Antibiotic use as a risk factor for inflammatory bowel disease across the ages: a population-based cohort study.

BACKGROUND: There is an increasing incidence of inflammatory bowel disease (IBD) for which environmental factors are suspected. Antibiotics have been associated with development of IBD in earlier generations, but their influence on IBD risk in adults is uncertain. OBJECTIVE: To assess the impact of antibiotic exposure, including dose-response, timing and antibiotic class, on the risk of IBD in all individuals aged ≥10 years. DESIGN: Using Denmark nationwide registries, a population-based cohort of residents aged ≥10 years was established between 2000 and 2018. Incidence rate ratios (IRRs) for IBD following antibiotic exposure were calculated using Poisson regression. RESULTS: There were a total of 6 104 245 individuals, resulting in 87 112 328 person-years of follow-up, and 52 898 new cases of IBD. Antibiotic exposure was associated with an increased risk of IBD as compared with no antibiotic exposure for all age groups, although was greatest among individuals aged 40-60 years and ≥60 years (age 10-40 years, IRR 1.28, 95% CI 1.25 to 1.32; age 40-60 years, IRR 1.48, 95% CI 1.43 to 1.54; age ≥60 years, IRR 1.47, 95% CI 1.42 to 1.53). For all age groups a positive dose-response was observed, with similar results seen for both ulcerative colitis and Crohn's disease. The highest risk of developing IBD was seen 1-2 years after antibiotic exposure, and after use of antibiotic classes often prescribed to treat gastrointestinal pathogens. CONCLUSION: Antibiotic exposure is associated with an increased risk of IBD, and was highest among individuals aged 40 years and older. This risk increased with cumulative antibiotic exposure, with antibiotics targeting gastrointestinal pathogens and within 1-2 years after antibiotic exposure.

Increasing Incidence of Pouchitis Between 1996 and 2018: A Population-Based Danish Cohort Study.

BACKGROUND & AIMS: Current knowledge regarding the epidemiology of pouchitis is based on highly selected, mostly single-center, patient cohorts. Our objective was to prospectively determine the population-based incidence of pouchitis in patients with ulcerative colitis in the first 2 years after ileal pouch-anal anastomosis and analyze time trends of the incidence of pouchitis. METHODS: Using national registries, we established a population-based cohort of all Danish patients undergoing proctocolectomy with ileal pouch-anal anastomosis for ulcerative colitis between 1996 and 2018. The primary outcome was the development of pouchitis within the first 2 years after surgery, evaluated by time period. We used Kaplan-Meier and Cox proportional hazard modeling to evaluate the time to development of pouchitis. RESULTS: Overall, 1664 patients underwent an ileal pouch-anal anastomosis. The cumulative incidence of pouchitis in the 2 years after ileal pouch-anal anastomosis increased throughout the study period, from 40% in the period from 1996 to 2000 (95% CI, 35%-46%) to 55% in the period from 2015 to 2018 (95% CI, 48%-63%). Patients undergoing surgery between 2015 and 2018 also showed an increased risk of pouchitis compared with the earliest study period (1996-2000) after adjusting for sex, age, and socioeconomic status (hazard ratio, 1.57; 95% CI, 1.20-2.05). CONCLUSIONS: This population-based study showed a 15% absolute and 38% relative increase in the incidence of pouchitis among patients undergoing surgery between 1996 and 2018, with the greatest cumulative incidence of pouchitis shown in the most recent era (2015-2018). The striking increase in the incidence of pouchitis highlights the need for further research into causes and prevention of pouchitis.

Early-Life Mebendazole Exposure Increases the Risk of Adult-Onset Ulcerative Colitis: A Population-Based Cohort Study.

INTRODUCTION: According to the hygiene hypothesis, exposure to parasites may protect against inflammatory bowel disease (IBD). Our aim was to examine the risk of IBD with childhood exposure to mebendazole, a broad-spectrum antihelminthic agent. METHODS: We conducted a population-based cohort study using prospectively collected historical data of all individuals born in Denmark between 1995 and 2018. We identified mebendazole exposure at age younger than 18 years and during early life (younger than 5 years). We performed adjusted Cox proportional hazards regression analysis to determine the risk of IBD, ulcerative colitis (UC), and Crohn's disease with mebendazole exposure after adjusting for potential confounders. RESULTS: Of 1,520,290 individuals in the cohort, 615,794 had childhood or adolescence mebendazole exposure. One thousand five hundred fifty-five and 1,499 individuals were subsequently diagnosed with pediatric-onset and adult-onset IBD, respectively. On multivariable analysis, mebendazole exposure at age younger than 18 years did not affect pediatric-onset or adult-onset IBD risk (adjusted hazard ratio [aHR] 0.97, 95% confidence interval [CI] 0.87, 1.07, and 1.08, 95% CI 0.97, 1.19, respectively). On limiting mebendazole exposure to age younger than 5 years while there was no association with pediatric-onset IBD (aHR 0.98, 95% CI 0.87, 1.11), adult-onset IBD risk was increased (aHR 1.17, 95% CI 1.04, 1.31). This increase in risk was driven by UC (aHR 1.32, 95% CI 1.12, 1.55), but not Crohn's disease (1.03, 95% CI 0.87, 1.22). DISCUSSION: Early-life mebendazole exposure is associated with an increase in the risk of adult-onset UC. These findings suggest the importance of early-life exposures in shaping the risk of IBD later in life.

Comparative Outcomes and Safety of Vedolizumab vs Tumor Necrosis Factor Antagonists for Older Adults With Inflammatory Bowel Diseases.

Importance: Observational comparative effectiveness studies can inform the positioning of biologic therapies for older patients with inflammatory bowel disease (IBD) who are underrepresented in clinical trials. Objective: To compare the effectiveness and safety of vedolizumab vs tumor necrosis factor (TNF) for older patients with IBD. Design, Setting, and Participants: This active comparator, new-user design, comparative effectiveness study was conducted between January 1, 2005, and December 31, 2018, among 754 older patients (aged ≥50 years) with IBD from the Danish National Patient Register. The mean follow-up after treatment initiation took place at 32 to 40 weeks. Statistical analysis was performed from February 1 to April 27, 2022. Interventions: Treatment with vedolizumab or TNF antagonists. Main Outcomes and Measures: The primary effectiveness outcome was treatment failure, defined as the composite risk of IBD-related hospitalization, IBD-related surgery, or a new corticosteroid prescription more than 6 weeks after initiation of treatment with biologic therapy. Secondary effectiveness outcomes were time to each individual component of the composite effectiveness outcome. The primary safety outcome was the risk of serious infections, defined as infections requiring hospitalization. A 1:1 propensity score-matched analysis was conducted, accounting for patient-, disease-, and treatment-associated factors. Results: The study compared 377 older patients with IBD with incident use of vedolizumab (202 women [53.6%]; mean [SD] age, 61.2 [8.3] years; 177 [46.9%] with Crohn disease) vs 377 patients with incident use of TNF antagonists (206 women [54.6%]; mean [SD] age, 61.3 [8.1] years; 182 [48.3%] with Crohn disease). Overall, vedolizumab was associated with an increased risk of treatment failure compared with TNF antagonists (1-year risk, 45.4% vs 34.7%; adjusted hazard ratio [HR], 1.31; 95% CI, 1.02-1.69), including higher risk of IBD-related hospitalization (1-year risk, 27.8% vs 16.3%; adjusted HR, 1.48; 95% CI, 1.03-2.15) and IBD-related major abdominal surgery (1-year risk, 21.3% vs 8.0%; adjusted HR, 2.39; 95% CI, 1.45-3.94). In subgroup analysis by IBD phenotype, among patients with Crohn disease, vedolizumab was associated with a 77% higher risk of treatment failure (adjusted HR, 1.77; 95% CI, 1.21-2.58), while no difference in risk of treatment failure was seen among patients with ulcerative colitis (adjusted HR, 1.04; 95% CI, 0.75-1.43; P = .03 for interaction). There was no significant difference in the risk of serious infections, overall (1-year risk, 8.2% vs 8.7%; adjusted HR, 1.04; 95% CI, 0.58-1.85) and by IBD phenotype. Conclusions and Relevance: In this comparative effectiveness study of older patients with IBD, vedolizumab was associated with a higher risk of treatment failure compared with TNF antagonists, particularly among patients with Crohn disease, without offering a significant safety advantage.

The Risk of Type 2 Diabetes in Patients With Inflammatory Bowel Disease After Bowel Resections: A Nationwide Cohort Study.

BACKGROUND AND AIMS: Patients with inflammatory bowel disease (IBD) are at increased risk of type 2 diabetes (T2D), but the underlying mechanisms remain elusive. We aimed to determine the impact of small and large bowel resections on the risk of developing T2D in patients with IBD. METHODS: We conducted a nationwide, prospective study of all IBD patients undergoing small bowel resection (Crohn's disease [CD]) and large bowel resection (CD and ulcerative colitis [UC]) in Denmark (1996-2018). Each patient was matched with up to 5 patients with IBD and no history of bowel resection. We used Cox proportional hazards regression models to estimate adjusted hazard ratios (aHRs) of T2D. RESULTS: We included 2469 patients with CD and small bowel resection, 1361 patients with CD and large bowel resection, and 3787 patients with UC and large bowel resection. Small bowel resection in CD patients was associated with lower risk of T2D (aHR 0.65, 95% CI, 0.44-0.92), compared with matched patients with CD and no bowel resection. Large bowel resection in patients with CD or UC was associated with aHRs of 0.95 (95% CI, 0.67-1.31) and 1.25 (95% CI, 1.03-1.51), respectively, compared with matched patients with CD or UC and no bowel resection. CONCLUSION: Patients with CD and small bowel resection have a lower risk of T2D, whereas patients with UC and large bowel resection have a higher risk of T2D, compared with patients with IBD and no bowel resection history. The underlying mechanisms remain to be explored.

Increased risk of genital warts in inflammatory bowel disease: A Danish registry-based cohort study (1996-2018).

BACKGROUND: Patients with inflammatory bowel disease (IBD) are at increased risk of human papillomavirus (HPV) related cancers such as anal squamous cell carcinoma. However, risk of non-malignant HPV infection has never been systematically studied in IBD. This study aims to assess the risk of genital warts (GW) in IBD patients. METHODS: Using the Danish nationwide registries, we identified 49,163 patients with IBD between 1996 and 2018 and matched them to 491,665 individuals from the general population by age, sex, and HPV immunisation. Cumulative incidence rates for GW in IBD and non-IBD patients were calculated by age. Cox proportional regression analysis was used to calculate hazard ratios (HR) for GW in IBD compared to matched population and in Crohn's disease (CD) compared to ulcerative colitis (UC). We undertook subgroup analysis for risk of GW by sex, year of IBD diagnosis, contraceptive exposure and IBD treatment exposure. RESULTS: The fully adjusted HR for GW in IBD patients compared to the matched non-IBD population was 1.33 (95% CI: 1.19-1.49) and 1.13 (95% CI: 1.01, 1.27) in CD as compared to UC. This increased risk was particularly observed in female (HR: 1.54, 95% CI: 1.33-1.79) over male (HR: 1.14, 95% CI: 0.97-1.34) IBD patients, but was also found across all periods of diagnosis with IBD, regardless of contraceptive treatment exposure, and also seen in IBD patients who had never been exposed to immunosuppressive treatment (HR: 1.33, 95% CI: 1.19-1.49). CONCLUSION: In this nationwide, population-representative cohort study, we observed a 33% increased risk of GW in patients with IBD compared to the matched population and a 13% increased risk of GW in CD compared with UC. This risk was particularly increased in female over male IBD patients and seen independent of IBD treatment exposure.

Development of Inflammatory Bowel Disease in HIV Patients: A Danish Cohort Study (1983-2018) With American Validation (1999-2018).

BACKGROUND AND AIMS: Human immunodeficiency virus (HIV) infection is associated with several immune-mediated disorders. However, the risk of inflammatory bowel disease (IBD) in people living with HIV (PLWH) remains unclear. We aimed to assess the risk of IBD among PLWH using a nationwide, population-based Danish cohort and to validate findings in a large American insurance-based database. METHODS: Using Danish registries (1983-2018), we identified 8995 PLWH and age- and sex-matched them to 449,750 HIV-negative individuals. Cox regression analysis was undertaken to calculate hazard ratios (HRs) with 95% confidence intervals (CIs) for IBD diagnosis. Results were stratified by sex, age, and year of HIV diagnosis. Using an American insurance-based cohort, Explorys (1999-2018), we assessed the prevalence odds ratio (OR) and 95% CI of IBD diagnosis in PLWH compared with HIV-negative individuals. RESULTS: IBD diagnosis among PLWH in Denmark was increased (HR: 2.25, 95% CI: 1.78-2.83) compared with matched HIV-negative individuals. This was seen for both Crohn's disease (HR: 2.25, 95% CI: 1.47-3.44) and ulcerative colitis (HR: 2.24, 95% CI: 1.70-2.96) and in male (HR: 2.75, 95% CI: 2.15-3.52) but not female (HR: 0.93, 95% CI: 0.48-1.79) PLWH. Explorys analysis also showed an increased odds of IBD diagnoses among PLWH (OR: 1.41; 95% CI: 1.35-1.49). CONCLUSION: This study finds an increased risk of IBD diagnosis among PLWH in both a Danish and US cohort, highlighting a need to consider IBD in PLWH with new-onset gastrointestinal symptoms. Further research into the role of antiretroviral therapy in this relationship is required.

Clinical procedures used to diagnose inflammatory bowel disease: real-world evidence from a Danish nationwide population-based study.

OBJECTIVE: Although clinical guidelines exist, the diagnostic work-up for diagnosing inflammatory bowel disease (IBD) is complex and varies in clinical practice. This study used real-life data to characterise the current diagnostic procedures used to establish IBD diagnoses in a Danish nationwide setting. DESIGN: Person-level data on patients diagnosed with IBD between 1 January 2014 and 30 June 2018 were linked between Danish health registers. Information on age, sex, registration of other gastrointestinal diseases, and diagnostic procedures (endoscopies, biopsies, and imaging) performed in relation to the first IBD hospital admission was analysed for the total study population and was stratified by IBD type, sex, and age. RESULTS: The majority of the 12 871 patients with IBD included underwent endoscopy (84%), had a biopsy taken (84%), and/or underwent imaging procedures (44%). In total, 7.5% of the population (6% for Crohn's disease and 8% for ulcerative colitis) were diagnosed with IBD despite not undergoing any of these diagnostic procedures. Patients with Crohn's disease underwent more procedures than patients with ulcerative colitis (94% vs 92%, p<0.001). Children underwent slightly fewer diagnostic procedures than adults (92% vs 93%, p=0.004). Slightly more men underwent at least one procedure than women (92% vs 94%, p<0.001). CONCLUSION: For 7.5% of patients with IBD, this study did not detect any registrations of the recommended diagnostic procedures for establishing an IBD diagnosis. Further research is needed to examine whether these findings are mainly explained by limitations of the register data or also indicate shortcomings of the general approach to IBD.