Sex-Based Differences in Incidence of Inflammatory Bowel Diseases-Pooled Analysis of Population-Based Studies From Western Countries

Unveiling the anti-inflammatory potential of 11β,13-dihydrolactucin for application in inflammatory bowel disease management

Management of inflammatory bowel disease (IBD) poses significant challenges, and there is a need for innovative therapeutic approaches. This study investigates the anti-inflammatory properties of the dietary sesquiterpene lactone (SL) 11β,13-dihydrolactucin, which can be found in chicory, in three distinct complementary models of intestinal inflammation (two cell models and a zebrafish model), offering comprehensive insights into its potential application for IBD treatment alternatives. In a triple cell co-culture composed of Caco-2, HT29-MTX-E12, and Raji B, 11β,13-dihydrolactucin demonstrated remarkable anti-inflammatory activity at several levels of the cellular inflammatory response. Notably, 11β,13-dihydrolactucin prevented the activation of critical signalling pathways associated with inflammation, namely NF-κB and MAPK p38. This SL also decreased the release of the neutrophil-recruiting chemokine IL-8. Additionally, the compound reduced the gene expression of IL-6 and TNF-α, as well as the gene and protein expression of the inflammatory inducible enzymes iNOS and COX-2. In a myofibroblast-like human cell model, 11β,13-dihydrolactucin decreased the release of the cytokine TNF-α and the COX-2-derived inflammation mediator PGE2. Finally, in a zebrafish model of gut inflammation, 11β,13-dihydrolactucin effectively reduced neutrophil infiltration, further supporting its anti-inflammatory efficacy in a physiological context. Collectively, our findings highlight the promising anti-inflammatory potential of 11β,13-dihydrolactucin across various facets of intestinal inflammation, providing a foundation for the consideration of chicory as a promising candidate for incorporation in food or nutraceutical products for the potential prevention of IBD.

Farming Activities and Risk of Inflammatory Bowel Disease: A French Nationwide Population-based Cohort Study

BACKGROUND AND AIMS

Epidemiological data regarding inflammatory bowel disease [IBD] are lacking, in particular for occupationally exposed populations. We investigated whether, among the entire French farm manager [FM] workforce, certain agricultural activities are more strongly associated with IBD than others.

METHODS

Nationwide, population-based, insurance claims and electronic health records from all FMs who worked at least once over the period 2002-2016 were used [n = 1 088 561, 69% males]. The outcome measure was the association between 26 farming activities and the risk of IBD, Crohn's disease [CD], and ulcerative colitis [UC], measured as hazard ratios [HRs], after adjusting for age, sex, pre-existing medical comorbidities, and farm location. The time to first chronic disease declaration was used as the underlying time scale. A model was generated for every activity and disease, using a reference group comprising all FMs who abstained from the specified activity from 2002 to 2016.

RESULTS

There were 1752 IBD cases, with 704 CD [40.2%] and 1048 UC [59.8%] cases, respectively. Elevated HRs were observed for fruit arboriculture [HR from 1.17 to 1.52] and dairy farming [HR from 1.22 to 1.46] for all IBD, in crop farming for CD only (HR = 1.26, 95% confidence interval [CI]: 1.06-1.49), and in shellfish farming [HR from 2.12 to 2.51] for both CD and IBD.

CONCLUSIONS

Further research regarding specific farming activities and exposures likely to modify the microbiota [eg, pesticides, pathogens] is required to identify potential occupational risk factors [agricultural exposome] for IBD. Exposure to Mycobacterium avium subspecies paratuberculosis, Cryptosporidium, environmental toxins, micro/nanoplastics, and pesticides represents promising research avenues.

Phenotypes of inflammatory bowel disease in the Māori population of New Zealand

BACKGROUND

Māori have historically seen a lower rate of inflammatory bowel disease (IBD) compared to New Zealand's non-Māori population. Recent reports have shown an increasing rate of IBD among Māori patients.

AIM

We performed a study to identify the phenotypes of IBD in the Māori population.

METHODS

Patients with IBD of Māori ethnicity were retrospectively identified from four large regions of New Zealand. Electronic records were reviewed to collect details of patients' demographics, phenotypes and clinical features.

RESULTS

We identified 165 Māori patients with IBD, of whom 74 (45.4%) had Crohn disease (CD), 86 (53.5%) had ulcerative colitis (UC) and 5 (3.0%) had IBD-unclassified (IBD-U). There were more female (61.8%) patients compared to male (38.2%). This was attributed to the higher ratio of female patients with CD over male (73.9% vs 26.1%), whereas sex was evenly distributed in UC (female 52.2%, male 48.8%). Ileocolonic CD was most frequently seen (36.2%), and the majority had non-stricturing disease (62.3%) with the absence of perianal involvement (78.2%). Bimodal age peaks were observed, with a first peak at 25-29 years and a second peak at 45-49 years. There was a five-fold increase in the incidence of IBD in Māori over 20 years.

CONCLUSIONS

We present the largest study describing IBD in Māori. IBD phenotypes in Māori were similar to previous regional IBD reports, but there was a significantly higher proportion of female patients with CD in Māori and an earlier second age peak at 45-49 years. Increasing incidence of IBD in Māori has again been demonstrated.

17β-estradiol promotes myeloid-derived suppressor cells functions and alleviates inflammatory bowel disease by activation of Stat3 and NF-κB signalings

Inflammatory bowel disease (IBD) describes a group of clinically common autoimmune diseases characterized by chronic intestinal inflammation, with gender differences in prevalence. Estrogen has been previously shown to exert anti-inflammatory action in IBD development, however, the mechanisms remain obscure. Recent research has revealed that myeloid-derived suppressor cells (MDSCs) play a protective role in IBD pathogenesis. To investigate the molecular mechanisms of estrogen steroid 17β-estradiol (E2) in IBD progression, we established IBD mouse models (DNB-induced) with or without prior ovariectomy (OVX) and E2 implantation. We found that OVX led to worse IBD symptoms and reduced MDSCs frequency, whereas E2 significantly alleviated these effects in vivo. Moreover, in vitro experiments showed that E2 promoted the proliferation and immunosuppressive function of MDSCs through phosphorylation of Stat3 and p65. Mechanistically, E2-mediated Stat3/p65 phosphorylation depends on the interaction between HOTAIR, a long non-coding RNA that are well-known in MDSCs proliferation, and Stat3/p65 respectively. In conclusion, our study revealed that E2 promotes the expansion and immunosuppressive function of MDSCs, and thus diminished the occurrence and development of IBD.

Temporal Trends of Inflammatory Bowel Diseases in Taiwan from 2016 to 2020: A Population-Based Study

BACKGROUND

There are scanty population-based studies investigating the incidence and prevalence rates of inflammatory bowel disease (IBD) in Taiwan.

AIMS

This study aimed to estimate the nationwide prevalence and incidence of IBD and identify its noticeable trends in Taiwan between 2016 and 2020.

METHODS

A retrospective study by analyzing the data from the National Health Insurance Research Database of Taiwan.

RESULTS

A total of 2595 patients with catastrophic IBD illness were registered from 2016 to 2020 in Taiwan (CD, 880; UC, 1715). The male-to-female ratio in the study sample was 1.83:1 for CD and 1.69:1 for UC. The median age of those registered with CD and UC was 37 and 47 years, respectively. The incidence rate of CD was 0.65 per 100,000 persons in 2016 and it was increased to 0.81 per 100,000 persons in 2020. The incidence rate of UC was 1.16 per 100,000 persons in 2016 and it was increased to 1.53 in 2020. Overall, the incidence of IBD was increase from 1.81 per 100,000 persons to 2.34 per 100,000 persons between 2016 and 2020. Overall, the prevalence rates of IBD was increase from 14.95 per 100,000 persons to 20.02 per 100,000 persons between 2016 and 2020.

CONCLUSION

The epidemiological stages of IBD in Taiwan was considered in the acceleration in incidence stage, during which incidence rises and prevalence is relatively low. Understanding these geographical differences is important for the rising global burden of IBD.

Exploring the relationship between ulcerative colitis, colorectal cancer, and prostate cancer

Chronic systemic inflammation caused by diseases such as ulcerative colitis (UC) and Crohn's disease (CD) increases the risk of developing colorectal cancer (CRC). Recent evidence indicates that patients with UC are more susceptible to prostate cancer (PCa), and individuals with PCa may also be at a higher risk of developing CRC. However, these relationships are not well defined. A better understanding of this phenomenon could improve the identification of high-risk populations. In this study, we characterized these relationships with experiments using preclinical mouse models of dextran sulfate sodium (DSS)-induced colitis (DSS-UC) and DSS/azoxymethane (AOM)-induced CRC (DSS/AOM-CRC) in wild-type and conditional transgenic mice of PCa. We showed that DSS-induced UC was more severe in mice with PCa and resulted in the development of CRC in the absence of AOM. We further showed that PCa-free mice that developed DSS-induced UC also showed histological changes in the normal prostate that resembled proliferative inflammatory atrophy. Finally, we used immunohistochemical immune profiling to show that mice with PCa-induced chronic systemic inflammation accumulated Gr1+ myeloid cells in the normal colon and exposure to DSS further enriched these cells in active colitis regions and colon tumors. Our study provides evidence to support a link between systemic chronic inflammation and cancer.

The Potential Role of Female Sex Hormones in Patients With Inflammatory Bowel Disease: A 2-Sample Mendelian Randomization Study

INTRODUCTION

An association between female sex hormones and inflammatory bowel disease (IBD) has been reported in epidemiological studies. However, a solid causal relationship has not been established. Therefore, we performed a 2-sample Mendelian randomization (MR) study to explore the causal association between genetically predicted female sex hormone exposure, especially estrogen, and IBD.

METHODS

Genetic variants for female sex hormone exposure (ovulatory function, reproductive function, oral contraceptive pills, and hormone replacement therapy) were obtained from genome-wide association studies. Summary statistics for IBD were derived from the International Inflammatory Bowel Disease Genetics Consortium. We applied inverse variance weighted (IVW), MR-Egger, and weighted median (WM) methods in this MR study. Heterogeneity, horizontal pleiotropy, and sensitivity analyses were conducted to confirm the accuracy and robustness of our results.

RESULTS

Our study found that genetically predicted age at menarche was associated with an increased risk of Crohn's disease (odds ratio [OR] IVW 1.235, 95% confidence interval [CI] 1.028-1.484, P = 0.024), genetically predicted age of the last used hormone replacement therapy was associated with an increased risk of ulcerative colitis (OR WM 1.636, 95% CI 1.011-2.648, P = 0.045), and genetically predicted number of live births was related to a decreased risk of Crohn's disease (OR IVW 0.583, 95% CI 0.373-0.912, P = 0.018).

DISCUSSION

This study provided evidence for a link between female sex hormone exposure, especially estrogen, and IBD. Further investigations are needed to explore the causal effect of estrogen on IBD activity and the underlying mechanism of estrogen in IBD.

Estrogen deprivation and estrogen receptor α antagonism decrease DSS colitis in female mice

The association of hormonal contraception with increased risk of inflammatory bowel disease (IBD) observed in females suggests involvement of ovarian hormones, such as estradiol, and the estrogen receptors in the progression of intestinal inflammation. Here, we investigated the effects of prophylactic SERM2 and estradiol supplementation in dextran sulfate sodium-induced colitis using mice with intact ovaries and ovariectomized (OVX) female mice. We found that graded colitis score was threefold reduced in the OVX mice, compared to mice with intact ovaries. Estradiol supplementation, however, aggravated the colitis in OVX mice, increasing the colitis score to a similar level than what was observed in the intact mice. Further, we observed that immune infiltration and gene expression of inflammatory interleukins Il1b, Il6, and Il17a were up to 200-fold increased in estradiol supplemented OVX colitis mice, while a mild but consistent decrease was observed by SERM2 treatment in intact animals. Additionally, cyclo-oxygenase 2 induction was increased in the colon of colitis mice, in correlation with increased serum estradiol levels. Measured antagonist properties of SERM2, together with the other results presented here, indicates an exaggerating role of ERα signaling in colitis. Our results contribute to the knowledge of ovarian hormone effects in colitis and encourage further research on the potential use of ER antagonists in the colon, in order to alleviate inflammation.

The prevalence and risk factors of sexual dysfunction among females with inflammatory bowel disease: a systematic review and meta-analysis

In recent years, numerous epidemiological studies have investigated the prevalence of female sexual dysfunction (FSD) in females with inflammatory bowel disease (IBD). However, a comprehensive systematic review with meta-analysis pooling their findings is lacking. This study aimed to determine the pooled prevalence estimates of FSD and its risk factors among females with IBD based on extensive research in electronic databases (PubMed, Embase, and Web of Science) from inception until April 1, 2023. The overall prevalence of FSD among females with IBD, along with its 95% confidence interval (CI), and subgroup-specific prevalence rates, were summarized. Sources of heterogeneity were identified through subgroup analyses and meta-regression. A total of 13 studies were included in this systematic review and meta-analysis. The pooled global prevalence of FSD among females with IBD was 61.4% (95% CI: 52.8-70.1%). Sensitivity analysis, which involved excluding individual studies, indicated no significant variation in the pooled prevalence, confirming the robustness of our results. Additionally, a significant risk factor for FSD among females with IBD was the quality of life (OR = 0.39, 95% CI: 0.19-0.79). In conclusion, our systematic review and meta-analysis revealed a high prevalence of FSD among females with IBD, which warrants attention from health organizations and clinical practitioners. Importantly, the quality of life was identified as a potential risk factor for FSD in this population. Nonetheless, future prospective cohort studies with a large sample size are warranted to confirm these findings.

Sex hormone deprivation abolishes sex-specific differences in murine colon inflammation and related lipid mediator production

Unresolved inflammation, due to unfavorable imbalances between pro-inflammatory and pro-resolving mediators, leads to chronic inflammatory pathologies that are often sex-biased and regulated by sex hormones, including inflammatory bowel disease. Lipid mediators (LM) produced from polyunsaturated fatty acids by various lipoxygenases (LOX) and cyclooxygenases govern all stages of inflammation, i.e., the initiation and progression by pro-inflammatory eicosanoids and its resolution by specialized pro-resolving mediators (SPM). Here, we reveal sex-specific differences in murine experimental colitis with male preponderance, which was abolished by sex hormone deprivation using gonadectomy, and this correlated to the levels of inflammation-relevant mediators in the colon. Oral dextran sodium sulfate administration caused more severe colon inflammation in male CD-1 mice than in female counterparts during the acute phase. Colitis in males yielded higher colonic cytokine/chemokine levels but lower 12-/15-LOX-derived LM including SPM compared to female animals in the resolving phase. Sex hormone deprivation in male mice by orchidectomy ameliorated colitis and impaired pro-inflammatory cytokine/chemokine levels but elevated 12-/15-LOX products including SPM, thus abolishing the observed sex differences. Conversely, ovariectomy impaired the levels of those LM that dominated in females and that were increased in males after gonadectomy. Our findings suggest that male sex hormones promote the development of colitis connected to the biosynthesis of inflammatory cytokines, chemokines, and certain LM, especially pro-resolving 12-/15-LOX products that appear to be suppressed in the male colon due to androgens.

Management of ulcerative colitis in Taiwan: consensus guideline of the Taiwan Society of Inflammatory Bowel Disease updated in 2023

Ulcerative colitis (UC) is a chronic inflammation of the gastrointestinal tract and is characterized by alternating periods of inflammation and remission. Although UC incidence is lower in Taiwan than in Western countries, its impact remains considerable, demanding updated guidelines for addressing local healthcare challenges and patient needs. The revised guidelines employ international standards and recent research, emphasizing practical implementation within the Taiwanese healthcare system. Since the inception of the guidelines in 2017, the Taiwan Society of Inflammatory Bowel Disease has acknowledged the need for ongoing revisions to incorporate emerging therapeutic options and evolving disease management practices. This updated guideline aims to align UC management with local contexts, ensuring comprehensive and context-specific recommendations, thereby raising the standard of care for UC patients in Taiwan. By adapting and optimizing international protocols for local relevance, these efforts seek to enhance health outcomes for patients with UC.

Inflammatory Bowel Disease: A Comprehensive Analysis of Molecular Bases, Predictive Biomarkers, Diagnostic Methods, and Therapeutic Options

In inflammatory bowel diseases (IBDs), such as Crohn's disease (CD) and ulcerative colitis (UC), the immune system relentlessly attacks intestinal cells, causing recurrent tissue damage over the lifetime of patients. The etiology of IBD is complex and multifactorial, involving environmental, microbiota, genetic, and immunological factors that alter the molecular basis of the organism. Among these, the microbiota and immune cells play pivotal roles; the microbiota generates antigens recognized by immune cells and antibodies, while autoantibodies target and attack the intestinal membrane, exacerbating inflammation and tissue damage. Given the altered molecular framework, the analysis of multiple molecular biomarkers in patients proves exceedingly valuable for diagnosing and prognosing IBD, including markers like C reactive protein and fecal calprotectin. Upon detection and classification of patients, specific treatments are administered, ranging from conventional drugs to new biological therapies, such as antibodies to neutralize inflammatory molecules like tumor necrosis factor (TNF) and integrin. This review delves into the molecular basis and targets, biomarkers, treatment options, monitoring techniques, and, ultimately, current challenges in IBD management.

Impact of sex and socioeconomic status on the likelihood of surgery, hospitalization, and use of medications in inflammatory bowel disease: a systematic review and meta-analysis

BACKGROUND

Inflammatory bowel diseases (IBDs) are associated with high healthcare utilization. This systematic review aimed to summarize what is known about the impact of sex, income, and education on the likelihood of bowel surgery, hospitalization, and use of corticosteroids and biologics among patients with IBD.

METHODS

We used EMBASE, MEDLINE, CINAHL, and Web of Science to perform a systematic literature search. Pooled hazard ratios (HRs) and odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using random effects meta-analysis for the impact of sex on the likelihood of surgery and hospitalization. In addition, we performed subgroup analyses of the effect of IBD type (Crohn's disease or ulcerative colitis) and age. Finally, meta-regression was undertaken for the year of publication.

RESULTS

In total, 67 studies were included, of which 23 studies were eligible for meta-analysis. In the main meta-analysis, male sex was associated with an increased likelihood of bowel surgery (HR 1.42 (95% CI 1.13;1.78), which was consistent with the subgroup analysis for UC only (HR 1.78, 95% CI 1.16; 2.72). Sex did not impact the likelihood of hospitalization (OR 1.05 (95% CI 0.86;1.30), although the subgroup analysis revealed an increased likelihood of hospitalization in CD patients (OR 1.42, 95% CI 1.28;1.58). In 9 of 10 studies, no significant sex-based differences in the use of biologics were reported, although in 6 of 6 studies, female patients had lower adherence to biologics. In 11 of 13 studies, no significant sex-based difference in the use of corticosteroids was reported. The evidence of the impact of income and education on healthcare utilization was sparse and pointed in different directions. The substantial heterogeneity between studies was explained, in part, by differences in IBD type and age.

CONCLUSIONS

The results of this systematic review indicate that male patients with IBD are significantly more likely to have surgery than female patients with IBD but are not, overall, more likely to be hospitalized, whereas female patients appear to have statistically significantly lower adherence to biologics compared to male patients. Thus, clinicians should not underestimate the impact of sex on healthcare utilization. Evidence for income- and education-based differences remains sparse.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42022315788.

Comparing the efficacy of vedolizumab between males and females: a post-hoc analysis of GEMINI-1 and VARSITY

Vedolizumab is a first-line treatment option for ulcerative colitis. There are differences in incidence of ulcerative colitis between males and females, but whether sex affects treatment outcomes is less clear. We examined sex-based differences in patients with ulcerative colitis initiated on vedolizumab from two major randomized controlled trials (RCTs). We conducted a post-hoc analysis on participants with ulcerative colitis from the VARSITY and GEMINI-1 RCTs who received vedolizumab. Outcomes of interest were rates of clinical improvement, clinical remission, and endoscopic improvement at weeks 6, 14, and 52 in male and female participants, as were differences in concentrations of trough vedolizumab and C-reactive protein; 1009 persons in GEMINI-1 and VARSITY trials were included. Male and female patients had similar disease characteristics aside from males being more likely to have Mayo 3 grade endoscopic severity at baseline (62.8 vs. 48.9%, P  < 0.001). At week 6, females were more likely to have endoscopic improvement (47.4 vs. 35.2%, P  = 0.001) and increased vedolizumab trough levels [34.0 (23.0-44.5) vs. 28.9 (19.0-34.6), P  < 0.001]. The probability of achieving clinical remission (28.9 vs. 34.5%, P  = 0.057) or endoscopic improvement (35.5 vs. 39.3%, P  = 0.212) at week 52 was not different between males and females. Females with ulcerative colitis treated with vedolizumab appear more likely to achieve early endoscopic improvement than males, though longer-term outcomes demonstrated no difference. Further studies are required to better understand mechanisms through which sex or sex-associated factors could influence response to therapy in ulcerative colitis.

The sex of organ geometry

Organs have a distinctive yet often overlooked spatial arrangement in the body1-5. We propose that there is a logic to the shape of an organ and its proximity to its neighbours. Here, by using volumetric scans of many Drosophila melanogaster flies, we develop methods to quantify three-dimensional features of organ shape, position and interindividual variability. We find that both the shapes of organs and their relative arrangement are consistent yet differ between the sexes, and identify unexpected interorgan adjacencies and left-right organ asymmetries. Focusing on the intestine, which traverses the entire body, we investigate how sex differences in three-dimensional organ geometry arise. The configuration of the adult intestine is only partially determined by physical constraints imposed by adjacent organs; its sex-specific shape is actively maintained by mechanochemical crosstalk between gut muscles and vascular-like trachea. Indeed, sex-biased expression of a muscle-derived fibroblast growth factor-like ligand renders trachea sexually dimorphic. In turn, tracheal branches hold gut loops together into a male or female shape, with physiological consequences. Interorgan geometry represents a previously unrecognized level of biological complexity which might enable or confine communication across organs and could help explain sex or species differences in organ function.

Sex-Related Differences in the Phenotype and Course of Inflammatory Bowel Disease: SEXEII Study of ENEIDA

BACKGROUND & AIMS

The impact of patient sex on the presentation of inflammatory bowel disease (IBD) has been poorly evaluated. Our aims were to assess potential disparities in IBD phenotype and progression between sexes.

METHODS

We performed an observational multicenter study that included patients with Crohn's disease (CD) or ulcerative colitis from the Spanish Estudio Nacional en Enfermedad Inflamatoria intestinal sobre Determinantes genéticos y Ambientales registry. Data extraction was conducted in July 2021.

RESULTS

A total of 51,595 patients with IBD were included, 52% were males and 25,947 had CD. The median follow-up period after diagnosis was 9 years in males and 10 years in females. In CD, female sex was an independent risk factor for medium disease onset (age, 17-40 y) (relative risk ratio, 1.45; 95% CI, 1.31-1.62), later disease onset (age, >40 y) (relative risk ratio, 1.55; 95% CI, 1.38-1.73), exclusive colonic involvement (odds ratio, 1.24; 95% CI, 1.14-1.34), inflammatory behavior (odds ratio, 1.14; 95% CI, 1.07-1.21), and extraintestinal manifestations (odds ratio, 1.48; 95% CI, 1.38-1.59). However, female sex was a protective factor for upper gastrointestinal involvement (odds ratio, 0.84; 95% CI, 0.79-0.90), penetrating behavior (odds ratio, 0.76; 95% CI, 0.70-0.82), perianal disease (odds ratio, 0.77; 95% CI, 0.71-0.82), and complications (odds ratio, 0.73; 95% CI, 0.66-0.80). In ulcerative colitis, female sex was an independent risk factor for extraintestinal manifestations (odds ratio, 1.48; 95% CI, 1.26-1.61). However, female sex was an independent protective factor for disease onset from age 40 onward (relative risk ratio, 0.76; 95% CI, 0.66-0.87), left-sided colonic involvement (relative risk ratio, 0.72; 95% CI, 0.67-0.78), extensive colonic involvement (relative risk ratio, 0.59; 95% CI, 0.55-0.64), and abdominal surgery (odds ratio, 0.78; 95% CI, 0.69-0.88).

CONCLUSIONS

There is sexual dimorphism in IBD. The patient's sex should be taken into account in the clinical management of the disease.

Appropriate Preconception Corticosteroid-Free Remission Period in Pregnant Women With Ulcerative Colitis

BACKGROUND

In women with inflammatory bowel disease, at least 3 months of preconception corticosteroid-free remission (CFREM) is recommended by experts in current consensus statements. However, data are lacking on the appropriate preconception remission period. We investigated the appropriate preconception CFREM period in women with ulcerative colitis to reduce maternal disease activity and adverse pregnancy outcomes (ie, preterm birth, low birth weight, and small for gestational age).

METHODS

We retrospectively examined 141 pregnancies in women with ulcerative colitis at 2 institutions. We categorized the patients into 3 subgroups by their preconception CFREM period (≥3 months, >0 to <3 months, and non-CFREM). We also investigated disease activity during pregnancy and postpartum and adverse pregnancy outcomes in each group.

RESULTS

During pregnancy, the rate of active disease was significantly lower in the ≥3 months and >0 to <3 months CFREM groups compared with that in the non-CFREM group (P < .001 and P = .0257, respectively). Postpartum, the rate of active disease was significantly lower in the ≥3 months CFREM group compared with that in the non-CFREM group (P = .0087). The preconception CFREM period of ≥3 months was an independent inhibitory factor for active disease during pregnancy and postpartum (adjusted odds ratio, 0.15; P = .0035; and adjusted odds ratio, 0.33; P = .027, respectively). Adverse pregnancy outcomes were less common in the >3 months CFREM group compared with those in the other groups, but this difference was not significant.

CONCLUSIONS

A preconception CFREM period of more than 3 months may be appropriate for better maternal and adverse pregnancy outcomes, as recommended in consensus statements.

Estimated Glomerular Filtration Rate and the Risk of Inflammatory Bowel Disease in Adults: A Swedish Population-Based Study

BACKGROUND

Kidney complications are common in patients with long-standing inflammatory bowel disease (IBD). Whether kidney complications, defined as low estimated glomerular filtration rate (eGFR), may predispose to later IBD is unknown.

METHODS

We analyzed the association between eGFR and the risk of being subsequently diagnosed with IBD among 1 612 160 adults from Stockholm. The exposure was categories of eGFR, with 90 to 104 mL/min/1.73 m2 as the reference. Cox regression models were used to investigate the association between eGFR, IBD, and IBD subtypes. Subgroup analyses included age strata, sex, education, and comorbidities. To explore the possibility of detection bias or reverse causation, we estimated IBD hazard ratios (HRs) after excluding cases and individuals censored during early years of follow-up.

RESULTS

During a median of 9 years of follow-up, we detected 9663 cases of IBD (3299 Crohn's disease, 5072 ulcerative colitis, 1292 IBD unclassified). Lower eGFR levels were associated with higher IBD risk (for eGFR 30-59 mL/min/1.73 m2: adjusted HR, 1.15; 95% confidence interval [CI], 1.01-1.33; and for eGFR <30 mL/min/1.73 m2: adjusted HR, 1.65; 95% CI, 1.16-2.37). This association was stronger in magnitude for Crohn's disease (for eGFR 30-59 mL/min/1.73 m2: HR, 1.33, 95% CI, 1.04-1.72; and for eGFR <30 mL/min/1.73 m2: HR, 2.25; 95% CI, 1.26-3.99). Results were consistent across strata of age, comorbidities, and attained education but suggested the association between eGFR and IBD to be stronger in women (P for interaction <.05). Results attenuated but were robust to exclusion of early IBD cases.

CONCLUSIONS

We observed an association between reduced eGFR and the risk of developing IBD, which was stronger in magnitude for Crohn's disease.

Forecasting the future prevalence of inflammatory bowel disease in Korea through 2048: an epidemiologic study employing autoregressive integrated moving average models

BACKGROUND AND AIM

The global inflammatory bowel disease (IBD) escalation has precipitated an increased disease burden and economic impact, particularly in Asia. This study primarily aimed to predict the future prevalence of IBD in Korea and elucidate its evolution pattern.

METHODS

Using a validated diagnostic algorithm, we analyzed data from the Korean National Health Insurance Service between 2004 and 2017 to identify patients with IBD. We predicted the number and prevalence of patients with IBD from 2018 to 2048 with the autoregressive integrated moving average method. A generalized linear model (GLM) was also employed to identify factors contributing to the observed trend in IBD prevalence.

RESULTS

Our prediction model validation demonstrated an acceptable error range for IBD prevalence, with a 2.45% error rate and a mean absolute difference of 2.61. We foresee a sustained average annual increase of 4.51 IBD cases per 100 000, culminating in a prevalence of 239.73 per 100 000 by 2048. The forecasted average annual percent change was 6.17% for males and 2.75% for females over the next 30 years. The GLM analysis revealed that age, gender and time significantly impact the prevalence of IBD, with notable disparities observed between genders in specific age groups for both Crohn's disease and ulcerative colitis (all interaction P < 0.05).

CONCLUSIONS

Our study forecasts a notable increase in Korean IBD prevalence by 2048, particularly among males and the 20-39 age group, highlighting the need to focus on these high-risk groups to mitigate the future disease burden.

Fmo5 plays a sex-specific role in goblet cell maturation and mucus barrier formation

The intestine plays a key role in metabolism, nutrient and water absorption, and provides both physical and immunological defense against dietary and luminal antigens. The protective mucus lining in the intestine is a critical component of intestinal barrier function that when compromised, can lead to dysfunctional intestinal barriers that are a defining characteristic of inflammatory bowel disease (IBD), among other intestinal diseases. Here, we define a new role for the flavin-containing monooxygenase family of enzymes in maintaining a healthy intestinal epithelium. In nematodes, we find that Cefmo-2 is necessary and sufficient for proper intestinal barrier function, intestinal actin expression, and is induced by intestinal damage. In mice, we utilize an intestine-specific, inducible knockout model of the prevalent gut Fmo (Fmo5) and find striking phenotypes within two weeks of knockout. These phenotypes include sex-dependent changes in colon epithelial histology, goblet cell localization and maturation factors, and mucus barrier formation. Each of these changes are significantly more severe in female mice, plausibly mirroring differences observed in some types of IBD in humans. Looking further at these phenotypes, we find increased protein folding stress in Fmo5 knockout animals and successfully rescue the severe female phenotype with addition of a chemical ER chaperone. Together, our results identify a new role for Fmo5 in the mammalian intestine and support a key role for Fmo5 in maintenance of ER/protein homeostasis and proper mucus barrier formation.

Associations between sex hormones, receptors, binding proteins and inflammatory bowel disease: a Mendelian randomization study

Background

Gender differences existed in inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC). Observational studies have revealed associations between sex hormones and IBD, such as estrogen and testosterone. However, the exact relationship between these sex hormones and IBD is unclear.

Method

Based on the genome-wide association studies data of eight sex hormones, two sex hormone receptors, sex hormone-binding globulin (SHBG), total IBD and its two subtypes, we performed a two-sample Mendelian randomization (MR) study to analyze their mutual relationship. For estradiol (E2), progesterone (PROG), bioavailable testosterone (BAT), total testosterone (TT) and SHBG, sex-stratified MR analyses were also performed. Inverse variance weighted method, MR-Egger regression and Weighted median method were used for causal analyses. Sensitivity analyses were conducted to test the stability of causal relationships. Besides, a reverse MR analysis was performed to estimate the reverse causation.

Results

E2 (P=0.028) and TT (P=0.034) had protective effects on CD. Sex-stratified analyses revealed protective roles of E2 in males on total IBD (P=0.038) and CD (P=0.020). TT in females had protective effects on total IBD (P=0.025) and CD (P=0.029), and BAT in females decreased the risk of developing CD (P=0.047) and UC (P=0.036). Moreover, SHBG in males was also associated with a decreased risk of CD (P=0.021). The reversed MR analysis showed that CD was negatively correlated with estrogen receptor (P=0.046). UC was negatively correlated with PROG in females (P=0.015) and positively correlated with SHBG levels in males (P=0.046).

Conclusion

Findings of this study revealed the mutual causal associations between sex hormones and the risk of developing IBD.

Sex differences in CD8+ T cell responses during adaptive immunity

Biological sex is an important variable that influences the immune system's susceptibility to infectious and non-infectious diseases and their outcomes. Sex dimorphic features in innate and adaptive immune cells and their activities may help to explain sex differences in immune responses. T lymphocytes in the adaptive immune system are essential to providing protection against infectious and chronic inflammatory diseases. In this review, T cell responses are discussed with focus on the current knowledge of biological sex differences in CD8+ T cell mediated adaptive immune responses in infectious and chronic inflammatory diseases. Future directions aimed at investigating the molecular and cellular mechanisms underlying sex differences in diverse T cell responses will continue to underscore the significance of understanding sex differences in protective immunity at the cellular level, to induce appropriate T cell-based immune responses in infection, autoimmunity, and cancer. This article is categorized under: Immune System Diseases > Molecular and Cellular Physiology Infectious Diseases > Molecular and Cellular Physiology.

Associations Between ABO Blood Groups and Diseases in the Digestive System and Vein

Purpose

The ABO blood type system is crucial for human blood transfusions. However, the relationships between ABO blood groups and diseases in the digestive system and vein have not been elucidated. We investigated the relationships between ABO blood groups and diseases in the digestive system and vein in this study.

Patients and Methods

A retrospective study on a Chinese population, including 1432 Crohn's disease (CD), 416 ulcerative colitis (UC), 1140 stomach cancer (SC), 841 colorectal cancer (CRC), 384 pancreatic cancer (PC), 520 liver cancer (LC), and 563 venous thrombosis (VT) patients, was performed. Furthermore, 896 healthy subjects were enrolled as normal controls (NC) in this study. The demographic characteristics of patients and NC were compared using the unpaired t-test and χ2 test. Multivariate logistic regression model was used to evaluate the association between ABO blood groups and CD and VT.

Results

ABO blood groups distributions in UC, SC, CRC, PC, and LC patients did not differ from that of NC, but CD and VT patients had significant difference of ABO blood group distribution from that of NC (p = 0.015 and p = 0.002, respectively). Patients with CD and VT had considerably lower rates of type O blood (p = 0.011 and p = 0.001, respectively) and significantly higher rates of type AB blood (p = 0.013 and p = 0.022, respectively) than those with NC. Multivariate logistic regression analysis showed the association of CD and VT with non-O blood types was still significant with a higher risk than with blood group O after adjusting for age and gender (OR = 1.355, 95% CI = 1.100-1.670, p = 0.004 and OR = 1.465, 95% CI = 1.131-1.903, p = 0.004, respectively).

Conclusion

ABO blood groups distributions in CD and VT patients significantly differed from that of NC. Non-O blood group could be a new predictor for CD and VT.

Crohn's disease

Crohn's disease is a chronic inflammatory disease of the gastrointestinal tract that might lead to progressive bowel damage and disability. The exact cause of Crohn's disease is unknown, but evidence points towards multifactorial events causing dysregulation of the innate immune system in genetically susceptible people. Commonly affecting the terminal ileum and proximal colon, Crohn's disease inflammation is often discontinuous and patchy, segmental, and transmural. Identification of characteristic findings on ileocolonoscopy and histology remains the diagnostic gold standard, but complete assessment involves laboratory abnormalities, including micronutrient deficiencies, cross-sectional imaging to identify transmural disease extent, severity and complications, and a psychosocial assessment. Treatment strategies for patients with Crohn's disease now go beyond achieving clinical remission to include deeper targets of endoscopic healing and consideration of adjunctive histological and transmural targets to alter disease progression potentially further. The use of early effective advanced therapies and development of therapies targeting alternative novel pathways with improved safety profiles have resulted in a new era of healing in Crohn's disease management. Future combination of advanced therapies with diet or other biological drugs and small molecules, together with improvements in tight control monitoring tools and predictive biomarkers might continue to improve outcomes for patients with Crohn's disease.

Multidrug resistance Gene-1 polymorphisms (C3435T and G2677T) and the risk of inflammatory bowel disease in Egyptian patients

BACKGROUND AND STUDY AIMS

The multidrug resistance 1 (MDR1) gene is a gene involved in the pathogenesis of inflammatory bowel disease (IBD).The aim of the study is to investigate the association of MDR-1 gene polymorphisms (C2345T and G2677T) and IBD incidence in Egyptian patients, and its relation with disease severity.

PATIENTS AND METHODS

This is a case-control study where genotyping of MDR-1 gene C3435T and G2677T single nucleotide polymorphisms (SNPs) were assayed.

RESULTS

Forty naïve IBD patients, who were composed of 25 UC and 15CD, were compared to 60 healthy controls. They were young aged with significant female predominance, particularly in CD (P = 0.004). UC was mainly (48 %) presented in moderate severity while CD was mainly (53.3 %) presented with mild severity. MDR-1 gene C3435T SNP was not statistically related to IBD, whether in terms of genotypes or alleles, yet its T allele was significantly related to moderate cases of UC (P = 0.014). However, GG genotype of G2677T SNP was significantly low in IBD (P = 0.013), while TT genotype and T allele were significantly related to CD (P = 0.011, and 0.012 respectively). Moreover, G allele proved to be associated significantly with moderate cases of UC (P = 0.001) and mild cases of CD (P = 0.002).

CONCLUSIONS

MDR-I gene G2677T SNP GG genotype proved to be protective against IBD, thus may be considered in diagnostic workup of IBD including its severity.

Global evolving patterns and cross-country inequalities of inflammatory bowel disease burden from 1990 to 2019: a worldwide report

AIMS

Inflammatory bowel disease (IBD) is a global disease. We aim to summarize the latest epidemiological patterns of IBD at the national, regional and global levels to give well-deserved attention and outline facilitating measures to reduce the disease burden.

METHODS

We collected the incidence, prevalence, mortality and disability-adjusted life years (DALYs) of IBD in 204 countries and territories from 1990 to 2019 using data from the Global Burden of Disease Study 2019. We further calculated the estimated annual percentage change (EAPC) to qualify the temporal trends of IBD burden by sex, age and region over the past 30 years.

RESULTS

Globally, a total of 404.55 thousand incident cases, 4898.56 thousand prevalent cases, 41.00 thousand deaths and 1622.50 thousand DALYs of IBD were estimated in 2019. The age-standardized DALYs decreased from 27.2 in 1990 to 20.15 per 100,000 people in 2019, with an EAPC of -1.04. The high socio-demographic index regions presented pronounced age-standardized rates (ASRs) consistently over the last 30 years. The high-income North America had the highest ASRs in 2019, followed by Western Europe and Australasia. No gender difference was observed after being stratified by sex.

CONCLUSIONS

The accumulated IBD patients are expected to increase in the future due to the increased rate of IBD in developing countries, and social aging in developed countries. Understanding the changes in epidemiological patterns helps to provide evidence to mitigate the rising burden of IBD.

Sex-Based Differences in IBD Surgical Outcomes

BACKGROUND

Although there are discrepancies in the development and progression of IBD based on biologic sex, little is known about differences in postoperative outcomes between men and women undergoing surgery for this condition.

OBJECTIVE

To compare rates of anastomotic leaks, wound complications, and serious adverse events between men and women undergoing surgery for IBD.

DESIGN

This was a retrospective cohort study.

SETTINGS

Data were obtained from the American College of Surgeons National Surgical Quality Improvement Program IBD Collaborative database, which includes 15 high-volume IBD surgery centers.

PATIENTS

All adult patients undergoing surgery for IBD were included. Participants with missing data for exposure or outcome variables were excluded.

MAIN OUTCOME MEASURES

Rates of anastomotic leaks, wound complications, and serious adverse events were compared between women and men.

RESULTS

A total of 3143 patients were included. There was a significant association between sex and BMI, IBD type, and preoperative medication use. Women had decreased odds of serious adverse events compared to men (OR 0.73; 95% CI, 0.55-0.96), but there was no significant association between sex and anastomotic leaks or wound complications. IBD type was found to be an effect measure modifier of the relationship between sex and serious adverse events. Among patients with ulcerative colitis, women had a 54% decrease in the odds of serious adverse events compared to men, whereas there was no significant difference between women and men with Crohn's disease.

LIMITATIONS

This study was limited by capturing only 30 days of postoperative outcomes.

CONCLUSIONS

Women undergoing surgery for ulcerative colitis had decreased odds of serious adverse events compared to men. Understanding sex-based differences in outcomes allows clinicians to make patient-centered decisions regarding surgical planning and perioperative management for patients with IBD. See Video Abstract .

DIFERENCIAS BASADAS EN EL SEXO EN LOS RESULTADOS QUIRRGICOS DE LA ENFERMEDAD INFLAMATORIA INTESTINAL

ANTECEDENTES:Aunque existen discrepancias en el desarrollo y la progresión de la enfermedad inflamatoria intestinal según el sexo biológico, se sabe poco sobre las diferencias en los resultados postoperatorios entre hombres y mujeres sometidos a cirugía por esta afección.OBJETIVO:Nuestro objetivo fue comparar las tasas de fugas anastomóticas, complicaciones de las heridas y eventos adversos graves entre hombres y mujeres sometidos a cirugía por enfermedad inflamatoria intestinal.DISEÑO:Este fue un estudio de cohorte retrospectivo.AJUSTES:Los datos se obtuvieron de la base de datos del Programa Nacional de Mejora de la Calidad Quirúrgica del Colegio Americano de Cirujanos para la Enfermedad Inflamatoria Intestinal, que incluye 15 centros de cirugía de enfermedad inflamatoria intestinal de alto volumen.PACIENTES:Se incluyeron todos los pacientes adultos sometidos a cirugía por enfermedad inflamatoria intestinal. Se excluyeron los sujetos a los que les faltaban datos sobre exposición o variables de resultado.PRINCIPALES MEDIDAS DE RESULTADO:Se compararon las tasas de fugas anastomóticas, complicaciones de las heridas y eventos adversos graves entre mujeres y hombres.RESULTADOS:Se incluyeron un total de 3.143 pacientes. Hubo una asociación significativa entre el sexo y el índice de masa corporal, el tipo de enfermedad inflamatoria intestinal y el uso de medicación preoperatoria. Las mujeres tuvieron menores probabilidades de sufrir eventos adversos graves en comparación con los hombres (OR = 0,73; IC del 95 %: 0,55 a 0,96), pero no hubo una relacion significativa entre el sexo y las fugas anastomóticas o las complicaciones de las heridas. Se encontró que el tipo de enfermedad inflamatoria intestinal era un modificador de la medida del efecto de la relación entre el sexo y los eventos adversos graves. Entre los pacientes con colitis ulcerosa, las mujeres tuvieron una disminución del 54 % en las probabilidades de sufrir eventos adversos graves en comparación con los hombres, mientras que no hubo diferencias significativas entre mujeres y hombres con enfermedad de Crohn.LIMITACIONES:Este estudio estuvo limitado al capturar solo 30 días de resultados posoperatorios.CONCLUSIONES:Las mujeres sometidas a cirugía por colitis ulcerosa tuvieron menores probabilidades de sufrir eventos adversos graves en comparación con los hombres. Comprender las diferencias en los resultados basadas en el sexo permite a los médicos tomar decisiones centradas en el paciente con respecto a la planificación quirúrgica y el manejo perioperatorio de los pacientes con enfermedad inflamatoria intestinal. (Traducción-Dr Yolanda Colorado).

Chronic Stress Exposure Alters the Gut Barrier: Sex-Specific Effects on Microbiota and Jejunum Tight Junctions

Background

Major depressive disorder (MDD) is the leading cause of disability worldwide. Of individuals with MDD, 30% to 50% are unresponsive to common antidepressants, highlighting untapped causal biological mechanisms. Dysfunction in the microbiota-gut-brain axis has been implicated in MDD pathogenesis. Exposure to chronic stress disrupts blood-brain barrier integrity; still, little is known about intestinal barrier function in these conditions, particularly for the small intestine, where absorption of most foods and drugs takes place.

Methods

We investigated how chronic social or variable stress, two mouse models of depression, impact the jejunum intestinal barrier in males and females. Mice were subjected to stress paradigms followed by analysis of gene expression profiles of intestinal barrier-related targets, fecal microbial composition, and blood-based markers.

Results

Altered microbial populations and changes in gene expression of jejunum tight junctions were observed depending on the type and duration of stress, with sex-specific effects. We used machine learning to characterize in detail morphological tight junction properties, identifying a cluster of ruffled junctions in stressed animals. Junctional ruffling is associated with inflammation, so we evaluated whether lipopolysaccharide injection recapitulates stress-induced changes in the jejunum and observed profound sex differences. Finally, lipopolysaccharide-binding protein, a marker of gut barrier leakiness, was associated with stress vulnerability in mice, and translational value was confirmed on blood samples from women with MDD.

Conclusions

Our results provide evidence that chronic stress disrupts intestinal barrier homeostasis in conjunction with the manifestation of depressive-like behaviors in a sex-specific manner in mice and, possibly, in human depression.

3D Printed Personalized Colon-targeted Tablets: A Novel Approach in Ulcerative Colitis Management

Ulcerative colitis (UC) and Crohn's disease (CD) are two types of idiopathic inflammatory bowel disease (IBD) that are increasing in frequency and incidence worldwide, particularly in highly industrialized countries. Conventional tablets struggle to effectively deliver anti-inflammatory drugs since the inflammation is localized in different areas of the colon in each patient. The goal of 3D printing technology in pharmaceutics is to create personalized drug delivery systems (DDS) that are tailored to each individual's specific needs. This review provides an overview of existing 3D printing processes, with a focus on extrusion-based technologies, which have received the most attention. Personalized pharmaceutical products offer numerous benefits to patients worldwide, and 3D printing technology is becoming more affordable every day. Custom manufacturing of 3D printed tablets provides innovative ideas for developing a tailored colon DDS. In the future, 3D printing could be used to manufacture personalized tablets for UC patients based on the location of inflammation in the colon, resulting in improved therapeutic outcomes and a better quality of life.

Global burden of inflammatory bowel disease 1990-2019: A systematic examination of the disease burden and twenty-year forecast

BACKGROUND

Inflammatory bowel disease (IBD) is an idiopathic intestinal disease with various levels and trends in different countries and regions. Understanding the current burden and trends of IBD in various geographical locations is essential to establish effective strategies for prevention and treatment. We report the average annual percentage change (AAPC) and estimated annual percentage change (EAPC) in age-standardized rates (ASR) of IBD in different regions based on the Global Burden of Disease (GBD) study from 1990-2019, and the relationships between IBD and the human development index (HDI) and socio-demographic index (SDI). The prevalence trends of IBD were predicted by gender from 2019-2039.

AIM

To comprehensively investigate IBD data, providing further insights into the management of this chronic disease.

METHODS

We collected the information on the incidence of IBD from the GBD study from 1990-2019 to calculate the AAPC and EAPC in ASR of IBD in different regions. The relationships between IBD, HDI, and SDI were analyzed. The Nordpred and Bayesian age-period-cohort models were used to predict the prevalence trends of IBD by gender from 2019-2039, and the reliability of the results was validated. Statistics of all the data in this study were performed using R software (version 4.2.1).

RESULTS

North America consistently had the highest IBD ASR, while Oceania consistently had the lowest. East Asia had the fastest average annual growth in ASR (2.54%), whereas Central Europe had the fastest decline (1.38%). Countries with a low age-standardized incidence rates in 1990 showed faster growth in IBD while there was no significant correlation in 2019. Additionally, IBD increased faster in countries with a low age-standardized death rates in 1990, whereas the opposite was true in 2019. Analysis of SDI and IBD ASR showed that countries with a high SDI generally had a higher IBD ASR. Finally, the projections showed a declining trend in the incidence of IBD from 2019-2039, but a gradual increase in the number of cases.

CONCLUSION

As the global population increases and ages, early monitoring and prevention of IBD is important to reduce the disease burden, especially in countries with a high incidence of IBD.

Global burden of inflammatory bowel disease 1990-2019: A systematic examination of the disease burden and twenty-year forecast

BACKGROUND

Inflammatory bowel disease (IBD) is an idiopathic intestinal disease with various levels and trends in different countries and regions. Understanding the current burden and trends of IBD in various geographical locations is essential to establish effective strategies for prevention and treatment. We report the average annual percentage change (AAPC) and estimated annual percentage change (EAPC) in age-standardized rates (ASR) of IBD in different regions based on the Global Burden of Disease (GBD) study from 1990-2019, and the relationships between IBD and the human development index (HDI) and socio-demographic index (SDI). The prevalence trends of IBD were predicted by gender from 2019-2039.

AIM

To comprehensively investigate IBD data, providing further insights into the management of this chronic disease.

METHODS

We collected the information on the incidence of IBD from the GBD study from 1990-2019 to calculate the AAPC and EAPC in ASR of IBD in different regions. The relationships between IBD, HDI, and SDI were analyzed. The Nordpred and Bayesian age-period-cohort models were used to predict the prevalence trends of IBD by gender from 2019-2039, and the reliability of the results was validated. Statistics of all the data in this study were performed using R software (version 4.2.1).

RESULTS

North America consistently had the highest IBD ASR, while Oceania consistently had the lowest. East Asia had the fastest average annual growth in ASR (2.54%), whereas Central Europe had the fastest decline (1.38%). Countries with a low age-standardized incidence rates in 1990 showed faster growth in IBD while there was no significant correlation in 2019. Additionally, IBD increased faster in countries with a low age-standardized death rates in 1990, whereas the opposite was true in 2019. Analysis of SDI and IBD ASR showed that countries with a high SDI generally had a higher IBD ASR. Finally, the projections showed a declining trend in the incidence of IBD from 2019-2039, but a gradual increase in the number of cases.

CONCLUSION

As the global population increases and ages, early monitoring and prevention of IBD is important to reduce the disease burden, especially in countries with a high incidence of IBD.

Sex-oriented perspectives in immunopharmacology

Several immunopharmacological agents are effective in the treatment of cancer and immune-mediated conditions, with a favorable impact on life expectancy and clinical outcomes for a large number of patients. Nevertheless, response variation and undesirable effects of these drugs represent major issues, and overall efficacy remains unpredictable. Males and females show a distinct difference in immune system responses, with females generally mounting stronger responses to a variety of stimuli. Therefore, exploring sex differences in the efficacy and safety of immunopharmacological agents would strengthen the practice of precision medicine. As a pharmacological target highlight, programmed cell death 1 ligand 1 (PD-L1) is the first functionally characterized ligand of the coinhibitory programmed death receptor 1 (PD-1). The PD-L1/PD-1 crosstalk plays an important role in the immune response and is relevant in cancer, infectious and autoimmune disease. Sex differences in the response to immune checkpoint inhibitors are well documented, with male patients responding better than female patients. Similarly, higher efficacy of and adherence to tumor necrosis factor inhibitors in chronic inflammatory conditions including rheumatoid arthritis and Crohn's disease have been reported in male patients. The pharmacological basis of sex-specific responses to immune system modulating drugs is actively investigated in other settings such as stroke and type 1 diabetes. Advances in therapeutics targeting the endothelium could soon be wielded against autoimmunity and metabolic disorders. Based on the established sexual dimorphism in immune-related pathophysiology and disease presentation, sex-specific immunopharmacological protocols should be integrated into clinical guidelines.

Sex-Dimorphic Analyses Identify Novel and Sex-Specific Genetic Associations in Inflammatory Bowel Disease

BACKGROUND

Sex is an integral variable often overlooked in complex disease genetics. Differences between sexes have been reported in natural history, disease complications, and age of onset in inflammatory bowel disease (IBD). While association studies have identified >230 IBD loci, there have been a limited number of studies investigating sex differences underlying these genetic associations.

METHODS

We report the first investigation of sex-dimorphic associations via meta-analysis of a sex-stratified association study (34 579 IBD cases, 39 125 controls). In addition, we performed chromosome (chr) X-specific analyses, considering models of X inactivation (XCI) and XCI escape. Demographic and clinical characteristics were also compared between sexes.

RESULTS

We identified significant differences between sexes for disease location and perianal complication in Crohn's disease and disease extent in ulcerative colitis. We observed genome-wide-significant sex-dimorphic associations (P < 5 × 10-8) at loci not previously reported in large-scale IBD genetic studies, including at chr9q22, CARMIL1, and UBASH3A. We identified variants in known IBD loci, including in chr2p15 and within the major histocompatibility complex on chr6, exhibiting sex-specific patterns of association (P < 5 × 10-7 in one sex only). We identified 3 chrX associations with IBD, including a novel Crohn's disease susceptibility locus at Xp22.

CONCLUSIONS

These analyses identified novel IBD loci, in addition to characterizing sex-specific patterns of associations underlying sex-dimorphic associations. By elucidating the role of sex in IBD genetics, our study will help enhance our understanding of the differences between the sexes in IBD biology and underscores a need to move beyond conventional sex-combined analyses to appreciate the genetic architecture of IBD more comprehensively.

Clinical and magnetic resonance imaging spectrum of complex perianal fistulizing Crohn's disease: A cohort study from northern India

BACKGROUND

Fistulizing perianal Crohn's disease (CD) is a debilitating condition associated with significant morbidity and reduction in the quality of life. Magnetic resonance imaging (MRI) of the pelvis is the preferred imaging modality for the comprehensive assessment of the perianal fistula. There is a paucity of data from India on the MRI spectrum of complex perianal fistula in CD.

METHODS

A single-centre cross-sectional analysis of patients with fistulizing perianal CD, who underwent pelvic MRI between January 2020 and December 2021, was performed. The clinical (age, sex, disease duration, disease location and behavior, disease activity [Perianal Disease Activity Index, PDAI] and treatment received) and radiological (number and location of fistulae, extensions, number and location of internal and external openings, fistula activity, presence or absence of perianal abscess and associated proctitis) characteristics of complex perianal fistula (defined according to the American Gastroenterological Association classification) were recorded.

RESULTS

Of total 175 patients with CD who attended the gastroenterology clinic during the study period, 27 (15.42%) (mean age 42±15.5 years, 62.96% females and median disease duration four years) had complex perianal fistula and were included in the analysis. The mean PDAI was 5.48±2.53. The median Van Assche Index was 17 (interquartile range [IQR] 13-19). A majority (96.29%) of the fistulae were trans-sphincteric and four (14.81%) fistulae extended into the supralevator space. All fistulae were active on MRI. Concomitant perianal abscess and proctitis were seen in 59.26% (n=16) and 62.96% (n=17) of patients, respectively. Combination therapy with biologics and antibiotics/immune-suppressants were the most commonly prescribed medical therapy. Six (22.22%) patients underwent combined medical and surgical (non-cutting seton, fistulectomy, fecal diversion) treatment.

CONCLUSION

The cumulative risk of the development of fistulizing perianal CD in a northern Indian cohort was similar to the western populations. Complex perianal fistulae were predominantly trans-sphincteric and commoner in females. MRI evaluation is pivotal for the delineation of fistula anatomy, assessment of disease extent and activity and the evaluation of concomitant perianal abscess and other complications.

The 2023 Impact of Inflammatory Bowel Disease in Canada: The Influence of Sex and Gender on Canadians Living With Inflammatory Bowel Disease

Sex (the physical and physiologic effects resulting from having specific combinations of sex chromosomes) and gender (sex-associated behaviours, expectations, identities, and roles) significantly affect the course of inflammatory bowel disease (IBD) and the experience of living with IBD. Sex-influenced physiologic states, like puberty, the menstrual cycle, pregnancy, and andropause/menopause may also impact and be impacted by IBD. While neither Crohn's disease nor ulcerative colitis is commonly considered sex-determined illnesses, the relative incidence of Crohn's disease and ulcerative colitis between males and females varies over the life cycle. In terms of gender, women tend to use healthcare resources at slightly higher rates than men and are more likely to have fragmented care. Women are more commonly prescribed opioid medications and are less likely than men to undergo colectomy. Women tend to report lower quality of life and have higher indirect costs due to higher rates of disability. Women are also more likely to take on caregiver roles for children with IBD. Women with IBD are more commonly burdened with adverse mental health concerns and having poor mental health has a more profound impact on women than men. Pregnant people with active IBD have higher rates of adverse outcomes in pregnancy, made worse in regions with poor access to IBD specialist care. The majority of individuals with IBD in Canada do not have access to a pregnancy-in-IBD specialist; access to this type of care has been shown to allay fears and increase knowledge among pregnant people with IBD.

The 2023 Impact of Inflammatory Bowel Disease in Canada: Special Populations-Children and Adolescents with IBD

Rates of inflammatory bowel disease (IBD) in Canadian children and adolescents are among the highest in the world, and the incidence is rising most rapidly in children under five years of age. These young children may have either a typical form of IBD with multi-factorial aetiology, or they may have a monogenic form. Despite the growing number of children in Canada living with this important chronic disease, there are few available medical therapies approved by Health Canada due to the omission of children from most clinical trials of newly developed biologics. As a result, off-label use of medications is common, and physicians have learned to use existing therapies more effectively. In addition, most Canadian children are treated in multidisciplinary, specialty clinics by physicians with extra training or experience in IBD, as well as specialist nurses, dietitians, mental health care providers and other allied health professionals. This specialized clinic approach has facilitated cutting edge research, led by Canadian clinicians and scientists, to understand the causes of IBD, the optimal use of therapies, and the best ways to treat children from a biopsychosocial perspective. Canadians are engaged in work to understand the monogenic causes of IBD; the interaction between genes, the environment, and the microbiome; and how to address the mental health concerns and medical needs of adolescents and young adults transitioning from paediatric to adult care.

Depressive and Anxiety Disorders in Patients with Inflammatory Bowel Diseases: Are There Any Gender Differences?

Gender differences were identified in the frequency and clinical presentations of inflammatory bowel disease (IBD) and depressive and anxiety disorders, which are more common in IBD patients than in the general population. The present manuscript provides a critical overview of gender differences in the frequency and clinical course of mood and anxiety disorders in IBD patients, with the aim of helping clinicians provide individualized management for patients. All of the included studies found that IBD patients reported a higher frequency of depressive and anxiety disorders than the general population. These findings should encourage healthcare providers to employ validated tools to monitor the mental health of their IBD patients, such as the Patient Health Questionnaire (PHQ-9). In addition, most studies confirm that women with IBD are more likely than men to develop affective disorders and show that up to 65% of women with IBD have depressive and anxiety disorders. Women with IBD require close mental health monitoring and ultimately a multidisciplinary approach involving mental health professionals. Drug treatment in women should be individualized and medications that may affect mental health (e.g., corticosteroids) should be thoroughly reconsidered. Further data are needed to ensure individualized treatment for IBD patients in a framework of precision medicine.

Creeping Fat in Crohn's Disease-Surgical, Histological, and Radiological Approaches

During the course of Crohn's disease, the response of mesenteric adipose tissue to the production of inflammatory mediators and bacterial invasion through the intestinal mucosa results in the formation of creeping fat. Creeping fat describes the arresting finger-like projections that surround the inflamed bowel. In this review, the microscopic and macroscopic features of creeping fat and histological evidence for the importance of this tissue are discussed. Moreover, the most recent insights into the radiological assessment of creeping fat in patients with Crohn's disease are reported. Advances in imaging techniques have revolutionized the possibility of visualization and quantification of adipose tissue depots with excellent accuracy. Visceral fat has been significantly correlated with various Crohn's-disease-related outcomes. Despite the difficulties in distinguishing physiologic perienteric fat from creeping fat, the growing interest in fat-wrapping in Crohn's disease has rejuvenated radiologic research. With regard to the noninvasive fat-wrapping assessment, a novel CT enterography-based mesenteric creeping fat index has been developed for the mitigation of the confounding effect of normal retroperitoneal and perienteric adipose tissue. Research on machine learning algorithms and computational radiomics in conjunction with mechanistic studies may be the key for the elucidation of the complex role of creeping fat in Crohn's disease.

Vaccination Against Measles, Mumps, Rubella and Incident Inflammatory Bowel Disease in a National Cohort of Privately Insured Children

BACKGROUND

Infection is believed to be a potential trigger for inflammatory bowel disease (IBD). Whether vaccination against childhood infections including measles, mumps, and rubella may reduce risk of IBD is uncertain.

METHODS

We conducted a retrospective cohort study using de-identified claims data from a national private payer (Optum Clinformatics Data Mart). Eligible infants were born between 2001 and 2018 and were continuously enrolled with medical and pharmacy coverage from birth for at least 2 years (n = 1 365 447). Measles, mumps, and rubella vaccination or MMR is administered beginning at 12 months of age. Cox proportional hazard regression models were used to compare time with incident disease in children by category of vaccination, after adjustment for sex, birth year, region of country, history of allergy to vaccines, and seizure history.

RESULTS

The incidence of early pediatric IBD increased between 2001 and 2018. Ten percent (n = 141 230) of infants did not receive MMR, and 90% (n = 1 224 125) received at least 1 dose of MMR. There were 334 cases of IBD, 219 cases of Crohn's disease, and 164 cases of ulcerative colitis. Children who had received at least 1 dose of MMR had lower risk for IBD than children who did not (hazard ratio, 0.71; 95% confidence interval, 0.59-0.85). These associations did not change after further adjustment for childhood comorbid conditions, preterm birth, or older siblings affected with IBD. Similar associations were observed for MMR with Crohn's disease and ulcerative colitis, although these did not reach statistical significance.

CONCLUSION

MMR is associated with decreased risk for childhood IBD.

A Mendelian Randomization Analysis Investigates Causal Associations between Inflammatory Bowel Diseases and Variable Risk Factors

The question of whether variable risk factors and various nutrients are causally related to inflammatory bowel diseases (IBDs) has remained unanswered so far. Thus, this study investigated whether genetically predicted risk factors and nutrients play a function in the occurrence of inflammatory bowel diseases, including ulcerative colitis (UC), non-infective colitis (NIC), and Crohn's disease (CD), using Mendelian randomization (MR) analysis. Utilizing the data of genome-wide association studies (GWASs) with 37 exposure factors, we ran Mendelian randomization analyses based on up to 458,109 participants. Univariable and multivariable MR analyses were conducted to determine causal risk factors for IBD diseases. Genetic predisposition to smoking and appendectomy as well as vegetable and fruit intake, breastfeeding, n-3 PUFAs, n-6 PUFAs, vitamin D, total cholesterol, whole-body fat mass, and physical activity were related to the risk of UC (p < 0.05). The effect of lifestyle behaviors on UC was attenuated after correcting for appendectomy. Genetically driven smoking, alcohol consumption, appendectomy, tonsillectomy, blood calcium, tea intake, autoimmune diseases, type 2 diabetes, cesarean delivery, vitamin D deficiency, and antibiotic exposure increased the risk of CD (p < 0.05), while vegetable and fruit intake, breastfeeding, physical activity, blood zinc, and n-3 PUFAs decreased the risk of CD (p < 0.05). Appendectomy, antibiotics, physical activity, blood zinc, n-3 PUFAs, and vegetable fruit intake remained significant predictors in multivariable MR (p < 0.05). Besides smoking, breastfeeding, alcoholic drinks, vegetable and fruit intake, vitamin D, appendectomy, and n-3 PUFAs were associated with NIC (p < 0.05). Smoking, alcoholic drinks, vegetable and fruit intake, vitamin D, appendectomy, and n-3 PUFAs remained significant predictors in multivariable MR (p < 0.05). Our results provide new and comprehensive evidence demonstrating that there are approving causal effects of various risk factors on IBDs. These findings also supply some suggestions for the treatment and prevention of these diseases.

Positive faecal immunochemical test predicts the onset of inflammatory bowel disease: A nationwide, propensity score-matched study

Background & aims

The faecal immunochemical test (FIT), a non-invasive test for screening colorectal cancer (CRC), is being increasingly understood to reflect heightened inflammation. We aimed to investigate the association between abnormal FIT results and onset of inflammatory bowel disease (IBD), a disease characterized with chronic gut mucosal inflammation.

Methods

Participants in the Korean National Cancer Screening Program for CRC between 2009-2013 were analysed and divided into positive and negative FIT result groups. The incidence rates of IBD after screening were calculated after excluding cases of haemorrhoids, CRC, and IBD at baseline. Cox proportional hazard analyses were used to identify independent risk factors for IBD occurrence during follow-up, and 1:2 propensity score matching was performed as a sensitivity analysis.

Results

In total, 229,594 and 815,361 participants were assigned to the positive and negative FIT result groups, respectively. The age- and sex-adjusted incidence rates of IBD in participants with positive and negative test results were 1.72 and 0.50 per 10,000 person-years, respectively. Adjusted Cox analysis revealed that FIT positivity was associated with a significantly higher risk of IBD (hazard ratio 2.93, 95% confidence interval: 2.46, 3.47, P <.001), which was consistent for both disease subtypes of ulcerative colitis and Crohn's disease. The results of Kaplan-Meier analysis in the matched population yielded identical findings.

Conclusions

Abnormal FIT results could be a preceding sign of incident IBD in the general population. Those with positive FIT results and suspected IBD symptoms could benefit from regular screening for early disease detection.

Risk Factors for Developing Inflammatory Bowel Disease Within and Across Families with a Family History of IBD

INTRODUCTION

A family history of inflammatory bowel disease [IBD] is the strongest risk factor for disease. However, some first-degree relatives (FDRs) will develop disease, while others will not.

METHODS

Using the nationwide Danish National Patient Register, we examined risk factors in families with two or more affected FDRs. First, we compared exposures between siblings with and without IBD within the same family [within-family analysis]. Second, we compared exposures between individuals with and without IBD across all families [across-family analysis]. Exposures included sex, birth order, mode of delivery, antibiotics, personal and family history of immune-mediated diseases, gastrointestinal infections, and surgical history preceding diagnosis. Uni- and multivariable conditional logistic regression analyses were conducted.

RESULTS

In the 'within-family analysis', 1669 families were included [1732 cases, 2447 controls]. Female sex (adjusted odds ratio [aOR]: 1.40, 95% confidence interval [CI] 1.23, 1.59), history of ankylosing spondylitis [aOR: 2.88, 95% CI 1.05, 7.91] and exposure to antibiotics [aOR: 1.28, 95% CI 1.02, 1.61] increased the risk for IBD. In the 'across-family analysis', 1254 cases and 37 584 controls were included, confirming an association with prior ankylosing spondylitis [aOR: 3.92, 95% CI 1.38, 11.12] and exposure to antibiotics [aOR: 1.29, 95% CI 1.04, 1.60]. Having two or more relatives [aOR: 6.26, 95% CI 1.34, 29.29] or a sibling with IBD [aOR: 1.36, 95% CI 1.18, 1.57] increased the risk of IBD. Appendectomy reduced the risk of ulcerative colitis [aOR: 0.32, 95% CI 0.14, 0.72].

CONCLUSION

In families with IBD, we identified risk factors for the unaffected FDR to develop disease. These findings provide an opportunity for counselling IBD relatives.

Impact of Female Gender in Inflammatory Bowel Diseases: A Narrative Review

Inflammatory bowel diseases show a gender bias, as reported for several other immune-mediated diseases. Female-specific differences influence disease presentation and activity, leading to a different progression between males and females. Women show a genetic predisposition to develop inflammatory bowel disease related to the X chromosome. Female hormone fluctuation influences gastrointestinal symptoms, pain perception, and the state of active disease at the time of conception could negatively affect the pregnancy. Women with inflammatory bowel disease report a worse quality of life, higher psychological distress, and reduced sexual activity than male patients. This narrative review aims to resume the current knowledge of female-related features in clinical manifestations, development, and therapy, as well as sexual and psychological implications related to inflammatory bowel disease. The final attempt is to provide gastroenterologists with a roadmap of female-specific differences, to improve patients' diagnosis, management, and treatment.

Inhibition of c-Jun in AgRP neurons increases stress-induced anxiety and colitis susceptibility

Psychiatric disorders, such as anxiety, are associated with inflammatory bowel disease (IBD), however, the neural mechanisms regulating this comorbidity are unknown. Here, we show that hypothalamic agouti-related protein (AgRP) neuronal activity is suppressed under chronic restraint stress (CRS), a condition known to increase anxiety and colitis susceptibility. Consistently, chemogenic activation or inhibition of AgRP neurons reverses or mimics CRS-induced increase of anxiety-like behaviors and colitis susceptibility, respectively. Furthermore, CRS inhibits AgRP neuronal activity by suppressing the expression of c-Jun. Moreover, overexpression of c-Jun in these neurons protects against the CRS-induced effects, and knockdown of c-Jun in AgRP neurons (c-Jun^∆AgRP) promotes anxiety and colitis susceptibility. Finally, the levels of secreted protein thrombospondin 1 (THBS1) are negatively associated with increased anxiety and colitis, and supplementing recombinant THBS1 rescues colitis susceptibility in c-Jun^∆AgRP mice. Taken together, these results reveal critical roles of hypothalamic AgRP neuron-derived c-Jun in orchestrating stress-induced anxiety and colitis susceptibility.

Gender-Based Differences in Response to Tumor Necrosis Factor Inhibitor Therapies for Ulcerative Colitis: Individual Participant Data Meta-Analyses of Clinical Trials

BACKGROUND

Gender-based differences are reported in inflammatory bowel diseases (IBD) pathogenesis, but their impacts on IBD outcomes are not well known. We determined gender-based differences in response to treatment with tumor necrosis factor inhibitor (TNFi) therapies in individuals with ulcerative colitis (UC).

METHODS

We used the Yale University Open Data Access (YODA) platform to abstract individual participant data from randomized clinical trials to study infliximab and golimumab as induction and maintenance therapies in moderately to severely active UC. Using multivariable logistic regression, we examined associations between gender and the endpoints of clinical remission, mucosal healing, and clinical response for each study individually and in a meta-analysis.

RESULTS

Of 1639 patients included in induction trials (Program of Ulcerative Colitis Research Studies Utilizing an Investigational Treatment-Subcutaneous [PURSUIT-SC], active ulcerative colitis trials [ACT] 1 and 2) and 1280 patients included in maintenance trials (Program of Ulcerative Colitis Research Studies Utilizing an Investigational Treatment-Maintenance [PURSUIT-IM], ACT 1 and 2), 696 (42.5%) and 534 (41.7%) were women, respectively. In a meta-analysis of induction trials, the adjusted odds ratios (aORs) of clinical remission (aOR, 0.55; 95% CI, 0.31-0.97), mucosal healing (aOR, 0.47; 95% CI, 0.27-0.83), and clinical response (aOR, 0.51; 95% CI, 0.29-0.90) in the treatment arm and of clinical remission in the placebo arm (aOR, 0.34; 95% CI, 0.15-0.82) were lower in men compared to women. There were no differences in outcomes by gender in the treatment and placebo arms in the meta-analysis of maintenance trials.

CONCLUSIONS

Men are less likely to achieve clinical remission, mucosal healing, and clinical response compared to women during induction treatment with TNFi for UC, but not during the maintenance phase. Future studies delineating the mechanisms underlying these observations would be informative.

The epidemiology of inflammatory bowel disease in Asia and Asian immigrants to Western countries

Inflammatory bowel disease (IBD), which comprises Crohn's disease and ulcerative colitis, is an idiopathic inflammatory condition of the gastrointestinal tract. The incidence and prevalence of IBD are rapidly increasing worldwide, particularly in newly industrialized regions such as Asia. Although a large medical armamentarium is available for treating this chronic disease, IBD imposes a marked global disease burden. To understand the complex etiopathogenesis of this condition, it is important to consider the rapidly changing trends in its epidemiology in Asia. During the past few decades, the incidence and prevalence of IBD have significantly increased in both Asian countries and Asian immigrants in Western countries. In this review, we aimed to study and update the epidemiology of IBD in diverse Asian regions and among Asian immigrants in North America and Europe. Moreover, we highlighted that this population exhibits a unique disease phenotype, such as male predominance and high frequency of perianal fistula in Crohn's disease. Also, a different disease phenotype including more complicated disease such as perianal complications was noted in Asian Americans and Asian Europeans.

The Rising Burden of Inflammatory Bowel Disease in Denmark Over Two Decades: A Nationwide Cohort Study

BACKGROUND & AIMS

Shifts in epidemiological stages of inflammatory bowel disease (IBD) carry implications toward understanding IBD etiology and managing clinical care. We conducted a temporal analysis of the epidemiology of IBD between 1995 and 2016 in the Danish nationwide cohort.

METHODS

We used the Danish registers to obtain data on demographics and IBD-related outpatient and inpatient contacts between 1995 and 2016. IBD diagnosis was defined as having ≥2 registrations related to Crohn's disease (CD) or ulcerative colitis (UC) within a 2-year period. We estimated overall and annual incidence rates and prevalence of CD and UC standardized with respect to age and sex.

RESULTS

A total of 47,830 individuals met the criteria for IBD diagnosis, of which 33% were diagnosed with CD and 67% with UC. Between 1995 and 2016, the incidence rate (95% confidence interval) per 100,000 person-years rose from 9.1 (8.3-10.0) to 17.8 (16.8-19.0) for CD, and from 21.0 (19.8-22.3) to 28.4 (27.0-29.8) for UC. The highest increase in CD and UC incidence rates occurred in children and young adults, respectively. The prevalence of IBD doubled from 1995 to 2016; the greatest increase (2.5-fold) was in UC prevalence among individuals aged >40 years. During this period, the median age of the IBD population increased by 6 to 7 years.

CONCLUSIONS

In Denmark, the incidence and prevalence of IBD have increased during the last 2 decades. The IBD population is shifting toward an older age. These findings have implications towards understanding environmental shifts as well as preparing health care systems for an aging IBD population.

Sex-related Differences in Inflammatory Bowel Diseases: The Potential Role of Sex Hormones

Inflammatory bowel disease (IBD), characterized by chronic inflammation of the gastrointestinal tract, is a global health care problem. Compelling evidence shows sex differences regarding the prevalence, pathophysiology, clinical presentation, and treatment outcome of IBD. Sex hormones, including estrogen, progesterone, and androgen, have been proposed to have a role in the pathogenesis of sexual dimorphism in IBD. Clinical and experimental data support the modulatory effects of sex hormones on various clinical characteristics of the disease, including intestinal barrier dysfunction and mucosal immune activation. Additionally, the potential role of sex hormones in the modulation of gut microbiota is attracting increasing attention. Here, we discuss the sex dimorphic disease profile and address the potential mechanisms involved in the sex-specific pathogenesis of IBD. Improved understanding of these sex differences in the clinic could improve the knowledge of patients with IBD with heterogeneous disease profiles.