Derivation and Internal Validation of a Clinical Prediction Tool to Predict Nonalcoholic Fatty Liver Disease in Patients With Crohn's Disease

NAFLD Is Associated With Quiescent Rather Than Active Crohn's Disease

BACKGROUND AND AIMS

Crohn's disease (CD) confers an increased risk of nonalcoholic fatty liver disease (NAFLD), but the pathogenesis remains poorly understood. We determined if active intestinal inflammation increases the risk of NAFLD in patients with CD.

METHODS

Two cohorts (2017/2018 and 2020) with CD and no known liver disease were enrolled consecutively during staging magnetic resonance enterography. We quantified proton density fat fraction, MaRIA (Magnetic Resonance Index of Activity), and visceral adipose tissue. NAFLD was diagnosed when proton density fat fraction ≥5.5%. Synchronous endoscopy was graded by the Simple Endoscopic Score for CD and Rutgeerts score, while clinical activity was graded by the Harvey-Bradshaw index. Cytokine profiling was performed for the 2020 cohort. Transient elastography and liver biopsy were requested by standard of care.

RESULTS

NAFLD was diagnosed in 40% (n = 144 of 363), with higher prevalence during radiographically quiescent disease (odds ratio, 1.7; P = .01), independent of body mass index/visceral adipose tissue (adjusted odds ratio, 7.8; P = .03). These findings were corroborated by endoscopic disease activity, but not by aggregate clinical symptoms. Circulating interleukin-8 was independent of body mass index to predict NAFLD, but traditional proinflammatory cytokines were not. NAFLD subjects had similar liver stiffness estimates regardless of CD activity. Definitive or borderline steatohepatitis was present in most patients that underwent liver biopsy.

CONCLUSIONS

Quiescent CD is associated with risk of NAFLD. These findings suggest potentially distinct pathogenic mechanisms of NAFLD in patients with CD compared with the prevailing leaky gut hypothesis proposed for individuals without inflammatory bowel disease. Future validation and mechanistic studies are needed to dissect these distinct disease modifying factors.

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.

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.

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.

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.

The evaluation of liver abnormalities in inflammatory bowel disease patients

PURPOSE OF REVIEW

Develop a clinical presentation-based approach for common liver abnormalities encountered by providers caring for patients with inflammatory bowel disease (IBD). Develop a treatment pathway for those with nonalcoholic fatty liver disease (NAFLD) arising in IBD. Discuss recent studies of prevalence, incidence, risk factors, and prognosis NAFLD in the IBD population.

RECENT FINDINGS

The work-up for liver abnormalities should be approached systematically in IBD patients, similar to the general population, while still appreciating the differing prevalence of underlying liver diagnoses. Although immune mediated liver diseases occur commonly in patients with IBD, NAFLD is still the most common liver disease in patients with IBD paralleling its expanding prevalence in the general population. IBD is also an independent risk factor for NAFLD, developing in many patients with lower degrees of adiposity. Furthermore, the more severe histologic subtype, nonalcoholic steatohepatitis, is both more common and difficult to treat considering the lower effectiveness of weight loss interventions.

SUMMARY

Having a standard approach to the most common liver disease presentations and care pathway for NAFLD will improve the quality of care provided and ease the medical decision making complexity for IBD patients. The early identification of these patients should prevent the development of irreversible complications like cirrhosis or hepatocellular carcinoma.

Nonalcoholic Fatty Liver Disease Is a Risk Factor for Thiopurine Hepatotoxicity in Crohn's Disease

Background

Patients with Crohn's disease (CD) are predisposed to nonalcoholic fatty liver disease (NAFLD). CD management often includes thiopurines which can promote hepatotoxicity. We aimed to identify the role of NAFLD on the risk of developing liver injury from thiopurines in CD.

Methods

In this prospective cohort analysis, CD patients at a single center were recruited 6/2017-5/2018. Patients with alternative liver diseases were excluded. The primary outcome was time to elevation of liver enzymes. Patients underwent MRI with assessment of proton density fat fraction (PDFF) on enrollment, where NAFLD was defined as PDFF >5.5%. Statistical analysis was performed using a Cox-proportional hazards model.

Results

Of the 311 CD patients studied, 116 (37%) were treated with thiopurines, 54 (47%) of which were found to have NAFLD. At follow-up, there were 44 total cases of elevated liver enzymes in those treated with thiopurines. Multivariable analysis demonstrated that NAFLD was a predictor of elevated liver enzymes in patients with CD treated with thiopurines (HR 3.0, 95% CI 1.2-7.3, P = .018) independent of age, body mass index, hypertension, and type 2 diabetes. Steatosis severity by PDFF positively correlated with peak alanine aminotransferase (ALT) at follow-up. Kaplan-Meier analysis demonstrated poorer complication-free survival (log-rank 13.1, P < .001).

Conclusions

NAFLD at baseline is a risk factor for thiopurine-induced hepatotoxicity in patients with CD. The degree of liver fat positively correlated with the degree of ALT elevation. These data suggest that evaluation for hepatic steatosis be considered in patients with liver enzyme elevations with thiopurine therapy.

Prevalence and predictors of non-alcoholic liver disease on MRI among patients with Crohn's disease

BACKGROUND

It has been documented that Crohn's disease (CD) patients were prone to develop non-alcoholic liver fatty liver disease (NAFLD) with less metabolic factors. Our purpose is to investigate the prevalence, clinical characteristics and possible indicators for NAFLD in a cohort of Chinese patients with CD.

METHODS

Established CD patients who underwent magnetic resonance enterography (MRE) at the gastroenterology unit of our hospital were consecutively enrolled between June 2018 and May 2020. The diagnosis of NAFLD was made by magnetic resonance proton density fat fraction (MR-PDFF) maps. Medical records during hospitalization were collected and examined by univariate and multivariate analyses. Then a predictive model was constructed based on logistic regression analysis to evaluate the risk of developing NAFLD.

RESULTS

A total of 340 CD subjects were enrolled in this study, 83 (24.4%) suffered from NAFLD. Compared with those without NAFLD, patients with NAFLD showed longer disease duration, higher body mass index (BMI), more frequent use of corticosteroid and pronouncedly elevated liver function tests. The comparison showed no difference in terms of prolonged anti tumor necrosis factor-α (TNF-α) use (> 54w). Multivariate analysis demonstrated that BMI, serum transaminase, pre-albumin and disease duration could independently predict hepatic steatosis.

CONCLUSION

NAFLD is frequent in chronic CD patients, while long term use of anti TNF-α seems to have no impact on the development of NAFLD in this population. The model incorporating duration, serum transaminase and body mass index presented as a clinical nomogram could well predict the risk of NAFLD in patient with CD.

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.