimmune predisposition to microscopic colitis.

All-cause and cause-specific mortality in microscopic colitis: a Danish nationwide matched cohort study.

BACKGROUND: The long-term natural history of microscopic colitis remains uncertain. AIM: To describe the mortality in a large unselected cohort of patients with microscopic colitis. METHODS: All Danish patients above 18 years with an incident diagnosis of microscopic colitis from 2001 to 2018 were identified from nationwide registries and compared to age- and sex-matched controls (variable 1:10 ratio). Patients were categorised according to subtypes: lymphocytic colitis and collagenous colitis. The relative risk of death by any cause was analysed with Cox regression models estimating both crude and comorbidity-adjusted hazard ratios (HRs) with 95% confidence intervals (CIs). Cause-specific death was evaluated with cumulative incidence functions. An E-value was calculated to address the impact of unmeasured confounding. RESULTS: The final cohort consisted of 14 024 patients with microscopic colitis. The mean follow-up was 5.8 (standard deviation SD, 2.9) years and the mean age at diagnosis was 61.1 (SD 13.9) years, 70% were women and 41% were diagnosed with lymphocytic colitis. The main results showed a 25% increased risk of all-cause death in patients with microscopic colitis; however, the relative risk was attenuated to 9% when adjusting for comorbidities (95% CI, 1.05-1.14). The E-value indicates that unmeasured confounding could explain the residual observed increased all-cause mortality. Mortality was significantly increased in patients with both lymphocytic colitis (HR 1.15; 95% CI, 1.08-1.23) and collagenous colitis (HR 1.06; 95% CI, 1.01-1.12) in fully adjusted analyses. The absolute difference in death between patients with microscopic colitis and matches was 0.9% at 1 year, 2.8% at 5 years, 5.0% at 10 years and 3.0% at 15 years. Cumulative incidence functions showed that patients with microscopic colitis were more likely to die due to smoking-related diseases including ischemic heart and lung diseases, but had a significant decreased risk of death due to colorectal cancers (P < 0.0001). CONCLUSION: In an unselected large nationwide cohort of patients with microscopic colitis, the risk of death was significantly increased compared to the background population. However, the increased mortality seemed to be associated to a high burden of comorbidities and unmeasured life-style factors including smoking and not microscopic colitis per se.

Risk of acute arterial events associated with treatment of inflammatory bowel diseases: nationwide French cohort study.

OBJECTIVE: Patients with IBD are at increased risk of acute arterial events. Antitumour necrosis factor (TNF) agents and thiopurines may, via their anti-inflammatory properties, lower the risk of acute arterial events. The aim of this study was to assess the impact of thiopurines and anti-TNFs on the risk of acute arterial events in patients with IBD. DESIGN: Patients aged 18 years or older and affiliated to the French national health insurance with a diagnosis of IBD were followed up from 1 April 2010 until 31 December 2014. The risks of acute arterial events (including ischaemic heart disease, cerebrovascular disease and peripheral artery disease) were compared between thiopurines and anti-TNFs exposed and unexposed patients with marginal structural Cox proportional hazard models adjusting for baseline and time-varying demographics, medications, traditional cardiovascular risk factors, comorbidities and IBD disease activity. RESULTS: Among 177 827 patients with IBD (96 111 (54%) women, mean age at cohort entry 46.2 years (SD 16.3), 90 205 (50.7%) with Crohn's disease (CD)), 4145 incident acute arterial events occurred (incidence rates: 5.4 per 1000 person-years). Compared with unexposed patients, exposure to anti-TNFs (HR 0.79, 95% CI 0.66 to 0.95), but not to thiopurines (HR 0.93, 95% CI 0.82 to 1.05), was associated with a decreased risk of acute arterial events. The magnitude in risk reduction was highest in men with CD exposed to anti-TNFs (HR 0.54, 95% CI 0.40 to 0.72). CONCLUSION: Exposure to anti-TNFs is associated with a decreased risk of acute arterial events in patients with IBD, particularly in men with CD.

Increased Risk of Inflammatory Bowel Disease in Families with Tonsillectomy: A Danish National Cohort Study.

BACKGROUND: The possible etiologic link between tonsillectomy and inflammatory bowel diseases remains unclear. To investigate the hereditary component, we assessed the risk of inflammatory bowel disease after own tonsillectomy as well as after tonsillectomy among family members. METHODS: A nationwide Danish cohort of 7,045,288 individuals was established and linked to comprehensive national registers with data on kinship, tonsillectomy surgery, and diagnosis of inflammatory bowel disease from all health sectors. We used Poisson regression models to estimate hospital contact rate ratios (RR) for Crohn's disease and ulcerative colitis, with 95% confidence intervals (CI), between individuals with or without tonsillectomy, as well as between individuals with or without tonsillectomized relatives. RESULTS: During 189 million person-years of follow-up between 1977 and 2014, 276,673 individuals were tonsillectomized, 22,015 developed Crohn's disease, and 49,550 developed ulcerative colitis. Rates of inflammatory bowel disease were elevated up to 20 years after own tonsillectomy (Crohn's disease: RR 1.52 [95% CI = 1.43, 1.61]; ulcerative colitis: RR 1.24 [95% CI = 1.18, 1.29]). RRs for Crohn's disease was 1.22 (95% CI = 1.17, 1.27) after first-degree relatives' tonsillectomy, 1.14 (95% CI = 1.08, 1.19) after second-degree relatives' tonsillectomy, and 1.08 (95% CI = 1.01, 1.15) after third-degree relatives' tonsillectomy. Corresponding RRs for ulcerative colitis were 1.10 (95% CI = 1.07, 1.13), 1.05 (95% CI = 1.01, 1.08), and 1.03 (95% CI = 0.98, 1.09). CONCLUSIONS: Even individuals with tonsillectomized family members were at increased risk of inflammatory bowel disease. These findings call into question a direct influence of tonsillectomy on gastrointestinal inflammation and point instead toward shared hereditary or environmental factors. See video abstract at, http://links.lww.com/EDE/B464.

Differences in epidemiological features between ulcerative colitis and Crohn's disease: The early life-programmed versus late dysbiosis hypothesis.

It is increasingly admitted that Crohn's disease and ulcerative colitis, the two entities of inflammatory bowel disease, are initiated and reactivated by environmental factors in genetically susceptible hosts, and result from aberrant immune response to specific intestinal microbes, in the context of altered composition of intestinal microbiota, called dysbiosis. We hypothesize that the role of the gut microbiota in Crohn's disease pathogenesis is linked to early-life abnormal crosstalk with the host immune system under construction. By contrast, in ulcerative colitis, the detrimental effect of intestinal dysbiosis could occur at any time of life, due to instant environment. This hypothesis could explain why the incidence of Crohn's disease raises many years later than that of ulcerative colitis in developing countries that adopt the Western lifestyle. This would also explain why many early-life events, such as caesarean section, increased hygiene and repeated antibiotic exposure, are risk factors for subsequent development of Crohn's disease, but not ulcerative colitis.

Reduced risk of UC in families affected by appendicitis: a Danish national cohort study.

OBJECTIVE: The possible aetiological link between appendicitis and UC remains unclear. In order to investigate the hereditary component of the association, we studied the risk of UC in family members of individuals with appendicitis. DESIGN: A cohort of 7.1 million individuals was established by linkage of national registers in Denmark with data on kinship and diagnoses of appendicitis and UC. Poisson regression models were used to calculate first hospital contact rate ratios (RR) for UC with 95% CIs between individuals with or without relatives with a history of appendicitis. RESULTS: During 174 million person-years of follow-up between 1977 and 2011, a total of 190 004 cohort members developed appendicitis and 45 202 developed UC. Individuals having a first-degree relative with appendicitis before age 20 years had significantly reduced risk of UC (RR 0.90; 95% CI 0.86 to 0.95); this association was stronger in individuals with a family predisposition to UC (RR 0.66; 95% CI 0.51 to 0.83). CONCLUSIONS: Individuals with a first-degree relative diagnosed with appendicitis before age 20 years are at reduced risk of UC, particularly when there is a family predisposition to UC. Our findings question a previously hypothesised direct protective influence of appendicitis on inflammation of the large bowel. Rather, genetic or environmental factors linked to an increased risk of appendicitis while being protective against UC may explain the repeatedly reported reduced relative risk of UC in individuals with a history of appendicitis.

Association between tumour necrosis factor-α inhibitors and risk of serious infections in people with inflammatory bowel disease: nationwide Danish cohort study.

OBJECTIVE: To investigate whether people with inflammatory bowel disease treated with tumour necrosis factor-α (TNF-α) inhibitors are at increased risk of serious infections. DESIGN: Nationwide register based propensity score matched cohort study. SETTING: Denmark, 2002-12. PARTICIPANTS: The background cohort eligible for matching comprised 52,392 people with inflammatory bowel disease, aged 15 to 75 years, of whom 4300 were treated with TNF-α inhibitors. To limit confounding, a two stage matching method was applied; firstly matching on age, sex, disease duration, and inflammatory bowel disease subtype, and secondly matching on propensity scores (1:1 ratio); this yielded 1543 people treated with TNF-α inhibitors and 1543 untreated to be included in the analyses. MAIN OUTCOME MEASURES: The main outcome was any serious infection, defined as a diagnosis of infection associated with hospital admission. Cox regression was used to estimate hazard ratios for two risk periods (90 and 365 days after the start of TNF-α inhibitor treatment). Hazard ratios of site specific serious infections were obtained solely for the 365 days risk period. RESULTS: Within the 90 days risk period, 51 cases of infection were observed in users of TNF-α inhibitors (incidence rate 14/100 person years), compared with 33 cases in non-users (9/100 person years), yielding a hazard ratio of 1.63 (95% confidence interval 1.01 to 2.63). Within the risk period of 365 days, the hazard ratio was 1.27 (0.92 to 1.75). In analyses of site specific infections, the hazard ratio was above 2 for several of the subgroups but only reached statistical significance for skin and soft tissue infections (2.51, 1.23 to 5.12). CONCLUSIONS: This nationwide propensity score matched cohort study suggests an increased risk of serious infections associated with use of TNF-α inhibitors within the first 90 days of starting treatment and a subsequent decline in risk. This calls for increased clinical awareness of potential infectious complications among people with inflammatory bowel disease using these drugs, especially early in the course of treatment.

Inflammatory bowel disease and risk of coronary heart disease.

Emerging data have shown consistent evidence of an association between inflammation and development of atherosclerosis. Systemic autoimmune diseases are characterized by chronic inflammation and immune dysregulation, and diseases such as rheumatoid arthritis and lupus erythematosus are now commonly accepted to associate with development of cardiovascular disease, including coronary artery disease. However, the risk of cardiovascular disease in inflammatory bowel disease (IBD), a chronic inflammatory disease of the gut, is still unclear and the magnitude of a potentially increased risk is continuously debated. The aim of this review is to give an update on the existing literature on the association between inflammatory bowel disease and risk of cardiovascular disease, in particular coronary artery disease, and further to discuss traditional and non-traditional risk factors in patients with inflammatory bowel disease.

Association between tumor necrosis factor-α antagonists and risk of cancer in patients with inflammatory bowel disease.

IMPORTANCE: A Cochrane review and network meta-analysis concluded that there is need for more research on adverse effects, including cancer, after treatment with tumor necrosis factor α (TNF-α) antagonists and that national registries and large databases would provide relevant sources of data to evaluate these effects. OBJECTIVE: To investigate whether patients with inflammatory bowel disease (IBD) exposed to TNF-α antagonists were at increased risk of developing cancer. DESIGN, SETTING, AND PARTICIPANTS: Nationwide register-based cohort study in Denmark, 1999-2012. Participants were 56,146 patients 15 years or older with IBD identified in the National Patient Registry, of whom 4553 (8.1%) were exposed to TNF-α antagonists. Cancer cases were identified in the Danish Cancer Registry. MAIN OUTCOMES AND MEASURES: Rate ratios (RRs) for incident cancer (overall and site-specific) comparing TNF-α antagonist users and nonusers, estimated using Poisson regression adjusted for age, calendar year, disease duration, propensity scores, and use of other IBD medications. RESULTS: During 489,433 person-years of follow-up (median, 9.3 years [interquartile range, 4.2-14.0]), 81 of 4553 patients exposed to TNF-α antagonists (1.8%) (median follow-up, 3.7 years [interquartile range, 1.8-6.0]) and 3465 of 51,593 unexposed patients (6.7%) developed cancer, yielding a fully adjusted RR of 1.07 (95% CI, 0.85-1.36). There was no significantly increased risk of cancer in analyses according to time since first TNF-α antagonist exposure (less than 1 year: RR, 1.10 [95% CI, 0.67-1.81]; 1 to less than 2 years: RR, 1.22 [95% CI, 0.77-1.93]; 2 to less than 5 years: RR, 0.82 [95% CI, 0.54-1.24]; 5 or more years: RR, 1.33 [95% CI, 0.88-2.03]) and in analyses according to the number of TNF-α antagonist doses received (1 to 3 doses: RR, 1.02 [95% CI, 0.71-1.47]; 4 to 7 doses: RR, 0.89 [95% CI, 0.55-1.42]; 8 or more doses: RR, 1.29 [95% CI, 0.90-1.85]). No site-specific cancers were in significant excess in fully adjusted models. CONCLUSIONS AND RELEVANCE: In this Danish nationwide study, exposure to TNF-α antagonists among patients with IBD was not associated with an increased risk of cancer over a median follow-up of 3.7 years among those exposed. An increased risk associated with longer-term accumulated doses and follow-up cannot be excluded.