Identification of Childhood-Onset Inflammatory Bowel Disease in Swedish Healthcare Registers: A Validation Study

Bidirectional association between inflammatory bowel disease and type 1 diabetes: a nationwide matched cohort and case-control study

Background

Co-occurrence of inflammatory bowel disease (IBD) and type 1 diabetes (T1D) has been linked to poor clinical outcomes, but evidence on their bidirectional associations remain scarce. This study aims to investigate their bidirectional associations.

Methods

A nationwide matched cohort and case-control study with IBD patients identified between 1987 and 2017. The cohort study included 20,314 IBD patients (≤28 years; Crohn's disease [CD, n = 7277], ulcerative colitis [UC, n = 10,112], and IBD-unclassified [IBD-U, n = 2925]) and 99,200 individually matched reference individuals, with a follow-up until December 2021. The case-control study enrolled 87,001 IBD patients (no age restriction) and 431,054 matched controls. We estimated adjusted hazard ratio (aHR) of incident T1D in the cohort study with flexible parametric survival model and adjusted odds ratio (aOR) of having a prior T1D in the case-control study with conditional logistic regression model, with 95% confidence intervals (CI).

Findings

During a median follow-up of 14 years, 116 IBD patients and 353 reference individuals developed T1D. Patients with IBD had a higher hazard of developing T1D (aHR = 1.58 [95% CI = 1.27-1.95]). The hazard was increased in UC (aHR = 2.02 [1.51-2.70]) but not in CD or IBD-U. In the case-control study, a total of 1018 (1.2%) IBD patients and 3496 (0.8%) controls had been previously diagnosed with T1D. IBD patients had higher odds of having prior T1D (aOR = 1.36 [1.26-1.46]). Such positive association was observed in all IBD subtypes. The sibling comparison analyses showed similar associations between IBD and T1D (aHR = 1.44 [0.97-2.15] and aOR = 1.32 [1.18-1.49]).

Interpretation

Patients with IBD had a moderately increased hazard of developing T1D and higher odds of having prior T1D. Their bidirectional associations may be partially independent of shared familial factors.

Funding

European Crohn's and Colitis Organisation, Stiftelsen Professor Nanna Svartz Fond, SSMF (project#: PG-23-0315-H-02), Ruth and Richard Julin Foundation; and FORTE (project#: 2016-00424).

Childhood Socioeconomic Characteristics and Risk of Inflammatory Bowel Disease: A Scandinavian Birth Cohort Study

BACKGROUND

Ecological observations suggest a negative relationship between childhood socioeconomic status (SES) and inflammatory bowel disease (IBD) risk. Individual-level analyses have been inconsistent and mostly lacked refined assessments of SES. We aimed to comprehensively study the association between early-life SES and later IBD.

METHODS

This study included 117 493 participants from the Norwegian Mother, Father and Child cohort and Swedish All Babies in Southeast Sweden cohorts. Participants were followed from birth (1997-2009) through 2021. IBD was identified through national patient registers. Questionnaire and register data were used to define parental educational level, employment, and household income level. Cox regression estimated adjusted hazard ratios (aHRs), accounting for other SES exposures and covariates (eg, parental IBD). Cohort-specific estimates were pooled using a random-effects model.

RESULTS

During 2 024 299 person-years of follow-up, 451 participants were diagnosed with IBD (All Babies in Southeast Sweden cohort, n = 113 and Norwegian Mother, Father and Child cohort, n = 338). Early-life maternal, but not paternal, educational level was associated with later IBD (low vs high educational level; pooled aHR, 1.81; 95% confidence interval [CI], 1.16-2.82; and pooled aHR, 1.20; 95% CI, 0.80-1.80; respectively). Having a nonworking mother or father was not significantly associated with IBD (pooled aHR, 0.69; 95% CI, 0.47-1.02; pooled aHR, 0.79; 95% CI, 0.45-1.37). High vs low household income level yielded a pooled aHR of 1.33 (95% CI, 0.94-1.89). Overall, results were largely consistent across cohorts.

CONCLUSIONS

In this prospective Scandinavian cohort study, low maternal educational level was, independent of other SES and covariates, significantly associated with later IBD in her child. Further research is needed to elucidate factors that may mediate this relationship.

Early-Life Hygiene-Related Factors and Risk of Inflammatory Bowel Disease: A Scandinavian Birth Cohort Study

BACKGROUND

We aimed to investigate whether early-life hygiene-related factors influenced the risk of inflammatory bowel disease (IBD) in a Scandinavian population and test the association's consistency across cohorts.

METHODS

This study followed 117 493 participants in the All Babies in Southeast Sweden study and the Norwegian Mother, Father, and Child Cohort Study. IBD diagnoses were defined by national registers. Comprehensive data on hygiene-related exposures, such as having pets, rural living, daycare attendance, and siblings, were retrieved from questionnaires administered from pregnancy until child's age of 36 months. A multivariable Cox regression model yielded adjusted hazard ratios (aHRs) for IBD accounting for socioeconomic status and perinatal factors. Cohort-specific estimates were pooled using a random-effects model.

RESULTS

In over 2 024 299 person-years of follow-up 451 participants developed IBD. In pooled estimates children attending daycare up to 36 months of life vs not attending daycare were less likely to develop Crohn's disease (aHR, 0.60; 95% confidence interval [CI], 0.37- 0.98). Children having 1 or more siblings had a modestly increased risk of IBD (aHR, 1.17; 95% CI, 0.96-1.42; aHR for each sibling, 1.12; 95% CI, 1.01-1.24). The other hygiene factors were not significantly linked to later IBD. In the Norwegian Mother, Father, and Child Cohort Study cohort, bed sharing was associated with an increased risk of IBD, most notably for ulcerative colitis (aHR, 1.67; 95% CI, 1.01-2.78).

CONCLUSIONS

In this birth cohort study from 2 high-income Scandinavian countries, some early-life hygiene-related exposures were associated with IBD risk. The generalizability of these results to countries of other socioeconomic level is unknown.

Spondyloarthritis in First-Degree Relatives and Spouses of Patients with Inflammatory Bowel Disease: A Nationwide Population-based Cohort Study from Sweden

BACKGROUND AND AIMS

Register-based research suggests a shared pathophysiology between inflammatory bowel disease [IBD] and spondyloarthritis [SpA], but the role of familial [genetic and environmental] factors in this shared susceptibility is largely unknown. We aimed to compare the risk of SpA in first-degree relatives [FDRs] and spouses of IBD patients with FDRs and spouses of matched, population-based, reference individuals.

METHODS

We identified 147 080 FDRs and 25 945 spouses of patients with incident IBD [N = 39 203] during 2006-2016, and 1 453 429 FDRs and 258 098 spouses of matched reference individuals [N = 390 490], by linking nationwide Swedish registers and gastrointestinal biopsy data. Study participants were followed 1987-2017. Cox regression was used to estimate hazard ratios [HRs] of SpA.

RESULTS

During follow-up, 2430 FDRs of IBD patients [6.5/10 000 person-years] and 17 761 FDRs of reference individuals [4.8/10 000 person-years] were diagnosed with SpA, corresponding to an HR of 1.35 [95% CI:1.29, 1.41]. In subgroup analyses, the increased risk of SpA was most pronounced in FDRs of Crohn's disease patients [HR = 1.44; 95% CI:1.34,1.5 6] and of IBD patients aged <18 years at diagnosis [HR = 1.46; 95% CI: 1.27, 1.68]. IBD patients' spouses also had a higher SpA rate than reference individuals' spouses, but the difference was less pronounced [4.3 vs 3.5/10 000 person-years; HR = 1.22; 95% CI:1.09, 1.37]. No subgroup-specific risk pattern was identified among spouses.

CONCLUSIONS

The observed shared familial risks between IBD and SpA support shared genetic factors in their pathogenesis. However, spouses of IBD patients were also at increased risk for SpA, reflecting the influence of environmental exposures or similarities in health-seeking patterns.

The Epidemiology of Inflammatory Bowel Diseases During the COVID-19 Pandemic: Comparison of Two Nationwide Cohorts

BACKGROUND

We aimed to explore the epidemiology of inflammatory bowel diseases [IBD] in association with the COVID-19 pandemic in two countries with different lockdown policies.

METHODS

We utilized nationwide IBD cohorts in Israel and Sweden to explore the incidence of IBD during the pandemic compared to 3 years prior [2017-2019]. We examined temporal trends through the presence of inflection points by Joinpoint regression analysis and reported average monthly percentage changes [AMPC].

RESULTS

A total of 155 837 patients with IBD were included [Israel, 58 640; Sweden, 97 197]. The annual incidence of IBD was stable until 2019 in both countries but then decreased in Israel (AAPC -16.6% [95% confidence interval, CI, -19.9% to -10.0%]) and remained stable in Sweden (AAPC -3.5% [95% CI -11.6% to 3.7%]). When exploring the monthly incidence during the pandemic, in Israel the rate remained stable until November 2020 (AMPC 2.3% [95% CI -13.4% to 29.9%]) and then decreased sharply (AMPC -6.4% [95% CI -20.8% to 17.0%] until February 2021 and to -20.1% [95% CI -38.9% to -4.7%] from February 2021), while in Sweden, which had a less stringent lockdown policy, it decreased slightly until July 2020 (AMPC -3.3% [95% CI -21.6% to 20.3%]), but increased thereafter (AMPC 13.6% [95% CI -12.6% to 27.0%]). The change of incidence rate in Sweden occurred mainly in elderly-onset patients, the only population with significant restrictions during the pandemic.

CONCLUSION

The incidence of IBD decreased during the pandemic in association with lockdowns, more so in Israel, which had more stringent policies. Future studies are needed to determine the long-term effect of the pandemic on IBD.

Risk of heart failure in inflammatory bowel disease: a Swedish population-based study

BACKGROUND AND AIMS

Dysregulation of inflammatory and immune responses has been implicated in the pathogenesis of heart failure (HF). But even if inflammation is a prerequisite for inflammatory bowel disease (IBD), little is known about HF risk in IBD.

METHODS

In this Swedish nationwide cohort, patients with biopsy-confirmed IBD were identified between 1969 and 2017 [n = 81 749, Crohn's disease (CD, n = 24 303), ulcerative colitis (UC, n = 45 709), and IBD-unclassified (IBD-U, n = 11 737)]. Each patient was matched with up to five general population reference individuals (n = 382 190) and IBD-free full siblings (n = 95 239) and followed until 31 December 2019. Flexible parametric survival models estimated the adjusted hazard ratio (aHR) and standardized cumulative incidence for HF, with 95% confidence intervals (CI).

RESULTS

There were 5582 incident HF identified in IBD patients (incidence rate [IR]: 50.3/10 000 person-years) and 20 343 in reference individuals (IR: 37.9) during a median follow-up of 12.4 years. IBD patients had a higher risk of HF than reference individuals (aHR 1.19, 95% CI 1.15-1.23). This increased risk remained significant ≥20 years after IBD diagnosis, leading to one extra HF case per 130 IBD patients until then. The increased risk was also observed across IBD subtypes: CD (IR: 46.9 vs. 34.4; aHR 1.28 [1.20-1.36]), UC (IR: 50.1 vs. 39.7; aHR 1.14 [1.09-1.19]), and IBD-U (IR: 60.9 vs. 39.0; aHR 1.28 [1.16-1.42]). Sibling-controlled analyses showed slightly attenuated association (IBD: aHR 1.10 [1.03-1.19]).

CONCLUSIONS

Patients with IBD had a moderately higher risk of developing HF for ≥20 years after IBD diagnosis than the general population.

Comparative Risk of Serious Infection With Vedolizumab vs Anti-Tumor Necrosis Factor in Inflammatory Bowel Disease: Results From Nationwide Swedish Registers

INTRODUCTION

We aimed to assess the risk of serious infection in patients with inflammatory bowel disease (IBD) treated with vedolizumab compared with those treated with anti-tumor necrosis factors (TNF) and the general population.

METHODS

In this Swedish cohort study, treatment episodes were identified from nationwide health registers. We used Cox regression with propensity score-matched cohorts to estimate hazard ratios (HRs) for incident serious infections, defined as infections requiring hospital admission.

RESULTS

During 1,376 treatment episodes in Crohn's disease, the rate of serious infections per 100 person-years (PY) was 5.18 (95% CI = 3.98-6.63) with vedolizumab vs 3.54 (95% CI = 2.50-4.85) with anti-TNF; HR = 1.72 (95% CI = 1.12-2.65), partly explained by more gastrointestinal infections. Compared with the rate of 0.75/100 PY (95% CI = 0.59-0.92) in a matched general population cohort, vedolizumab demonstrated higher risk (HR = 7.00; 95% CI = 5.04-9.72). During 1,294 treatment episodes in ulcerative colitis, the corresponding rates were 3.74/100 PY (95% CI = 2.66-5.11) with vedolizumab vs 3.42/100 PY (95% CI = 2.31-4.89) with anti-TNF; HR = 0.80 (95% CI = 0.47-1.36) during the initial 1.1 years and HR = 2.03 (95% CI = 0.65-6.32) after 1.1 years (truncated due to nonproportional hazards). Pneumonia accounted for 40% of all infections among anti-TNF, whereas no case was observed among vedolizumab episodes. Compared with the rate of 0.69/100 PYs (95% CI = 0.53-0.87) in a matched general population cohort, vedolizumab showed an HR of 5.45 (95% CI = 3.67-8.11).

DISCUSSION

Vedolizumab was associated with increased risks of serious infections compared with anti-TNF in Crohn's disease but not in ulcerative colitis. Nonetheless, the panorama of serious infections seemed to differ between the drugs. Our findings underscore the importance of clinical awareness of infections and the safety profile of the 2 therapies.

Higher incidence of paediatric inflammatory bowel disease by increasing latitude in Norway, but stable incidence by age

AIM

To examine possible geographical and temporal differences in the incidence of childhood-onset inflammatory bowel disease (IBD) in Norway, motivated by previous research indicating relevant environmental factors explaining changing epidemiology.

METHODS

We analysed data from children born in Norway from 2004 to 2012 (n = 541 036) in a registry-based nationwide study. After validating registry diagnoses against medical records, we defined IBD as ≥2 entries of International Classification of Diseases, 10th revision (ICD-10) codes K50, K51 and K52.3 in the Norwegian Patient registry. We estimated hazard ratios (HR) for IBD across four geographical regions with a south-to-north gradient and the incidence by period of birth.

RESULTS

By the end of follow-up on 31 December 2020, 799 IBD diagnoses were identified (Crohn's disease: n = 465; ulcerative colitis, n = 293, IBD: unclassified, n = 41). Compared to children in the southernmost region, there was almost a two-fold HR for IBD in children in the most Northern region (HR = 1.94, 95% Cl = 1.47-2.57; Mid region: HR = 1.68, 95% CI = 1.29-2.19, ptrend <0.001). These estimates remained largely unchanged after adjustment for potential confounding factors. The cohorts born in 2004-2006 and 2010-2012 had comparable cumulative incidences, with a slightly higher incidence for those born in 2007-2009.

CONCLUSION

We observed an increase in the risk of IBD by increasing latitude which may suggest that environmental factors influence the development of IBD, although non-causal explanations cannot be ruled out.

Tobacco Smoke Exposure in Early Childhood and Later Risk of Inflammatory Bowel Disease: A Scandinavian Birth Cohort Study

OBJECTIVES

To examine the association between early-life smoking exposure and later risk of inflammatory bowel disease [IBD].

METHODS

We followed 115663 participants from the Norwegian Mother, Father and Child [MoBa] and All Babies in Southeast Sweden [ABIS] cohorts from birth [1997-2009] through 2021. IBD was identified through national patient registers. Validated questionnaire data defined maternal smoking during pregnancy, maternal environmental tobacco smoke [ETS] exposure during pregnancy, and child ETS exposure by ages 12 and 36 months. Cox regression was used to estimate adjusted hazard ratios [aHRs] for sex, maternal age, education level, parental IBD, and origin. Cohort-specific estimates were pooled using a random-effects model.

RESULTS

During 1 987 430 person-years of follow-up, 444 participants developed IBD [ABIS, 112; MoBa, 332]. Any vs no maternal smoking during pregnancy yielded a pooled aHR of 1.30 [95% CI = 0.97-1.74] for offspring IBD. Higher level of maternal smoking during pregnancy (compared with no smoking, average ≥6 cigarettes/day: pooled aHR = 1.60 [95% CI = 1.08-2.38]) was associated with offspring IBD, whereas a lower smoking level was not (average 1-5 cigarettes/day: pooled aHR = 1.09 [95% CI = 0.73-1.64]). Child ETS exposure in the first year of life was associated with later IBD (any vs no ETS, pooled aHR = 1.32 [95% CI = 1.03-1.69]). Estimates observed for child ETS exposure by 36 months were similar but not statistically significant.

CONCLUSIONS

In this prospective Scandinavian cohort study, children exposed to higher levels of maternal smoking during pregnancy or ETS during the first year of life were at increased risk of later IBD.

Impact of inflammatory bowel disease on the risk of acute coronary syndrome: A Swedish Nationwide Cohort Study

BACKGROUND

There are conflicting data on the risk of acute coronary syndrome (ACS) in patients with inflammatory bowel disease (IBD). Only a few previous reports include patients diagnosed during the last decade.

AIM

To assess and compare the risk of ACS between patients with IBD and the general population.

METHODS

In this cohort study, we used nationwide registers to identify patients diagnosed with IBD in Sweden 2003-2021. Every patient was matched by birth year, sex, calendar year and area of residence with up to 10 general population comparators. The primary outcome was incident ACS. We used semi-parametric Cox proportional hazard models to estimate hazard ratios (HRs).

RESULTS

We identified 76,517 patients with IBD (Crohn's disease [CD], N = 22,732; ulcerative colitis [UC], N = 42,194 and IBD-unclassified, N = 11,591) and 757,141 comparators. During a median follow-up of 8 years, 2546 patients with IBD (37.5/10,000 person-years) were diagnosed with ACS compared with 19,598 (28.0/10,000 person-years) among comparators (HR 1.30; 95% confidence interval 1.24-1.35) after adjustments for confounding factors, and approximately one extra case of ACS in 100 IBD patients followed for 10 years. The highest HRs for ACS were in patients with elderly onset IBD (≥60 years) and among patients with CD or UC with extra-intestinal manifestations. No increased HRs were observed in patients diagnosed with IBD before the age of 40.

CONCLUSION

In this contemporary cohort of patients with IBD, exposed to modern IBD care, there was an increased risk for ACS compared with individuals from the general population.

Children and Adolescents Diagnosed With Inflammatory Bowel Disease Are at Increased Risk of Developing Diseases With a Possible Autoimmune Pathogenesis

BACKGROUND

The development of diseases with a possible autoimmune pathogenesis is common in adults with inflammatory bowel disease (IBD). In early onset IBD, it may differ but the evidence is sparse. We aimed to investigate the risk and time span from IBD diagnosis to outcomes with different associated disorders with possible autoimmune pathogenesis.

METHODS

A register-based study included all Danish patients with early onset of IBD (≤18 years) between 1980 and 2021 and 50 matched references without IBD for each case. We examined the risk of type 1 and type 2 diabetes, celiac disease, thyroid disease, rheumatoid arthritis, psoriatic arthritis, and spondyloarthritis in Cox regression models.

RESULTS

In total, 6822 patients with IBD were identified, and 337 728 matched references. The median age at the time of IBD diagnosis or index date for the matched references was 16 years (25-75 percentile: 13-18 years), and the median age at the time of an outcome or at the end of follow-up was 28.1 years (25-75 percentile: 21.5-37.0 years). According to the cumulative incidence plots psoriatic arthritis, and spondyloarthritis was diagnosed approximately 10 years after the IBD onset, and the remaining outcomes later. The adjusted hazard ratio after full follow-up was 4.72 (95% CI, 3.85-5.80) for psoriatic arthritis, 5.21 (95% CI, 4.17-6.50) for spondyloarthritis, 2.77 (95% CI, 1.92-4.00) for celiac disease, 2.15 (95% CI, 1.54-3.01) for rheumatoid arthritis, 1.69 (95% CI, 1.23-2.32) and 1.64 (95% CI, 1.21-2.21) for type 1 and type 2 diabetes, respectively. For thyroid disease, it was 1.16 (95% CI, 0.97-1.40).

CONCLUSIONS

The risk estimates were significantly increased for all outcomes at the end of follow-up, except for thyroid disease, but according to the cumulative incidence plots, only psoriatic arthritis and spondyloarthritis occurred earlier in the IBD cohort than in the matched references.

Early-life diet and risk of inflammatory bowel disease: a pooled study in two Scandinavian birth cohorts

OBJECTIVE

We assessed whether early-life diet quality and food intake frequencies were associated with subsequent IBD.

DESIGN

Prospectively recorded 1-year and 3-year questionnaires in children from the All Babies in Southeast Sweden and The Norwegian Mother, Father and Child Cohort Study were used to assess diet quality using a Healthy Eating Index and intake frequency of food groups. IBD was defined as >2 diagnoses in national patient registers. Cox regression yielded HRs adjusted (aHRs) for child's sex, parental IBD, origin, education level and maternal comorbidities. Cohort-specific results were pooled using a random-effects model.

RESULTS

During 1 304 433 person-years of follow-up, we followed 81 280 participants from birth through childhood and adolescence, whereof 307 were diagnosed with IBD. Compared with low diet quality, medium and high diet quality at 1 year of age were associated with a reduced risk of IBD (pooled aHR 0.75 (95% CI=0.58 to 0.98) and 0.75 (95% CI=0.56 to 1.00)). The pooled aHR per increase of category was 0.86 (0.74 to 0.99). Pooled aHR for children 1 year old with high versus low fish intake was 0.70 (95% CI=0.49 to 1.00) for IBD, and showed association with reduced risk of UC (pooled aHR=0.46; 95% CI=0.21, 0.99). Higher vegetable intake at 1 year was associated with a risk reduction in IBD. Intake of sugar-sweetened beverages was associated with an increased risk of IBD. Diet quality at 3 years was not associated with IBD.

CONCLUSION

In this Scandinavian birth cohort, high diet quality and fish intake in early life were associated with a reduced risk of IBD.

Physical activity in childhood and later risk of inflammatory bowel disease: A Scandinavian birth cohort study

BACKGROUND AND OBJECTIVE

Retrospective data have linked adult physical activity (PA) to reduced risk of inflammatory bowel disease (IBD). We aimed to prospectively examine the association of PA and screen time (ST) in childhood with later risk of IBD, for which data are scarce.

METHODS

Using two population-based birth cohorts (All Babies in Southeast Sweden [ABIS] and Norwegian Mother, Father, and Child Cohort Study [MoBa]), we retrieved parent-reported data on PA and ST degree at ages 3 and 8 years. Data were modelled as binary (high vs. low) and numerical (hours/day) exposures. Inflammatory bowel disease was defined as ≥2 diagnostic records in national health registers. Cox regression estimated hazard ratios adjusted for potential confounding from parental IBD, country of origin, education, and smoking habits (Adjusted hazard ratio (aHR)). Our 8-year analyses included a 2-year lag period to reduce the risk of reverse causation. Cohort-specific estimates were pooled using random-effects model.

RESULT

Among 65,978 participants from ABIS (n = 8810) and MoBa (n = 57,168) with available data, 266 developed IBD. At 3 years, children with high versus low PA had an aHR of 1.12 for IBD (95%CI = 0.87-1.43); high versus low ST showed an aHR of 0.91 (95%CI = 0.71-1.17). Conversely, at 8 years, high versus low ST was associated with increased risk of later IBD (aHR = 1.51; 95%CI = 1.02-2.25), but PA at 8 years, was not linked to IBD (aHR = 1.19; 95%CI = 0.80-1.76). Subtype-specific analyses for Crohn's disease and ulcerative colitis did not differ appreciably.

CONCLUSION

Acknowledging possible confounding variables, children with high versus low ST at 8 years were at increased risk of IBD. In contrast, PA degree was not linked to IBD at any age category.

Microscopic Colitis and Risk of Incident Acute Pancreatitis: A Nationwide Population-Based Matched Cohort Study

INTRODUCTION

Several gastrointestinal diseases have been linked to acute pancreatitis, but the risk of acute pancreatitis in microscopic colitis (MC) has not been studied.

METHODS

We conducted a nationwide, population-based, matched cohort study in Sweden of 12,140 patients with biopsy-verified MC (diagnosed in 2003-2017), 57,806 matched reference individuals, and 12,781 siblings without MC with a follow-up until 2021. Data on MC were obtained from all of Sweden's regional pathology registers (n = 28) through the ESPRESSO cohort. Data on acute pancreatitis were collected from the National Patient Register. Adjusted hazard ratios (aHR) and 95% confidence intervals (CI) were calculated using Cox regression.

RESULTS

During a mean follow-up of 9.9 years (SD = 4.3), 146 patients with MC and 437 reference individuals were diagnosed with acute pancreatitis (127.8 vs 80.1 per 100,000 person-years), corresponding to an aHR of 1.57 (95% CI = 1.30-1.90). Moreover, we found a positive association between MC and acute nongallstone-related pancreatitis (aHR 1.99 [95% CI = 1.57-2.51]), but not with acute gallstone-related pancreatitis (aHR 1.08 [95% CI = 0.78-1.49]). Comparing patients with MC with their unaffected siblings yielded an aHR of 1.28 (95% CI = 0.92-1.78). The risk of acute pancreatitis remained elevated also for patients with MC with a follow-up exceeding 10 years (aHR 1.75 [95% CI = 1.14-2.67]).

DISCUSSION

This nationwide study of more than 12,000 patients with MC demonstrated an increased risk of acute pancreatitis after MC. Hence, clinicians should have a low threshold for the evaluation of acute pancreatitis in patients with MC. In addition, these patients should receive advice and care aimed at reducing the risk of acute pancreatitis.

Causal atlas between inflammatory bowel disease and mental disorders: a bi-directional 2-sample Mendelian randomization study

Background

The brain-gut axis link has attracted increasing attention, with observational studies suggesting that the relationship between common mental disorders and inflammatory bowel disease (IBD) may run in both directions. However, so far, it is not clear whether there is causality and in which direction.

Methods

We conducted a bidirectional 2-sample Mendelian randomization study to investigate the relationship between IBD, including Crohn's disease (CD) and ulcerative colitis (UC), and mental disorders, using summary-level GWAS data. The main analysis was the inverse variance weighted method. IBD (including CD and UC), and nine mental disorders were used as both exposures and outcomes.

Results

We found that UC could significantly lead to obsessive-compulsive disorder, attention deficit hyperactivity disorder, and autism spectrum disorder, with odds ratio (OR) of 1.245 (95% confidence intervals [CI]: 1.069-1.450; P=0.008), 1.050 (95%CI: 1.023-1.077; P=2.42×10-4), and 1.041 (95%CI: 1.015-1.068; P=0.002) respectively. In addition, we found that bipolar disorder and schizophrenia could increase the odds of IBD, with OR values of 1.138 (95%CI: 1.084-1.194; P=1.9×10-7), and 1.115 (95%CI: 1.071-1.161; P=1.12×10-7), respectively. Our results also indicate that obsessive-compulsive disorder could lead to IBD, especially for UC, with OR values of 1.091 (95%CI: 1.024-1.162; P=0.009), and 1.124 (95%CI: 1.041-1.214; P=0.004), respectively.

Conclusions

Our findings indicate that the brain-gut axis involves the association between IBD, especially UC, and some mental disorders, which guides the targeted prevention, management, and mechanism exploration of these diseases.

Long-term risk of arrhythmias in patients with inflammatory bowel disease: A population-based, sibling-controlled cohort study

BACKGROUND

Although previous evidence has suggested an increased risk of cardiovascular disease (CVD) in patients with inflammatory bowel disease (IBD), its association with arrhythmias is inconclusive. In this study, we aimed to explore the long-term risk of arrhythmias in patients with IBD.

METHODS AND FINDINGS

Through a nationwide histopathology cohort, we identified patients with biopsy-confirmed IBD in Sweden during 1969 to 2017, including Crohn's disease (CD: n = 24,954; median age at diagnosis: 38.4 years; female: 52.2%), ulcerative colitis (UC: n = 46,856; 42.1 years; 46.3%), and IBD-unclassified (IBD-U: n = 12,067; 43.8 years; 49.6%), as well as their matched reference individuals and IBD-free full siblings. Outcomes included overall and specific arrhythmias (e.g., atrial fibrillation/flutter, bradyarrhythmias, other supraventricular arrhythmias, and ventricular arrhythmias/cardiac arrest). Flexible parametric survival models estimated hazard ratios (aHR) with 95% confidence intervals (95% CIs), after adjustment for birth year, sex, county of residence, calendar year, country of birth, educational attainment, number of healthcare visits, and cardiovascular-related comorbidities. Over a median of approximately 10 years of follow-up, 1,904 (7.6%) patients with CD, 4,154 (8.9%) patients with UC, and 990 (8.2%) patients with IBD-U developed arrhythmias, compared with 6.7%, 7.5%, and 6.0% in reference individuals, respectively. Compared with reference individuals, overall arrhythmias were increased in patients with CD [54.6 versus 46.1 per 10,000 person-years; aHR = 1.15 (95% CI [1.09, 1.21], P < 0.001)], patients with UC [64.7 versus 53.3 per 10,000 person-years; aHR = 1.14 (95% CI [1.10, 1.18], P < 0.001)], and patients with IBD-U [78.1 versus 53.5 per 10,000 person-years; aHR = 1.30 (95% CI [1.20, 1.41], P < 0.001)]. The increased risk persisted 25 years after diagnosis, corresponding to 1 extra arrhythmia case per 80 CD, 58 UC, and 29 IBD-U cases over the same period. Patients with IBD also had a significantly increased risk of specific arrhythmias, except for bradyarrhythmias. Sibling comparison analyses confirmed the main findings. Study limitations include lack of clinical data to define IBD activity, not considering the potential role of IBD medications and disease activity, and the potential residual confounding from unmeasured factors for arrhythmias.

CONCLUSIONS

In this study, we observed that patients with IBD were at an increased risk of developing arrhythmias. The excess risk persisted even 25 years after IBD diagnosis. Our findings indicate a need for awareness of this excess risk among healthcare professionals.

Long-term Risk of Stroke in Patients With Inflammatory Bowel Disease: A Population-Based, Sibling-Controlled Cohort Study, 1969-2019

BACKGROUND AND OBJECTIVES

Patients with inflammatory bowel disease (IBD) are at an increased risk of thromboembolic events, but evidence on the long-term risk of stroke remains scarce. We aimed to explore whether patients with a biopsy-confirmed IBD had an increased long-term risk of stroke.

METHODS

This cohort included all patients with biopsy-confirmed IBD in Sweden between 1969 and 2019 and up to 5 matched reference individuals per patient who were randomly selected from the general population and IBD-free full siblings. The primary outcome was incident overall stroke; secondary outcomes were ischemic and hemorrhagic strokes. Stroke was identified from the Swedish National Patient Register by using both primary and secondary diagnoses. Adjusted hazard ratios (aHRs) for stroke were estimated by flexible parametric survival models.

RESULTS

A total of 85,006 patients with IBD (including Crohn disease [CD, n = 25,257], ulcerative colitis [UC, n = 47,354], and IBD-unclassified [IBD-U, n = 12,395]), 406,987 matched reference individuals, and 101,082 IBD-free full siblings were included in the analysis. We observed 3,720 incident strokes in patients with IBD (incidence rate [IR] 32.6 per 10,000 person-years) and 15,599 in reference individuals (IR 27.7; aHR 1.13, 95% CI 1.08-1.17). The elevated aHR remained increased even 25 years after diagnosis, corresponding to 1 additional stroke case per 93 patients with IBD until then. The excess aHR was mainly driven by ischemic stroke (aHR 1.14; 1.09-1.18) rather than hemorrhagic stroke (aHR 1.06; 0.97-1.15). The risk of ischemic stroke was significantly increased across IBD subtypes (CD [IR 23.3 vs 19.2; aHR 1.19; 1.10-1.29], UC [IR 25.7 vs 22.6; aHR 1.09; 1.04-1.16], and IBD-U [IR 30.5 vs 22.8; aHR 1.22; 1.08-1.37]). Similar results were found when patients with IBD were compared with their siblings.

DISCUSSION

Patients with IBD were at an increased risk of stroke, especially of ischemic events, irrespective of the IBD subtype. The excess risk persisted even 25 years after diagnosis. These findings highlight the need for clinical vigilance about the long-term excess risk of cerebrovascular events in patients with IBD.

Outcomes of bariatric surgery for patients with prevalent inflammatory bowel disease: A nationwide registry-based cohort study

BACKGROUND

Obesity is becoming more prevalent in patients with inflammatory bowel disease. Although bariatric surgery is an effective treatment for obesity, questions remain regarding its safety and effectiveness for patients with inflammatory bowel disease. The aim of this study was to evaluate the safety and effectiveness of bariatric surgery in patients with inflammatory bowel disease.

METHOD

This registry-based, propensity-matched cohort study included all patients who had primary Roux-en-Y gastric bypass or sleeve gastrectomy in Sweden from January 2007 to June 2020 who had an inflammatory bowel disease diagnosis and matched control patients without an inflammatory bowel disease diagnosis. The study included data from the Scandinavian Obesity Surgery Registry, the National Patient Register, the Swedish Prescribed Drugs Register, the Total Population Register, and the Education Register from Statistics Sweden.

RESULTS

In total, 71,093 patients who underwent bariatric surgery, including 194 with Crohn's disease and 306 with ulcerative colitis, were 1:5 matched to non-inflammatory bowel disease control patients. The patients with Crohn's disease had a higher readmission rate within 30 days (10.7% vs 6.1%, odds ratio = 1.84, 95% confidence interval 1.02-3.31) than the control patients, with no significant difference between the surgical methods. The patients with ulcerative colitis had a higher risk for serious postoperative complications after Roux-en-Y gastric bypass (8.0% vs 3.7%, odds ratio = 2.64, 95% confidence interval 1.15-6.05) but not after sleeve gastrectomy compared to control patients (0.8% vs 2.3%). No difference was observed in postoperative weight loss or postoperative health-related quality of life.

CONCLUSION

Sleeve gastrectomy appears to be a safe and effective treatment for obesity in patients with inflammatory bowel disease, whereas Roux-en-Y gastric bypass was associated with a higher risk for postoperative complications in patients with ulcerative colitis.

Epidemiology, validation, and clinical characteristics of inflammatory bowel disease: the ABIS birth cohort study

BACKGROUND

Birth cohort studies with linked register-based data on inflammatory bowel disease (IBD) provide opportunities to prospectively study early-life determinants of the disease. However, register-based data often lack information on clinical characteristics and rely on diagnostic algorithms. Within the All Babies in Southeast Sweden (ABIS) cohort, we examined the validity of a register-based definition of IBD, its incidence, and clinical and therapeutic characteristics at diagnosis.

METHODS

We followed 16,223 children from birth (1997-1999) until the end of 2020 for the diagnosis of IBD as defined by a minimum of two diagnostic codes for IBD in the Swedish National Patient Register (NPR). We described the incidence and cumulative incidence of IBD. Through a medical record review of cases diagnosed by the end of 2017, we examined the positive predictive value (PPV) for IBD and described its clinical characteristics and treatment.

RESULTS

By 2020, at an average age of 22.2 years, 113 participants (0.74%, 95% confidence interval [CI] = 0.61-0.89) had a register-based diagnosis of IBD, corresponding to an incidence of 31.3 per 100,000 person-years of follow-up; the incidence for Crohn's disease (CD) was 11.1 per 100,000 person-years and 15.8 for ulcerative colitis (UC). Of 77 participants with a register-based definition of IBD by the end of 2017, medical records were identified for 61 participants, of whom 57 had true IBD (PPV = 93%; 95%CI = 0.87-1.00). While oral 5-aminosalicylic acid treatment was equally common in newly diagnosed CD and UC patients, biologics were more often used for newly diagnosed CD. The median faecal calprotectin levels were 1206 mg/kg at diagnosis and 93 mg/kg at the last follow-up (P < 0.001).

CONCLUSIONS

In this population-based sample of Swedish children and young adults the cumulative IBD incidence was 0.74. The validity of register-based definition of IBD was high and supports using such data to identify IBD patients in cohort studies.

Histological remission in inflammatory bowel disease and risk of adverse pregnancy outcomes: A nationwide study

BACKGROUND

Inflammatory bowel disease (IBD) has been linked to adverse pregnancy outcomes, but it is unclear how risks vary by histological activity.

METHODS

We performed a nationwide study of Swedish women diagnosed with IBD 1990-2016 and a pre-pregnancy (<12 months) colorectal biopsy with vs. without histological inflammation (1223 and 630 births, respectively). We also examined pregnancy outcomes in 2007-2016 of women with vs. without clinically active IBD (i.e., IBD-related hospitalization, surgery, or medication escalation) <12 months before pregnancy (2110 and 4993 births, respectively). Accounting for smoking, socio-demographics, and comorbidities, generalized linear models estimated adjusted risk ratios (aRRs) for preterm birth (<37 gestational weeks) and small-for-gestational age (SGA, <10th percentile weight for age).

FINDINGS

Of infants to women with vs. without histological inflammation, 9.6% (n = 117) and 6.5% (n = 41) were preterm, respectively (aRR = 1.46; 95%CI = 1.03-2.06). Histological inflammation was associated with preterm birth in ulcerative colitis (UC) (aRR = 1.64; 95%CI = 1.07-2.52), especially extensive colitis (aRR = 2.37; 95%CI = 1.12-5.02), but not in Crohn's disease (aRR = 0.99; 95%CI = 0.55-1.78). Of infants to women with vs. without histological inflammation, 116 (9.6%) and 56 (8.9%), respectively, were SGA (aRR = 1.09; 95%CI = 0.81-1.47). Clinically active disease before pregnancy was linked to preterm birth (aRR = 1.42; 95%CI = 1.20-1.69), but not to SGA birth (aRR = 1.13; 95%CI = 0.96-1.32). Finally, of infants to women without clinical activity, histological inflammation was not significantly associated with preterm birth (aRR = 1.20; 95%CI = 0.68-2.13).

INTERPRETATION

Histological and clinical activity in IBD, especially in UC, were risk factors for preterm birth. Further research is needed to determine the importance of pre-pregnancy histological activity in women without clinically-defined disease activity.

FUNDING

The Swedish Society of Medicine.

Colorectal Cancer in Childhood-onset Inflammatory Bowel Disease: A Scandinavian Register-based Cohort Study, 1969-2017

Through linkage of data from Danish and Swedish national registers we identified 6937 patients with childhood (&lt;18 years)-onset Crohn disease (CD), 8514 patients with childhood-onset ulcerative colitis (UC) and up to 10 times as many matched (sex, age, residence) reference individuals 1969-2017. During follow-up to a median age of 27 (interquartile range = 21-39) years, 25 (0.36%) CD patients were diagnosed with colorectal cancer (CRC) versus 43 (0.06%) reference individuals, and 113 (1.33%) UC patients versus 45 (0.05%) reference individuals. The hazard ratio (HR) for CRC was 6.46 (95% CI = 3.95-10.6) in CD and 32.5 (95% CI = 23.0-45.9) in UC and increased with decreasing age at diagnosis. The HR for CRC was increased for all phenotypes, but with higher estimates for colonic CD [17.9 (95% CI = 7.43-43.3)] and UC with extensive/pancolitis [36.3 (95% CI = 22.8-57.8)]. The relative risk of CRC was increased for all phenotypes of childhood-onset inflammatory bowel disease. Age at onset may be considered an additional risk factor when implementing surveillance programs.

Earnings during adulthood in patients with childhood-onset inflammatory bowel disease: a nationwide population-based cohort study

BACKGROUND

IBD with onset during childhood seems to represent a severe disease phenotype with increased morbidity. We have previously demonstrated that children with IBD have significantly lower final grades in compulsory school compared to healthy peers.

AIM

To evaluate the association of childhood-onset IBD with a later professional career and subsequent earnings METHODS: We identified 5404 individuals diagnosed with childhood-onset (<18 years) IBD between 1990 and 2014 (2818 with ulcerative colitis and 2328 with Crohn's disease) in the Swedish National Patient Register. Patients were matched with 10 general population reference individuals by sex, birth year, and place of residence (n = 51,295). Data on earnings during 1992-2017 were obtained through the longitudinal integration database for health insurance and labour market studies. Earnings were converted into Euros (inflation-adjusted to 2019). The differences in earnings between patients and general population reference individuals were calculated through quantile regression.

RESULTS

Patients with childhood-onset IBD had significantly lower annual taxable earnings from ages 20 to 30 (adjusted median annual income difference (AMAID) at age 30: -5.4% [95% CI -9.1% to -1.8%]). In particular, annual taxable earnings through early adult age were lower in patients who, during childhood, had had surgery or long-term inpatient treatment for IBD (AMAID at age 30: -16.3% [95% CI -24.7% to -7.9%]).

CONCLUSIONS

Overall, the negative influence of disease on earnings in early adult age was modest for patients with childhood-onset IBD. The markedly larger negative income gap from ages 20 to 30 in patients with more severe IBD during childhood should be recognised.