Systematic Review With Meta-analysis: Epidemiology of Nonalcoholic Fatty Liver Disease in Patients With Inflammatory Bowel Disease

Hepatobiliary and pancreatic manifestations in inflammatory bowel disease: an umbrella review of meta-analyses

Background

Inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn's disease (CD), can affect the hepatobiliary system and pancreas, substantially impacting the life quality of patients.

Objectives

To evaluate the quality of evidence and comprehensively assess the validity of associations of IBD with hepatobiliary and pancreatic diseases.

Design

We performed an umbrella review of existing meta-analyses in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) recommendations.

Data sources and methods

We systematically searched PubMed, Embase, and Web of Science from inception to April 2024, to identify and appraise meta-analyses examining IBD and risk of hepatobiliary and pancreatic manifestations. Methodologic quality was assessed with A Measurement Tool to Assess Systematic Reviews (AMSTAR 2) and the strength of evidence was graded according to prespecified criteria.

Results

A total of 14 meta-analyses of observational studies were included. The strongest-validity evidence suggested the significant associations between IBD and risk of gallstones (odds ratio (OR) = 1.72; 95% confidence interval (CI) = 1.40-2.12) and acute pancreatitis (OR = 3.11; 95% CI = 2.93-3.30). Highly suggestive evidence indicated a significantly increased risk of hepatobiliary cancer in UC (incidence rate ratio (IRR) = 2.05; 95% CI = 1.52-2.76) and CD (IRR = 2.31; 95% CI = 1.25-4.28). In addition, highly suggestive evidence indicated that IBD was associated with portal venous system thrombosis. Suggestive evidence showed a significantly higher prevalence of primary sclerosing cholangitis, non-alcoholic fatty liver disease, autoimmune hepatitis, and autoimmune pancreatitis in IBD patients than in the general population.

Conclusion

The associations between IBD and multiple hepatobiliary and pancreatic disorders showed varying levels of evidence and magnitude of risk. Further high-quality primary studies are needed to identify IBD patients who are more at risk and would benefit the most from screening and prevention programs.

Trial registration PROSPERO

CRD42023451461.

Association between nonalcoholic fatty liver disease and incidence of inflammatory bowel disease: a nationwide population‑based cohort study

BACKGROUND/AIMS

Nonalcoholic fatty liver disease (NAFLD) is a common disease with severe inflammatory processes associated with numerous gastrointestinal diseases, such as inflammatory bowel disease (IBD). Therefore, we investigated the relationship between NAFLD and IBD and the possible risk factors associated with the diagnosis of IBD.

METHODS

This longitudinal nationwide cohort study investigated the risk of IBD in patients with NAFLD alone. General characteristics, comorbidities, and incidence of IBD were also compared.

RESULTS

Patients diagnosed with NAFLD had a significant risk of developing IBD compared to control individuals, who were associated with a 2.245-fold risk of the diagnosis of IBD and a 2.260- and 2.231-fold of increased diagnosis of ulcerative colitis and Crohn's disease, respectively (P< 0.001). The cumulative risk of IBD increased annually during the follow-up of patients with NAFLD (P< 0.001).

CONCLUSIONS

Our results emphasize that NAFLD significantly impacts its incidence in patients with NAFLD. If patients with NAFLD present with risk factors, such as diabetes mellitus and dyslipidemia, these conditions should be properly treated with regular follow-ups. Furthermore, we believe that these causes may be associated with the second peak of IBD.

PPARα affects hepatic lipid homeostasis by perturbing necroptosis signals in the intestinal epithelium

Rapid turnover of the intestinal epithelium is a critical strategy to balance the uptake of nutrients and defend against environmental insults, whereas inappropriate death promotes the spread of inflammation. PPARα is highly expressed in the small intestine and regulates the absorption of dietary lipids. However, as a key mediator of inflammation, the impact of intestinal PPARα signaling on cell death pathways is unknown. Here, we show that Pparα deficiency of intestinal epithelium up-regulates necroptosis signals, disrupts the gut vascular barrier, and promotes LPS translocation into the liver. Intestinal Pparα deficiency drives age-related hepatic steatosis and aggravates hepatic fibrosis induced by a high-fat plus high-sucrose diet (HFHS). PPARα levels correlate with TRIM38 and MLKL in the human ileum. Inhibition of PPARα up-regulates necroptosis signals in the intestinal organoids triggered by TNF-α and LPS stimuli via TRIM38/TRIF and CREB3L3/MLKL pathways. Butyric acid ameliorates hepatic steatosis induced by intestinal Pparα deficiency through the inhibition of necroptosis. Our data suggest that intestinal PPARα is essential for the maintenance of microenvironmental homeostasis and the spread of inflammation via the gut-liver axis.

The Effect of Biologic Agents on Steatotic Liver Disease in Patients with Inflammatory Bowel Disease: A Prospective, Open-Label Comparative Trial

BACKGROUND

Biologic agents used in patients with inflammatory bowel diseases (IBD) may influence the pathophysiology of coexistent metabolic-dysfunction associated steatotic liver disease (MASLD). This study primarily aimed to evaluate the six-month effect of infliximab or vedolizumab vs. no biologics on presumed hepatic steatosis in patients with IBD. Secondary endpoints were their effect on hepatic fibrosis and parameters related to hepatic metabolism.

METHODS

This prospective, non-randomized, controlled trial assigned adult bio-naïve patients with IBD into three groups: infliximab, vedolizumab, or controls (receiving no biologic). The baseline was the time of the initiation of biologic agents and the endpoint six months later. Hepatic steatosis was evaluated with transabdominal ultrasonography (Hamaguchi score), whereas controlled attenuation parameter (CAP), fatty liver index (FLI), and hepatic steatosis index (HSI) were used as surrogates. Hepatic fibrosis was evaluated with liver stiffness (LS), fibrosis-4 index (FIB-4), and nonalcoholic fatty liver disease (NAFLD) fibrosis score.

RESULTS

Sixty-six patients were assigned to infliximab (n = 26), vedolizumab (n = 14), or control (n = 26); At the endpoint, the Hamaguchi score, CAP, FLI, and HSI were not different between groups. LS was not different between groups; however, FIB-4 was increased within all groups, and NAFLD fibrosis score was increased within infliximab and control groups, without significant biologic × time interactions.

CONCLUSIONS

No positive or adverse effect of infliximab or vedolizumab vs. no biologic agents was shown on presumed hepatic steatosis in patients with IBD, who have not been previously exposed to biologic agents. Although no effect of both biologic agent on LS, a slight but significant increase in FIB-4 and NAFLD fibrosis score warrants further studying.

Heavy arch: from inflammatory bowel diseases to metabolic disorders

BACKGROUND

Metabolic disorders and inflammatory bowel diseases (IBD) have captured the globe during Westernisation of lifestyle and related dietary habits over the last decades. Both disease entities are characterised by complex and heterogeneous clinical spectra linked to distinct symptoms and organ systems which, on a first glimpse, do not have many commonalities in clinical practice. However, experimental studies indicate a common backbone of inflammatory mechanisms in metabolic diseases and gut inflammation, and emerging clinical evidence suggests an intricate interplay between metabolic disorders and IBD.

OBJECTIVE

We depict parallels of IBD and metabolic diseases, easily overlooked in clinical routine.

DESIGN

We provide an overview of the recent literature and discuss implications of metabolic morbidity in patients with IBD for researchers, clinicians and healthcare providers.

CONCLUSION

The Western lifestyle and diet and related gut microbial perturbation serve as a fuel for metabolic inflammation in and beyond the gut. Metabolic disorders and the metabolic syndrome increasingly affect patients with IBD, with an expected negative impact for both disease entities and risk for complications. This concept implies that tackling the obesity pandemic exerts beneficial effects beyond metabolic health.

Current epidemiology of chronic liver disease

Chronic liver disease presents a significant global health burden, characterized by several etiologies, including metabolic dysfunction-associated steatotic liver disease (MASLD), alcohol-related liver disease (ALD), chronic hepatitis B virus infection, and chronic hepatitis C virus infection. This review explored current epidemiological trends and projections for each etiology, looking into their respective burdens and challenges. MASLD, formerly known as nonalcoholic fatty liver disease, is the most prevalent cause of chronic liver disease, and its global incidence and prevalence are steadily rising. ALD, fueled by increased alcohol consumption, is also on the rise, with concerning implications for future mortality rates. Chronic hepatitis B and C infections remain major public health concerns, particularly in specific regions of the world, necessitating concerted efforts for screening and treatment. The coronavirus disease 2019 (COVID-19) pandemic has impacted the epidemiology of chronic liver disease, exacerbating mortality rates and disrupting healthcare services. Mental health issues arising from the pandemic further complicate the treatment of chronic liver disease, making comprehensive healthcare strategies essential. Despite advancements in treatment, chronic liver disease continues to impose a substantial economic burden, emphasizing the importance of preventive measures and early intervention. In conclusion, ongoing surveillance and research efforts are crucial for understanding and addressing the evolving landscape of chronic liver disease. Comprehensive strategies that encompass prevention, screening, and treatment of its different etiologies are essential for mitigating its impact and improving patient outcomes.

Exploration of the core pathway of inflammatory bowel disease complicated with metabolic fatty liver and two-sample Mendelian randomization study of the causal relationships behind the disease

Background

Inflammatory bowel disease (IBD) is often associated with complex extraintestinal manifestations. The incidence of nonalcoholic fatty liver disease (NAFLD) in IBD populations is increasing yearly. However, the mechanism of interaction between NAFLD and IBD is not clear. Consequently, this study aimed to explore the common genetic characteristics of IBD and NAFLD and identify potential therapeutic targets.

Materials and methods

Gene chip datasets for IBD and NAFLD were obtained from the Gene Expression Omnibus (GEO) database. Weighted gene co-expression network analysis (WGCNA) was performed to identify modules in those datasets related to IBD and NAFLD. ClueGO was used for biological analysis of the shared genes between IBD and NAFLD. Based on the Human MicroRNA Disease Database (HMDD), microRNAs (miRNAs) common to NAFLD and IBD were obtained. Potential target genes for the miRNAs were predicted using the miRTarbase, miRDB, and TargetScan databases. Two-sample Mendelian randomization (MR) and two-way MR were used to explore the causal relationship between Interleukin-17 (IL-17) and the risk of IBD and NAFLD using data from GWAS retrieved from an open database.

Results

Through WGCNA, gene modules of interest were identified. GO enrichment analysis using ClueGO suggested that the abnormal secretion of chemokines may be a common pathophysiological feature of IBD and NAFLD, and that the IL-17-related pathway may be a common key pathway for the pathological changes that occur in IBD and NAFLD. The core differentially expressed genes (DEGs) in IBD and NAFLD were identified and included COL1A1, LUM, CCL22, CCL2, THBS2, COL1A2, MMP9, and CXCL8. Another cohort was used for validation. Finally, analysis of the miRNAs identified potential therapeutic targets. The MR results suggested that although there was no causal relationship between IBD and NAFLD, there were causal relationships between IL-17 and IBD and NAFLD.

Conclusion

We established a comorbid model to explain the potential mechanism of IBD with NAFLD and identified the chemokine-related pathway mediated by cytokine IL-17 as the core pathway in IBD with NAFLD, in which miRNA also plays a role and thus provides potential therapeutic targets.

Hepatic Steatosis but Not Fibrosis Is Independently Associated with Poor Outcomes in Patients with Inflammatory Bowel Disease

BACKGROUND/AIMS

Increased prevalence of nonalcoholic fatty liver disease (NAFLD) and inflammatory bowel disease (IBD) has been reported. However, the effects of NAFLD on the outcome of IBD remains unclear. We investigated whether the presence of NAFLD could influence the outcomes of patients with IBD.

METHODS

We recruited 3,356 eligible patients with IBD into our study between November 2005 and November 2020. Hepatic steatosis and fibrosis were diagnosed using hepatic steatosis index of ≥30 and fibrosis-4 of ≥1.45, respectively. The primary outcome was clinical relapse, defined based on the following: IBD-related admission, surgery, or first use of corticosteroids, immunomodulators, or biologic agents for IBD.

RESULTS

The prevalence of NAFLD in patients with IBD was 16.7%. Patients with hepatic steatosis and advanced fibrosis were older, had a higher body mass index, and were more likely to have diabetes (all p<0.05).

CONCLUSIONS

Hepatic steatosis was independently associated with increased risks of clinical relapse in patients with ulcerative colitis and Crohn's disease, whereas fibrotic burden in the liver was not. Future studies should investigate whether assessment and therapeutic intervention for NAFLD will improve the clinical outcomes of patients with IBD.

Inflammatory Bowel Diseases and Non-Alcoholic Fatty Liver Disease: Piecing a Complex Puzzle Together

Inflammatory bowel diseases (IBD), comprising Crohn's disease and ulcerative colitis, are systemic and multifaceted disorders which affect other organs in addition to the gastrointestinal tract in up to 50% of cases. Extraintestinal manifestations may present before or after IBD diagnosis and negatively impact the intestinal disease course and patients' quality of life, often requiring additional diagnostic evaluations or specific treatments. Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide. Current evidence shows an increased prevalence of NAFLD (and its more advanced stages, such as liver fibrosis and steatohepatitis) in IBD patients compared to the general population. Many different IBD-specific etiopathogenetic mechanisms have been hypothesized, including chronic inflammation, malabsorption, previous surgical interventions, changes in fecal microbiota, and drugs. However, the pathophysiological link between these two diseases is still poorly understood. In this review, we aim to provide a comprehensive overview of the potential mechanisms which have been investigated so far and highlight open issues still to be addressed for future studies.

"Prevalence, Predictors, and Impact of Hepatic Steatosis in Patients With Ulcerative Colitis: A Prospective Observational Cohort Study"

BACKGROUND AND AIMS

There are no prospective studies evaluating effect of non-alcoholic fatty liver disease (NAFLD) in patients with ulcerative colitis (UC). This prospective observational study assessed the prevalence of NAFLD, its predictors, and its effect on long-term outcomes in UC.

METHODS

Consecutive UC patients underwent transient elastography, body composition analysis, bone densitometry, anthropometry, and baseline demographic and subjective global assessment. NAFLD was diagnosed by controlled attenuation parameter of >260 dB/m. To evaluate predictors and outcomes, patients of UC with NAFLD (n = 29) were compared with age- and sex-matched patients of UC without NAFLD (n = 27).

RESULTS

Among 107 patients of UC (mean age-29 ± 10.6 years; males = 56%, median disease duration-48 [interquartile range: 24-84] months, left sided/pancolitis = 84%), 27% (n = 29) had NAFLD. Patients with body mass index (BMI) > 23 kg/m2 had higher proportion of NAFLD than with normal or low BMI (54.7% [23/42] vs 10% [5/50] vs 6.7% [1/15]). Patients with NAFLD had high BMI (P < 0.001), waist circumference, and fat mass (P < 0.001) but similar fat-free mass (P = 0.798) compared to patients without NAFLD. There was no difference in immunosuppressant and cumulative steroid exposure between two groups. Dietary parameters including daily energy, protein, fat, and carbohydrate intake were similar between the two groups. On multivariate analysis, high BMI was found to be predictive and low socioeconomic status as a protective factor of NAFLD. On long-term follow-up of three years, there was no difference in steroid, or biologic requirement, disease-related hospitalization, or composite of all three outcomes between two groups.

CONCLUSION

The prevalence of NAFLD was found in nearly a quarter of patients of UC and was affected by metabolic parameters rather than disease activity.

Prevalence of Hepatobiliary Manifestations in Inflammatory Bowel Disease: A GRADE Assessed Systematic Review and Meta-Analysis of more than 1.7 Million Patients

BACKGROUND AND AIMS

Inflammatory bowel disease [IBD] comprises an immune-mediated group of chronic gastrointestinal disorders. Patients with IBD may experience extraintestinal manifestations, such as hepatobiliary complications. This meta-analysis aims to assess the prevalence of different hepatic manifestations in IBD patients.

METHODS

For this systematic review and meta-analysis, PubMed, Scopus, Web of Science, and Embase were searched until July 20, 2022, by specifying keywords for IBD, hepatic manifestations, and study type. Full texts of cohort studies in English that examined the prevalence of different hepatic manifestations were included in this study. The primary outcome was the overall prevalence of hepatic manifestations in IBD patients. For the statistical analysis, a proportion by random effect model meta-analysis was performed. The registration number for the protocol of this study in PROSPERO is CRD42022369595.

RESULTS

From the 4421 articles retrieved from the primary search, 118 met the inclusion criteria and were included in the final analysis. After a pooled analysis of 1 729 128 patients, the overall prevalence of hepatic manifestations was 3.49% (95% confidence interval [CI]: 3.31-3.68%; I2: 99.55%). The pooled prevalence of non-alcoholic fatty liver disease in 228 216 patients was 26.1% [95% CI: 22.1-30.2%; I2: 99.018%]. After pooled analysis of 9642 patients, the prevalence of primary sclerosing cholangitis was 1.67% [95% CI: 1.47-1.88%; I2: 99.10%]. The pooled prevalence of biliary stones was 4.1% [95% CI: 3.6-4.7%; I2: 97.43%]. Autoimmune hepatitis (0.51% [95% CI: 0.26-0.75%]; I2: 85.36%) and portal vein thrombosis (0.21% [95% CI: 0.08-0.33%]; I2: 97.95%) are considered as rare manifestations.

CONCLUSION

This study summarizes the prevalence and importance of different hepatic manifestations in IBD patients. These findings are crucial for the management of extraintestinal manifestations, especially hepatic manifestations, in IBD patients.

Gut-liver axis calibrates intestinal stem cell fitness

The gut and liver are recognized to mutually communicate through the biliary tract, portal vein, and systemic circulation. However, it remains unclear how this gut-liver axis regulates intestinal physiology. Through hepatectomy and transcriptomic and proteomic profiling, we identified pigment epithelium-derived factor (PEDF), a liver-derived soluble Wnt inhibitor, which restrains intestinal stem cell (ISC) hyperproliferation to maintain gut homeostasis by suppressing the Wnt/β-catenin signaling pathway. Furthermore, we found that microbial danger signals resulting from intestinal inflammation can be sensed by the liver, leading to the repression of PEDF production through peroxisome proliferator-activated receptor-α (PPARα). This repression liberates ISC proliferation to accelerate tissue repair in the gut. Additionally, treating mice with fenofibrate, a clinical PPARα agonist used for hypolipidemia, enhances colitis susceptibility due to PEDF activity. Therefore, we have identified a distinct role for PEDF in calibrating ISC expansion for intestinal homeostasis through reciprocal interactions between the gut and liver.

Identifying inflammatory bowel disease patients at risk of metabolic dysfunction-associated fatty liver disease: usefulness of non-invasive steatosis predictive scores

BACKGROUND

Inflammatory bowel disease (IBD) patients have a higher risk of metabolic dysfunction-associated fatty liver disease (MAFLD) compared with the general population. However, it is not known whether available non-invasive hepatic steatosis scores are useful in predicting MAFLD in IBD patients. We aimed to analyze the performances of MAFLD screening score (MAFLD-S), Fatty Liver Index (FLI), Hepatic Steatosis Index (HSI) and Clinical Prediction Tool for NAFLD in Crohn's Disease (CPN-CD), in identifying MAFLD in IBD patients.

METHODS

A cross-sectional study was carried out including consecutive adult IBD outpatients submitted to transient elastography (TE). MAFLD criteria were assessed, and hepatic steatosis (HS) was defined by a controlled attenuation parameter (CAP) >248 dB/m using TE. MAFLD-S, FLI, HSI, and CPN-CD were calculated and their accuracy for the prediction of MAFLD was evaluated through their areas under the receiver-operating characteristic (AUROC) curves.

RESULTS

Of 168 patients, body mass index ≥25, type 2 diabetes mellitus, dyslipidemia and arterial hypertension were present in 76 (45.2%), 10 (6.0%), 53 (31.5%), 20 (11.9%), respectively. HS was identified in 77 (45.8%) patients, of which 65 (84.4%) fulfilled MAFLD criteria. MAFLD-S (AUROC, 0.929 [95% CI, 0.888-0.971]) had outstanding and FLI (AUROC, 0.882 [95% CI, 0.830-0.934]), HSI (AUROC, 0.803 [95% CI, 0.736-0.871]), and CPN-CD (AUROC, 0.822 [95% CI, 0.753-0.890) had excellent discrimination in predicting MAFLD.

CONCLUSIONS

MAFLD-S, FLI, HSI and CPN-CD scores can accurately identify MAFLD in IBD patients, allowing the selection of those in whom hepatic steatosis and metabolic risk factors assessment may be particularly beneficial.

Prospective therapeutics for intestinal and hepatic fibrosis

Currently, there are no effective therapies for intestinal and hepatic fibrosis representing a considerable unmet need. Breakthroughs in pathogenesis have accelerated the development of anti-fibrotic therapeutics in recent years. Particularly, with the development of nanotechnology, the harsh environment of the gastrointestinal tract and inaccessible microenvironment of fibrotic lesions seem to be no longer considered a great barrier to the use of anti-fibrotic drugs. In this review, we comprehensively summarize recent preclinical and clinical studies on intestinal and hepatic fibrosis. It is found that the targets for preclinical studies on intestinal fibrosis is varied, which could be divided into molecular, cellular, and tissues level, although little clinical trials are ongoing. Liver fibrosis clinical trials have focused on improving metabolic disorders, preventing the activation and proliferation of hepatic stellate cells, promoting the degradation of collagen, and reducing inflammation and cell death. At the preclinical stage, the therapeutic strategies have focused on drug targets and delivery systems. At last, promising remedies to the current challenges are based on multi-modal synergistic and targeted delivery therapies through mesenchymal stem cells, nanotechnology, and gut-liver axis providing useful insights into anti-fibrotic strategies for clinical use.

Shared biomarkers and immune cell infiltration signatures in ulcerative colitis and nonalcoholic steatohepatitis

The coexistence of ulcerative colitis (UC) and nonalcoholic steatohepatitis (NASH) involves a intricate interplay, though the precise pathophysiological mechanisms remain elusive. To shed light on this, our study endeavors to unravel the shared gene signatures and molecular mechanisms by employing quantitative bioinformatics analysis on a publicly available RNA-sequencing database. Gene expression profiles of UC (GSE87466) and NASH (GSE89632) were retrieved from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were analyzed using R software. After identifying common DEGs, functional enrichment analysis, protein-protein interaction (PPI) network analysis and module construction were performed to obtain candidate hub genes. GSE47908 for UC and GSE159676 for NASH were selected to validate the obtained candidate genes. A total of 119 common DEGs were found in NASH and UC patients. Functional and pathway analyses emphasized that viral infection, inflammation and immune response were enriched in these two diseases. After module construction and validation, CD2, CD8A, GNLY, IFI44, NKG7 and OAS2 were identified as hub genes. 6 hub genes and their combined prediction scores were found with an impressive accuracy and sensitivity. Functional estimation, gene set enrichment analysis and immune infiltration signature identification showed notable associations of the six hub genes with T cells, natural killer cells and type I interferon levels. In addition, we constructed UC combined with NASH mice model successfully with significantly higher expression of hub genes in both liver and colonic tissues than those in control group. Our study elucidates 6 hub genes of UC and NASH, which may participate in immune, inflammatory and antiviral effects. These findings provide some potential biochemical markers for further exploration of UC coexistence with NASH.

Systematic Review and Meta-Analysis: Prevalence of Non-Alcoholic Fatty Liver Disease and Liver Fibrosis in Patients with Inflammatory Bowel Disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a common concomitant condition in patients with inflammatory bowel disease (IBD). We aim to assess the magnitude of this association.

METHODS

We searched MEDLINE, EMBASE and Scopus libraries for the period up to February 2023 to identify studies reporting cohorts of IBD patients in which NALFLD was evaluated.

RESULTS

Eighty-nine studies were analyzed. The overall prevalence of NAFLD was 24.4% (95%CI, 19.3-29.8) in IBD, 20.2% (18.3-22.3) in Crohn's disease and 18.5% (16.4-20.8) for ulcerative colitis. Higher prevalence was found in male compared to female patients, in full papers compared to abstracts, and in cross-sectional studies compared to prospective and retrospective ones. The prevalence of NAFLD in IBD has increased in studies published from 2015 onwards: 23.2% (21.5-24.9) vs. 17.8% (13.2-22.9). Diagnostic methods for NAFLD determined prevalence figures, being highest in patients assessed by controlled attenuation parameter (38.8%; 33.1-44.7) compared to ultrasonography (28.5%; 23.1-34.2) or other methods. The overall prevalence of fibrosis was 16.7% (12.2-21.7) but varied greatly according to the measurement method.

CONCLUSION

One-quarter of patients with IBD might present with NAFLD worldwide. This proportion was higher in recent studies and in those that used current diagnostic methods.

Metabolic Dysfunction-Associated Fatty Liver Disease in Taiwanese Patients with Inflammatory Bowel Disease: A Study in Patients with Clinical Remission

The prevalence of inflammatory bowel disease (IBD) has increased worldwide. The prevalence of metabolic dysfunction associated fatty liver disease (MAFLD) has also risen. However, there is limited research on the connection between MAFLD and IBD in the Asian population. This study aims to analyze the prevalence and clinical significance of MAFLD in Taiwanese IBD patients with clinical remission. We retrospectively analyzed IBD patients who received transient elastography for liver fibrosis and controlled attenuation parameter evaluation for liver steatosis. This study enrolled 120 patients with IBD, including 45 Crohn's disease (CD) and 75 ulcerative colitis (UC). MAFLD prevalence in IBD was 29.2%. Patients with MAFLD had a shorter disease duration (2.8 years vs. 5.3 years, p = 0.017), higher alanine aminotransferase levels (24 U/L vs. 17 U/L, p = 0.003), a lower estimated glomerular filtration rate (91.37 mL/min/1.73 m2 vs. 103.92 mL/min/1.73 m2, p = 0.004), and higher γ-glutamyl transferase (γ-GT) (24 mg/dL vs. 13 mg/dL, p < 0.001). The prevalence of significant fibrosis in IBD with MAFLD was 17.1%. Significant fibrosis was found in older age (58.5 years vs. 40 years, p = 0.004) and the high type 2 diabetes mellitus proportion (50.0% vs. 10.3%, p = 0.049). A trend of longer disease duration was found in significant fibrosis (4.9 years vs. 1.6 years, p = 0.051). The prevalence of MALFD in IBD was 29.2%. and 17.1% of them had significant fibrosis. In addition to the intestinal manifestation, the study findings remind clinicians that they should be aware of the possibility of hepatic complications for IBD patients.

The impact of nonalcoholic fatty liver disease on inflammatory bowel disease-related hospitalization outcomes: a systematic review

Evidence suggests that patients with inflammatory bowel disease are at higher risk of developing nonalcoholic fatty liver disease (NAFLD). However, there is limited information currently available on how NAFLD may affect the clinical course of IBD. Thus, we conducted a systematic review to evaluate the impact of NAFLD on IBD-related hospitalization outcomes. All observational studies assessing IBD-related hospitalization outcomes in patients with NAFLD were included. Exclusion criteria were studies published in languages other than English or French, or those involving pediatric population. Outcomes included IBD-related hospitalization and readmission rates, need for surgery, length of stay, inpatient mortality, and costs. Overall, 3252 citations were retrieved and seven studies met the inclusion criteria (1 574 937 patients); all were observational, of high quality, and originated in the United States. Measurable outcomes reported in these studies were few and with insufficient similarity across studies to complete a quantitative assessment. Only one study reports NAFLD severity. Two studies suggested a higher rate of hospitalization for patients with both NAFLD and IBD compared to IBD alone (incidence rate ratio of 1.54; 95% confidence interval: 1.33-1.79). This is the first systematic review to date that evaluates any possible association of NAFLD with IBD-related hospitalization outcomes. Despite the paucity and low quality of available data, our findings indicate that NAFLD may be associated with worse outcomes amongst IBD patients (especially Crohn's disease). Further and higher certainty of evidence is needed for better characterization of such clinical impact.

Influence of genetically predicted autoimmune diseases on NAFLD

Introduction

Non-alcoholic fatty liver disease (NAFLD), the emerging cause of end-stage liver disease, is the most common liver disease. Determining the independent risk factors of NAFLD and patients who need more monitoring is important.

Methods

Two-Sample Mendelian randomization (MR) was performed in the analysis to investigate the causal association of different autoimmune diseases with NAFLD using summary level data. Genome-wide association study (GWAS) of 5 autoimmune diseases including celiac disease (CeD), Crohn's disease (CD), multiple sclerosis (MS), rheumatoid arthritis (RA), and type 1 diabetes (T1D) were selected for Instrument variables (IVs). NAFLD was included as outcome.

Result

After adjusting for confounding factors, genetic predisposition of CeD (OR= 0.973, [0.949,0.997], IVW p-value=0.026), MS (OR= 1.048, [1.012,1.085], IVW p-value= 0.008), RA (OR= 1.036, [1.006,1.066], IVW p-value=0.019), T1D (OR= 1.039, [1.002,1.079], IVW p-value= 0.041) is causally associated with NAFLD. No causal effect was found between CD and NAFLD.

Conclusion

CeD itself may be a protective factor for NAFLD, the results of previous observational studies have been influenced by confounding factors, and the morbidity of NAFLD may be higher in patients with MS, RA, and T1D than in common populations, and monitoring the prevalence of NAFLD in these populations is considerable.

Steroid Use and Risk of Nonalcoholic Fatty Liver Disease in Patients With Inflammatory Bowel Disease: Systematic Review and Meta-analysis

GOALS

We sought to evaluate the association of steroids with nonalcoholic fatty liver disease (NAFLD) among patients with inflammatory bowel disease (IBD).

BACKGROUND

Patients with IBD are at increased risk of NAFLD. Steroids may have a role in the pathogenesis of NAFLD.

STUDY

We searched MEDLINE (through PubMed) and Embase for studies from inception to July 2021. We included published interventional and observational studies of adults 18 years or older with ulcerative colitis or Crohn's disease. We reported odds ratios, 95% confidence intervals, and generated forest plots. A random effects model generated a summary effect estimate. Publication bias was assessed by funnel plot and Egger's test. Study quality was examined using modified Newcastle-Ottawa scale (NOS) and Agency for Healthcare Research and Quality (AHRQ).

RESULTS

A total of 12 observational studies with 3497 participants were included. NAFLD was identified in 1017 (29.1%) patients. The pooled odds ratio for the development of NAFLD in steroid users versus non-users was 0.87 (95% confidence interval: 0.72-1.04). There was no significant heterogeneity between studies ( I ²=0.00%, P =0.13). No publication bias was detected by funnel plot or Egger's test ( P =0.24). Findings were consistent among subgroup analyses stratified by study quality.

CONCLUSION

In this meta-analysis, steroids were not associated with NAFLD in patients with IBD. Steroids may not need to be withheld from patients with IBD for the purposes of preventing NAFLD. Additional prospective studies that systematically document steroid exposure and important confounders among patients with IBD are warranted.

Liver Fibrosis in Non-Alcoholic Fatty Liver Disease and Progression to Hepatocellular Carcinoma in Patients with Inflammatory Bowel Disease: A Systematic Review

The aim of the systematic review is to assess the prevalence and risk factors of liver fibrosis in patients with Inflammatory Bowel Disease (IBD) and Non-Alcoholic Fatty Liver Disease (NAFLD) and to discuss the role of liver fibrosis in the progression to hepatocellular carcinoma (HCC). We performed a structured search in PubMed, Web of Science, Embase, and Scopus up to 3 March 2023 to identify observational studies reporting liver fibrosis in patients with NAFLD and IBD. Quality of studies was assessed using the Newcastle-Ottawa Scale (NOS) score. A total of 23 studies met our inclusion criteria, including 629,781 patients. A total of 10 cross-sectional, 3 case-control, and 10 cohort studies were included. Fourteen studies had a NOS score ≥ 7 points. NAFLD was diagnosed in 2162/6332 (34.1%) IBD participants. However, NAFLD diagnosis was established in 924/2962 (31.2%) healthy individuals without IBD. Advanced liver fibrosis was found in 116 (11.6%) of 992 IBD patients with NAFLD. Most studies found an association between NAFLD and classic cardiovascular risk factors such as older age, male sex, higher BMI, diabetes, hypertension and dyslipidemia. In addition, metabolic syndrome features were also associated with an increased risk of significant and advanced liver fibrosis. Although no strong association between NAFLD and IBD therapy was reported, some studies associated NAFLD with IBD diagnosis, Crohn's Disease, a complicated course of IBD, disease activity, and IBD duration. Advanced liver fibrosis was also associated with Crohn's disease in several studies. In conclusion, NAFLD and advanced liver fibrosis are prevalent and clinically relevant extraintestinal manifestations, so its diagnosis and potential progression to HCC should be carefully considered in daily clinical practice.

Prevention of colitis-induced liver oxidative stress and inflammation in a transgenic mouse model with increased omega-3 polyunsaturated fatty acids

Inflammatory bowel disease (IBD) is an immune-mediated gut dysfunction, which might also be associated with an inflammatory phenotype in the liver. It is known that the nutritional intake of omega-3 polyunsaturated fatty acids (n-3 PUFA) is inversely correlated to the severity and occurrence of IBD. In order to investigate whether n-3 PUFA can also reduce liver inflammation and oxidative liver damage due to colon inflammation, we explored the dextran sulfate sodium (DSS)-induced colitis model in wild-type and fat-1 mice with endogenously increased n-3 PUFA tissue content. Besides confirming previous data of alleviated DSS-induced colitis in the fat-1 mouse model, the increase of n-3 PUFA also resulted in a significant reduction of liver inflammation and oxidative damage in colitis-affected fat-1 mice as compared to wild-type littermates. This was accompanied by a remarkable increase of established inflammation-dampening n-3 PUFA oxylipins, namely docosahexaenoic acid-derived 19,20-epoxydocosapentaenoic acid and eicosapentaenoic acid-derived 15-hydroxyeicosapentaenoic acid and 17,18-epoxyeicosatetraenoic acid. Taken together, these observations demonstrate a strong inverse correlation between the anti-inflammatory lipidome derived from n-3 PUFA and the colitis-triggered inflammatory changes in the liver by reducing oxidative liver stress.

Increased Risk of Non-Alcoholic Steatohepatitis in Patients With Inflammatory Bowel Disease: A Population-Based Study

Background and objective The global health burden of inflammatory bowel disease (IBD) stems from its increasing incidence over the years. Comprehensive studies on the topic hypothesize that IBD plays a more dominant in the development of non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH). In light of this, we conducted this study with the aim of assessing the prevalence and risk factors of developing NASH in patients who have had a diagnosis of ulcerative colitis (UC) and Crohn's disease (CD). Methodology A validated multicenter and research platform database of more than 360 hospitals from 26 different healthcare systems across the United States from 1999 to September 2022 was utilized for conducting this study. Patients aged 18-65 years were included. Pregnant patients and individuals diagnosed with alcohol use disorder were excluded. The risk of developing NASH was calculated using a multivariate regression analysis to account for potential confounding variables including male gender, hyperlipidemia, hypertension, type 2 diabetes mellitus (T2DM), and obesity. A two-sided p-value <0.05 was considered statistically significant, and all statistical analyses were performed using R version 4.0.2 (R Foundation for Statistical Computing, Vienna, Austria, 2008). Results A total of 79,346,259 individuals were screened in the database and 46,667,720 were selected for the final analysis based on the inclusion and exclusion criteria. Using multivariate regression analysis, the risk of developing NASH among patients with UC and CD was calculated. The odds of having NASH among patients with UC was 2.37 (95% CI: 2.17-2.60, p<0.001). Similarly, the odds of having NASH were high in patients with CD as well, at 2.79 (95% CI: 2.58-3.02, p<0.001). Conclusion Based on our findings, patients with IBD have an increased prevalence and higher odds of developing NASH after controlling for common risk factors. We believe that a complex pathophysiological relationship exists between both disease processes. Further research is required to establish appropriate screening times to enable earlier disease identification and thereby improve patient outcomes.

Crohn's Disease Is Associated with Liver Fibrosis in Patients with Nonalcoholic Fatty Liver Disease

BACKGROUND

Chronic inflammation in IBD is postulated to drive NAFLD progression from steatosis to fibrosis.

AIMS

To study the histopathological spectrum of NAFLD in Crohn disease (CD) and Ulcerative colitis (UC).

METHODS

Patients with biopsy proven NAFLD at a quaternary center from 2008 to 2018 were included in this retrospective analysis. Inflammatory bowel disease (IBD) diagnosed either clinically and/or endoscopically at the time of liver biopsy. Multivariable regression and propensity score (PS) weighted analysis were conducted. Statistical analysis were performed using SAS statistical software.

RESULTS

Among 1009 patients with NAFLD a diagnosis of IBD was identified in 50 cases (34 CD and 16 UC). On multivariable analysis; CD was independently associated with significantly higher odds of advanced fibrosis (AF) on liver biopsy (adjusted OR = 4.09, 95% CI = 1.40-11.94) compared to NAFLD patients without IBD. Similar results were obtained with both the overlap PS weighted model (OR = 3.17, 95% CI = 1.55-6.49) and the PS matched model (OR = 3.49, 95% CI = 1.50-8.13).

CONCLUSION

In a large cohort of patients with histologically well characterized NAFLD, AF was more common in CD patients than NAFLD patients without IBD. These findings must be confirmed in a larger cohort, but suggest CD patients with NAFLD could be at greater risk for liver fibrosis.

Premorbid Steatohepatitis Increases the Seriousness of Dextran Sulfate Sodium-induced Ulcerative Colitis in Mice

BACKGROUND AND AIMS

The concurrence of nonalcoholic steatohepatitis (NASH) and ulcerative colitis (UC) is increasingly seen in clinical practice, but the underlying mechanisms remain unclear. This study aimed to develop a mouse model of the phenomenon by combining high-fat high-cholesterol diet (HFHCD)-induced NASH and dextran sulfate sodium (DSS)-induced UC, that would support mechanistic studies.

METHODS

Male C57BL/6 mice were randomly assigned to two groups receiving either a chow diet or HFHCD for 12 weeks of NASH modeling. The mice were the divided into four subgroups for UC modeling: (1) A control group given a chow diet with normal drinking water; (2) A colitis group given chow diet with 2% DSS in drinking water; (3) A steatohepatitis group given HFHCD with normal drinking water; and (4) A steatohepatitis + colitis group given HFHCD with 2% DSS in drinking water.

RESULTS

NASH plus UC had high mortality (58.3%). Neither NASH nor UC alone were fatal. Although DSS-induced colitis did not exacerbate histological liver injury in HFHCD-fed mice, premorbid NASH significantly increased UC-related gut injury compared with UC alone. It was characterized by a significantly shorter colon, more colonic congestion, and a higher histopathological score (p<0.05). Inflammatory (tumor necrosis factor-alpha, interleukin 1 beta, C-C motif chemokine ligand 2, and nuclear factor kappa B) and apoptotic (Bcl2, Bad, Bim, and Bax) signaling pathways were significantly altered in distal colon tissues collected from mice with steatohepatitis + colitis compared with the other experimental groups.

CONCLUSIONS

Premorbid steatohepatitis significantly aggravated DSS-induced colitis and brought about a lethal phenotype. Potential links between NASH and UC pathogeneses can be investigated using this model.

Screening for Liver Steatosis and Fibrosis in Patients with Inflammatory Bowel Disease Using Vibration Controlled Transient Elastography with Controlled Attenuation Parameter

BACKGROUND AND AIMS

Inflammatory bowel diseases (IBD) are frequently associated with extraintestinal manifestations, hepatic injury being of concern in these patients. Current literature reports an increased prevalence of liver steatosis and fibrosis in subjects with IBD and the pathophysiology is yet to be completely understood. The aim of this study was to assess the prevalence of non-alcoholic fatty liver disease (NAFLD) in patients with IBD, as well as to determine the factors that connect these two disorders.

METHODS

From September 2021 to June 2022, 82 consecutive IBD patients were enrolled from a tertiary care center hospital in Iasi. Vibration-Controlled Transient Elastography with Controlled Attenuation Parameter (CAP) was used to assess the presence of NAFLD, with a cut-off score for CAP of 248 dB/m. Significant liver fibrosis was considered at a cut-off for liver stiffness measurements (LSM) of 7.2 kPa.

RESULTS

In total, 82 IBD patients (54.8% men, mean age of 49 ± 13 years) were included, 38 (46.3%) of them being diagnosed with NAFLD, with a mean CAP score of 286 ± 35.4 vs. 203 ± 29.7 in patients with IBD only. Age (β = 0.357, p = 0.021), body mass index (BMI) (β = 0.185, p = 0.048), disease duration (β = 0.297, p = 0.041), C-reactive protein (β = 0.321, p = 0.013), fasting plasma glucose (β = 0.269, p = 0.038), and triglycerides (β = 0.273, p = 0.023) were strongly associated with the presence of liver steatosis. The multivariate analysis showed that older age, BMI, and disease duration were strongly associated with significant liver fibrosis in our group.

CONCLUSIONS

NAFLD is a multifaced pathology with growing prevalence among IBD patients. Additional studies are needed to completely understand this problem and to create a solid evidence-based framework for more effective preventative and intervention strategies.

Polysaccharide from Salviae miltiorrhizae Radix et Rhizoma Attenuates the Progress of Obesity-Induced Non-Alcoholic Fatty Liver Disease through Modulating Intestinal Microbiota-Related Gut–Liver Axis

Non-alcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease worldwide, thus treatments for it have attracted lots of interest. In this study, the Salviae miltiorrhizae Radix et Rhizoma (SMRR) polysaccharide was isolated by hot water extraction and ethanol precipitation, and then purified by DEAE anion exchange chromatography and gel filtration. With a high-fat-diet-induced obesity/NAFLD mouse model, we found that consumption of the SMRR polysaccharide could remarkably reverse obesity and its related progress of NAFLD, including attenuated hepatocellular steatosis, hepatic fibrosis and inflammation. In addition, we also reveal the potential mechanism behind these is that the SMRR polysaccharide could regulate the gut–liver axis by modulating the homeostasis of gut microbiota and thereby improving intestinal function.

Inflammatory Bowel Disease-associated Fatty Liver Disease: the Potential Effect of Biologic Agents

Inflammatory bowel diseases [IBD] exhibit intestinal and systemic manifestations. Nonalcoholic fatty liver disease [NAFLD] is a common co-existing condition, possibly contributing to the cardio-metabolic burden and overall morbidity. Εmerging therapeutic choices of biologic agents have modified the clinical course of IBD; however, their impact on IBD-associated NAFLD has not been extensively evaluated. The prevalence of NAFLD varies among IBD patients, but it appears higher than in the general population in the majority of quality studies. In terms of pathogenetic and risk factors of NAFLD, they may vary with IBD activity. Dysbiosis, mucosal damage, and cytokine release have been implicated in the pathogenesis during the relapses, whereas metabolic risk factors seem to play a dominant role during the remissions of IBD. Considering biologics, although quality data are scarce, agents suppressing tumour necrosis factor may offer potential benefits in IBD-associated NAFLD, whereas anti-integrins do not appear to confer any therapeutic advantage. In conclusion, IBD-associated NAFLD possibly follows two different patterns, one manifested during the relapses and one during the remissions of IBD. Some, but not all, biologics may benefit NAFLD in patients with IBD. Further mechanistic and prospective cohort studies are warranted to illuminate the effects of various biologics on NAFLD.

The Impact of NAFLD on Hospitalization Outcomes in Patients With Inflammatory Bowel Diseases: Nationwide Analysis

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is highly prevalent in patients with inflammatory bowel diseases (IBD). Yet, the impact of NAFLD on outcomes, along with the contribution of nonmetabolic factors to NAFLD development, is unclear. To investigate these topics, we conducted a nationwide study examining the impact of NAFLD on hospitalization outcomes in IBD patients after adjusting for metabolic factors.

METHODS

Patients with IBD-related hospitalizations were identified using the Nationwide Readmissions Database from 2016 to 2018. Inflammatory bowel disease patients with and without NAFLD were matched based on IBD type, age, sex, metabolic syndrome, and diabetes mellitus. Primary outcomes were IBD-related readmission, IBD-related surgery, and death. Secondary outcomes were length of stay (LOS) and cost of care (COC). The primary multivariable model adjusted for obesity, dyslipidemia, Charlson-Deyo comorbidity index, hospital characteristics, payer, patient income, and elective status of admissions.

RESULTS

Nonalcoholic fatty liver disease was associated with a higher risk of IBD-related readmission (adjusted hazard ratio, 1.90; P < .01) and death (adjusted hazard ratio, 2.73; P < .01), 0.71-day longer LOS (P < .01), and $7312 higher COC (P < .01) in those with Crohn's disease. Nonalcoholic fatty liver disease was also associated with a higher risk of IBD-related readmission (adjusted hazard ratio, 1.65; P < .01), 0.64-day longer LOS (P < .01), and $9392 (P < .01) higher COC, but there was no difference in death in those with UC. No differences in risk of IBD-related surgery were observed.

CONCLUSIONS

Nonalcoholic fatty liver disease is associated with worse hospitalization outcomes in IBD patients after adjusting for metabolic factors. These data suggest nonmetabolic factors may be implicated in the pathogenesis of NAFLD in IBD patients and may contribute to worsened clinical outcomes.

Mendelian Randomization Rules Out Causation Between Inflammatory Bowel Disease and Non-Alcoholic Fatty Liver Disease

Background: Inflammatory bowel disease (IBD) and non-alcoholic fatty liver disease (NAFLD) usually co-exist clinically. However, whether such association is causal is still unknown.

Methods: Genetic variants were extracted as instrumental variables from the largest genome-wide association study (GWAS) of IBD, Crohn’s disease (CD) and ulcerative colitis (UC) with 25,042 cases and 34,915 controls (GWAS p-value < 5 × 10⁻⁸). Information of genetic variants in NAFLD was extracted from a GWAS with 1,483 cases and 17,781controls. Also, liver fat content (LFC) was included as the outcome. Then, a bi-direction Mendelian randomization (MR) was carried out to appraise the causal relationship between NAFLD on IBD. Besides, a multivariable MR (MVMR) design was carried to adjust for body mass index (BMI) and type 2 diabetes (T2D) as well.

Results: Generally, IBD might not affect the risk of NAFLD (OR = 0.994 [0.970, 1.019]), together with its subtypes including UC and CD. However, genetically-elevated risk of IBD might cause liver fat accumulation (beta = 0.019, p-value = 0.016) while turning insignificant at Bonferroni correction. Besides, no causal effect of NAFLD on IBD was observed (OR = 0.968 [0.928, 1.009]), together with UC and CD. Also, genetically-elevated LFC could not impact IBD, UC and CD either. The MR CAUSE analysis supported these null associations and MVMR analysis also supported such null associations even after adjusting for BMI and T2D.

Conclusion: This MR study ruled out the causal relationship between IBD and NAFLD, suggesting therapeutics targeting NAFLD might not work for IBD and vice versa.

Glucocorticosteroids and the Risk of NAFLD in Inflammatory Bowel Disease

Each year, the incidence of nonalcoholic fatty liver (NAFLD) disease increases. NAFLD is a chronic disease. One of the most common causes of NAFLD is an inadequate lifestyle, which is characterized by a lack or low physical activity and eating highly processed foods rich in saturated fat and salt and containing low amount of fiber. Moreover, disturbances in intestinal microbiome and the use of certain drugs may predispose to NAFLD. NAFLD is an increasingly described disease in patients with inflammatory bowel disease (IBD). Recent data also indicate a frequent coexistence of metabolic syndrome in this group of patients. Certain groups of drugs also increase the risk of developing inflammation, liver fibrosis, and cirrhosis. Particularly important in the development of NAFLD are steroids, which are used in the treatment of many diseases, for example, IBD. NAFLD is one of the most frequent parenteral manifestations of the disease in IBD patients. However, there is still insufficient information on what dose and exposure time of selected types of steroids may lead to the development of NAFLD. It is necessary to conduct further research in this direction. Therefore, patients with IBD should be constantly monitored for risk factors for the development of NAFLD.

Meta-analysis: prevalence of, and risk factors for, non-alcoholic fatty liver disease in patients with inflammatory bowel disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is found in inflammatory bowel disease (IBD). However, uncertainties remain on the magnitude of the association.

AIMS

To explore systematically the prevalence of, and risk factors for, NAFLD in IBD patients.

METHODS

We searched medical literature using Embase, PubMed, Web of Science, Scopus and ProQuest, from inception to September 30, 2021. We included observational studies reporting the prevalence of NAFLD in ≥50 adult patients with IBD. Diagnosis of NAFLD could be based on imaging, histopathology, and/or hepatic steatosis index. Sex, age, body mass index (BMI), diabetes, hypertension, dyslipidemia, prior surgery (bowel resection), corticosteroids, biologics and immunomodulators were assessed as potential risk factors for NAFLD.

RESULTS

Of 1893 citations, 44 eligible studies were finally included, comprising 14 947 subjects from 18 different countries. Pooled prevalence of NAFLD was 30.7% (95% confidence interval [CI] 26.5-34.9) in patients with IBD worldwide, which varied regionally. No significant difference was observed in the odds ratio (OR) of NAFLD among Crohn's disease (CD) patients compared with ulcerative colitis (UC) patients (1.16, 95% CI 0.93-1.44). Risk of NAFLD was almost twice as high in patients with IBD as in healthy subjects (OR 1.96, 95% CI 1.13-3.41). Age (adjusted OR 1.03, 95% CI 1.01-1.05) and BMI (adjusted OR 1.27, 95% CI 1.22-1.32) were statistically significantly associated with increased risk of NAFLD. The pooled prevalence of advanced liver fibrosis in IBD patients with NAFLD was 13.6% (95% CI 7.6-19.7) based on six studies.

CONCLUSION

Up to one-third of patients with IBD experienced NAFLD worldwide. The risk of NAFLD was two times higher in IBD patients versus healthy subjects.

Hepatobiliary manifestations in inflammatory bowel disease: A practical approach

Inflammatory bowel diseases (IBD) are associated with various hepatobiliary disorders. They can occur at any moment in the course of the disease or associated with the treatment. The prevalence of liver dysfunction can reach up to 50% in different studies. Nonalcoholic fatty liver disease is considered the most common hepatobiliary complication in IBD, while primary sclerosing cholangitis is the most specific. Management of hepatic manifestations in IBD involves a multidisciplinary approach that includes a high index of suspicion and joint management with hepatologists. The medical confrontation with abnormal liver tests must include an exhaustive study to determine if these patterns can be related to IBD, associated diseases or to the therapies used.

Analysis of Common Pathways and Markers From Non-Alcoholic Fatty Liver Disease to Immune-Mediated Diseases

Metabolic associated fatty liver disease (MAFLD) is the most prevalent form of liver disease worldwide, accounting for a high liver-related mortality and morbidity with extensive multi-organ involvement. This entity has displaced viral hepatitis as the main cause of severe forms of hepatic diseases, although the onset and transition of MAFLD stages still remains unclear. Nevertheless, innate and adaptive immune responses seem to play an essential role in the establishment and further progression of this disease. The immune system is responsible of safeguard and preserves organs and systems function, and might be altered under different stimuli. Thus, the liver suffers from metabolic and immune changes leading to different injuries and loss of function. It has been stablished that cell-cell crosstalk is a key process in the hepatic homeostasis maintenance. There is mounting evidence suggesting that MAFLD pathogenesis is determined by a complex interaction of environmental, genetic and host factors that leads to a full plethora of outcomes. Therefore, herein we will revisit and discuss the interplay between immune mechanisms and MAFLD, highlighting the potential role of immunological markers in an attempt to clarify its relationship.

Liver involvement in inflammatory bowel disease: What should the clinician know?

Inflammatory bowel disease (IBD) may show a wide range of extraintestinal manifestations. In this context, liver involvement is a focal point for both an adequate management of the disease and its prognosis, due to possible serious comorbidity. The association between IBD and primary sclerosing cholangitis is the most known example. This association is relevant because it implies an increased risk of both colorectal cancer and cholangiocarcinoma. Additionally, drugs such as thiopurines or biologic agents can cause drug-induced liver damage; therefore, this event should be considered when planning IBD treatment. Additionally, particular consideration should be given to the evidence that IBD patients may have concomitant chronic viral hepatitis, such as hepatitis B and hepatitis C. Chronic immunosuppressive regimens may cause a hepatitis flare or reactivation of a healthy carrier state, therefore careful monitoring of these patients is necessary. Finally, the spread of obesity has involved even IBD patients, thus increasing the risk of non-alcoholic fatty liver disease, which has already proven to be more common in IBD patients than in the non-IBD population. This phenomenon is considered an emerging issue, as it will become the leading cause of liver cirrhosis.

Non-alcoholic fatty liver disease in patients with intestinal, pulmonary or skin diseases: Inflammatory cross-talk that needs a multidisciplinary approach

Non-alcoholic fatty liver disease (NAFLD) is currently considered the most common cause of liver disease. Its prevalence is increasing in parallel with the obesity and type 2 diabetes mellitus (DM2) epidemics in developed countries. Several recent studies have suggested that NAFLD may be the hepatic manifestation of a systemic inflammatory metabolic disease that also affects other organs, such as intestine, lungs, skin and vascular endothelium. It appears that local and systemic proinflammatory/anti-inflammatory cytokine imbalance, together with insulin resistance and changes in the intestinal microbiota, are pathogenic mechanisms shared by NAFLD and other comorbidities. NAFLD is more common in patients with extrahepatic diseases such as inflammatory bowel disease (IBD), obstructive syndrome apnea (OSA) and psoriasis than in the general population. Furthermore, there is evidence that this association has a negative impact on the severity of liver lesions. Specific risk characteristics for NAFLD have been identified in populations with IBD (i.e. age, obesity, DM2, previous bowel surgery, IBD evolution time, methotrexate treatment), OSA (i.e. obesity, DM2, OSA severity, increased transaminases) and psoriasis (i.e. age, metabolic factors, severe psoriasis, arthropathy, elevated transaminases, methotrexate treatment). These specific phenotypes might be used by gastroenterologists, pneumologists and dermatologists to create screening algorithms for NAFLD. Such algorithms should include non-invasive markers of fibrosis used in NAFLD to select subjects for referral to the hepatologist. Prospective, controlled studies in NAFLD patients with extrahepatic comorbidities are required to demonstrate a causal relationship and also that appropriate multidisciplinary management improves these patients’ prognosis and survival.

Anti-TNFα treatment in Crohn's disease: Impact on hepatic steatosis, gut-derived hormones and metabolic status

BACKGROUND AND AIMS

An association between Crohn's disease (CD) and hepatic steatosis has been reported. However, the underlying mechanisms of steatosis progression in CD are not clear. Among the most effective CD treatments are agents that inhibit Tumor-Necrosis-Factor (TNF) activity, yet it is unclear why anti-TNFα agents would affect steatosis in CD. Recent studies suggest that microbiome can affect both, CD and steatosis pathogenesis. Therefore, we here analysed a potential relationship between anti-TNF treatment and hepatic steatosis in CD, focusing on the gut-liver axis.

METHODS

This cross-sectional study evaluated patients with established CD, with and without anti-TNFα treatment, analysing serum markers of liver injury, measurement of transient elastography, controlled attenuation parameter (CAP) and MRI for fat detection. Changes in lipid and metabolic profiles were assessed by serum and stool lipidomics and metabolimics. Additionally, we analysed gut microbiota composition and mediators of bile acid (BA) signalling via stool and serum analysis.

RESULTS

Patients on anti-TNFα treatment had less hepatic steatosis as assessed by CAP and MRI. Serum FGF19 levels were significantly higher in patients on anti-TNFα therapy and associate with reduced steatosis and increased bowel motility. Neutral lipids including triglycerides were reduced in the serum of patients on anti-TNF treatment. Bacteria involved in BA metabolism and FGF19 regulation, including Firmicutes, showed group-specific alterations with low levels in patients without anti-TNFα treatment. Low abundance of Firmicutes was associated with higher triglyceride levels.

CONCLUSIONS

Anti-TNFα treatment is associated with reduced steatosis, lower triglyceride levels, alterations in FXR-signalling (eg FGF19) and microbiota composition in CD.

Hepatobiliary phenotype of individuals with chronic intestinal disorders

Despite the known functional relationship between the gut and the liver, the clinical consequences of this circuit remain unclear. We assessed the hepatobiliary phenotype of cohorts with celiac disease (CeD), Crohn´s disease (CD) and ulcerative colitis (UC). Baseline liver function tests and the frequency of hepatobiliary diseases were analyzed in 2377 CeD, 1738 CD, 3684 UC subjects and 488,941 controls from the population-based UK Biobank cohort. In this cohort study associations were adjusted for age, sex, BMI, diabetes, and alcohol consumption. Compared to controls, cohorts with CeD, but not CD/UC displayed higher AST/ALT values. Subjects with CD/UC but not CeD had increased GGT levels. Elevated ALP and cholelithiasis were significantly more common in all intestinal disorders. Non-alcoholic steatohepatitis and hepatocellular carcinoma (HCC) were enriched in CeD and CD (NASH: taOR = 4.9 [2.2-11.0] in CeD, aOR = 4.2 [1.7-10.3] in CD, HCC: aOR = 4.8 [1.8-13.0] in CeD, aOR = 5.9 [2.2-16.1] in CD), while cholangitis was more common in the CD/UC cohorts (aOR = 11.7 [9.1-15.0] in UC, aOR = 3.5 [1.8-6.8] in CD). Chronic hepatitis, autoimmune hepatitis (AIH) and cirrhosis were more prevalent in all intestinal disorders. In UC/CD, a history of intestinal surgery was associated with elevated liver enzymes and increased occurrence of gallstones (UC: aOR = 2.9 [2.1-4.1], CD: 1.7 [1.2-2.3]). Our data demonstrate that different intestinal disorders predispose to distinct hepatobiliary phenotypes. An increased occurrence of liver cirrhosis, NASH, AIH and HCC and the impact of surgery warrant further exploration.

Nonalcoholic Fatty Liver Disease Is Common in IBD Patients However Progression to Hepatic Fibrosis by Noninvasive Markers Is Rare

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disorder in western countries and an increasing cause of end-stage liver disease and hepatocellular carcinoma. NAFLD is known to coexist in patients with inflammatory bowel disease (IBD). This study aims to examine the prevalence of NAFLD, as well as trends in NAFLD-associated fibrosis, in a well-characterized IBD cohort utilizing a validated noninvasive test.

METHODS

We conducted a single-center retrospective chart review of patients at a large academic IBD center between 2007 and 2017. Patients with IBD and concurrent hepatic steatosis were identified. Charts were reviewed for baseline characteristics and laboratory data in order to calculate and trend NAFLD progression over time by a noninvasive marker, the NAFLD fibrosis score (NFS).

RESULTS

Of 207 patients with IBD and concurrent NAFLD, NFS was able to be calculated for 138 patients at index diagnosis. A subsequent NFS was able to be calculated at 5-year follow-up for 56 patients. Over 5 years, 9 patients (16%) had worsening in NFS category, 4 patients (7%) had improvement in NFS category, and the remaining 43 patients (77%) stayed within their index NFS category.

CONCLUSIONS

IBD patients with NAFLD tend to have stable liver disease over 4-6 years, and the risk of liver disease progression is low. This is the first study to document the progression of NAFLD by noninvasive testing over time.

Gut inflammation exacerbates high-fat diet induced steatosis by suppressing VLDL-TG secretion through HNF4α pathway

Nonalcoholic fatty liver disease (NAFLD) is increasingly identified in inflammatory bowel disease (IBD) patients with unclear etiology. In the current study we assessed the contribution of colonic inflammation to NAFLD development and the underlying mechanism in a mouse model for IBD. Our results showed that dextran sulfate sodium (DSS)-induced gut colitis directly led to hepatic inflammation, injury and further exacerbated hepatic steatosis caused by high fat diet (HF) feeding. The essential genes assessment, hepatic metabolic analysis and triglyceride-rich very low-density lipoprotein (VLDL-TG) secretion assays revealed a higher β-oxidation of fatty acids (FAs) but impaired VLDL-TG secretion in liver of DSS-treated mice. Disruption of the intestinal barrier by DSS promoted liver inflammation, which strongly suppressed hepatic VLDL-TG secretion and further aggravated HF-induced VLDL-TG secretion impairment through down-regulation of apolipoprotein B (APOB), hence promoting the storage of triglycerides (TG) in the liver. Inflammation induced by mixed proinflammatory cytokines or LPS obviously inhibited the expression of microsomal triglyceride transfer protein (MTP) and APOB expression and subsequently increased TG content via the suppression of HNF4α in mouse primary hepatocytes. In addition, the downregulation of MTP and APOB by proinflammatory cytokines was also rescued through activating Hnf4α by cortisol. Altogether, our results demonstrated that chronic inflammation exacerbated hepatic steatosis by inhibiting the secreting of hepatic VLDL-TG through HNF4α pathway, suggesting that restoring hepatic VLDL-TG secretion may be a novel strategy for treatment of NAFLD in IBD.

Noninvasive assessment of liver fibrosis in Crohn's disease patients exposed to methotrexate

BACKGROUND

Methotrexate is widely used to treat some inflammatory chronic disorders, though it is hampered by the risk of liver fibrosis. Many recommendations have been made to assess methotrexate-related hepatotoxicity, including liver biopsy. However, other noninvasive methods to assess liver fibrosis have been developed and could be implemented for patients treated with methotrexate.

AIM

The aim of the study was to compare the prevalence of liver fibrosis by means of noninvasive methods [aspartate transaminase-to-platelet ratio index (APRI) Forns index, and transient elastography] in patients with Crohn's disease exposed or not to methotrexate, and to identify risk factors for liver fibrosis.

METHODS

Prospective, cross-sectional study. All patients with Crohn's disease exposed to methotrexate were included and compared to an unselected cohort of outpatients with Crohn's disease never exposed to methotrexate.

RESULTS

A total of 84 patients with Crohn's disease, 56 exposed to methotrexate, and 28 controls, were included. Significant liver fibrosis was found in 7% of methotrexate-exposed patients with Crohn's disease and 10% of controls as measured by transient elastography, and in 7% of controls as measured by the Forns index. No cases of liver fibrosis were detected by APRI. Only alcohol consumption, diabetes mellitus, and age were associated with significant liver fibrosis.

CONCLUSIONS

Significant liver fibrosis is uncommon among patients with Crohn's disease, even among those exposed to methotrexate. The risk of liver fibrosis in Crohn's disease seems to depend on common risk factors for liver disease.

Evaluation of non-alcoholic fatty liver disease in patients with inflammatory bowel disease using controlled attenuation parameter technology: A Taiwanese retrospective cohort study

Background/purpose

An increased prevalence of non-alcoholic fatty liver disease (NAFLD) is observed in patients with inflammatory bowel disease (IBD) in Western countries. Both intestinal inflammation and metabolic factors contribute to the pathogenesis of IBD-associated NAFLD. The burden of NAFLD is not clear in the Asian population. This study aimed to evaluate the prevalence of NAFLD and liver fibrosis in a cohort of Taiwanese patients with IBD.

Methods

From January to December 2019, patients with IBD who underwent ultrasound examination were enrolled. Hepatic steatosis and fibrosis were measured with liver stiffness measurement (LSM) and controlled attenuation parameter (CAP) using FibroScan. Patients with a history of excessive alcohol or recent steroid use were excluded. Univariate and multivariate analysis were performed.

Results

A total of 81 consecutive patients were enrolled and included in the analysis (45 with ulcerative colitis, 36 with Crohn’s disease). The median age was 42 years old. The patients were classified in terms of body mass index as normal weight (54.3%), underweight (11.1%), overweight (28.4%), and obese (6.2%). The mean CAP increased to 162.22 dB/m in the underweight group, 210.86 dB/m in the normal weight group, 260.7 dB/m in the overweight group, and 274.0 dB/m in the obese group. NAFLD was observed in 29.6% of the patients, 1.2% of which had significant fibrosis. Increased body mass index (odds ratio [OR] 1.33, 95% confidence interval [CI] 1.1–1.62) and older age at IBD diagnosis (OR: 1.05, 95% CI 1–1.11) was found to be associated with the presence of NAFLD.

Conclusion

In this study, the prevalence of NAFLD was lower (29.6%) in IBD patients than in the Western population. Higher BMI and older age were associated with NAFLD in our study.

Evaluation of Nonalcoholic Fatty Liver Disease in Pediatric Patients With Inflammatory Bowel Disease

Adult studies demonstrate the co-existence of nonalcoholic fatty liver disease (NAFLD) and inflammatory bowel disease (IBD) without traditional risk factors. Data in children with IBD are lacking. Here, we sought to establish the prevalence of NAFLD in a single-center pediatric IBD cohort, and identify potential risk factors. After institutional review board approval, we enrolled children with IBD who underwent routine abdominal magnetic resonance enterography. Proton density fat fraction (PDFF) was then estimated on magnetic resonance enterography. A total of 83 patients with IBD were identified and PDFF maps completed. Five (6%) were found to have PDFF >5%, meeting criteria for NAFLD. Compared to the patients with IBD without NAFLD, none of the evaluated risk factors including age, sex, diagnosis, time since diagnosis, medication, median alanine aminotransferase, and weight status were statistically significant. Our findings demonstrate the occult nature of NAFLD in pediatric IBD. The prevalence is not at variance with what is expected in general teenage populations.

Prevalence and risk factors of nonalcoholic fatty liver disease in patients with inflammatory bowel diseases: A cross-sectional and longitudinal analysis

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is common in the German population, with an even higher prevalence in inflammatory bowel disease patients.

AIM

To investigate the risk factors for NAFLD in inflammatory bowel disease patients.

METHODS

This monocentric retrospective study with a cross-sectional and a longitudinal part included 694 patients. Inclusion criteria were diagnosed inflammatory bowel disease, age ≥ 18 years, availability of at least one abdominal ultrasound. Patients with infectious or suspected alcoholic fatty liver disease were excluded. NAFLD was defined by increased echogenicity at liver ultrasound. Demographic characteristics, disease activity and medications were analyzed as potential risk factors. Parameters influencing the course of NAFLD were identified by a generalized linear mixed model.

RESULTS

Forty-eight percent of Crohn’s disease (CD) patients and 44% of ulcerative colitis patients suffered from NAFLD. Its occurrence was associated with greater age, hypertension and body mass index (BMI) in both groups, and with higher disease activity and dyslipidemia in CD. 2467 ultrasound results were included in the longitudinal analysis. Risk factors for NAFLD were age, BMI, higher disease activity, bowel resection(s), endoscopic activity and azathioprine use in CD; and BMI and endoscopic activity in ulcerative colitis.

CONCLUSION

NAFLD was highly prevalent in this cohort of German inflammatory bowel disease patients. Its risk increased mainly with rising age and BMI. This analysis provides a rationale for non-invasive liver screening in inflammatory bowel disease patients.

Liver steatosis is a risk factor for hepatotoxicity in inflammatory bowel disease patients treated with azathioprine

BACKGROUND AND AIMS

The literature demonstrates that hepatic steatosis reduces the tolerance of immunosuppression in people with inflammatory bowel disease. It also shows that elevated methylmercaptopurine may be responsible for thiopurine-induced hepatitis. This exploratory study investigates the relationship between hepatic steatosis, methylmercaptopurine and alanine transaminase.

METHODS

We performed a retrospective review of patients started on azathioprine treatment at University Hospitals Bristol NHS Foundation Trust between 2014 and 2017. There were 600 patients in total. Ninety-one patients met our inclusion criteria which were at least one ultrasound scan commenting on the appearance of the liver, liver function tests at commencement of azathioprine and liver function tests and a methylmercaptopurine level between 6 and 8 weeks after starting treatment.

RESULTS

Of 91 patients included in our study, 32 patients (32%) were identified as having radiological hepatic steatosis on ultrasound imaging and 59 patients had no evidence of steatosis. We found a positive association between methylmercaptopurine levels and change in alanine transaminase in patients with hepatic steatosis (P < 0.001) but not in those with a normal liver on ultrasound imaging.

CONCLUSION

We conclude that the higher levels of methylmercaptopurine may be a risk factor for hepatitis in patients with hepatic steatosis but not in those with a normal liver.

Aortic Stiffening Is an Extraintestinal Manifestation of Inflammatory Bowel Disease: Review of the Literature and Expert Panel Statement

Current guidelines state that systemic inflammation, together with endothelial dysfunction, calcification, and hypercoagulability, predispose to premature atherosclerosis in patients with inflammatory bowel disease (IBD). We assessed whether IBD can affect aortic stiffness, a well-recognized vascular biomarker and an independent risk factor for cardiovascular (CV) disease (CVD) in several populations. Recent studies reported that aortic stiffness is increased in adults with IBD compared with matched controls. This association is dependent on inflammatory burden and disease duration, and is reduced by antitumor necrosis factor therapy. Considered together, current findings suggest that increased aortic stiffness is an extraintestinal manifestation of IBD. This is clinically relevant since measuring aortic stiffness in patients with IBD could improve risk assessment, especially in those without established CVD. Moreover, effective control of inflammation could lower CV risk in patients with IBD by reducing aortic stiffness. Further longitudinal studies are needed to better clarify (i) the relationship between disease duration and irreversible changes of the arterial wall, (ii) the clinical characteristics of patients with IBD that have an increased arterial stiffness at least in part reversible, and (iii) whether arterial stiffness is useful to evaluate the efficacy of immunosuppressive therapy.

Prevalence of Nonalcoholic Fatty Liver Disease in Patients With Inflammatory Bowel Disease: A Systematic Review and Meta-analysis

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a significant public health burden, with up to 30% of the US population affected. The prevalence of NAFLD among inflammatory bowel disease (IBD) patients is unknown. Understanding risk factors for NAFLD in IBD patients has implications in the treatment of these patients. The purpose of this study was to determine the prevalence of NAFLD among IBD patients and to identify risk factors associated with NAFLD development.

METHODS

Embase and MEDLINE databases were searched using Medical Subject Headlines to find studies that assessed the prevalence of NAFLD among IBD patients. Twenty-seven English-language research abstracts/articles were identified between January 2005 and April 2018. Meta-analyses were performed using random-effects models. Prevalence of NAFLD among IBD patients was compared with prevalence of NAFLD in the general population.

RESULTS

Based on data pooled from all 27 studies, the prevalence of NAFLD among IBD patients was 32% (95% CI, 24%-40%) with substantial heterogeneity (I2 = 98%). The prevalence of NAFLD among IBD patients (32%) is statistically significantly higher than the prevalence of NAFLD in the general population (25.2%; P < 0.001). Factors associated with the development of NAFLD among IBD patients included age, BMI, diabetes, IBD duration, and prior history of bowel resection.

CONCLUSIONS

There is a higher prevalence of NAFLD among IBD patients compared with the general population. Previous treatment regimens may be a risk factor for the development of NAFLD. Future studies are needed to further clarify these risk factors and determine screening recommendations.

Hepatobiliary manifestations in children with inflammatory bowel disease: A single-center experience in a low/middle income country

BACKGROUND

There has been a worldwide increase in the reported incidence of inflammatory bowel disease (IBD) in children over the past 2-3 decades. The hepatobiliary (HB) manifestations of IBD have been well-studied in children in industrialized and developed countries but are infrequently reported in low- and middle-income countries (LMIC) such as Egypt.

AIM

To determine the prevalence of the HB manifestations in a cohort of Egyptian children with IBD.

METHODS

This cross-sectional observational study was carried out over a period of 6 mo (between June 2013 to December 2013) at the Paediatric Hepatology and Gastroenterology Units of Cairo University Children's Hospital, which is the largest paediatric tertiary care centre in the country.

RESULTS

The study included 48 patients with confirmed IBD based upon clinical, laboratory, endoscopic and histopathological features, 29 (60.4%) were male. Twenty-four patients (50%) had ulcerative colitis (UC), 11 (22.9%) had Crohn's disease (CD) and 13 (27.1%) had unclassified-IBD (IBD-U), which was formerly known as indeterminate colitis. The mean age of the patients at the time of presentation was 8.14 (± SD 4.02) years and the mean age at the time of study enrolment was 10.16 (± SD 4.19) years. All patients were screened for HB manifestations by physical examination, liver function tests, imaging and liver biopsy when indicated. HB disorders were confirmed in 13 patients (27.1%). Transaminases were elevated in 3 patients (6.3%). Two patients (4.2%) had elevated biliary enzymes (one was diagnosed as primary sclerosing cholangitis (PSC) and the other was diagnosed with PSC/autoimmune hepatitis overlap syndrome and the third patient had hepatitis C virus infection. Ten patients (20.8%) had bright echogenic liver on ultrasound suggesting fatty infiltration as a sequel of malnutrition or medication toxicity.

CONCLUSION

The commonest HB disorders in Egyptian children with IBD were abnormal liver function tests, fatty infiltration and PSC. These HB manifestations in paediatric patients in LMIC may be relatively more common than in industrialized countries. Therefore, IBD patients in LMIC should be meticulously screened for liver disease to allow prompt diagnosis and management.

A comparison of the efficacy and safety of complementary and alternative therapies for ulcerative colitis: A protocol for systematic review and meta-analysis

BACKGROUND

The incidence of ulcerative colitis (UC) is increasing year by year worldwide, and it is listed as one of the refractory diseases by World Health Organization. In addition to typical intestinal manifestations such as abdominal pain, diarrhea, mucus, pus, and bloody stool, it can also accompany multiorgan and multisystem extraintestinal manifestations, seriously affecting the life and work of patients. Furthermore, UC patients with a tremendous psychological pressure and affects their physical and mental health. In recent years, many complementary and alternative therapies have been used for treatment of UC, but only pair-wised drugs have been evaluated in the traditional meta-analyses and some results are inconsistent. Consequently, it is essential to propose a protocol for systematic review and meta-analysis to discuss the efficacy and safety of complementary and alternative therapies in the treatment of UC.

METHODS

We will search Chinese and English databases comprehensively and systematically from the establishment of databases to May 2020, free of language or publication restrictions. All randomized controlled trials on complementary and alternative therapies for UC will be included. Two researchers will independently screen titles, abstracts, full texts, and extract data, then assess the bias risk of each study. We will conduct pairwise meta-analyses and Bayesian network meta-analyses to the relative outcomes of the efficacy and safety. Data analysis will use STATA and WinBUGs 1.4.3 software in this meta-analysis.

RESULTS

This study will evaluate the efficacy and safety of complementary and alternative therapies for UC based on changes in symptoms, clinical efficacy, quality of life and adverse events.

CONCLUSION

This study will provide evidence for whether complementary and alternative therapies are beneficial to the treatment of UC. In order to provide reliable evidence-based medicine for clinical practice.

INPLASY REGISTRATION NUMBER

INPLASY202060015.