Visceral adiposity predicts post-operative Crohn's disease recurrence

Reviewing the impact of obesity on inflammatory bowel disease and considerations for optimizing management

PURPOSE OF REVIEW

This review examines the complex relationship between obesity and inflammatory bowel disease (IBD), encompassing their potentially shared pathogenesis, the impact of obesity on the natural history and treatment outcomes of IBD, and the management of obesity in the patient with IBD.

RECENT FINDINGS

Obesity represents a state of chronic inflammation that may not only contribute to IBD pathogenesis, but also influence disease progression, complications, and response to treatment. Increased visceral adiposity may carry negative prognostic implications for disease and treatment-specific outcomes. Antiobesity medications, endoscopic bariatric therapies, and even bariatric surgery may be effective and well tolerated in selected patients with IBD.

SUMMARY

The intersection of obesity and IBD presents a significant clinical challenge, with obesity influencing the natural history of IBD and potentially affecting treatment efficacy. As obesity prevalence among IBD patients rises, a tailored approach to management is crucial, taking into account the individualized risks and benefits of various treatment strategies, including lifestyle interventions, pharmacotherapy, endoscopic procedures, and bariatric surgery.

Mesenteric-based surgery for Crohn's disease: evidence and perspectives

Postoperative anastomotic recurrence of Crohn's disease is challenging and can lead to symptom recurrence and further surgery. The mesenteric pole of the intestine is the initial site of macroscopic anastomotic recurrence, and the mesentery may play an important role in recurrence after surgical resection. Therefore, "mesenteric-based surgery" has gained increasing attention by clinicians. However, the role of mesentery in the postoperative recurrence remains controversial. This review will examine mesenteric changes in Crohn's disease, proposed roles for mesentery in disease progression, and the potential for mesenteric-based surgery in the surgical management of Crohn disease.

Systematic review: Patient-related, microbial, surgical, and histopathological risk factors for endoscopic post-operative recurrence in patients with Crohn's disease

BACKGROUND

Risk stratification for endoscopic post-operative recurrence (ePOR) in Crohn's disease (CD) is required to identify patients who would benefit most from initiation of prophylactic medication and intensive monitoring of recurrence.

AIMS

To assess the current evidence on patient-related, microbial, surgical and histopathological risk factors for ePOR in patients with CD after ileocolic (re-)resection.

METHODS

Multiple online databases (Embase, MEDLINE, Web of Science and Cochrane Library) were searched up to March 2024. Studies with reported associations of patient-related, microbial, surgical and/or histopathological factors for ePOR (i.e., Rutgeerts' score ≥i2 or modified Rutgeerts' score ≥i2a) were included. The risk of bias was assessed with the Newcastle-Ottawa Scale for observational cohort studies and case-control studies.

RESULTS

In total, 47 studies were included (four RCTs, 29 cohort studies, 12 case-control studies, one cross-sectional study and one individual participant data meta-analysis) including 6006 patients (median sample size 87 patients [interquartile range 46-170]). Risk of bias assessment revealed a poor quality in 41% of the studies. An association was reported in multiple studies of ePOR with active smoking at and post-surgery, male sex and prior bowel resection. A heterogeneous association with ePOR was reported for other risk factors included in the current guidelines (penetrating disease, perianal disease, younger age, extensive small bowel disease and presence of granulomas in the resection specimen or myenteric plexitis in the resection margin), and other patient-related, microbial, surgical and histopathological factors.

CONCLUSION

Risk factors for ePOR in international guidelines are not consistently reported as risk factors in current literature except for active smoking and prior bowel resection. To develop evidence-based, personalised strategies, large prospective studies are warranted to identify risk factors for ePOR. Validation studies of promising (bio)markers are also required.

Impact of Obesity and Metabolic Syndrome on IBD Outcomes

PURPOSE OF REVIEW

The recent surge in inflammatory bowel disease (IBD) cases has paralleled a significant rise in obesity and metabolic comorbidities rates. In this article, we explore the potential influence of obesity and associated metabolic comorbidities on disease progression, complications, treatment response, surgical outcomes, health economics, and the potential impact of obesity treatment on the course of IBD.

FINDINGS

Contrary to visceral adiposity, obesity does not consistently result in an increased risk of IBD-related complications. Patients with IBD have a higher risk of acute arterial events, likely linked to systemic inflammation. Substantial evidence suggests that obesity has a negative impact on the response to IBD treatment, with this effect being most thoroughly studied in biologics and immunomodulators. The rates of overall complications and post-operative infections are higher in patients who are obese. There are limited but promising data regarding the impact of weight loss techniques, including exercise, medications, and bariatric interventions, on the outcomes in IBD. Both obesity and diabetes have adverse effects on the overall quality of life and place an increased financial burden on the IBD population. A growing body of evidence indicates a connection between obesity and associated metabolic comorbidities and negative outcomes in IBD, yet further efforts are required to fully understand this relationship.

Magnetic resonance enterography findings 46 weeks after initiation of biological therapy predict long-term adverse outcomes in Crohn's disease

BACKGROUND AND AIMS

Magnetic resonance enterography (MRE) depicts transmural changes in response to biological treatment for Crohn's disease (CD); however, the long-term prognostic significance of these findings is unknown. The primary objective of this study was to identify findings on MRE 46 weeks after initiating biological treatment that predict adverse long-term outcomes.

METHODS

Patients with CD underwent MRE 46 weeks after initiating biological treatment and were prospectively followed for 2 years. A logistic regression analysis was performed to assess the prognostic value of different radiologic findings for various predefined adverse outcomes.

RESULTS

Of the 89 patients included, 46 (51.7%) had ≥1 adverse outcome during follow-up: 40 (44.9%) had clinical recurrence; 18 (20.2%) required surgery, 8 (9%) endoscopic balloon dilation, 12 (13.5%) hospitalization and 7 (7.8%) required corticosteroids. In the multivariate analysis, persistence of severe lesions (MaRIA ≥11) in any intestinal segment was associated with an increased risk of surgery [OR 11.6 (1.5-92.4)], of surgery and/or endoscopic balloon dilation [OR 6.3 (1.3-30.2)], and of clinical relapse [OR 4.6 (1.6-13.9)]. Penetrating lesions were associated with surgery [OR 3.4 (1.2-9.9)]. Creeping fat with hospitalization [OR 5.1 (1.1-25.0)] and corticosteroids requirement [OR 16.0 (1.2-210.0)]. The presence of complications (stricturing and/or penetrating lesions) was associated with having ≥1 adverse outcome [OR 3.35 (1.3-8.5)].

CONCLUSION

MRE findings at week-46 after initiating biological therapy can predict long-term adverse outcomes in CD. Therapeutic intervention may be required in patients with persistence of severe inflammatory lesions, CD-associated complications, or creeping fat.

Pre-operative visceral adipose tissue radiodensity is a potentially novel prognostic biomarker for early endoscopic post-operative recurrence in Crohn's disease

BACKGROUND

Evidence suggests inflammatory mesenteric fat is involved in post-operative recurrence (POR) of Crohn's disease (CD). However, its prognostic value is uncertain, in part, due to difficulties studying it non-invasively.

AIM

To evaluate the prognostic value of pre-operative radiographic mesenteric parameters for early endoscopic POR (ePOR).

METHODS

We conducted a retrospective cohort study of CD subjects ≥ 12 years who underwent ileocecal or small bowel resection between 1/1/2007 to 12/31/2021 with computerized tomography abdomen/pelvis ≤ 6 months pre-operatively and underwent ileocolonoscopy ≤ 15 months post-operatively. Visceral adipose tissue (VAT) volume (cm3), ratio of VAT:subcutaneous adipose tissue (SAT) volume, VAT radiodensity, and ratio of VAT:SAT radiodensity were generated semiautomatically. Mesenteric lymphadenopathy (LAD, largest lymph node > 10 mm) and severe vasa recta (VR) engorgement (diameter of the VR supplying diseased bowel ≥ 2 × VR supplying healthy bowel) were derived manually. The primary outcome was early ePOR (Rutgeert's score ≥ i2 on first endoscopy ≤ 15 months post-operatively) and the secondary outcome was ePOR severity (Rutgeert's score i0-4). Regression analyses were performed adjusting for demographic and disease-related characteristics to calculate adjusted odds ratio (aOR) and 95% confidence interval (CI).

RESULTS

Of the 139 subjects included, 45% of subjects developed early ePOR (n = 63). VAT radiodensity (aOR 0.59, 95%CI: 0.38-0.90) and VAT:SAT radiodensity (aOR 8.54, 95%CI: 1.48-49.28) were associated with early ePOR, whereas, VAT volume (aOR 1.23, 95%CI: 0.78-1.95), VAT:SAT volume (aOR 0.80, 95%CI: 0.53-1.20), severe VR engorgement (aOR 1.53, 95%CI: 0.64-3.66), and mesenteric LAD (aOR 1.59, 95%CI: 0.67-3.79) were not. Similar results were observed for severity of ePOR.

CONCLUSION

VAT radiodensity is potentially a novel non-invasive prognostic imaging marker to help risk stratify CD patients for POR.

Radiological biomarkers reflecting visceral fat distribution help distinguish inflammatory bowel disease subtypes: a multicenter cross-sectional study

OBJECTIVES

To achieve automated quantification of visceral adipose tissue (VAT) distribution in CT images and screen out parameters with discriminative value for inflammatory bowel disease (IBD) subtypes.

METHODS

This retrospective multicenter study included Crohn's disease (CD) and ulcerative colitis (UC) patients from three institutions between 2012 and 2021, with patients with acute appendicitis as controls. An automatic VAT segmentation algorithm was developed using abdominal CT scans. The VAT volume, as well as the coefficient of variation (CV) of areas within the lumbar region, was calculated. Binary logistic regression and receiver operating characteristic analysis was performed to evaluate the potential of indicators to distinguish between IBD subtypes.

RESULTS

The study included 772 patients (365 CDs, median age [inter-quartile range] = 31.0. (25.0, 42.0) years, 255 males; 241 UCs, 46.0 (34.0, 55.5) years, 138 males; 166 controls, 40.0 (29.0, 53.0) years, 80 males). CD patients had lower VAT volume (CD = 1584.95 ± 1128.31 cm3, UC = 1855.30 ± 1326.12 cm3, controls = 2470.91 ± 1646.42 cm3) but a higher CV (CD = 29.42 ± 15.54 %, p = 0.006 and p ˂ 0.001) compared to UC and controls (25.69 ± 12.61 % vs. 23.42 ± 15.62 %, p = 0.11). Multivariate analysis showed CV was a significant predictor for CD (odds ratio = 6.05 (1.17, 31.12), p = 0.03). The inclusion of CV improved diagnostic efficiency (AUC = 0.811 (0.774, 0.844) vs. 0.803 (0.766, 0.836), p = 0.08).

CONCLUSION

CT-based VAT distribution can serve as a potential biomarker for distinguishing IBD subtypes.

CRITICAL RELEVANCE STATEMENT

Visceral fat distribution features extracted from CT images using an automated segmentation algorithm (1.14 min) show differences between Crohn's disease and ulcerative colitis and are promising for practical radiological screening.

KEY POINTS

• Radiological parameters reflecting visceral fat distribution were extracted for the discrimination of Crohn's disease (CD) and ulcerative colitis (UC). • In CD, visceral fat was concentrated in the lower lumbar vertebrae, and the coefficient of variation was a significant predictor (OR = 6.05 (1.17, 31.12), p = 0.03). • The differences between CD, UC, and controls are promising for practical radiological screening.

Residual abnormalities on CTE predict adverse outcomes in Crohn's disease with endoscopic healing

BACKGROUND

Residual abnormalities on computed tomography enterography (CTE) in Crohn's disease (CD) with endoscopic healing (EH) may have prognostic implications and affect therapeutic strategy.

METHODS

CD patients with EH who underwent CTE between March 2015 and June 2022 were enrolled. CTE findings of the terminal ileum and the most severe segment of colon at the time of EH were assessed respectively for each patient. Cox regression analysis and Kaplan-Meier curves were used to evaluate the association between residual abnormalities and adverse outcomes.

RESULTS

A total of 140 patients (217 digestive segments) were included. Mesenteric edema (hazard ratio [HR] = 3.61, 95% CI = 1.81-7.20, P<0.001), fibrofatty proliferation (HR = 3.40, 95% CI = 1.97-5.85, P<0.001) and active small bowel inflammation (HR = 2.74, 95% CI = 1.59-4.71, P<0.001) were risk factors for clinical relapse. Furthermore, we built a scoring system using the three parameters. Radiologic score ≥ 1 was the best threshold to predict clinical relapse (HR = 4.56, 95% CI = 2.54-8.19, P<0.001) and it was validated in different outcomes.

CONCLUSION

The scoring system based on three residual abnormalities on CTE can predict adverse outcomes in CD patients with EH.

CT-based radiomics signature of visceral adipose tissue and bowel lesions for identifying patients with Crohn's disease resistant to infliximab

PURPOSE

To develop a CT-based radiomics model combining with VAT and bowel features to improve the predictive efficacy of IFX therapy on the basis of bowel model.

METHODS

This retrospective study included 231 CD patients (training cohort, n = 112; internal validation cohort, n = 48; external validation cohort, n = 71) from two tertiary centers. Machine-learning VAT model and bowel model were developed separately to identify CD patients with primary nonresponse to IFX. A comprehensive model incorporating VAT and bowel radiomics features was further established to verify whether CT features extracted from VAT would improve the predictive efficacy of bowel model. Area under the curve (AUC) and decision curve analysis were used to compare the prediction performance. Clinical utility was assessed by integrated differentiation improvement (IDI).

RESULTS

VAT model and bowel model exhibited comparable performance for identifying patients with primary nonresponse in both internal (AUC: VAT model vs bowel model, 0.737 (95% CI, 0.590-0.854) vs. 0.832 (95% CI, 0.750-0.896)) and external validation cohort [AUC: VAT model vs. bowel model, 0.714 (95% CI, 0.595-0.815) vs. 0.799 (95% CI, 0.687-0.885)), exhibiting a relatively good net benefit. The comprehensive model incorporating VAT into bowel model yielded a satisfactory predictive efficacy in both internal (AUC, 0.840 (95% CI, 0.706-0.930)) and external validation cohort (AUC, 0.833 (95% CI, 0.726-0.911)), significantly better than bowel alone (IDI = 4.2% and 3.7% in internal and external validation cohorts, both p < 0.05).

CONCLUSION

VAT has an effect on IFX treatment response. It improves the performance for identification of CD patients at high risk of primary nonresponse to IFX therapy with selected features from RM.

CRITICAL RELEVANCE STATEMENT

Our radiomics model (RM) for VAT-bowel analysis captured the pathophysiological changes occurring in VAT and whole bowel lesion, which could help to identify CD patients who would not response to infliximab at the beginning of therapy.

KEY POINTS

• Radiomics signatures with VAT and bowel alone or in combination predicting infliximab efficacy. • VAT features contribute to the prediction of IFX treatment efficacy. • Comprehensive model improved the performance compared with the bowel model alone.

The value of whole-body dual-energy x-ray absorptiometry in assessing body composition in patients with inflammatory bowel disease: a prospective study

OBJECTIVES

Low skeletal muscle index (SMI) is common in inflammatory bowel disease (IBD) but has an uncertain relationship with active intestinal inflammation. This study evaluated body composition by whole-body dual-energy X-ray absorptiometry (DXA) in patients with IBD and healthy controls to enable the value of formal body composition analysis to be judged.

METHODS

Patients with IBD and sex/age-matched controls prospectively underwent full body composition assessment by DXA, assessment by BMI, eating questionnaires and handgrip strength. Disease activity was assessed by faecal calprotectin (active ≥150 µg/g). A cohort undergoing biologic induction therapy were assessed at baseline and after ≥13 weeks.

RESULTS

Total fat mass was higher in 54 patients with IBD (56% Crohn's disease, 61% male) than in 30 controls (median 25.1 vs. 18.7 kg, P  = 0.042). DXA offered little more than BMI. Low SMI was more common than in controls (15% vs. 0%, P  = 0.027). A normal BMI was seen in many patients with low SMI and handgrip strength was a poor marker of change in SMI. Body composition was similar in 28 patients with active vs. 22 with inactive disease. However, SMI increased specifically by 9.7% ( P  = 0.004) and BMI by 6.4% ( P  = 0.012) in 9 responders to therapy.

CONCLUSION

DXA identifies many patients with reduced SMI who are not detected by standard methodologies. While disease activity is not associated with low SMI, resolution of inflammation leads to improved SMI. The potential for recognition of such patients to influence therapeutic decisions underlines the need for DXA assessment in clinical practice.

Results of the Eighth Scientific Workshop of ECCO: Pathophysiology and Risk Factors of Postoperative Crohn's Disease Recurrence after an Ileocolonic Resection

Postoperative recurrence [POR] after an ileocolonic resection with ileocolonic anastomosis is frequently encountered in patients with Crohn's disease. The 8th Scientific Workshop of ECCO reviewed the available evidence on the pathophysiology and risk factors for POR. In this paper, we discuss published data on the role of the microbiome, the mesentery, the immune system and the genetic background. In addition to investigating the causative mechanisms of POR, identification of risk factors is essential to tailor preventive strategies. Potential clinical, surgical and histological risk factors are presented along with their limitations. Emphasis is placed on unanswered research questions, guiding prevention of POR based on individual patient profiles.

Mesenteric creeping fat index defined by CT enterography is associated with early postoperative recurrence in patients with Crohn's disease

OBJECTIVES

To investigate the value of mesenteric creeping fat index (MCFI) defined by computed-tomography enterography (CTE) in patients with Crohn's Disease (CD) for predicting early postoperative recurrence.

METHODS

A total of 110 patients with CD who underwent CTE and I-stage intestinal resection surgery from December 2013 to December 2018 were enrolled. Two radiologists independently assessed CTE parameters, including MCFI, with scores ranging from 1 to 8; bowel-wall thickening, with a scale of 1 to 3; mural hyperenhancement, mural stratification, submucosal fat deposition, mesenteric fibrofatty proliferation, mesenteric hypervascularity, mesenteric fat stranding, with a scale of 0 to 2; abscess/fistula, enlarged mesenteric lymph node, abdominal and pelvic effusion, with a scale of 0 to 1. Imaging findings associated with early recurrence were assessed using logistic regression analysis.

RESULTS

Within one year follow-up, early postoperative recurrence occurred in 56.4 % (62/110) patients with CD. In univariate analysis, MCFI, bowel-wall thickening, mesenteric hypervascularity, mesenteric fat stranding, abscess/fistula and mesenteric lymphadenopathy were associated with early postoperative recurrence. Among all variables, MCFI (score ≥ 4) contributes the optimal AUC (0.838 [0.758-0.919]), specificity (89.6 %), positive predictive value (90.7 %), accuracy (83.6 %), and risk ratio (OR = 32.42 [10.69-98.33], p < 0.001). In multivariate analysis, only MCFI was an independent predictor of early postoperative recurrence (OR = 25.71 [7.65-86.35], p < 0.001).

CONCLUSION

CTE features are useful in predicting early postoperative recurrence in patients with CD, MCFI may be a valuable tool for clinical monitoring and follow-up.

Enhancing the Differentiation between Intestinal Behçet's Disease and Crohn's Disease through Quantitative Computed Tomography Analysis

Behçet's disease (BD) behaves similarly to Crohn's disease (CD) when the bowel is involved. Computed tomography enterography (CTE) can accurately show intestinal involvement and obtain body composition data. The objective of this study was to evaluate whether CTE could improve the ability to distinguish between intestinal BD and CD. This study evaluated clinical, laboratory, endoscopic, and CTE features on first admission. Body composition analysis was based on the CTE arterial phase. The middle layers of the L1-L5 vertebral body were selected. The indicators assessed included: the area ratio of visceral adipose tissue (VAT)/subcutaneous adipose tissue (SAT) (VSR) in each layer, the total volume ratio of VAT/SAT, the quartile of VAT attenuation in each layer and the coefficient of variation (CV) of the VAT area for each patient was also calculated. Two models were developed based on the above indicators: one was a traditional model (age, gender, ulcer distribution) and the other was a comprehensive model (age, gender, ulcer distribution, proximal ileum involvement, asymmetrical thickening of bowel wall, intestinal stenosis, VSRL4, and CV). The areas under the receiver operating characteristic (ROC) curve of the traditional (sensitivity: 80.0%, specificity: 81.0%) and comprehensive (sensitivity: 95.0%, specificity: 87.2%) models were 0.862 and 0.941, respectively (p = 0.005).

Appearance of the Bowel and Mesentery During Surgery Is Not Predictive of Postoperative Recurrence After Ileocecal Resection for Crohn's Disease: A Prospective Monocentric Study

BACKGROUND

Very few risk factors for postoperative recurrence (POR) of Crohn's Disease (CD) after ileocecal resection have been identified. The aim of the present study was to verify the association between an a priori defined list of intraoperative macroscopic findings and POR.

METHODS

This was a prospective observational study including patients undergoing primary ileocecal resection for CD. Four intraoperative factors were independently evaluated by 2 surgeons: length of resected ileum, mesentery thickness, presence of areas of serosal fat infiltration, or abnormal serosal vasodilation on normal bowel proximal to the resected bowel. The primary end point was early endoscopic POR at month 6 and defined as modified Rutgeerts score ≥i2b. Secondary end points were clinical and surgical recurrence.

RESULTS

Between September 2020 and November 2022, 83 consecutive patients were included. Early endoscopic recurrence occurred in 45 of 76 patients (59.2%). Clinical and biochemical recurrence occurred in 17.3% (95% confidence interval, [CI], 10.4%-28.0%) and 14.6% of the patients after 12 months. The risk of developing endoscopic and clinical recurrence was 1.127 (95% CI, 0.448;2.834, P = .799) and 0.896 (95% CI, 0.324-2.478, P = .832) when serosal fat infiltration was observed, and 1.388 (95% CI, 0.554-3.476, P = .484), and 1.153 (95% CI, 0.417;3.187, P = .783) when abnormal serosal vasodilation was observed. Similarly, length of the resected bowel and mesentery thickness showed no association with POR. A subgroup analysis on patients who received no postoperative medical prophylaxis did not identify any risk factor for endoscopic POR.

CONCLUSIONS

The macroscopic appearance of the bowel and associated mesentery during surgery does not seem to be predictive of POR after ileocecal resection for CD.

Stemming the tide with ileocecal Crohn's disease: when is pharmacotherapy enough?

INTRODUCTION

Crohn's disease (CD) mostly affects the terminal ileum and ileocecal region and up to 80% of patients end up requiring surgery. Previously reserved for complicated or refractory forms, surgery is now considered as an alternative to medical treatment in localized ileocecal disease.

AREAS COVERED

This review examines factors associated with response to medical treatment and those associated with the need for surgery in ileocecal CD to identify the patients' profile for whom pharmacotherapy might be enough. Factors associated with the recurrence and the postoperative complications are also reviewed to help the clinician identify patients for whom medical therapy might be preferred.

EXPERT’S OPINION

LIR!C study long-term follow-up data show that 38% of infliximab-treated patients were still treated with infliximab at the end of their follow-up, while 14% had switched to another biologic or had received immunomodulator or corticosteroid and 48% had CD-related surgery. Only the combination with an immunomodulator was associated with a greater likelihood of continuing infliximab. Patients with ileocecal CD for whom pharmacotherapy might be sufficient are probably those with no risk factors for CD-related surgery.In addition, patients with high risk of recurrence or of post-operative complications may benefit more from medical treatment than from surgery.

Nutrition, Nutritional Status, Micronutrients Deficiency, and Disease Course of Inflammatory Bowel Disease

During the disease course, most Inflammatory Bowel Disease patients present a condition of malnutrition, undernutrition, or even overnutrition. These conditions are mainly due to suboptimal nutritional intake, alterations in nutrient requirements and metabolism, malabsorption, and excessive gastrointestinal losses. A suboptimal nutritional status and low micronutrient serum levels can have a negative impact on both induction and maintenance of remission and on the quality of life of Inflammatory Bowel Disease patients. We performed a systematic review including all the studies evaluating the connection between nutrition, nutrition status (including undernutrition and overnutrition), micronutrient deficiency, and both disease course and therapeutic response in Inflammatory Bowel Disease patients. This systematic review was performed using PubMed/MEDLINE and Scopus. Four main clinical settings concerning the effect of nutrition on disease course in adult Inflammatory Bowel Disease patients were analyzed (induction of remission, maintenance of remission, risk of surgery, post-operative recurrence, and surgery-related complications). Four authors independently reviewed abstracts and manuscripts for eligibility. 6077 articles were found; 762 duplicated studies were removed. Out of 412 full texts analyzed, 227 were included in the review. The evidence summarized in this review showed that many nutritional aspects could be potential targets to induce a better control of symptoms, a deeper remission, and overall improve the quality of life of Inflammatory Bowel Disease patients.

Two-year real-world outcome data from a single tertiary centre shows reduced ustekinumab persistence in a non-bio-naïve Crohn's disease cohort with penetrating disease, -ostomies and sarcopenia

Background

Ustekinumab was approved in 2016 for the treatment of moderate-severe Crohn's disease (CD). Clinical trials and real-world studies have suggested ustekinumab to be a safe and effective treatment; however, studies to date infrequently use imaging techniques to predict response to biologics in CD.

Objectives

We assessed the 2-year real-world effectiveness and safety of ustekinumab in a tertiary CD cohort with the use of novel imaging techniques.

Design

Retrospective cohort study.

Methods

Retrospective data were collected between 2016 and 2021. Study end points included ustekinumab persistence, biological and/or clinical response and remission at 12, 18 and 24 months. Statistical analysis included demographic and inferential analyses.

Results

In all, 131 CD patients [57.3% female, median age of 26.0 (21.0-37.0)] were included. Patients were non-bio naïve, and the majority received ustekinumab as third- or fourth-line treatment. At 24 months, 61.0% (80/131) persisted with ustekinumab [52.7% (69/131) steroid free]. Clinical response was reported in 55.2% (37/67), clinical remission in 85.7% (57/67), biological response in 46.8% (22/47) and biological remission in 31.9% (15/47) of patients at 24 months. The low outcome numbers were attributable to missing data. Improvements in routine disease markers, including C-reactive protein and Harvey-Bradshaw Index, were also reflected in magnetic resonance imaging-derived disease scores. The presence of penetrating CD, an -ostomy and sarcopenia were all predictors of poorer ustekinumab outcomes (p < 0.05).

Conclusion

Ustekinumab is effective in non-bio-naïve CD patients with non-stricturing, non-penetrating disease with an unremarkable safety profile but may be less effective in those with penetrating disease, -ostomies and sarcopenia.

Diagnostic Criteria and Prognostic Relevance of Sarcopenia in Patients with Inflammatory Bowel Disease-A Systematic Review

BACKGROUND

Sarcopenia is a syndrome characteristic in elderly patients and is also associated with a significant proportion of chronic disorders such as inflammatory bowel disease (IBD). In this case, it can lead to a worse prognosis of the disease and a decreased quality of life.

STUDY AIM

This study aims to identify the best ways to diagnose sarcopenia in patients with IBD, establish its impact on the course of the disease, and find preventive methods to counteract the effects of sarcopenia in the outcome of patients with IBD and, therefore, minimize disabilities and increase the health-related quality of life (HRQoL).

MATERIAL AND METHODS

A systematic review with the Prospero registration number CRD42023398886 was performed in PubMed and Web of Science databases, evaluating all original articles published in the last 10 years (clinical trials and randomized control trials) that describe sarcopenia and IBD in the human adult population.

RESULTS

From the 16 articles that were included, 5 articles defined sarcopenia by the skeletal muscle index (SMI) and reported data regarding its correlation with body composition: BMI; visceral fat (VF); subcutaneous fat (SC); and VF/SC index. Other articles evaluated the link between sarcopenia and the total psoas muscle area, thigh circumference, calf circumference, subjective global assessment, hand grip strength, and appendicular SMI, alongside inflammatory markers such as IL-6 and C-reactive protein, level of disability, malnutrition, frailty, resistance training alone and in combination with whey protein, and infliximab treatment.

DISCUSSIONS AND CONCLUSIONS

There is a great heterogeneity regarding the assessment criteria and methods used to diagnose sarcopenia due to the variability of population characteristics, both anthropometric and socio-cultural, alongside the high variability in the cut-offs. Therefore, any method which identifies sarcopenia in IBD patients, thus enabling intervention, may provide good results for patient quality of life and outcomes.

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

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

Systematic review of sarcopenia in inflammatory bowel disease

INTRODUCTION

There is growing evidence of increased muscle atrophy in IBD patients, likely resulting in a higher sarcopenia prevalence in IBD. The aims of this systematic review are A1; to estimate sarcopenia prevalence in IBD patients, A2; to investigate its impact on IBD patients, and A3; the effectiveness of nutritional interventions on muscle mass and/or strength in IBD patients.

METHODS

On 28 July 2021, three electronic databases were used to identify eligible studies, including peer-reviewed studies (randomised controlled trials [RCTs], non-RCTs, observation studies) in adult (⩾ 18 years) IBD patients. For A1 and A2 only, studies defined low muscle mass and/or strength cut-off points. For A2, studies assessed association between sarcopenia and IBD complication. For A3, studies assessed the nutrition effect among IBD patients.

RESULTS

35 studies were included, 34 for A1, 20 for A2, and three for A3. 42% of adult IBD patients have myopenia, 34% have pre-sarcopenia, and 17% sarcopenia. Myopenic IBD was significantly associated with therapy failure including IBD-related surgery risk in six studies, risk of medical therapy failure in four studies, risk of hospitalisation in one study. A significant association existed with postoperative complications risk in IBD patients in four studies, reduction in BMD in two studies, and increased incidence of non-alcoholic fatty liver disease (NAFLD) in one study. Sarcopenia in IBD was significantly associated with a reduction in BMD in one study. Two studies found a personalised nutrition plan (high protein) in IBD patients significantly improved muscle mass. One study found a significant positive association between muscle mass and dietary intake including high protein intake.

CONCLUSION

Over one third of adult IBD patients have myopenia and pre-sarcopenia, and nearly a fifth have sarcopenia. Myopeninc IBD is significantly associated with increased risk of IBD therapy failure, postoperative complications, and low BMD, with possible association with increased NAFLD risk. Nutritional therapy may play a role in reversing low muscle mass though yet unclear if this is through disease activity reversal. Further studies on adult IBD patients focusing on sarcopenia/myopenia are needed with recommended study designs of 1) standardised population-based definitions with recommended standard methods used to measure skeletal muscle mass, 2) prospective studies with IBD patients stratified by Montreal classification, disease activity, disease duration and concomitant medication to observe muscle changes, 3) mechanistic studies on sarcopenia aetiology, specifically focusing on protein handling atrophy and absorption, 4) properly designed RCT to assess nutrition intervention in sarcopenic IBD patients.

A systematic review of the effect of structured exercise on inflammation and body composition in inflammatory bowel disease

PURPOSE

Given the substantial risk of treatment failure in inflammatory bowel disease (IBD), adjuvant therapies may play a role in disease management. We aim to carry out a systematic review to examine the effects of structured exercise on the inflammatory response in patients with IBD. Our secondary aim is to examine the effect of structured exercise programmes on body composition given both an increase in visceral obesity and the presence of sarcopenia have deleterious effects on outcomes in IBD.

METHODS

A systematic review was carried out following the Methodological Expectations of Cochrane Intervention Reviews (MECIR) manual and the Cochrane Handbook for Systematic Reviews of Interventions. Title/Abstract and MeSH Terms were used to search for relevant studies.

RESULTS

In total, 1516 records were screened for eligibility, and 148 records were reviewed for eligibility, of which 16 were included and a further 7 studies were identified from hand searching references. Four studies included body composition outcomes, and 14 studies reviewed the inflammatory response to exercise.

CONCLUSION

Further studies of adequate duration are required to include patients with more active disease to demonstrate an inflammatory response to exercise. Body composition measurements including muscle mass and visceral adiposity may play a key role in response to medical therapy in IBD and should be included as exploratory outcomes in future studies. A meta-analysis was not carried out due to the significant heterogeneity amongst studies.

Imaging-based assessment of body composition in patients with Crohn's disease: a systematic review

BACKGROUND AND AIMS

Body composition changes in patients with Crohn's disease (CD) have received increasing attention in recent years. This review aims to describe the changes in body composition in patients with CD on imaging and to analyze and summarize the prognostic value of body composition.

METHODS

We systematically searched Web of Science, PubMed, Embase, Cochrane Library, and Medline via OVID for literature published before November 2022, and two researchers independently evaluated the quality of the retrieved literature.

RESULTS

A total of 39 publications (32 cohort studies and 7 cross-sectional studies) involving 4219 patients with CD were retrieved. Imaging methods for body composition assessment, including dual-energy X-ray absorptiometry (DXA), computed tomography (CT) and magnetic resonance imaging (MRI), were included in this review. The study found that patients with CD typically have more visceral adipose tissue and less skeletal muscle mass, and the prevalence of sarcopenia and visceral obesity was significantly different in different studies (sarcopenia: 16-100%; visceral obesity: 5.3-30.5%). Available studies suggest that changes in the body composition of CD patients are significantly related to inflammatory status, disease behavior, poor outcomes, and drug efficacy.

CONCLUSION

Altered body composition can be a significant predictor of poor outcomes for CD patients. Therefore, the body composition of CD patients may serve as a potential therapeutic target to help optimize disease management strategies in clinical practice.

Effects of visceral adipose tissue on anti-tumour necrosis factor-α in Crohn's disease

Background

It remains unclear whether visceral adipose tissue (VAT) can predict the response of patients with Crohn's disease (CD) to anti-tumour necrosis factor-α (anti-TNF-α) therapy.

Objectives

This study aimed to investigate whether VAT predicts the efficacy of infliximab (IFX) for different sites of CD and its relationship with serum TNF-α levels and IFX serum trough concentration.

Design

This is a multicentre retrospective study.

Methods

Patients with CD treated with IFX from January 2014 to January 2021 were included. The perimeter of the visceral adipose area was obtained by a Computed Tomography (CT) scan. Participants were classified according to the lesion site (L1, L2, and L3) and visceral fat area. The participants were divided into colon-uninvolved non-visceral obesity (L1-VATL), colon-uninvolved visceral obesity (L1-VATH), colon-involved non-visceral obesity (L2 + L3-VATL), and colon involved visceral obesity (L2 + L3-VATH) groups. The end points of this study were set as disease remission status at 6 and 12 months.

Results

The final cohort included 140 patients. Regarding efficacy at 6 and 12 months, there was a significant difference between L1-VATL (73.8% versus 36.8%, p = 0.006) and L1-VATH (81.0% versus 47.4%, p = 0.008) groups. In the analysis of serum TNF-α levels and IFX serum trough concentrations, there was a significant difference between L1-VATL and L1-VATH (59.5 pg/mL versus 236.0 pg/mL, pTNF-α = 0.006), (10.0 μg/mL versus 0.4 μg/mL, pIFX = 0.000), and L1-VATH and L2 + L3-VATH (78.7 pg/mL versus 118.6 pg/mL, pTNF-α = 0.031), (0.4 μg/mL versus 6.40 μg/mL, pIFX = 0.017).

Conclusion

In L1 patients, the VAT level predicted the efficacy of IFX, with high VAT values indicating poor efficacy. The VAT level may be a useful radiological marker to predict the efficacy of IFX in patients with various types of CD.

Parameters of body composition and creeping fat are associated with activity of Crohn's disease

AIM

This study aimed at assessing body composition parameters, creeping fat (CrF), and Crohn's disease's (CD) activity based on the Magnetic Resonance Index of Activity (MaRIA).

METHODS

114 CD patients who underwent magnetic resonance enterography (MRE) between June 2010 and April 2020 were retrospectively assessed. The semi-automated body composition segmentation, the qualitative evaluation of CrF, and MaRIA were performed. Based on their MaRIA score, patients were divided into two groups: mild-to-moderate disease (MaRIA <11, n = 50) and severe disease (MaRIA ≥11, n = 64). MRE parameters were analyzed between both groups. Patients were dichotomized according to body composition categories and the presence of CrF. Univariate regression analyses were performed to investigate the association between dichotomized variables and severe disease. Significant variables were incorporated into the multivariate logistic regression model.

RESULTS

The severe disease group exhibited higher serum C-reactive protein (CRP) levels compared to the mild-to-moderate disease group (p ≤0.001). In the mild-to-moderate disease group, a higher proportion of patients had a body mass index (BMI) ≥ 25 (kg/m²) (32.0%) compared to the severe disease group (16.5%) (p = 0.04). The subcutaneous adipose tissue index (SATI) was significantly higher in the mild-to-moderate disease group (p = 0.04). The visceral to subcutaneous adipose tissue (VAT/SAT) ratio tended to be higher in the severe disease group (p = 0.09). There was no significant difference between both groups regarding total adipose tissue index (TATI) (p = 0.10), visceral adipose tissue index (VATI) (p = 0.51), intramuscular adipose tissue index (IMATI) (p = 0.38), skeletal muscle index (SMI) (p = 0.83), and sarcopenia (p = 0.75). In the multivariate analysis, CrF was significantly associated with severe disease (odds ratio [OR] 11.50, 95% confidence interval [CI] 3.13-42.17; p ≤0.001). Additionally, a BMI ≥ 25 (kg/m²) was protective against severe disease (OR: 0.34, 95% CI 0.12-0.95; p = 0.04).

CONCLUSION

CrF is significantly associated with CD activity.

Review article: Putting some muscle into sarcopenia-the pathogenesis, assessment and clinical impact of muscle loss in patients with inflammatory bowel disease

BACKGROUND

Sarcopenia, a loss of skeletal muscle mass or function, affects up to 50% of patients with inflammatory bowel disease (IBD) and is associated with poor clinical outcomes including increased hospitalizations, need for surgery and post-operative complications. Despite the high prevalence and clinical significance of sarcopenia in patients with IBD, few patients undergo routine muscle evaluation.

AIM

The goal of this study was to review the mechanisms of sarcopenia in patients with IBD and understand novel modalities to assess and treat impaired muscle mass or function.

METHODS

Pubmed and Cochrane databases were searched including articles published up to February 2023 utilizing the following keywords: "inflammatory bowel disease", "IBD", "Crohn's disease", "ulcerative colitis", "sarcopenia", "myosteatosis", "muscle health", and "frailty".

RESULTS

The pathogenesis of sarcopenia in IBD is not well defined, however, there is evidence supporting the role of malabsorption, reduced protein intake, chronic inflammation, dysbiosis, decreased physical activity, medication effects and hormone signaling from visceral adiposity. Traditional sarcopenia assessment techniques include direct measurements on cross sectional imaging. However, given the time, cost and radiation exposure associated with cross sectional imaging, new bedside tools are now available to estimate muscle mass, including assessment of grip strength, mid upper arm circumference and body composition utilizing bioelectrical impedance analysis. In addition, novel biomarkers for assessing muscle mass and techniques utilizing point of care ultrasound have been proposed to make sarcopenia evaluation more streamlined in the IBD clinic.

CONCLUSION

Sarcopenia is associated with poor clinical outcomes independent of IBD activity and therefore muscle health should be assessed in all IBD patients at routine intervals. Future studies to better our understanding of the pathophysiology as well as most effective management of sarcopenia in IBD will help guide clinical care and reduce disease related complications.

Body composition and Crohn's disease behavior: Is adiposity the main game changer?

OBJECTIVE

We investigated the association between body composition upon diagnosis and complicated phenotypes and time until surgery in patients with Crohn's disease (CD).

METHODS

We conducted a retrospective cohort study including patients with CD who had a computed tomography enterography or a magnetic resonance enterography performed ≤6 mo of diagnosis. Skeletal muscle and visceral and subcutaneous adipose tissue cross-sectional areas were determined with computed tomography or magnetic resonance images at the third lumbar vertebral level, processed with the sliceOmatic (TomoVison, Magog, QC, Canada) and ABACS plugin.

RESULTS

We included 63 patients: 33 (52%) men, median age 35 y. Disease location (L) and behavior (B) according to the Montreal classification were L1 (ileal disease) = 28 (44%), L2 (colonic disease) = 13 (21%), L3(ileocolonic disease) = 18 (28%), L1 + L4 (ileal and isolated upper disease) = 1 (2%), L3 + L4 (ileocolonic and isolated upper disease) = 3 (5%), B1 (non-stricturing) = 39 (62%), B2 (stricturing) = 11 (17%), and B3 (penetrating)= 13 (21%); 20 (32%) patients had perianal disease. Visceral obesity was present in 12 (19%) patients and was associated with higher age of CD onset (median 60 versus 34 y; P = 0.002) and complicated disease behavior (B2 and B3) (66.7% versus 31.7%; P = 0.021). After adjusting for age and perianal disease, total adipose tissue was associated with a 4% increase in the odds of complicated behavior per 10 cm² of total adipose tissue (odds ratio [OR] = 1.004; 95% confidence interval [CI], 1.00-1.008; P = 0.043). Median follow-up time was 3.35 y, during which 15 (24%) of patients underwent abdominal surgery. Visceral obesity was associated with 5.10-times higher risk of abdominal surgery (95% CI, 1.52-17.09; P = 0.008); after adjusting for disease behavior, visceral obesity maintained a near-significant association with a 2.90-times higher risk of surgery (95% CI, 0.83-10.08; P = 0.09).

CONCLUSION

Total fat was associated with complicated disease phenotype and visceral obesity, with higher risk of abdominal surgery and shorter time until surgery.

Preoperative computed tomography enterography-based radiomics signature: A potential predictor of postoperative anastomotic recurrence in patients with Crohn's disease

BACKGROUND

More than half of patients with Crohn's disease (CD) require at least one surgery for symptom management; however, approximately half of the patients may experience postoperative anastomotic recurrence (PAR).

OBJECTIVES

This study aims to develop and validate a preoperative computed tomography enterography (CTE)-based radiomics signature to predict early PAR in CD.

DESIGN

A total of 186 patients with CD (training cohort, n = 134; test cohort, n = 52) who underwent preoperative CTE and surgery between January 2014 and June 2020 were included in this retrospective multi-centre study.

METHODS

106 radiomic features were initially extracted from intestinal lesions and peri-intestinal mesenteric fat, respectively; significant radiomic features were selected from them and then used to develop intestinal or mesenteric radiomics signatures, using the least absolute shrinkage and selection operator and a Cox regression model. A radiomics-based nomogram incorporating these signatures with clinical-radiological factors was created for comparison with a model based on clinical-radiological features alone.

RESULTS

68 of 134 patients in training cohort and 16 of 52 patients in test cohort suffered from PAR. The intestinal radiomic signature (hazard ratio [HR]: 2.17; 95% confidence interval [CI]: 1.32-3.58; P = 0.002) and mesenteric radiomic signature (HR: 2.19; 95% CI: 1.14-4.19; P = 0.018) were independent risk factors for PAR in the training cohort as per a multivariate analysis. The radiomics-based nomogram (C-index: 0.710; 95% CI: 0.672-0.748) yielded superior predictive performance than the clinical-radiological model (C-index, 0.607; 95% CI: 0.582-0.632) in the test cohort. Decision curve analysis demonstrated that the radiomics-based nomogram outperformed the clinical-radiological model in terms of clinical usefulness.

CONCLUSIONS

Preoperative mesenteric and intestinal CTE radiomics signatures are potential non-invasive predictors of PAR in postoperative patients with CD.

Medical and Surgical Implications of Mesenteric Adipose Tissue in Crohn's Disease: A Review of the Literature

Mesenteric adipose tissue (MAT) has gained substantial attention as an active player in Crohn's disease (CD), but its clinical significance is poorly understood and likely reflects, in part, difficulties assessing MAT noninvasively. Recent radiologic studies have identified candidate surrogate markers that may reflect inflammatory alterations of MAT in CD and have found that certain features including visceral adipose tissue may inform risk of complicated disease behavior, risk for surgery, and postoperative outcomes. Additionally, emerging surgical data have suggested MAT may even be a therapeutic target to mitigate postoperative recurrence of CD. However, the current studies have variable results, reduced sample sizes, and methodological limitations that preclude incorporating the radiologic and surgical findings into clinical practice. Nonetheless, the results are promising and potentially have important implications for the medical and surgical management of CD, which merits that additional studies are warranted. Thus, we have reviewed the available literature on the medical and surgical implications of MAT in CD to summarize our current understanding and identify gaps in knowledge to inform future investigations.

Impact of Sarcopenia on Clinical Course of Inflammatory Bowel Disease in Korea

BACKGROUND AND AIMS

Reduced body muscle mass is a poor prognostic factor for inflammatory bowel disease (IBD). In this study, we investigated the prevalence of sarcopenia at diagnosis and its clinical significance in Korean patients with IBD.

METHODS

The prevalence of sarcopenia in IBD patients between June 1989 and December 2016 was investigated using a well-characterized referral center-based cohort. Abdominopelvic computed tomography within six months from IBD diagnosis was used for the evaluation. Sarcopenia was defined as an L3 skeletal muscle index of < 49 cm²/m² for male and < 31 cm²/m² for female. The clinical characteristics and outcomes were evaluated with respect to sarcopenia.

RESULTS

A total of 1,027 patients (854 Crohn's disease [CD]; 173 ulcerative colitis [UC]) were evaluated. Sarcopenia was found in 56.8% of the population (CD, 57.5%; UC, 53.2%), and male were more likely to be sarcopenic (CD, 94.3%; UC, 91.6%). There were no significant differences in the cumulative risk of using steroids, immunomodulators, biologics, and bowel resections (or colectomy) with or without sarcopenia during follow-up (median: CD, 5.8 years; UC, 3.7 years). In sarcopenic patients with CD, there was a significantly higher cumulative risk of perianal surgeries than in non-sarcopenic patients with CD (Log-rank test; P = 0.001). However, the risk of perianal surgeries was not significant in multivariate analysis (Odds ratio 1.368; 95% confidence interval 0.782-2.391; P = 0.272).

CONCLUSION

Sarcopenia at diagnosis may have no significant prognostic value for medical treatment and bowel resection, but it may be associated with perianal CD.

Perioperative optimization of Crohn's disease

Crohn's disease (CD) is a chronic inflammatory disease mainly affecting the gastrointestinal tract. With the increased availability of modalities in the last two decades, the treatment of CD has advanced remarkably. Although medical treatment is the mainstay of therapy, most patients require surgery during the course of their illness, especially those who experience complications. Nutritional optimization and ERAS implementation are crucial for patients with CD who require surgical intervention to reduce postoperative complications. The increased surgical risk was found to be associated with the use of corticosteroids, but the association of surgical risk with immunomodulators, biologic therapy, such as anti-TNF mediations, anti-integrin medications, and anti-IL 12/23 was low in certainty. Decisions about preoperative medication must be made on an individual case-dependent basis. Preoperative imaging studies can assist in the planning of appropriate surgical strategies and approaches. However, patients must be informed of any alterations to their treatment. In summary, the management of perioperative medications and surgery-related decision-making should be individualized and patient-centered based on a multidisciplinary approach.

Dietary management of adults with IBD - the emerging role of dietary therapy

Historically, dietitians played a minor part in the management of inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis. Patients were commonly referred for consequences of uncontrolled disease, such as malnutrition and bowel obstruction risk. Today, dietitians are fundamental members of the multidisciplinary IBD team, from educating on the role of diet at diagnosis and throughout the lifespan of a patient with IBD to guiding primary induction therapy. This aspect is reflected in published guidelines for IBD management, which previously placed diet as only a minor factor, but now have diet-specific publications. This Review describes a four-step approach in a dietitian's assessment and management of diet in patients with IBD: (1) identifying and correcting nutritional gaps and dietary imbalances; (2) considering diet to treat active disease with the use of exclusive enteral nutrition (EEN) or emerging diets that could replace EEN; (3) using therapeutic diets to control existing complications of IBD, such as reduced fibre to prevent bowel obstruction in stricturing disease or a fermentable oligosaccharides, disaccharides, monosaccharides and polyols diet to manage co-existing functional gut symptoms; and (4) considering the role of diet in preventing IBD development in high-risk populations.

The relationship between perianal fistula activity and abdominal adipose tissue in Crohn’s disease: an observational study

Objective

The aim of this study was to analyze the relationship between abdominal adipose tissue and perianal fistula activity in patients with Crohn's disease (CD) using cross-sectional imaging.

Methods

Patients with perianal fistulizing CD who underwent pelvic magnetic resonance imaging (MRI) and abdominal computed tomography (CT) were retrospectively enrolled. We scored the fistulas in each patient's MRI images based on Van Assche's classification. The area and density of subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) (at the third, fourth, and fifth lumbar (L3, L4, and L5) levels were measured by averaging five slices of measurements at each vertebral level in CT images, and areas were further standardized by the lumbar height2 (heightL1-5). The VAT/SAT ratio (VSR) and VAT/Total adipose tissue (VA/TA) index were calculated. Based on MRI scores, patients were divided into two groups with low and high activity, and their clinical, MRI features, and CT parameters were compared. We evaluated patients with follow-up MRI and compared the differences in clinical and radiological indicators among patients with different outcomes.

Results

Overall, 136 patients were included, 77 in the low-activity group and 59 in the high-activity group. Patients in the high activity group had lower subcutaneous adipose index (all levels, p < 0.05) and visceral adipose index (L3 level, p < 0.01), but higher SAT and VAT density (all levels, p < 0.01), VSR (L5 level, p = 0.07) and VA/TA index (L5 level, p < 0.05).

Conclusion

There were differences in adipose tissue composition among CD patients with different active perianal fistulas.

Systematic Review: The Impact and Importance of Body Composition in Inflammatory Bowel Disease

BACKGROUND AND AIMS

Alterations in body composition are common in inflammatory bowel disease [IBD] and have been associated with differences in patient outcomes. We sought to consolidate knowledge on the impact and importance of body composition in IBD.

METHODS

We performed a systematic search of MEDLINE, EMBASE and conference proceedings by combining two key research themes: inflammatory bowel disease and body composition.

RESULTS

Fifty-five studies were included in this review. Thirty-one focused on the impact of IBD on body composition with a total of 2279 patients with a mean age 38.4 years. Of these, 1071 [47%] were male. In total, 1470 [64.5%] patients had Crohn's disease and 809 [35.5%] had ulcerative colitis. Notably, fat mass and fat-free mass were reduced, and higher rates of sarcopaenia were observed in those with active IBD compared with those in clinical remission and healthy controls. Twenty-four additional studies focused on the impact of derangements in body composition on IBD outcomes. Alterations in body composition in IBD are associated with poorer prognoses including higher rates of surgical intervention, post-operative complications and reduced muscle strength. In addition, higher rates of early treatment failure and primary non-response are seen in patients with myopaenia.

CONCLUSIONS

Patients with IBD have alterations in body composition parameters in active disease and clinical remission. The impacts of body composition on disease outcome and therapy are broad and require further investigation. The augmentation of body composition parameters in the clinical setting has the potential to improve IBD outcomes in the future.

Visceral adipose volume is correlated with surgical tissue fibrosis in Crohn's disease of the small bowel

Background

This study explored the diagnostic performance of visceral adiposity to predict the degree of intestinal inflammation and fibrosis.

Methods

The patients with Crohn’s disease (CD) who underwent surgical small bowel resection at the First Affiliated Hospital of Sun Yat-sen University (Guangzhou, China) between January 2007 and December 2017 were enrolled. We evaluated the intestinal imaging features of computed tomography enterography (CTE), including mesenteric inflammatory fat stranding, the target sign, mesenteric hypervascularity, bowel wall thickening, lymphadenopathy, stricture diameter, and maximal upstream diameter. We used A.K. software (Artificial Intelligence Kit, version 1.1) to calculate the visceral fat (VF) and subcutaneous fat (SF) volumes at the third lumbar vertebra level. Pathological tissue information was recorded. Diagnostic models were established based on the multivariate regression analysis results, and their effectiveness was evaluated by area under the curve (AUC) and decision curve analyses.

Results

Overall, 48 patients with CD were included in this study. The abdominal VF/SF volume ratio (odds ratio, 1.20; 95% confidence interval, 1.05–1.38; P = 0.009) and the stenosis diameter/upstream intestinal dilatation diameter (ND) ratio (odds ratio, 0.90; 95% confidence interval, 0.82–0.99; P = 0.034) were independent risk factors for the severe fibrosis of the small intestine. The AUC values of the VF/SF ratio, the ND ratio, and their combination were 0.760, 0.673, and 0.804, respectively. The combination of the VS/SF volume ratio and ND ratio achieved the highest net benefit on the decision curve.

Conclusion

The VF volume on CTE can reflect intestinal fibrosis. The combination of the VF/SF volume ratio and ND ratio of CD patients assessed using CTE can help predict severe fibrosis stenosis of the small intestine.

Impact of Sarcopenia on Clinical Outcomes in a Cohort of Caucasian Active Crohn's Disease Patients Undergoing Multidetector CT-Enterography

(1) Background: Sarcopenia has a high incidence in Crohn’s disease (CD) with considerable heterogeneity among ethnicities and variable impact on clinical outcomes. Aim: to assess the impact of sarcopenia on clinical outcomes in a cohort of Caucasian patients with active CD undergoing CT-enterography (CTE) for clinical assessment. We further investigated the prevalence of sarcopenia and its predictors. (2) Methods: Caucasian CD patients with moderate−severe clinical activity, who underwent CTE in an emergency setting, were retrospectively recruited. The skeletal muscle index (SMI) at the third lumbar vertebra was used to detect sarcopenia in the early stages. Clinical malnutrition was defined according to global clinical nutrition criteria. Clinical outcomes included the rate of surgery and infections within one year. (3) Results: A total of 63 CD patients (34 M; aged 44 ± 17 years) were recruited, and 48 patients (68.3%) were sarcopenic. Malnutrition occurred in 28 patients (44.4%) with a significant correlation between body mass index (BMI) and sarcopenia (r = 0.5, p < 0.001). The overall rate of surgery was 33%, without a significant difference between sarcopenic and non-sarcopenic (p = 0.41). The rate of infection in patients with sarcopenia was significantly higher than in non-sarcopenic (42%vs15%, p = 0.03). BMI (OR 0.73,95%, CI 0.57−0.93) and extraintestinal manifestations (EIM) (OR 19.2 95%, CI 1.05−349.1) were predictive of sarcopenia (p < 0.05). (4) Conclusions: Sarcopenia was associated with an increased rate of infections, and it was observed in 68.3% of the Caucasian cohort with active CD.

Is Ustekinumab Effective in Refractory Crohn's Disease of the Pouch and Chronic Pouchitis? A Systematic Review

Crohn's disease (CD) of the pouch and chronic pouchitis represent the most common long-term complications of total proctocolectomy and ileal pouch anal anastomosis (IPAA) for refractory ulcerative colitis (UC). These conditions are treated with multiple agents, including antibiotics, immunomodulators, and biologics. Among the latter, ustekinumab is approved for both CD and UC. We performed a systematic review to evaluate the efficacy of this anti-IL12/23 in CD of the pouch and chronic refractory pouchitis. Pubmed, Embase, Ovid, and the Cochrane Controlled Trials Register were searched to identify studies published until August 2020 investigating the use of ustekinumab for these conditions. Eighty-six eligible patients with IPAA-51 with CD of the pouch, 35 with chronic pouchitis-were identified from 2 retrospective studies and 5 case reports. Reported clinical response to ustekinumab was 63 and 85% in chronic pouchitis and CD of the pouch after 4-12 and 4-16 weeks, respectively. Clinical remission was reported in 10% of patients with chronic pouchitis and 27% of patients with CD of the pouch after 8-52 and 4-52 weeks of treatment, respectively. Endoscopic response was reported in 60% and 67% of patients with chronic pouchitis and CD of the pouch after 24-32 and 8-24 weeks of treatment respectively. Small sample sizes and large heterogeneity of therapy protocols/outcome definitions were significant studies limitations. In conclusion, there is a limited and inconclusive body of evidence suggesting that ustekinumab may be a therapeutic option for patients with chronic pouchitis and CD of the pouch refractory to other therapies.

Deep Learning Analysis of Histologic Images from Intestinal Specimen Reveals Adipocyte Shrinkage and Mast Cell Infiltration to Predict Postoperative Crohn Disease

Most patients with Crohn disease (CD), a chronic inflammatory gastrointestinal disease, experience recurrence despite treatment, including surgical resection. However, methods for predicting recurrence remain unclear. This study aimed to predict postoperative recurrence of CD by computational analysis of histopathologic images and to extract histologic characteristics associated with recurrence. A total of 68 patients who underwent surgical resection of the intestine were included in this study and were categorized into two groups according to the presence or absence of postoperative disease recurrence within 2 years after surgery. Recurrence was defined using the CD Activity Index and the Rutgeerts score. Whole-slide images of surgical specimens were analyzed using deep learning model EfficientNet-b5, which achieved a highly accurate prediction of recurrence (area under the curve, 0.995). Moreover, subserosal tissue images with adipose cells enabled highly accurate prediction. Adipose cell morphology showed significant between-group differences in adipose cell size, cell-to-cell distance, and cell flattening values. These findings suggest that adipocyte shrinkage is an important histologic characteristic associated with recurrence. Moreover, there was a significant between-group difference in the degree of mast cell infiltration in the subserosa. These findings show the importance of mesenteric adipose tissue in patient prognosis and CD pathophysiology. These findings also suggest that deep learning-based artificial intelligence enables the extraction of meaningful histologic features.

Can visceral adipose tissue and skeletal muscle predict recurrence of newly diagnosed Crohn's disease in different treatments

BACKGROUND AND AIMS

It is crucial to manage the recurrence of Crohn's disease (CD). This study is aimed to explore whether visceral adipose tissue (VAT) and skeletal muscle (SM) are associated with the recurrence of CD upon different treatments.

METHODS

All patients with a definite diagnosis of CD were retrospectively divided into three groups according to distinct treatment regimens: 5-amino salicylic acid group (Group A), steroids + azathioprine (Group B) and biologics (Group C). The pretreatment computerized tomography (CT) images and clinical data were collected. The VAT area, mesenteric fat index (MFI), the ratio of VAT area to fat mass (VAT area/FM) were assessed. The primary end point was the recurrence of CD within 1 year of follow-up.

RESULTS

A total of 171 CD patients were enrolled, including 57 (33.33%) patients in Group A, 70 (40.94%) patients in Group B and 44 (25.73%) patients in Group C. Patients with 1-year recurrence had higher MFI (P = 0.011) and VAT area/FM (P = 0.000). ROC curve demonstrated that patients with the ratio of VAT area/FM and MFI higher than 0.578 and 1.394 tended to have recurrence with the AUC of 0.707 and 0.709. Similar results could be observed in Group A & B but not in Group C.

CONCLUSIONS

High VAT area/FM and MFI are related to recurrence within 1 year for newly diagnosed CD patients treated by 5-amino salicylic or azathioprine + steroids rather than biologics. We could not observe any radiological data associated with the recurrence of CD patients under biological treatment.

The GLIM Criteria Represent a More Appropriate Tool for Nutritional Assessment in Patients With Crohn's Disease

Background

The early recognition of malnutrition is essential for improving the prognosis of patients with Crohn's disease (CD). The Global Leadership Initiative on Malnutrition (GLIM) criteria represent a new consensus for the diagnosis of malnutrition but need to be validated in CD. The aims were to explore the related factors of malnutrition in CD and explore whether GLIM-positive patients who did not meet the Nutritional Risk Screening 2002 (NRS 2002) would benefit from nutritional treatment.

Methods

This study retrospectively enrolled patients with CD at the Gastroenterology Department of Xiangya Hospital Central South University between March 2020 and March 2021. After bioelectrical impedance analysis, all patients underwent nutritional screening and diagnosis using the NRS 2002 and GLIM criteria, respectively. Multivariable analysis was performed to evaluate risk factors related to malnutrition in patients with CD. A multivariable Cox hazard model was used to assess the association between nutritional therapy and prognostic outcomes.

Results

Of the 118 patients included, fifty were classified as having a high malnutrition risk according to the NRS 2002, while 76 were diagnosed with malnutrition by the GLIM criteria. Multivariate analysis showed that a high malnutrition risk was independently associated with the L4 phenotype [odds ratio (OR) (95% confidence interval (CI)) = 4.718 (1.108, 20.10), p = 0.036] and Crohn's Disease Activity Index (CDAI) [OR (95% CI) = 1.018 (1.007, 1.029), p = 0.002] based on the NRS 2002. The age at onset [OR (95% CI) = 0.828 (0.699, 0.980), p = 0.028] and CDAI [OR (95% CI) = 1.111 (1.034, 1.195), p = 0.004] were regarded as independent risk factors related to malnutrition, as determined by the GLIM criteria. Among 26 GLIM+/NRS− patients, significantly more patients who received nutritional support achieved 6-week remission than patients who did not (100 vs. 71.4%, p < 0.05). The 6-week remission risk in patients treated with nutrition therapy was more than 4-fold higher than those without nutritional therapy.

Conclusion

The GLIM criteria could diagnose more malnourished patients with CD who are not positively screened by the NRS 2002, among whom nutritional support therapy would be beneficial for disease remission. The new criteria should be more appropriate for assessing the nutritional status of patients with CD.

Body Composition as a Modulator of Bone Health Changes in Patients with Inflammatory Bowel Disease

Background: Bone impairment of multifactorial etiology is a common feature in inflammatory bowel disease (IBD). Body composition parameters, which might be selectively modified in these patients, are important determinants of bone strength. Our aim was to investigate the relationship between components of body composition and bone parameters in IBD patients. Methods: This is a cross-sectional, retrospective study including 80 IBD patients (43 women, 37 men). Lumbar spine (LS), femoral neck (FN) and whole body DXA scans were performed to analyze regional bone mineral density (BMD), as well as body composition, including appendicular skeletal muscle mass index (ASMI), total and visceral fat mass (VAT). Trabecular bone score (TBS) was assessed using iNsight Software. Results: Twenty (25%) IBD patients had inadequate LS-BMD z scores (<=−2DS). Lean mass (LM) was a significant determinant of LS-BMD, after adjusting for age, gender, BMI and fat mass (p < 0.01), while fat mass% remained associated with FN-BMD (p < 0.01). TBS correlated positively with BMI (r = 0.24, p < 0.05), LS-BMD (r = 0.56, p < 0.001), ASMI (r = 0.34, p < 0.001) and negatively with VAT/total fat% (r = −0.27, p < 0.05). Multivariate analysis showed that ASMI, LS-BMD (positively) and VAT/total fat% (negatively) were independently associated with TBS. Conclusions: In IBD patients, skeletal muscle mass and fat percentage and distribution are important factors associated with bone health.

A Novel Clinical Radiomics Nomogram to Identify Crohn's Disease from Intestinal Tuberculosis

Purpose

To establish a clinical radiomics nomogram to differentiate Crohn’s disease (CD) from intestinal tuberculosis (ITB).

Patients and Methods

Ninety-three patients with CD and 67 patients with ITB were recruited (111 in training cohort and 49 in test cohort). The region of interest (ROI) for the lesions in the ileocecal region was delineated on computed tomography enterography and radiomics features extracted. Radiomics features were filtered by the gradient boosting decision tree (GBDT), and a radiomics score was calculated by using the radiomics signature-based formula. We constructed a clinical radiomics model and nomogram combining clinical factors and radiomics score through multivariate logistic regression analysis, and the internal validation was undertaken by ten-fold cross validation. Analyses of receiver operating characteristic (ROC) curves and decision curve analysis (DCA) were used to evaluate the prediction performance. DeLong test was applied to evaluate the performance of the clinical, radiomics and combined model.

Results

The clinical radiomics nomogram, which was based on the 9 radiomics signature and two clinical factors, indicated that the clinical radiomics model had an area under the ROC curve (AUC) value of 0.96 (95% confidence interval [CI]: 0.93–0.99) in the training cohort and 0.93 (95% CI: 0.86–1.00) in validation cohort. The clinical radiomics model was superior to the clinical model and radiomics model, and the difference was significant (P = 0.006, 0.004) in the training cohort. DCA confirmed the clinical utility of clinical radiomics nomogram.

Conclusion

CTE-based radiomics model has a good performance in distinguishing CD from ITB. A nomogram constructed by combining radiomics and clinical factors can help clinicians accurately diagnose and select appropriate treatment strategies between CD and ITB.

Visceral adiposity and inflammatory bowel disease

BACKGROUND

Rates of obesity are increasing worldwide, as is the incidence of inflammatory bowel disease (IBD). Obesity is now considered an inflammatory state. Visceral adiposity in particular may be associated with a more severe inflammatory phenotype in IBD.

AIM

The aim of this review article is to summarise the current literature on the association between visceral adiposity and outcomes in inflammatory bowel disease METHODS: To collect relevant articles, PubMed/MEDLINE and Embase searches were performed using Boolean search phrases. Grey literature and manual searches were also performed. Abstracts were selected by two independent reviewers based on pre-determined criteria. Full text articles were reviewed, and data extracted and assessed.

RESULTS

One hundred twenty-seven abstracts were obtained through the initial search, with 85 abstracts reviewed and 22 full text articles included. Characteristics are included in Table 1. Most of these were retrospective studies and of moderate or weak quality. Studies suggested visceral fat content is higher in Crohn's disease than in healthy controls. Visceral adiposity was associated with an increased risk of complex Crohn's disease phenotype (OR 26.1 95% CI 2-75.4; p = 0.02). Post-operative recurrence was higher in patients with higher visceral fat indices (RR 2.1; CI 1.5-3; p = 0.012). There were conflicting data regarding the effect of visceral adiposity on post-operative complications and the efficacy of medical therapy. Table 1 Study characteristics Author Year Country Study type Study numbers Control group Disease type Methodology e.g. CT Body composition measurements Results Argeny [24] 2018 Austria Retrospective cohort N = 95 N/A Crohn's disease CT; L3 level Visceral fat area (cm²) Visceral fat index (VFA/m²) No association between VFA or VFI and short-term post-operative outcomes Bryant [30] 2018 Australia Prospective cohort N = 110 N/A Crohn's disease and UC DXA Visceral adipose tissue (VAT) (cm³) Visceral adipose tissue (grams) VAT/height index (cm³/m²) VAT:subcutaneous adipose tissue ratio Fat mass index (kg/m²) VAT and VHI increased significantly over 24 months Bryant [13] 2018 Australia Prospective cohort N = 72 N/A Crohn's disease; female DXA Visceral adipose tissue (VAT) (cm³) Visceral adipose tissue (grams) VAT/height index (cm³/m²) VAT:subcutaneous adipose tissue ratio VAT:SAT positively associated with stricturing disease Adiposity not associated with fistulising disease phenotype VAT:SAT significantly associated with faecal calprotectin in L3 phenotype VAT:SAT significantly negatively associated with VHI and QoL over 24 months Buning [25] 2015 Germany Case control N = 50 N = 19 healthy controls Crohn's disease MRI US VAT Thickness of abdominal fat Distance to posterior wall of aorta Area of inferior part of perirenal fat VAT accumulation was higher in CD patients vs healthy controls VAT and VAT/fat mass ratio higher in patients in short-term remission vs long-term remission VAT/FM higher in stricturing/fistulising disease vs inflammatory subtype No association between VAT/FM and CDAI, HBI or anti-TNF treatment Connolly [26] 2014 US Retrospective cohort N = 143 N/A Crohn's disease CT (L1-L5 level) Visceral/intra-abdominal adiposity (VA) Subcutaneous adiposity (SA) VA not associated with post-operative morbidity Decreased SA and increased visceral/subcutaneous ratio were predictive of post-op complications. (p = 0.02; p < 0.001) Cravo [27] 2017 Portugal Retrospective cohort N = 71 N/A Crohn's disease CT (L3 level) Smooth muscle area (cm²) Visceral fat area (cm²) Subcutaneous fat area (cm²) Visceral fat index Muscle radiation attenuation L2 phenotype associated with lower muscle attenuation and higher visceral fat index (non-significant) B2/B3/surgery - significantly lower muscle attenuation. VFI associated with increased risk of complicated phenotype. (OR 26.1; 95% CI 1-75; p = 0.02) Ding [17] 2016 US Retrospective cohort N = 164 N/A Crohn's disease CT (L3 level) Visceral fat area (cm²) Subcutaneous fat area Total fat area Visceral obesity associated with longer duration of surgery, increased intra-operative blood loss and longer length of bowel resected Higher complication rates in patients with visceral obesity (p < 0.001) VFA independent risk factor of adverse post-op outcomes Ding [14] 2017 Retrospective cohort N = 106 N/A Crohn's disease CT (L3 level) Visceral fat area Subcutaneous fat area Skeletal muscle area Skeletal muscle index Visceral obesity and myopenic obesity not significantly associated with risk of primary non-response Body composition factors not associated with secondary loss of response Erhayiem [18] 2011 UK Retrospective cohort N = 50 N/A Crohn's disease CT (L4 level) Mesenteric fat index (visceral:subcutaneous area ratio)N = 50 Mesenteric fat index was significantly higher in complicated Crohn's disease. ROC analysis for MFI in identifying complicated Crohn's disease: AUC = 0.95 (95% CI 0.89-1.0) Feng [28] 2018 China Retrospective cohort N = 80 Non-IBD GI patients Crohn's disease CT-energy spectral Visceral fat area (cm²) Subcutaneous fat area (cm²) Mesenteric fat index No significant difference in VFA between Crohn's disease cohort and control group. (p = 0.669). ROC analysis: detection of disease based on VFA and MFI: AUC 0.776 Sensitivity 77.5% Specificity 67.5% Hafraoui [16] 1998 France/Belgium Prospective N = 43 Healthy volunteers n = 13 Intestinal resection n = 9 Crohn's disease MRI (umbilicus) Total abdominal fat (cm²) Intra-abdominal fat (cm²) Subcutaneous fat (cm²) Ratio of intra-abdominal:total fat area was significantly higher in patients with Crohn's vs controls. (p = 0.012) No correlation between abdominal fat tissue and disease activity, duration or steroid therapy Holt [29] 2017 Australia/New Zealand RCT N = 44 N = 11 placebo group Crohn's disease CT/MRI (L3, L4-5 levels) Visceral adipose tissue area Subcutaneous adipose tissue area Skeletal muscle area Visceral adipose tissue/height index VHI > 1.5 times gender mean was specific for endoscopic recurrence (100%) with sensitivity of 29%. PPV = 1 (0.59-1.00) There was no significant difference in disease activity at 18 months post-resection based on VHI > 1.5 gender mean Li [31] 2015 China Retrospective cohort N = 72 N/A Crohn's disease CT (umbilicus) Visceral fat area (cm²) Subcutaneous fat area (cm²) Mesenteric fat index Post-op recurrence was more frequent with high VFA values. (p = 0.019) VFA and MFI were independent risk factors for post-operative recurrence. (p = 0.013 and p = 0.028, respectively) High VFA and high MFI were significantly higher in patients with endoscopic activity (p = 0.023) Liu [32] 2016 Retrospective case-control N = 59 N = 30 (< 15% increase VFA) IBD with IPAA CT (L3) Visceral fat area Subcutaneous fat area No difference in pouchitis, pouch sinus formation and composite adverse pouch outcomes between the 2 groups with and without VFA increase > 15%. Excessive VAT gain was an independent risk factor for the composite adverse pouch outcomes. (OR 12.6 (95% CI 1.19-133.5) Magro [33] 2018 Brazil Cross-sectional study N = 78 N = 28 Health control Crohn's disease DEXA Fat and lean masses Visceral fat (kg) Visceral fat/BMI Visceral fat per %body fat VF was higher in Crohn's disease group (p = 0.004) compared to controls Parmentier-Decrucq [34] 2009 Prospective study N = 132 N/A Crohn's disease MRI Subcutaneous fat Visceral fat Total abdominal fat increased 18% in Crohn's disease patients treated with infliximab induction therapy Shen [35] 2018 China Retrospective N = 97 N/A Crohn's disease CT (umbilicus) Subcutaneous fat area Visceral fat area Mesenteric fat index VFA and MFI were significantly lower in patients with mucosal healing (post-infliximab). (p < 0.0001) SFA was not significantly different VFA correlated with CDAI (p < 0.001) and was an independent predictive factor for mucosal healing Stidham [15] 2015 Retrospective N = 269 N/A Crohn's disease CT(T10-L5) Subcutaneous fat volume Visceral fat volume No significant difference in visceral fat volume between patients with surgical complications Thiberge [36] 2018 France Retrospective N = 149 N/A Crohn's disease CT (L3 level) Skeletal muscle index Visceral adiposity index Subcutaneous adiposity index SAI and VAI were significantly lower in patients who underwent surgery or who died in 6 months post-CT(p = 0.009 and p < 0.001) VanDerSloot [37] 2017 Cohort study N/A Crohn's disease CT (T11-S5) Visceral adipose tissue volume Non-significant trend toward increased risk of surgery and penetrating disease with increasing VAT Wei [38] 2018 China Retrospective N = 86 N/A IBD post-resection CT (L3 level) Visceral adipose volume Subcutaneous adipose volume Increased visceral:subcutaneous fat ratio was associated with increased procalcitonin levels on post-op days 1, 3 and 5 Yadav [39] 2017 India Prospective N = 97 N/A IBD CT (L4 level) Visceral fat area Subcutaneous fat area No statistically significant correlation between visceral fat and disease behaviour in Crohn's disease N/A not applicable, VFA visceral fat area, VFI visceral fat index, VAT visceral adipose tissue, VHI visceral adipose tissue to height index, SAT subcutaneous adipose tissue, DXA dual-energy X-ray absorptiometry, CT computer tomography, MRI magnetic resonance imaging, US ultrasound, CDAI Crohn's disease activity index, HBI Harvey-Bradshaw Index, anti-TNF anti-tumour necrosis factor, SA subcutaneous adiposity, ROC receiver operating curve, AUC area under the curve, MFI mesenteric fat index, SAI subcutaneous adiposity index, PPV positive predictive value CONCLUSION: Visceral adiposity appears to be increased in Crohn's disease with some evidence that it is also associated with more complex disease phenotypes. There is also a signal that post-operative recurrence rates are affected by increasing mesenteric adiposity. There is a relative lack of data in UC patients and further high-quality studies are necessary to elucidate the relationship between visceral adiposity and IBD and the implications for patient outcomes.

Role of Extended Mesenteric Excision in Postoperative Recurrence of Crohn's Colitis: A Single-Center Study

INTRODUCTION

The mesentery is involved in Crohn's disease. The impact of the extent of mesenteric resection on postoperative disease progression in Crohn's disease remains unconfirmed. This study aimed to determine the association between resection of the mesentery and postoperative outcomes in patients with Crohn's colitis (CC) undergoing colorectal surgery.

METHODS

Patients with CC who underwent colorectal resection between January 2000 and December 2018 were reviewed, and the data were gathered from a prospectively maintained database. Patients were divided into 2 groups according to the extent of mesenteric resection, the extensive mesenteric excision (EME) group and the limited mesenteric excision (LME) group. Outcomes including early postoperative morbidities and surgical recurrence were compared between the 2 groups.

RESULTS

Of the 126 patients included, 60 were in the LME group and 66 in the EME group. There was no significant difference between the 2 groups in early postsurgical outcomes except the intraoperative blood loss was increased in the LME group (P = 0.002). Patients in the EME group had a longer postoperative surgical recurrence-free survival time when compared with those in the LME group (P = 0.01). LME was an independent predictor of postoperative surgical recurrence (hazard ratio 2.67, 95% confidence interval 1.04-6.85, P = 0.04). This was further confirmed in the subgroup analysis of patients undergoing colorectal resection and anastomosis (hazard ratio 2.83, 95% confidence interval 1.01-7.96, P = 0.048).

DISCUSSION

In patients undergoing surgery for CC, inclusion of the mesentery is associated with similar short-term outcomes and improved long-term outcomes compared with those seen when the mesentery is retained.

Computed tomography-based multiple body composition parameters predict outcomes in Crohn's disease

Background

The efficacy of computed tomography-based multiple body composition parameters in assessing disease behavior and prognosis has not been comprehensively evaluated in Crohn’s disease. This study aimed to assess the association of body composition parameters with disease behavior and outcomes in Crohn’s disease and to compare the efficacies of indexes derived from body and lumbar spinal heights in body composition analysis.

Results

One hundred twenty-two patients with confirmed Crohn’s disease diagnoses and abdominal computed tomography scans were retrospectively included in this study. Skeletal muscle, visceral, and subcutaneous fat indexes were calculated by dividing each type of tissue area by height² and lumbar spinal height². Parameters reflecting the distribution of adiposity were also assessed. Principal component analysis was used to deal with parameters with multicollinearity. Patients were grouped according to their disease behavior (inflammatory vs. structuring/penetrating) and outcomes. Adverse outcome included need for intestinal surgery or anti-TNF therapy. Predictors of disease course from multiple parameters were evaluated using multivariate analysis. Indexes derived from body and lumbar spinal heights were strongly correlated (r, 0.934–0.995; p < 0.001). Low skeletal muscle-related parameters were significantly associated with complicated disease behavior in multivariate analysis (p = 0.048). Complicated disease behavior (p < 0.001) and adipose tissue parameters-related first principal component (p = 0.029) were independent biomarkers for predicting adverse outcomes.

Conclusions

Skeletal muscle and adipose tissue principle component were associated with complicated Crohn’s disease behavior and adverse outcome, respectively. Indexes derived from body and lumbar spinal heights have similar efficacies in body composition analysis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13244-021-01083-6.

Inflammatory Bowel Disease and Sarcopenia: Its Mechanism and Clinical Importance

Malnutrition is a major contributor to muscle loss and muscle dysfunction, known as sarcopenia. Malnutrition is common in patients with inflammatory bowel disease (IBD). IBD includes ulcerative colitis (UC) and Crohn’s disease (CD). The number of patients with IBD has recently been increasing. More severe malnutrition is often seen in CD compared to UC, probably due to CD affecting the main site of nutrient absorption, extensive mucosal lesions, fistulas, short bowel syndrome after resection, or obstruction of the gastrointestinal tract. A recent meta-analysis showed the high prevalence of sarcopenia in patients with IBD, and thus sarcopenia is a very important problem for IBD. Although IBD is more common in younger patients, sarcopenia can develop through a variety of mechanisms, including malnutrition, chronic inflammation, increased inflammatory status in adipose tissue, vitamin deficiency, and imbalance of the muscle–gut axis. In addition, sarcopenia has a negative impact on postoperative complications and hospital stay in patients with IBD. Appropriate intervention for sarcopenia may be important, in addition to clinical remission and endoscopic mucosal healing in patients with IBD. Much more attention will thus be paid to sarcopenia in patients with IBD. In this review, we outline IBD and sarcopenia, based on the current evidence.

Assessment of Body Composition From CT Images at the Level of the Third Lumbar Vertebra in Inflammatory Bowel Disease

BACKGROUND

Although there are several reports of associations between body composition parameters and outcomes in patients with inflammatory bowel disease (IBD), it is not clear which muscle tissue parameters and/or adipose tissue parameters most strongly affect outcomes. Therefore, this study sought to determine the associations of such parameters determined at the level of the third lumbar vertebra (L3) on computed tomography (CT) images with outcomes in IBD patients.

METHODS

Subjects were IBD patients who were admitted to our hospital and underwent abdominal CT. The following parameters were assessed: skeletal muscle index, psoas muscle index, visceral adipose tissue/height index, visceral to subcutaneous adipose tissue area ratio, and intramuscular adipose tissue content. In this study, short- and long-term outcomes were defined as prolonged length of stay (≥30 days) and intestinal resection during the overall period of observation, respectively.

RESULTS

In total, 187 patients were enrolled, 99 with Crohn's disease and 88 with ulcerative colitis. For all IBD patients, multivariate logistic regression analysis revealed that low albumin level and low psoas muscle index on admission were associated with prolonged length of stay. Multivariate Cox regression analysis revealed that male sex, Crohn's disease (not ulcerative colitis), low psoas muscle index, and high visceral to subcutaneous adipose tissue area ratio were associated with intestinal resection.

CONCLUSIONS

This study revealed that muscle volume is associated with the short-term outcome of prolonged length of stay, whereas muscle volume and visceral adipose tissue volume (relative to subcutaneous adipose tissue volume) are associated with the long-term outcome of intestinal resection.

The Effect of Adiposity on Anti-Tumor Necrosis Factor-Alpha Levels and Loss of Response in Crohn's Disease Patients

INTRODUCTION

A high body mass index is known to adversely affect antitumor necrosis factor-alpha trough levels and secondary loss of response (SLOR) in patients with Crohn's disease. We hypothesize that high levels of adiposity negatively affect these outcomes and aimed to determine if this relationship exists.

METHODS

We performed a retrospective cross-sectional study of 69 patients with Crohn's disease from two tertiary inflammatory bowel disease centers between February 1, 2015, and June 30, 2018. Primary responders to infliximab (IFX) or adalimumab (ADA) who had a trough level performed within 6 months of CT or MRI scan and at least 12 months of clinical follow-up were eligible for inclusion. Body composition as measured on CT/MRI scans were correlated with trough concentration and time SLOR. Multivariate adjustments were made for established risk factors known to affect trough levels and SLOR.

RESULTS

Of 69 included patients, 44 (63.8%) and 25 (36.2%) patients received IFX and ADA, respectively. Multivariate analysis revealed that IFX trough concentrations were inversely correlated with visceral fat area (-0.02 [-0.04, -0.003], P = 0.03), visceral fat index (-0.07 [-0.12, -0.01], P = 0.02) and visceral fat: skeletal muscle area ratio (-3.81 [-7.13, -0.50], P = 0.03), but not body mass index (-0.23 [-0.52, 0.06], P = 0.11). No predictive factors were found for ADA. Increased total adipose area was associated with an increased risk of SLOR in ADA-treated patients, but not IFX-treated patients (hazard ratio = 1.01 [1.002, 1.016], P = 0.011).

DISCUSSION

Visceral adiposity is an important predictor of IFX trough levels, and high total adiposity predicts for SLOR to ADA.

Obesity in inflammatory bowel disease: A review of its role in the pathogenesis, natural history, and treatment of IBD

In contrast to previous perceptions that inflammatory bowel disease (IBD) patients are generally malnourished and underweight, there is mounting evidence to suggest that rates of obesity in IBD now mirror that of the general population. IBD is an immune-mediated condition that appears to develop in individuals who have not only a genetic predisposition to immune dysregulation but also likely exposure to various environmental factors which further potentiate this risk. With the surge in obesity alongside the rising incidence of IBD, particularly in developing nations, the role that obesity may play, not only in the pathogenesis but also in the natural history of disease has become a topic of growing interest. Currently available data exploring obesity's impact on the natural history of IBD are largely conflicting, potentially limited by the use of body mass index as a surrogate measure of obesity at varying time points throughout the disease course. While there are pharmacokinetic data to suggest possible detrimental effects that obesity may have on the response to medical therapy, results in this realm are also inconsistent. Moreover, not only is it unclear whether weight loss improves IBD outcomes, little is known about the safety and efficacy of available weight-loss strategies in this population. For these reasons, it becomes increasingly important to further understand the nature of any interaction between obesity and IBD.

A systematic review and meta-analysis of prospective studies on obesity and risk of inflammatory bowel disease

CONTEXT

There are only a few systematic reviews on the association of obesity with risk of inflammatory bowel disease (IBD) to date.

OBJECTIVE

The current study was undertaken to systematically review prospective cohort studies on the association between body mass index (BMI) and risk of IBD. It was carried out according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines.

DATA SOURCES

Relevant prospective cohort studies published from 1969 to July 2020 were searched through PubMed, MEDLINE, SCOPUS, EMBASE, and Google Scholar, using suitable keywords.

DATA EXTRACTION

Hazard ratios (HRs) or relative risks (RRs) and 95% confidence intervals (CIs) for IBD or its subtypes across categories of BMI were extracted.

DATA ANALYSIS

The log HRs/RRs, including standard errors, were calculated based on reported HRs or RRs and their 95% CIs, and overall effect size was calculated using a fixed-effects model. All statistical analyses were done using STATA version 14.0 (Stata Corp LP, College Station, TX, USA).

CONCLUSION

Overall, 9 studies were included. Combining findings from 5 studies, a statistically significant 21% lower risk of ulcerative colitis incidence was found in patients with obesity than in those with normal weight (RR, 0.79; 95% CI, 0.68-0.92; I2= 0.0%), but not with risk of ulcerative colitis exacerbation, as found by meta-analysis of 3 studies. Pooling data from 5 studies, no significant differences were seen in the risk of Crohn's disease incidence between patients in the highest range of BMI and those in the normal range. In addition, no significant nonlinear association was found between BMI and risk of Crohn's disease (P=0.94). A significant inverse association was found between obesity and total IBD incidence (RR, 0.76; 95% CI, 0.66-0.88; I2=93.2%), but not between increasing BMI and IBD exacerbation, or between increasing BMI and IBD incidence.