Association between high visceral fat area and postoperative complications in patients with Crohn's disease following primary 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.

Three-dimensional body composition parameters using automatic volumetric segmentation allow accurate prediction of colorectal cancer outcomes

BACKGROUND

Parameters obtained from two-dimensional (2D) cross-sectional images have been used to determine body composition. However, data from three-dimensional (3D) volumetric body images reflect real body composition more accurately and may be better predictors of patient outcomes in cancer. This study aimed to assess the 3D parameters and determine the best predictive factors for patient prognosis.

METHODS

Patients who underwent surgery for colorectal cancer (CRC) between 2010 and 2016 were included in this study. Preoperative computed tomography images were analysed using an automatic segmentation program. Body composition parameters for muscle, muscle adiposity, subcutaneous fat (SF) and abdominal visceral fat (AVF) were assessed using 2D images at the third lumbar (L3) level and 3D images of the abdominal waist (L1-L5). The cut-off points for each parameter were determined using X-tile software. A Cox proportional hazards regression model was used to identify the association between the parameters and the treatment outcomes, and the relative influence of each parameter was compared using a gradient boosting model.

RESULTS

Overall, 499 patients were included in the study. At a median follow-up of 59 months, higher 3D parameters of the abdominal muscles and SF from the abdominal waist were found to be associated with longer overall survival (OS) and disease-free survival (all P < 0.001). Although the 3D parameters of AVF were not related to survival outcomes, patients with a high AVF volume and mass experienced higher rate of postoperative complications than those with low AVF volume (27.4% vs. 18.7%, P = 0.021, for mass; 27.1% vs. 19.0%, P = 0.028, for volume). Low muscle mass and volume (hazard ratio [HR] 1.959, P = 0.016; HR 2.093, P = 0.036, respectively) and low SF mass and volume (HR 1.968, P = 0.008; HR 2.561, P = 0.003, respectively), both in the abdominal waist, were identified as independent prognostic factors for worse OS. Along with muscle mass and volume, SF mass and volume in the abdominal waist were negatively correlated with mortality (all P < 0.001). Both AVF mass and volume in the abdominal waist were positively correlated with postoperative complications (P < 0.05); 3D muscle volume and SF at the abdominal waist were the most influential factors for OS.

CONCLUSIONS

3D volumetric parameters generated using an automatic segmentation program showed higher correlations with the short- and long-term outcomes of patients with CRC than conventional 2D parameters.

Role of Adipose Tissue Hormones in Pathogenesis of Cryptoglandular Anal Fistula

The cryptoglandular perianal fistula is a common benign anorectal disorder that is managed mainly with surgery and in some cases may be an extremely challenging condition. Perianal fistulas are often characterized by significantly decreased patient quality of life. Lack of fully recognized pathogenesis of this disease makes it difficult to treat it properly. Recently, adipose tissue hormones have been proposed to play a role in the genesis of cryptoglandular anal fistulas. The expression of adipose tissue hormones and epithelial-to-mesenchymal transition (EMT) factors were characterized based on 30 samples from simple fistulas and 30 samples from complex cryptoglandular perianal fistulas harvested during surgery. Tissue levels of leptin, resistin, MMP2, and MMP9 were significantly elevated in patients who underwent operations due to complex cryptoglandular perianal fistulas compared to patients with simple fistulas. Adiponectin and E-cadherin were significantly lowered in samples from complex perianal fistulas in comparison to simple fistulas. A negative correlation between leptin and E-cadherin levels was observed. Resistin and MMP2 levels, as well as adiponectin and E-cadherin levels, were positively correlated. Complex perianal cryptoglandular fistulas have a reduced level of the anti-inflammatory adipokine adiponectin and have an increase in the levels of proinflammatory resistin and leptin. Abnormal secretion of these adipokines may affect the integrity of the EMT in the fistula tract. E-cadherin, MMP2, and MMP9 expression levels were shifted in patients with more advanced and complex perianal fistulas. Our results supporting the idea of using mesenchymal stem cells in the treatment of cryptoglandular perianal fistulas seem reasonable, but further studies are warranted.

The Impact of Obesity on Inflammatory Bowel Disease

Obesity is prevalent in the inflammatory bowel disease (IBD) population, particularly in newly developed countries where both IBD and obesity in the general population are on the rise. The role of obesity in the pathogenesis of IBD was entertained but results from available studies are conflicting. It does, however, appear to negatively influence disease course whilst impacting on our medical and surgical therapies. The pro-inflammatory profile of the visceral adipose tissue might play a role in the pathogenesis and course of Crohn's Disease (CD). Interestingly, isolating the mesentery from the surgical anastomosis using a KONO-S technique significantly decreases anastomotic recurrence rate. Anti-obesity therapy is not widely used in IBD but was suggested as an adjunctive therapy in those patients. In this review, we aimed to highlight the epidemiology of obesity in IBD and to describe its influence on disease course and outcomes.

Strong impact of sarcopenic state defined by skeletal muscle mass index on postoperative complication of Crohn's disease patients

Background

Malnutrition impacts the clinical course of Crohn's disease; however, there is little evidence of its influence on perioperative adverse events. We assessed whether nutritional indicators are associated with postoperative complications in surgical treatment of Crohn's disease.

Methods

137 patients with Crohn's disease who underwent surgical treatment between January 2011 and December 2020 were included. Skeletal muscle index was calculated by a single CT slice. We analyzed the risk factors for adverse events.

Results

37 % of patients had postoperative complications. Adverse events occurred more frequently in patients with high serum C-reactive protein, low serum albumin, prognostic nutritional index <38.3, skeletal muscle index <38.9 cm2/m2, abdominoperineal resection, long surgical duration, and mass hemorrhage. Among patients with skeletal muscle index <38.9 cm2/m2, patients who experienced adverse events had higher visceral fat index compared with those who did not (0.85 vs. 0.45, P = 0.04). Multivariate analysis revealed that skeletal muscle index <38.9 cm2/m2 and low serum albumin were the independent risk factors for postoperative complications (Odds ratio, 2.85; 95 % confidence interval, 1.13-7.16; P = 0.03, 2.62; 1.09-6.26; P = 0.03, respectively). Separated by sex, low serum albumin (<3.5 and <2.8 g/dL, male and female, respectively) and skeletal muscle index (<38.9 and <36.6 cm2/m2, male and female, respectively) were statistically related to postoperative complications.

Conclusions

Skeletal muscle index is the most useful nutritional predictor of postoperative complications in Crohn's disease patients among other nutritional indices. We believe that these patients are at high risk of postoperative complications and need appropriate nutritional support in the perioperative period.

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.

Visceral obesity and anastomotic leakage rates in colorectal cancer: a systematic review and meta-analysis

Background

Numberous studies have heatedly discussed whether obesity is a risk factor for anastomotic leakage (AL) because of the increasing number of colorectal cancer (CRC) cases and high incidence of CRC in patients with obesity.

Objective

We aimed to explore the relationship between visceral obesity(VO) and AL after CRC surgery. The databases of Pubmed, Embase, and the Cochrane Library were searched for relevant data and articles published until November 1, 2022. We identified the difference in the incidence of AL after CRC surgery between patients with and without VO. The quality of included studies was evaluated using the Newcastle- Ottawa Scale, and odds ratio (OR) and 95% CI were used to assess the association between VO and AL.

Results

This meta-analysis included 7 studies with 2,136 patients. The OR of patients with VO versus those without VO was 2.15 (95%CIs = 1.46-3.15, test for heterogeneity: P = 0.29, I2 = 18%) based on the fixed-effect model in seven studies. Notably, the difference between the two groups was statistically significant (Z = 3.91 P < 0.0001). Patients with VO in the colon cancer group exhibited a higher incidence of AL (OR = 2.88, 95% CIs = 1.38-5.99, test for heterogeneity: P = 0.27, I2 = 20%) than those in the rectal cancer group (OR = 2.74, 95% CIs = 1.13-6.65, test for heterogeneity: P = 0.20, I2 = 38%). In the studies in the relevant literature, heterogeneity was low. Regarding patients with VO, four Asian studies reported increased morbidity due to AL (OR = 2.79, 95% CIs = 1.35-5.78, test for heterogeneity: P = 0.35, I2 = 9%) compared with three non-Asian studies.

Conclusions

Our findings confirmed the significant relationship between VO and AL. Thus, VO could be considered a reliable risk factor of surgery for colon cancer.

Sarcopenia and visceral fat in patients with incisional hernia after urgent laparotomy

PURPOSE

Various risk factors have been associated with the development of incisional hernia (IH). Some recent papers underlined that visceral fat could be a reliable indicator. Another risk factor which is of increasing clinical interest is sarcopenia. Recent studies have identified it as an independent predictor of poor postoperative outcomes following abdominal surgery. We aimed to investigate the role of visceral fat and skeletal muscle as emerging risk factors for IH after urgent laparotomy.

METHODS

Patients aged 18 years or older who underwent urgent median laparotomy and with continuous direct suturing of the laparotomy were included. They were categorized into two groups: those with a median IH and those without IH at 12-month follow-up. Demographic data were prospectively collected while CT scans were retrospectively reviewed. The data were compared among two groups.

RESULTS

From January 2018 to May 2021, 364 patients underwent urgent surgery in our Department, of whom 222 were aged >18 years old and underwent median laparotomy. Forty-four patients had diagnosis of median IH, while 41 patients without IH were identified as the control group. Statistically significant differences emerged for BMI and for the area of visceral fat. The association with the presence/absence of sarcopenia was not significant.

CONCLUSION

Even when surgery is performed in urgent settings, it could be important to identify patients at risk, especially as CT scans are generally available for all patients with urgent abdominal disease.

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.

Quantitative analysis of adipose tissue for predicting Crohn's disease postoperative endoscopic recurrence and anastomotic ulcer

OBJECTIVE

Inflammation and ulcers at the anastomotic site are frequently observed after intestinal resection surgery for Crohn's disease (CD), which often signify postoperative recurrence. Crohn's disease causes abnormalities in whole-body fat metabolism, and alterations in subcutaneous and visceral fat are potential indicators of disease development. This study aimed to quantify the areas of subcutaneous (SFA) and visceral fat (VFA) and investigate the relationship between fat tissue and endoscopic recurrence and anastomotic ulceration after Crohn's disease surgery.

METHODS

We conducted a retrospective analysis of clinical data from 279 patients diagnosed with Crohn's disease. Using abdominal CT (Computed Tomography) scans at the level of the umbilicus, we measured the area of subcutaneous and visceral fat, and calculated the Mesenteric Fat Index (MFI), which is defined as the ratio of the area of visceral fat to subcutaneous fat. We compared the changes in fat tissue between surgical Crohn's disease patients and non-surgical patients in remission, as well as changes in fat tissue before and after surgery, and between patients with and without endoscopic recurrence after surgery.

RESULTS

The MFI value of the surgical group was higher than that of the non-surgical group(0.88(1.27 ± 1.26) VS 0.39(0.44 ± 0.21), P < 0.001), while the SFA value was lower(70.16(92.97 ± 78.23) VS 157.64(175.96 ± 101.58), P < 0.001). Of the 134 surgical patients who underwent abdominal CT examination after surgery, the SFA value was significantly higher after surgery(143.61 ± 81.86 VS 90.87 ± 71.93, P < 0.001), and the MFI value decreased accordingly(0.57 ± 0.36 VS 1.30 ± 1.35, P < 0.001). Multivariate Cox analysis indicated that high VFA and MFI values, smoking history, and preoperative biologic therapy were all risk factors for postoperative endoscopic recurrence(p < 0.05), while high MFI values and preoperative biologic therapy were also risk factors for anastomotic ulcers(p < 0.05). The Kaplan-Meier analysis showed that these factors increased the risk of reaching the endpoint with time(p < 0.05). The ROC curve results showed that MFI value had high diagnostic value for postoperative endoscopic recurrence [AUC:0.831, 95% CI: 0.75-0.91, p < 0.001] and anastomotic ulcers [AUC:0.801, 95% CI: 0.71-0.89, p < 0.001].

CONCLUSIONS

Surgical CD patients have significantly higher MFI values but the values decline after surgery. When the preoperative MFI value is > 0.82, the risk of postoperative endoscopic recurrence increases significantly, and when the MFI value is ≥ 1.10, the risk of anastomotic ulceration after surgery increases significantly. Meanwhile, biologic therapy preoperatively also is a high-risk factor for early postoperative endoscopic recurrence or anastomotic ulcers after intestinal resection surgery.

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.

Obesity Measured via Body Mass Index May Be Associated with Increased Incidence but Not Worse Outcomes of Immune-Mediated Diarrhea and Colitis

Obesity defined by high body mass index (BMI) has traditionally been associated with gastrointestinal inflammatory processes but has recently been correlated with better survival in patients receiving immune checkpoint inhibitors (ICI). We sought to investigate the association between BMI and immune-mediated diarrhea and colitis (IMDC) outcomes and whether BMI reflects body fat content on abdominal imaging. This retrospective, single-center study included cancer patients with ICI exposure who developed IMDC and had BMI and abdominal computed tomography (CT) obtained within 30 days before initiating ICI from April 2011 to December 2019. BMI was categorized as <25, ≥25 but <30, and ≥30. Visceral fat area (VFA), subcutaneous fat area (SFA), total fat area (TFA: VFA+SFA), and visceral to subcutaneous fat (V/S) ratio were obtained from CT at the umbilical level. Our sample comprised 202 patients; 127 patients (62.9%) received CTLA-4 monotherapy or a combination, and 75 (37.1%) received PD-1/PD-L1 monotherapy. Higher BMIs ≥ 30 were associated with a higher incidence of IMDC than BMIs ≤ 25 (11.4% vs. 7.9%, respectively; p = 0.029). Higher grades of colitis (grade 3-4) correlated with lower BMI (p = 0.03). BMI level was not associated with other IMDC characteristics or did not influence overall survival (p = 0.83). BMI is strongly correlated with VFA, SFA, and TFA (p < 0.0001). Higher BMI at ICI initiation was linked to a higher incidence of IMDC but did not appear to affect outcomes. BMI strongly correlated with body fat parameters measured by abdominal imaging, suggesting its reliability as an obesity index.

Practical guideline on obesity care in patients with gastrointestinal and liver diseases - Joint ESPEN/UEG guideline

BACKGROUND

Patients with chronic gastrointestinal disease such as inflammatory bowel disease (IBD), irritable bowel syndrome (IBS), celiac disease, gastroesophageal reflux disease (GERD), pancreatitis, and chronic liver disease (CLD) often suffer from obesity because of coincidence (IBD, IBS, celiac disease) or related pathophysiology (GERD, pancreatitis and CLD). It is unclear if such patients need a particular diagnostic and treatment that differs from the needs of lean gastrointestinal patients. The present guideline addresses this question according to current knowledge and evidence.

OBJECTIVE

The present practical guideline is intended for clinicians and practitioners in general medicine, gastroenterology, surgery and other obesity management, including dietitians and focuses on obesity care in patients with chronic gastrointestinal diseases.

METHODS

The present practical guideline is the shortened version of a previously published scientific guideline developed according to the standard operating procedure for ESPEN guidelines. The content has been re-structured and transformed into flow-charts that allow a quick navigation through the text.

RESULTS

In 100 recommendations (3× A, 33× B, 24 × 0, 40× GPP, all with a consensus grade of 90% or more) care of gastrointestinal patients with obesity - including sarcopenic obesity - is addressed in a multidisciplinary way. A particular emphasis is on CLD, especially metabolic associated liver disease, since such diseases are closely related to obesity, whereas liver cirrhosis is rather associated with sarcopenic obesity. A special chapter is dedicated to obesity care in patients undergoing bariatric surgery. The guideline focuses on adults, not on children, for whom data are scarce. Whether some of the recommendations apply to children must be left to the judgment of the experienced pediatrician.

CONCLUSION

The present practical guideline offers in a condensed way evidence-based advice how to care for patients with chronic gastrointestinal diseases and concomitant obesity, an increasingly frequent constellation in clinical practice.

Role of Machine Learning-Based CT Body Composition in Risk Prediction and Prognostication: Current State and Future Directions

CT body composition analysis has been shown to play an important role in predicting health and has the potential to improve patient outcomes if implemented clinically. Recent advances in artificial intelligence and machine learning have led to high speed and accuracy for extracting body composition metrics from CT scans. These may inform preoperative interventions and guide treatment planning. This review aims to discuss the clinical applications of CT body composition in clinical practice, as it moves towards widespread clinical implementation.

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.

CT-based radiomics signature of visceral adipose tissue for prediction of disease progression in patients with Crohn's disease: A multicentre cohort study

BACKGROUND

Visceral adipose tissue (VAT) is involved in the pathogenesis of Crohn's disease (CD). However, data describing its effects on CD progression remain scarce. We developed and validated a VAT-radiomics model (RM) using computed tomography (CT) images to predict disease progression in patients with CD and compared it with a subcutaneous adipose tissue (SAT)-RM.

METHODS

This retrospective study included 256 patients with CD (training, n = 156; test, n = 100) who underwent baseline CT examinations from June 19, 2015 to June 14, 2020 at three tertiary referral centres (The First Affiliated Hospital of Sun Yat-Sen University, The First Affiliated Hospital of Shantou University Medical College, and The First People's Hospital of Foshan City) in China. Disease progression referred to the development of penetrating or stricturing diseases or the requirement for CD-related surgeries during follow-up. A total of 1130 radiomics features were extracted from VAT on CT in the training cohort, and a machine-learning-based VAT-RM was developed to predict disease progression using selected reproducible features and validated in an external test cohort. Using the same modeling methodology, a SAT-RM was developed and compared with the VAT-RM.

FINDINGS

The VAT-RM exhibited satisfactory performance for predicting disease progression in total test cohort (the area under the ROC curve [AUC] = 0.850, 95% confidence Interval [CI] 0.764-0.913, P < 0.001) and in test cohorts 1 (AUC = 0.820, 95% CI 0.687-0.914, P < 0.001) and 2 (AUC = 0.871, 95% CI 0.744-0.949, P < 0.001). No significant differences in AUC were observed between test cohorts 1 and 2 (P = 0.673), suggesting considerable efficacy and robustness of the VAT-RM. In the total test cohort, the AUC of the VAT-RM for predicting disease progression was higher than that of SAT-RM (AUC = 0.786, 95% CI 0.692-0.861, P < 0.001). On multivariate Cox regression analysis, the VAT-RM (hazard ratio [HR] = 9.285, P = 0.005) was the most important independent predictor, followed by the SAT-RM (HR = 3.280, P = 0.060). Decision curve analysis further confirmed the better net benefit of the VAT-RM than the SAT-RM. Moreover, the SAT-RM failed to significantly improve predictive efficacy after it was added to the VAT-RM (integrated discrimination improvement = 0.031, P = 0.102).

INTERPRETATION

Our results suggest that VAT is an important determinant of disease progression in patients with CD. Our VAT-RM allows the accurate identification of high-risk patients prone to disease progression and offers notable advantages over SAT-RM.

FUNDING

This study was supported by the National Natural Science Foundation of China, Guangdong Basic and Applied Basic Research Foundation, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Nature Science Foundation of Shenzhen, and Young S&T Talent Training Program of Guangdong Provincial Association for S&T.

TRANSLATION

For the Chinese translation of the abstract see Supplementary Materials section.

Serial Changes in Body Composition and the Association with Disease Activity during Treatment in Patients with Crohn's Disease

Objectives: To analyze serial changes in body composition and investigate the association between body composition changes and disease activity changes in patients with Crohn’s disease (CD). Methods: Seventy-one patients with CD who had been treated and followed-up at our institution were included. Two to four computed tomography images were acquired at baseline, and the 2−5-year, 5−8-year, and last follow-ups were selected per patient for body composition and disease activity analyses. Visceral fat area (VFA), skeletal muscle index (SMI; skeletal muscle area/height2), and subcutaneous fat area (SFA) were assessed using an artificial-intelligence-driven fully automated method. Disease activity was assessed using a modified computed tomography scoring system and the Simple Endoscopic Score for Crohn’s Disease. The associations between body composition, disease activity, and remission were investigated. Results: The mean age was 29.83 ± 11.27 years; most patients were men (48/71, 67.6%); and the median follow-up was 144 (12−264) months. Overall, VFA and SFA gradually increased, while SMI decreased during the follow-up. Sarcopenia was associated with the female sex, higher disease activities at baseline (p = 0.01) and the last follow-up (p = 0.001). SMI and SFA inversely correlated with the disease activity, i.e., the more severe the disease activity, the lower the SMI and SFA (p < 0.05). SMI at the last follow-up was the only significant predictor of remission (OR = 1.21, 95% confidence interval: 1.03−1.42, p = 0.021). Conclusion: SMI decreased while VFA and SFA increased during the treatment follow-up in patients with CD. Sarcopenia was associated with higher disease activity, and SMI and SFA inversely correlated with disease activity. SMI at the last follow-up was the significant factor for remission.

Principles, Preparation, Indications, Precaution, and Damage Control of Endoscopic Therapy in Inflammatory Bowel Disease

Interventional inflammatory bowel disease (IBD) or endoscopic therapy for IBD or IBD surgery-associated complications has emerged as a main treatment modality bridging medical and surgical treatment. It delivers therapy more definitive than medical therapy and less invasive than surgical treatment. The main applications of interventional IBD are strictures, fistulas, abscesses, bleeding, foreign bodies, postoperative complications, and colitis-associated neoplasia. The major endoscopic treatment modalities are balloon dilation, stricturotomy, strictureplasty, fistulotomy, sinusotomy, septectomy, banding ligation, incision and drainage, polypectomy, endoscopic mucosal resection, and endoscopic submucosal dissection.

Correlation between magnetic resonance enterography and ileo-colonoscopy for assessment of disease activity in terminal ileal Crohn's disease

BACKGROUND

Magnetic resonance enterography (MRE) has emerged as a novel tool for the assessment of disease activity in Crohn's disease (CD). Real world data from Indian subcontinent on performance of MRE in terminal ileal CD are lacking.

METHODS

Retrospective analysis of patients with terminal ileal CD who underwent both ileo-colonoscopy and MRE was performed. Ileo-colonoscopy was considered the gold standard for assessment of disease activity. On ileo-colonoscopy, a simple endoscopic score for Crohn's disease (SES-CD) ≥2 was considered active disease; presence of ulcers indicated severe disease. MRE scoring of the disease activity was performed using magnetic resonance index of activity (MARIA) and simplified MARIA (MARIAs). The measure of agreement between ileo-colonoscopy and MRE and comparison of MARIA and MARIAs for assessment of disease activity and sensitivity of MRE to detect mucosal ulcerations were calculated.

RESULTS

Seventy patients with terminal ileal CD (mean age 40.74±15.56 years; 71.4% males [n=50]) were evaluated. The sensitivities of MARIA and MARIAs scores to detect active disease were 0.76 and 0.84, respectively. The area under the receiver operating characteristic curve (AUROC) for detecting severe disease was 0.836 (p<0.0001) for MARIA and 0.861 (p<0.0001) for MARIAs. For mild active disease, there was no agreement between SES-CD and MARIA or MARIAs; however, for severe disease, the agreement was fair and moderate for MARIA and MARIAs, respectively. MARIA and MARIAs were comparable for identification of active and severe disease (κ 0.759, p<0.0001 and κ 0.840, p<0.0001, respectively). MRE was 68.18% sensitive to detect mucosal ulcers.

CONCLUSION

MRE is a reliable and sensitive tool for detection of endoscopically severe, but not mild, terminal ileal CD.

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.

Interventional inflammatory bowel disease: endoscopic therapy of complications of Crohn's disease

Endoscopic therapy for inflammatory bowel diseases (IBD) or IBD surgery-associated complications or namely interventional IBD has become the main treatment modality for Crohn’s disease, bridging medical and surgical treatments. Currently, the main applications of interventional IBD are (i) strictures; (ii) fistulas and abscesses; (iii) bleeding lesions, bezoars, foreign bodies, and polyps; (iv) post-operative complications such as acute and chronic anastomotic leaks; and (v) colitis-associated neoplasia. The endoscopic treatment modalities include balloon dilation, stricturotomy, strictureplasty, fistulotomy, incision and drainage (of fistula and abscess), sinusotomy, septectomy, banding ligation, clipping, polypectomy, endoscopic mucosal resection, and endoscopic submucosal dissection. The field of interventional IBD is evolving with a better understanding of the underlying disease process, advances in endoscopic technology, and interest and proper training of next-generation IBD interventionalists.

European guideline on obesity care in patients with gastrointestinal and liver diseases - Joint European Society for Clinical Nutrition and Metabolism / United European Gastroenterology guideline

BACKGROUND

Patients with chronic gastrointestinal (GI) disease such as inflammatory bowel disease (IBD), irritable bowel syndrome (IBS), celiac disease, gastroesophageal reflux disease (GERD), pancreatitis, and chronic liver disease (CLD) often suffer from obesity because of coincidence (IBD, IBS, celiac disease) or related pathophysiology (GERD, pancreatitis and CLD). It is unclear if such patients need a particular diagnostic and treatment that differs from the needs of lean GI patients. The present guideline addresses this question according to current knowledge and evidence.

OBJECTIVE

The objective of the guideline is to give advice to all professionals working in the field of gastroenterology care including physicians, surgeons, dietitians and others how to handle patients with GI disease and obesity.

METHODS

The present guideline was developed according to the standard operating procedure for European Society for Clinical Nutrition and Metabolism guidelines, following the Scottish Intercollegiate Guidelines Network grading system (A, B, 0, and good practice point [GPP]). The procedure included an online voting (Delphi) and a final consensus conference.

RESULTS

In 100 recommendations (3x A, 33x B, 24x 0, 40x GPP, all with a consensus grade of 90% or more) care of GI patients with obesity - including sarcopenic obesity - is addressed in a multidisciplinary way. A particular emphasis is on CLD, especially fatty liver disease, since such diseases are closely related to obesity, whereas liver cirrhosis is rather associated with sarcopenic obesity. A special chapter is dedicated to obesity care in patients undergoing bariatric surgery. The guideline focuses on adults, not on children, for whom data are scarce. Whether some of the recommendations apply to children must be left to the judgment of the experienced pediatrician.

CONCLUSION

The present guideline offers for the first time evidence-based advice how to care for patients with chronic GI diseases and concomitant obesity, an increasingly frequent constellation in clinical practice.

Impact of a physician-led exercise programme on quality of life, muscle mass and clinical response in inflammatory bowel disease patients during induction with disease-modifying therapy: a study protocol

Introduction

Biologic and small-molecule therapies have revolutionised the treatment of moderate-to-severe inflammatory bowel disease (IBD). A significant proportion of patients experience early or delayed treatment failure. Patients with IBD with greater visceral obesity are less likely to respond to biologics. Sarcopenia has been identified as a predictor of disease severity and need for rescue therapy in acute severe ulcerative colitis. The aim of this study is to assess the feasibility of a physician-derived exercise programme in patients with IBD commencing biologic or small-molecule therapy in addition to the effect on physical fitness, body composition and objective measures of quality of life, fatigue scores and disease activity.

Methods and analysis

This is a randomised controlled feasibility study comparing the effects of a physician-derived exercise programme and standard medical care (biologic/small-molecule therapy) with standard care alone in patients with moderate to severe IBD. Patients with IBD in the intervention group will undergo a structured exercise programme for 20 weeks. Both IBD groups will carry out body composition, disease activity and quality-of-life assessments at baseline, week 12 and week 26. The primary objective is to assess the feasibility of the physician-derived exercise programme in patients with IBD commencing disease-modifying therapies. Secondary endpoints include a change in cardiorespiratory fitness, disease activity/inflammation, fatigue, health-related quality of life outcomes and body composition between the two IBD groups. Exploratory endpoints include validation of anterior thigh ultrasound for sarcopenia screening, assessment of proinflammatory cytokines and markers of immunometabolism.

Ethics and dissemination

This study has received ethical approval from the Beaumont Hospital Ethics committee on 22 October 2021 (reference number 21/21). Data generated or analysed during this study will be published as an article and supplementary appendix in relevant medical journals. The data will also be presented at national and international conferences.

Trial registration number

NCT05174754.

European guideline on obesity care in patients with gastrointestinal and liver diseases - Joint ESPEN/UEG guideline

BACKGROUND

Patients with chronic gastrointestinal (GI) disease such as inflammatory bowel disease (IBD), irritable bowel syndrome (IBS), celiac disease, gastroesophageal reflux disease (GERD), pancreatitis, and chronic liver disease (CLD) often suffer from obesity because of coincidence (IBD, IBS, celiac disease) or related pathophysiology (GERD, pancreatitis and CLD). It is unclear if such patients need a particular diagnostic and treatment that differs from the needs of lean GI patients. The present guideline addresses this question according to current knowledge and evidence.

OBJECTIVE

The objective of the guideline is to give advice to all professionals working in the field of gastroenterology care including physicians, surgeons, dietitians and others how to handle patients with GI disease and obesity.

METHODS

The present guideline was developed according to the standard operating procedure for ESPEN guidelines, following the Scottish Intercollegiate Guidelines Network (SIGN) grading system (A, B, 0, and good practice point (GPP)). The procedure included an online voting (Delphi) and a final consensus conference.

RESULTS

In 100 recommendations (3x A, 33x B, 24x 0, 40x GPP, all with a consensus grade of 90% or more) care of GI patients with obesity - including sarcopenic obesity - is addressed in a multidisciplinary way. A particular emphasis is on CLD, especially fatty liver disease, since such diseases are closely related to obesity, whereas liver cirrhosis is rather associated with sarcopenic obesity. A special chapter is dedicated to obesity care in patients undergoing bariatric surgery. The guideline focuses on adults, not on children, for whom data are scarce. Whether some of the recommendations apply to children must be left to the judgment of the experienced pediatrician.

CONCLUSION

The present guideline offers for the first time evidence-based advice how to care for patients with chronic GI diseases and concomitant obesity, an increasingly frequent constellation in clinical practice.

Prehabilitation prior to intestinal resection in Crohn’s disease patients: An opinion review

Patients with Crohn’s disease (CD) are at a considerable risk for intestinal surgery. Approximately 25% of patients with CD will undergo an intestinal resection within 10 years of diagnosis. Postoperative complications after CD surgery have been reported in 20%-47% of the patients. Both general and CD-related risk factors are associated with postoperative complications, and comprise non-modifiable (e.g., age) and potentially modifiable risk factors (e.g., malnutrition). Prehabilitation focuses on the preoperative period with strategies designed to optimize modifiable risk factors concerning the physical and mental condition of the individual patient. The aim of prehabilitation is to enhance postoperative recovery and return to or even improve preoperative functional capacity. Preoperative improvement of nutritional status, physical fitness, cessation of smoking, psychological support, and critical revision of preoperative use of CD medication are important strategies. Studies of the effect on postoperative outcome in CD patients are scarce, and guidelines lack recommendations on tailored management. In this opinion review, we review the current evidence on the impact of screening and management of nutritional status, physical fitness, CD medication and laboratory values on the postoperative course following an intestinal resection in CD patients. In addition, we aim to provide guidance for individualized multimodal prehabilitation in clinical practice concerning these modifiable factors.

Impact of Obesity on Inflammatory Bowel Disease

PURPOSE OF REVIEW

This review highlights recent work that evaluates the impact of obesity on inflammatory bowel disease (IBD) pathogenesis and management.

RECENT FINDINGS

The impact of obesity on IBD prevalence, clinical course, and management, has been studied and described more so in recent years. Studies have shown that obesity increases IBD disease activity, leads to longer hospitalization courses, and increases the likelihood of the development of extraintestinal manifestations. Recent evidence has also suggested that obese IBD patients have a higher frequency of extended steroid treatment and increased use of antibiotics compared to non-obese IBD patients. The effect of obesity on patients with IBD is a topic that has garnered widespread interest in the last decade due to the increasing prevalence of both diseases. To date however, although there are still many unanswered questions. It is quite clear that obesity, and more specifically, visceral adiposity, affects numerous IBD-related outcomes in regard to pathogenesis, extra-intestinal manifestations, response to medical and surgical therapies, hospital length of stay, healthcare-related costs, and health-related quality of life. Future studies should include larger patient populations and evaluate additional factors that are altered in those with obesity including the gut microbiome, dietary patterns, and whether weight loss and/or degree of weight loss impact clinical outcomes.

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.

Review article: The aetiology of fatigue in inflammatory bowel disease and potential therapeutic management strategies

BACKGROUND

Fatigue is the inability to achieve or maintain an expected work output resulting from central or peripheral mechanisms. The prevalence of inflammatory bowel disease (IBD) fatigue can reach 86% in active disease, persisting in 50%-52% of patients with mild to inactive disease. Fatigue is the commonest reason for work absence in IBD, and patients often report fatigue burden to be greater than that of primary disease symptoms. Relatively few evidence-based treatment options exist, and the aetiology is poorly understood.

AIM

To review the available data and suggest a possible aetiology of IBD fatigue and to consider the efficacy of existing management strategies and highlight potential future interventions.

METHODS

We reviewed fatigue-related literature in IBD using PubMed database.

RESULTS

Disease related factors such as inflammation and pharmacological treatments negatively impact skeletal muscle and brain physiology, likely contributing to fatigue symptoms. Secondary factors such as malnutrition, anaemia, sleep disturbance and psychological comorbidity are potential determinants. Immune profile, faecal microbiota composition and physical fitness differ significantly between fatigued and non-fatigued patients, suggesting these may be aetiological factors. Solution-focused therapy, high-dosage thiamine supplementation and biological therapy may reduce fatigue perception in IBD. The effect of physical activity interventions is inconclusive.

CONCLUSIONS

A multimodal approach is likely required to treat IBD fatigue. Established reversible factors like anaemia, micronutrient deficiencies and active disease should initially be resolved. Psychosocial intervention shows potential efficacy in reducing fatigue perception in quiescent disease. Restoring physical deconditioning by exercise training intervention may further improve fatigue burden.

The Relationship Between Visceral Obesity and Post-operative Complications: A Meta-analysis

BACKGROUND

Body composition can have important influence on surgical outcome. There is substantial literature examining sarcopenia, however much less in known about the impact of fat. Visceral fat area (VFA) is a reliable measures of fat distribution that can be quantified with CT scan. The aim of this study is to determine the impact of VFA to predict complications and mortality after emergent or elective surgery.

MATERIALS AND METHODS

A systematic review and meta-analysis was performed in accordance with the Preferred.

Sarcopenia in Patients With Normal Body Mass Index Is an Independent Predictor for Postoperative Complication and Long-Term Survival in Gastric Cancer

Malnutrition in patients with gastric cancer (GC) with normal body mass index (BMI) is often ignored. This study aimed to explore the role of sarcopenia in predicting postoperative complication and long-term survival in patients with GC with normal BMI. We included patients with normal BMI (18.5 kg/m²  ≤ BMI < 23 kg/m² ) who underwent radical gastrectomy between July 2014 and December 2016. Sarcopenia was assessed by muscle mass, handgrip strength, and gait speed. Kaplan-Meier survival analysis was used to analyze the association between sarcopenia and the prognosis of patients with GC. Univariate and multivariate analyses were used to identify risk factors contributing to postoperative complications and long-term survival. Overall, 267 patients with GC with normal BMI were included in this study; of which 49 (18.35%) patients were diagnosed with sarcopenia. Patients with sarcopenia had higher incidence of a major postoperative complication, longer postoperative hospital stays, and greater hospital costs. The Kaplan-Meier survival analysis showed that patients with sarcopenia had poorer overall survival than non-sarcopenia patients. Univariate and multivariate analyses showed that sarcopenia was an independent predictor for postoperative complication and long-term survival in such patients. Sarcopenia is an independent predictor for postoperative complications and long-term survival in patients with normal BMI after radical gastrectomy for GC. We recommend that patients with normal BMI should perform nutritional risk screening by sarcopenia.

Increased proinflammatory cytokines in mesenteric fat in major surgery and Crohn's disease

BACKGROUND

Proinflammatory cytokines play an important role in abdominal surgery and are often associated with the development of postoperative ileus, especially in Crohn's disease. The aim of this study was to investigate proinflammatory cytokine levels in mesenteric fat in Crohn's disease and patients without Crohn's disease.

METHODS

Human mesenteric tissue specimen were divided into 3 patient groups (n = 10 each): minor surgery (laparoscopic cholecystectomy), major surgery (colectomy) in patients without Crohn's disease, and major surgery (colectomy) in patients with Crohn's disease. Levels of interleukin 6, interleukin 1-β, and tumor necrosis factor α were determined by cytometric bead array, enzyme-linked immunosorbent assay and reverse transcription polymerase chain reaction. The Kruskal-Wallis and the Mann-Whitney U test were used to compare continuous variables. For categorical variables, the χ² test or Fisher exact test was used.

RESULTS

In minor surgery, cytokines levels of interleukin 6, interleukin 1-β and Tumor necrosis factor α were low (ie, interleukin 6: 1 pg/mL [0-36], interleukin 1-β: 0 fg/mL [0-18], tumor necrosis factor α: 157 fg/mL [91-237]) compared with major surgery in patients with and without Crohn's disease. Cytokines were significantly higher in major surgery (ie, interleukin 6: 147 pg/mL [29-347], interleukin 1-β: 660 fg/mL [0-2580], tumor necrosis factor α: 532 fg/mL [289-1647]; P = .02 and major surgery with CD (cytometric bead array: interleukin 6: 94 pg/mL [24-627], interleukin 1-β: 708 fg/mL [0-1664], tumor necrosis factor α: 733 fg/mL [209-1,354]; P < .05). Cytokine levels in major surgery with Crohn's disease showed a further increase of interleukin 6 in polymerase chain reaction in comparison to major surgery in patients without Crohn's disease (1.2 vs 4, P = .04).

CONCLUSION

Proinflammatory cytokines are increased in the mesenteric fat in major operations compared to minor operations, which indicates local mesenteric inflammation. In Crohn's disease, levels of proinflammatory cytokines are even higher, which may put the patients at risk for postoperative ileus.

Computed Tomography Assessment of Fat Distribution and Staple-Line Leak Risk After Sleeve Gastrectomy

PURPOSE

Sleeve gastrectomy (SG) has become the most frequent bariatric procedure and staple-line leak represents its most feared complication. Visceral obesity, a core component of the metabolic syndrome, has been associated with worst postoperative outcomes after various abdominal surgical procedures, and can be estimated by computed tomography (CT). The aim of this study was to assess the impact of radiologically determined visceral obesity in the risk of staple-line leak after SG.

MATERIAL AND METHODS

A retrospective analysis of a prospective database was performed in consecutive patients undergoing SG. Several anthropometric variables were measured on a preoperative CT scan. Multivariate analysis was performed to determine preoperative risk factors for staple-line leak.

RESULTS

During the study period, 377 patients were included in the analysis. The median BMI was 39.7 kg/m² (36.5-43.5) and 8 patients (2.1%) presented a gastric leak. After multivariate analysis, visceral obesity defined by visceral fat area (VFA)/body surface area (BSA) ≥ 85 cm²/m² was the only independent predictive factor for gastric leak (OR = 5312).

CONCLUSION

CT scan-assessed visceral obesity defined by a VFA/BSA ratio ≥ 85 cm²/m² is associated with an increased risk of gastric leak after SG. Preoperatively radiological examination in patients suspected of visceral obesity would be useful to optimize preoperative management.

What was First, Obesity or Inflammatory Bowel Disease? What Does the Gut Microbiota Have to Do with It?

A sedentary lifestyle and inadequate nutrition often leads to disturbances in intestinal homeostasis, which may predispose people to excess body weight and metabolic syndrome. Obesity is frequently observed in patients with inflammatory bowel diseases (IBD), similar to the general population. Obesity may exert a negative effect on the course of IBD as well as reduce the response to treatment. Moreover, it may also be an additional risk factor for vein thromboembolism during the flare. In both obesity and IBD, it is of great importance to implement proper dietary ingredients that exert desirable effect on gut microbiota. The key to reducing body mass index (BMI) and alleviating the course of IBD is preserving healthy intestinal microflora.

The Value of Morphometric Measurements in Risk Assessment for Donor-Site Complications after Microsurgical Breast Reconstruction

Microsurgical abdominally-based reconstruction is considered the gold standard in autologous breast reconstruction. Despite refined surgical procedures, donor-site complications still occur, reducing patient satisfaction and quality of life. Recent work has outlined the potential of morphometric measurements in risk assessment for postoperative hernia development. With rising demand for personalised treatment, the goal of this study was to investigate their potential in risk assessment for any donor site complication. In this retrospective cohort study, 90 patients were included who each received microsurgical breast reconstruction at the hands of one surgeon between January 2015 and May 2017. Donor-site complications formed the primary outcome and were classified according to Clavien-Dindo. Morphometric measurements were taken on a routinely performed computed tomographic angiogram. Complications occurred in 13 of the 90 (14.4%) cases studied. All patients who developed any type of postoperative donor site complication had a history of abdominal surgery. The risk of postoperative complications increased by 3% with every square centimetre of omental fat tissue (OR 1.03, 95% CI 1.00-1.06, and p-value = 0.022). Morphometric measurements provide valuable information in risk assessment for donor-site complications in abdominally-based breast reconstruction. They may help identify personalised reconstructive options for maximal postoperative patient satisfaction and quality of life.

Magnetic resonance imaging assessment of body composition parameters in Crohn's disease

BACKGROUND

Body composition, currently evaluated by computed tomography scan, is related to poor evolution and severity of Crohn's disease (CD). Few MRI studies have been performed, yet it is the most commonly used imaging modality for the surveillance of the disease.

AIM

Evaluate the feasibility of MRI body composition measurement and compare the variation according to the activity of the disease.

METHODS

A cohort of 132 consecutive patients was studied. The visceral adiposity index (VAI), subcutaneous adiposity index (SAI) and skeletal muscle index (SMI) were measured. Patients were divided into 2 groups according to disease activity. Sarcopenic status was defined according to the cut off value (SMI < 38.9 cm²/m² in women and < 54.4 cm²/m² in men).

RESULTS

MRI measurements of body composition parameters were feasible and reproducible. After adjustment, sarcopenia was more common (2.07 [1.02; 4.27], p = 0.046), and the SMI (-4.90 [-9.36; -0.431], p = 0.032) was lower in active disease. The SAI was lower (-14.7 [-29.8; 0.258], p = 0.054) in active disease. The VAI tended to be higher with active disease (3.91 [-3.50; 11.9], p = 0.34), and the VAI/SAI+VAI ratio was higher (9.40 [4.72; 14.1], p<0.001).

CONCLUSION

Assessment of body composition is feasible and reproducible in routine MR and parameters are related to disease activity.

Perioperative Dietary Therapy in Inflammatory Bowel Disease

BACKGROUND AND AIMS

The incidence of inflammatory bowel disease [IBD] is rising worldwide and no cure is available. Many patients require surgery and they often present with nutritional deficiencies. Although randomised controlled trials of dietary therapy are lacking, expert IBD centres have long-established interdisciplinary care, including tailored nutritional therapy, to optimise clinical outcomes and resource utilisation. This topical review aims to share expertise and offers current practice recommendations to optimise outcomes of IBD patients who undergo surgery.

METHODS

A consensus expert panel consisting of dietitians, surgeons, and gastroenterologists, convened by the European Crohn's and Colitis Organisation, performed a systematic literature review. Nutritional evaluation and dietary needs, perioperative optimis ation, surgical complications, long-term needs, and special situations were critically appraised. Statements were developed using a Delphi methodology incorporating three successive rounds. Current practice positions were set when ≥80% of participants agreed on a recommendation.

RESULTS

A total of 26 current practice positions were formulated which address the needs of IBD patients perioperatively and in the long term following surgery. Routine screening, perioperative optimisation by oral, enteral, or parenteral nutrition, dietary fibre, and supplements were reviewed. IBD-specific situations, including management of patients with a restorative proctocolectomy, an ostomy, strictures, or short-bowel syndrome, were addressed.

CONCLUSIONS

Perioperative dietary therapy improves the outcomes of IBD patients who undergo a surgical procedure. This topical review shares interdisciplinary expertise and provides guidance to optimise the outcomes of patients with Crohn's disease and ulcerative colitis. taking advantage of contemporary nutrition science.

Which obesity-associated parameters can better reflect the risk of the occurrence of the anastomotic leakage?

Purpose: We investigated which obesity-associated parameters can better predict the risk of anastomotic leakage (AL) in rectal cancer patients that underwent anterior resection of the rectum.Method: Patients (n = 589) who underwent anterior resection of the rectum with a primary anastomosis were included in this study, including 44 patients with AL and 545 without AL. Univariate analysis was used to compare demographic characteristics and to select risk factors that were used in one-to-one propensity score matching (PSM). Obesity-associated parameters, including preoperative body mass index (BMI), visceral fat area (VFA), subcutaneous fat area (SFA), total fat area (TFA), VFA/TFA ratio, serum cholesterol, and triglycerides, were compared between the two groups after PSM.Results: Sex, neoadjuvant chemotherapy, operation time, and anastomosis level from the anal verge were risk factors for AL (p < .05). After the PSM, BMI, VFA, SFA, TFA, VFA/TFA, and serum cholesterol showed no significant difference between the two group (p > .05). However, the level of serum triglycerides was an independent risk factor for AL (p = .024, odds ratio = 2.95).Conclusions: Serum triglycerides have potential as a predictive indicator for AL, which may improve the treatment and outcomes of patients with AL.

Sarcopenia and visceral obesity assessed by computed tomography are associated with adverse outcomes in patients with Crohn's disease

BACKGROUND

Altered body composition may impact on the clinical course of Crohn's disease (CD) but is not detected by the simple body mass index (BMI) assessment.

AIM

To assess the prevalence of sarcopenia and visceral obesity by a single computed tomography (CT) slice, and its association with adverse events in an adult hospitalized CD cohort.

METHODS

88 CD patients who had abdominal CT scans during hospitalization were retrospectively enrolled. The skeletal muscle index (SMI) at the third lumbar vertebra level was used to assess sarcopenia. Sarcopenia was defined as a SMI <38.5 cm²/m² in women, <52.4 cm²/m² in men and visceral obesity as a visceral fat area ≥130 cm². Clinical malnutrition was defined by a BMI <18.5 kg/m². Univariate analysis was performed, and predictors for surgery in the follow-up were entered in a stepwise logistic regression model for multivariate analysis.

RESULTS

The prevalence of sarcopenia was 58%, malnutrition 21.6%, and visceral obesity 19.3%. Among sarcopenic patients, 49% had a normal BMI, 13.7% were overweight, and 1(2%) was obese. Sarcopenic CD patients had significantly more abscesses (51% vs 16.7%, p = 0.001), hospitalizations (61.2% vs 36.1%, p = 0.022) and digestive surgery (63.3% vs 27.8%, p = 0.001) than non-sarcopenic patients during the follow-up, whereas usual malnutrition assessment was not correlated with disease outcomes. In multivariate analysis, both sarcopenia and visceral obesity were associated with further occurrence of digestive surgery.

CONCLUSION

Both sarcopenia and visceral obesity were associated with adverse outcomes in severe CD patients whereas usual nutritional assessment was not.

Outcomes of inflammatory bowel disease surgery in obese versus non-obese patients: a meta-analysis

BACKGROUND

Obesity is considered a risk factor for many chronic diseases and obese patients are often considered higher risk surgical candidates. The aim of this meta-analysis was to evaluate the outcomes of obese (body mass index ≥ 30 kg/m²) versus non-obese patients undergoing surgery for inflammatory bowel disease (IBD).

METHODS

PubMed, Scopus, and Embase libraries were searched up to March 2019 for studies comparing outcomes of obese with non-obese patients undergoing surgery for IBD. A meta-analysis was conducted using Review Manager software to create forest plots and calculate odds ratios and mean differences.

RESULTS

Four thousand three hundred and eleven patients from five observational studies were included. Obese patients were older at the time of surgery and more likely to have diabetes. Obese patients had longer operative times (MD 23.28, 95% CI 14.63-31.93, p < 0.001), higher intra-operative blood loss (MD 45.32, 95% CI 5.89-84.76, p = 0.02), longer length of stay (MD 0.90, 95% CI 0.60-1.20, p < 0.001), higher wound infection rates (OR 1.76, 95% CI 1.39-2.23, p < 0.001), and higher total postoperative complication rates (OR 1.33, 95% CI 1.04-1.70, p = 0.02).

CONCLUSIONS

Obesity is associated with significantly worse outcomes following IBD-specific surgery, including longer operative times, greater blood loss, longer length of stay, higher wound infection rates, and higher total postoperative complication rates. Clinicians should be mindful of these increased risks when counselling patients and consider weight reduction strategies where possible.

Obesity in Liver Transplantation: A Risk Factor for Unplanned Reoperation and Prolonged Operative Time

Selection of orthotopic liver transplantation (OLT) candidates is increasingly inclusive of patients with high BMI. We aim to characterize the influence of obesity on the surgical outcome measures of prolonged operative time and unplanned reoperation. We reviewed the records of obese and normal weight OLT recipients over a 10-year period from a single institution. Variables that trended ( P < 0.1) with endpoints on univariate analysis were put into multivariate logistic regression models to determine independent association ( P < 0.05). We included 195 obese and 171 normal weight OLT recipients in our study. On multivariate analysis, obesity was the only preoperative risk factor that trended with unplanned reoperation (odds ratio 2, P = 0.05). Similarly, only obesity remained independently associated with prolonged length of operation (defined as ≥275 minutes) on multivariate analysis (odds ratio 1.7, P = 0.04). In summary, obesity may make OLT more technically challenging and, thus, represents an independent risk factor for unplanned reoperations and prolonged operative time.

The Adipokine Metrnl Ameliorates Chronic Colitis in Il-10-/- Mice by Attenuating Mesenteric Adipose Tissue Lesions During Spontaneous Colitis

BACKGROUND

Crosstalk between mesenteric adipose tissue [MAT] and the intestines affects the progression of Crohn's disease [CD]. The adipokine metrnl regulates adipocyte function and has anti-inflammatory activity. We aimed to explore metrnl expression in CD MAT, investigate the influence of metrnl on the experimental colitis disease course and determine the mechanism underlying this effect.

METHODS

Metrnl expression in MAT specimens obtained from patients with and without CD was tested by immunohistochemistry. Male Il-10-/- mice with spontaneous enteritis were divided into positive control and metrnl-treated [Metrnl-Fc, 10 mg/kg/d, intraperitoneally, 8 weeks] groups. Age-matched male wild-type [WT] mice were used as negative controls. The effects of metrnl on enteritis and mesenteric lesions and the potential controlling mechanisms were evaluated.

RESULTS

Metrnl expression was higher in human CD MAT than in control MAT. Systemic delivery of metrnl significantly ameliorated chronic colitis in Il-10-/- mice, as demonstrated by decreases in the disease activity index, inflammatory score and proinflammatory mediators. The protective effects of metrnl on MAT included reduced mesenteric hypertrophy, increased adipocyte size, improved adipocyte intrinsic function and ameliorated inflammation. Metrnl treatment activated STAT5/PPAR-γ signaling and promoted adipocyte differentiation in the MAT.

CONCLUSIONS

Metrnl expression was increased in the MAT of CD patients. Metrnl administration attenuated mesenteric lesions by promoting adipocyte function and differentiation partly through STAT5/PPAR-γ signaling pathway activation, thereby ameliorating CD-like colitis in mice.

The Role of Adipose Tissue in the Pathogenesis and Therapeutic Outcomes of Inflammatory Bowel Disease

Though historically regarded as an inert energy store, adipose tissue is a complex endocrine organ, which is increasingly implicated in the pathogenesis of inflammatory bowel disease (IBD). Accumulating evidence points to visceral adipose tissue and specifically to its mesenteric component, or “creeping fat” as impacting on the disease course through its immunomodulatory properties. On the one hand, mesenteric fat acts as a physical barrier to inflammation and is involved in controlling host immune response to translocation of gut bacteria. On the other hand, however, there exists a strong link between visceral fat and complicated course of the disease with unfavorable therapeutic outcomes. Furthermore, “creeping fat” appears to play different roles in different IBD phenotypes, with the greatest pathogenetic contribution probably to an ileal form of Crohn’s disease. In this review, we summarize and discuss the existing literature on the subject and identify high-priority areas for future research. It may be that a better understanding of the role of mesenteric fat in IBD will determine new therapeutic targets and translate into improved clinical outcomes.

Visceral Adipose Tissue Is Associated With Stricturing Crohn's Disease Behavior, Fecal Calprotectin, and Quality of Life

BACKGROUND

Visceral adipose tissue (VAT) has been proposed to play a pathogenic role in Crohn's disease (CD); however, prospective clinical data are lacking. The aim was to evaluate whether VAT, beyond body mass index (BMI), is associated with CD behavior, disease activity, quality of life (QoL), or outcomes.

METHODS

Body composition data and clinical, anthropometric, disease activity (fecal calprotectin [FC]), and QoL scores were gathered prospectively on adults with CD at 0, 12, and 24 months. BMI and, VAT metrics (visceral adipose tissue volume [cm3]/height [m2] index and VAT:subcutaneous adipose tissue [SAT] ratio) were calculated. Inflammatory bowel disease-related surgery and hospitalization were recorded over extended follow-up (median, 51 months). Multivariable linear mixed effects and logistic regression analyses were performed.

RESULTS

Ninety-seven participants were assessed at baseline (55% male; median age, 31 years), 84 at 12 months, and 72 at 24 months. VAT:SAT was positively associated with stricturing disease behavior (log odds ratio [OR], 1.7; 95% confidence interval [CI], 0.32 to 3; P = 0.01) and elevated FC in patients with ileocolonic disease (β, 1.3; 95% CI, 0.32 to 2.3; P = 0.01). VAT:SAT was associated with lower QoL, particularly in those with ileal disease (β, -12; 95% CI, -19 to -4.5; P = 0.05). However, no prospective associations were observed between serial VAT measurements and time to surgery or hospitalization. No correlations were found between BMI and disease behavior, activity, or QoL.

CONCLUSIONS

VAT:SAT, rather than BMI, is associated with stricturing CD behavior, elevated FC, and reduced QoL in a disease distribution-dependent manner. Further studies are required to substantiate the role of VAT as a useful biomarker in CD.

Lower Subcutaneous or Visceral Adiposity Assessed by Abdominal Computed Tomography Could Predict Adverse Outcome in Patients With Crohn's Disease

BACKGROUND AND AIMS

Changes in body composition have been described in patients with Crohn's disease, but their predictive performances on disease evolution remain undefined. The aims of our study were to assess, in patients with Crohn's disease requiring abdominal computed tomography, body composition by computed tomography, and to study the outcome according to various body composition parameters at the time of the computed tomography.

METHODS

Patients with Crohn's disease who underwent abdominal computed tomography for suspected complications were retrospectively included. The definition of adverse outcome included death or need for surgery within 6 months of the computed tomography. Skeletal muscle index and visceral and subcutaneous adiposity indexes were calculated from tissue surface areas measured at the third lumbar vertebra, divided by the height squared.

RESULTS

The prevalence of underweight was 26.8% and the prevalence of sarcopenia was 33.6%. After gender adjustment, skeletal muscle index tended to be reduced in patients with adverse outcome, compared with patients without surgery or death [p = 0.07]. Moreover, subcutaneous adiposity index and visceral adiposity index were significantly lower in patients with surgery or death [p = 0.009 and p < 0.001, respectively]. These differences were almost equivalent in both genders for the subcutaneous adiposity index but were clearly stronger in men for the visceral adiposity index.

CONCLUSIONS

Subcutaneous and visceral adiposity indexes correlate inversely with adverse outcome in patients with Crohn's disease. Alteration of body composition assessed by computed tomography in these patients appears to be a marker of disease severity.