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

Myosteatosis Evaluated Based on Intramuscular Adipose Tissue Content Is a Risk Factor for Postoperative Complications in Crohn's Disease

BACKGROUND

Crohn's disease causes acute and chronic inflammation that often make the preoperative evaluation of surgical risks difficult. Myosteatosis is used for the evaluation of muscle quality to assess sarcopenia. However, data on the relationship between myosteatosis and surgical outcomes in patients with Crohn's disease are lacking.

METHODS

Among patients with Crohn's disease who underwent surgery between 2007 and 2022, we investigated the impact of myosteatosis on postoperative complications using intramuscular adipose tissue content (IMAC). Our study included data from 97 patients who underwent analysis for cutoff values and factors associated with IMAC and 72 who underwent analysis for risk factors of postoperative complications.

RESULTS

Body mass index (BMI; P < .001) and visceral adipose tissue/height index (P < .001) were significantly correlated with IMAC. High BMI (P < .001) and a history of abdominal surgery for Crohn's disease (P = .012) were identified as factors affected with high IMAC. Multivariate analysis revealed high IMAC and external fistulas as independent risk factors for postoperative complications (odds ratio [OR], 5.010; 95% CI, 1.300-19.30; P = .019 and OR, 7.850; 95% CI, 1.640-37.50; P = .010, respectively), especially infectious complications.

CONCLUSIONS

This study established IMAC as a valuable marker for sarcopenic obesity and predicting postoperative complications in patients with Crohn's disease. Furthermore, evaluating myosteatosis using IMAC will facilitate the decision of the optimal timing of surgery, prediction of complications, and treatment of sarcopenia in patients with Crohn's disease.

Impact of sarcopenia and fat distribution on outcomes in penile cancer

Sarcopenia, defined as age-associated loss of skeletal muscle function and muscle mass, is a negative prognostic marker for survival in several tumor entities. However, data evaluating the impact of sarcopenia and fat distribution on penile cancer are rarely described. We performed a retrospective study including 38 patients who were diagnosed with squamous cell carcinoma of the penis. By measuring skeletal muscle mass and fat distribution at axial abdominal computed tomography images at the third lumbar vertebra several body composition parameters including skeletal muscle index (SMI), psoas muscle index (PMI), visceral obesity and visceral-to-subcutaneous fat ratio were determined. Among 38 patients, 26% (n = 10) of the patients with penile cancer were identified as sarcopenic. SMI, age, lymph node metastases, distant metastases and penile cancer of the shaft were identified as significant risk factors for overall survival. PMI and distant metastases were significantly associated with cancer specific survival. None of the analysed adipose tissue parameters could be identified as risk factors for survival in this study. We showed that sarcopenia occurs in a relevant part of patients with penile cancer and is a significant risk factor for overall survival (p = 0.032) and cancer specific survival (p = 0.034) for patients with penile cancer. Regarding fat distribution further studies are needed to evaluate its impact on sarcopenia and survival.

Enhancing radiologist's detection: an imaging-based grading system for differentiating Crohn's disease from ulcerative colitis

BACKGROUND

Delayed diagnosis of inflammatory bowel disease (IBD) is common, there is still no effective imaging system to distinguish Crohn's Disease (CD) and Ulcerative Colitis (UC) patients.

METHODS

This multicenter retrospective study included IBD patients at three centers between January 2012 and May 2022. The intestinal and perianal imaging signs were evaluated. Visceral fat information from CT images was extracted, including the ratio of visceral to subcutaneous fat volume (VSR), fat distribution, and attenuation values. The valuable indicators were screened out in the derivation cohort by binary logistic regression and receiver working curve (ROC) analysis to construct an imaging report and data system for IBD (IBD-RADS), which was tested in the validation cohort.

RESULTS

The derivation cohort included 606 patients (365 CD, 241 UC), and the validation cohort included 155 patients (97 CD, 58 UC). Asymmetric enhancement (AE) (OR = 87.75 [28.69, 268.4]; P < 0.001), perianal fistula (OR = 4.968 [1.807, 13.66]; P = 0.002) and VSR (OR = 1.571 [1.087, 2.280]; P = 0.04) were independent predictors of CD. VSR improved the efficiency of imaging signs (AUC: 0.929 vs. 0.901; P < 0.001), with a threshold greater than 0.97 defined as visceral fat predominance (VFP). In IBD-RADS, AE was the major criterion, VFP and perianal fistula were auxiliary criteria, and intestinal fistula, limited small bowel disease, and skip distribution were special favoring items as their 100% specificity. Grade 3 to 5 correctly classified most CD patients (derivation: 96.5% (352/365), validation: 98.0% (95/97)), and 98% of those were eventually diagnosed with CD (derivation: 97.8% (352/360), validation: 98.0% (95/97)).

CONCLUSIONS

IBD-RADS can help radiologists distinguish between CD and UC in patients with suspected IBD.

Body composition analysis by radiological imaging - methods, applications, and prospects

BACKGROUND

 This review discusses the quantitative assessment of tissue composition in the human body (body composition, BC) using radiological methods. Such analyses are gaining importance, in particular, for oncological and metabolic problems. The aim is to present the different methods and definitions in this field to a radiological readership in order to facilitate application and dissemination of BC methods. The main focus is on radiological cross-sectional imaging.

METHODS

 The review is based on a recent literature search in the US National Library of Medicine catalog (pubmed.gov) using appropriate search terms (body composition, obesity, sarcopenia, osteopenia in conjunction with imaging and radiology, respectively), as well as our own work and experience, particularly with MRI- and CT-based analyses of abdominal fat compartments and muscle groups.

RESULTS AND CONCLUSION

 Key post-processing methods such as segmentation of tomographic datasets are now well established and used in numerous clinical disciplines, including bariatric surgery. Validated reference values are required for a reliable assessment of radiological measures, such as fatty liver or muscle. Artificial intelligence approaches (deep learning) already enable the automated segmentation of different tissues and compartments so that the extensive datasets can be processed in a time-efficient manner - in the case of so-called opportunistic screening, even retrospectively from diagnostic examinations. The availability of analysis tools and suitable datasets for AI training is considered a limitation.

KEY POINTS

  · Radiological imaging methods are increasingly used to determine body composition (BC).. · BC parameters are usually quantitative and well reproducible.. · CT image data from routine clinical examinations can be used retrospectively for BC analysis.. · Prospectively, MRI examinations can be used to determine organ-specific BC parameters.. · Automated and in-depth analysis methods (deep learning or radiomics) appear to become important in the future..

CITATION FORMAT

· Linder N, Denecke T, Busse H. Body composition analysis by radiological imaging - methods, applications, and prospects. Fortschr Röntgenstr 2024; 196: 1046 - 1054.

Skeletal Muscle Segmentation at the Level of the Third Lumbar Vertebra (L3) in Low-Dose Computed Tomography: A Lightweight Algorithm

BACKGROUND

The cross-sectional area of skeletal muscles at the level of the third lumbar vertebra (L3) measured from computed tomography (CT) images is an established imaging biomarker used to assess patients' nutritional status. With the increasing prevalence of low-dose CT scans in clinical practice, accurate and automated skeletal muscle segmentation at the L3 level in low-dose CT images has become an issue to address. This study proposed a lightweight algorithm for automated segmentation of skeletal muscles at the L3 level in low-dose CT images.

METHODS

This study included 57 patients with rectal cancer, with both low-dose plain and contrast-enhanced pelvic CT image series acquired using a radiotherapy CT scanner. A training set of 30 randomly selected patients was used to develop a lightweight segmentation algorithm, and the other 27 patients were used as the test set. A radiologist selected the most representative axial CT image at the L3 level for both the image series for all the patients, and three groups of observers manually annotated the skeletal muscles in the 54 CT images of the test set as the gold standard. The performance of the proposed algorithm was evaluated in terms of the Dice similarity coefficient (DSC), precision, recall, 95th percentile of the Hausdorff distance (HD95), and average surface distance (ASD). The running time of the proposed algorithm was recorded. An open source deep learning-based AutoMATICA algorithm was compared with the proposed algorithm. The inter-observer variations were also used as the reference.

RESULTS

The DSC, precision, recall, HD95, ASD, and running time were 93.2 ± 1.9% (mean ± standard deviation), 96.7 ± 2.9%, 90.0 ± 2.9%, 4.8 ± 1.3 mm, 0.8 ± 0.2 mm, and 303 ± 43 ms (on CPU) for the proposed algorithm, and 94.1 ± 4.1%, 92.7 ± 5.5%, 95.7 ± 4.0%, 7.4 ± 5.7 mm, 0.9 ± 0.6 mm, and 448 ± 40 ms (on GPU) for AutoMATICA, respectively. The differences between the proposed algorithm and the inter-observer reference were 4.7%, 1.2%, 7.9%, 3.2 mm, and 0.6 mm, respectively, for the averaged DSC, precision, recall, HD95, and ASD.

CONCLUSION

The proposed algorithm can be used to segment skeletal muscles at the L3 level in either the plain or enhanced low-dose CT images.

Obesity, Sarcopenia and Myosteatosis: Impact on Clinical Outcomes in the Operative Management of Crohn's Disease

BACKGROUND

Obesity, sarcopenia, and myosteatosis in inflammatory bowel disease may confer negative outcomes, but their prevalence and impact among patients with Crohn's disease (CD) have not been systematically studied. The aim of this study was to assess nutritional status and body composition among patients undergoing resectional surgery for CD and determine impact on operative outcomes.

METHODS

Consecutive patients with CD undergoing resection from 2000 to 2018 were studied. Total, subcutaneous, and visceral fat areas and lean tissue area (LTA) and intramuscular adipose tissue (IMAT) were determined preoperatively by computed tomography at L3 using SliceOmatic (Tomovision, Canada). Univariable and multivariable linear, logistic, and Cox proportional hazards regression were performed.

RESULTS

One hundred twenty-four consecutive patients were studied (ileocolonic disease 53%, n = 62, biologic therapy 34.4% n = 43). Mean fat mass was 22.7 kg, with visceral obesity evident in 23.9% (n = 27). Increased fat stores were associated with reduced risk of emergency presentation but increased corticosteroid use (β 9.09, standard error 3.49; P = .011). Mean LBM was 9.9 kg. Sarcopenia and myosteatosis were associated with impaired baseline nutritional markers. Myosteatosis markers IMAT (P = .002) and muscle attenuation (P = .0003) were associated with increased grade of complication. On multivariable analysis, IMAT was independently associated with increased postoperative morbidity (odds ratio [OR], 1.08; 95% confidence interval (CI), 1.01-1.16; P = .037) and comprehensive complications index (P = .029). Measures of adiposity were not associated with overall morbidity; however, increased visceral fat area independently predicted venous thromboembolism (OR, 1.02; 95% CI, 1.00-1.05; P = .028), and TFA was associated with increased wound infection (OR, 1.00; 95% CI, 1.00-1.01; P = .042) on multivariable analysis.

CONCLUSION

Myosteatosis is associated with nutritional impairment and predicts increased overall postoperative morbidity following resection for CD. Despite its association with specific increased postoperative risks, increased adiposity does not increase overall morbidity, reflecting preservation of nutritional status and relatively more quiescent disease phenotype. Impaired muscle mass and function represent an appealing target for patient optimization to improve outcomes in the surgical management of CD.

Navigating the Intersection: Sarcopenia and Sarcopenic Obesity in Inflammatory Bowel Disease

Inflammatory bowel diseases (IBDs) are intricate systemic conditions that can extend beyond the gastrointestinal tract through both direct and indirect mechanisms. Sarcopenia, characterized by a reduction in muscle mass and strength, often emerges as a consequence of the clinical course of IBDs. Indeed, sarcopenia exhibits a high prevalence in Crohn's disease (52%) and ulcerative colitis (37%). While computed tomography and magnetic resonance imaging remain gold-standard methods for assessing muscle mass, ultrasound is gaining traction as a reliable, cost-effective, and widely available diagnostic method. Muscle strength serves as a key indicator of muscle function, with grip strength test emerging nowadays as the most reliable assessment method. In IBDs, sarcopenia may arise from factors such as inflammation, malnutrition, and gut dysbiosis, leading to the formulation of the 'gut-muscle axis' hypothesis. This condition determines an increased need for surgery with poorer post-surgical outcomes and a reduced response to biological treatments. Sarcopenia and its consequences lead to reduced quality of life (QoL), in addition to the already impaired QoL. Of emerging concern is sarcopenic obesity in IBDs, a challenging condition whose pathogenesis and management are still poorly understood. Resistance exercise and nutritional interventions, particularly those aimed at augmenting protein intake, have demonstrated efficacy in addressing sarcopenia in IBDs. Furthermore, anti-TNF biological therapies showed interesting outcomes in managing this condition. This review seeks to furnish a comprehensive overview of sarcopenia in IBDs, elucidating diagnostic methodologies, pathophysiological mechanisms, and clinical implications and management. Attention will also be paid to sarcopenic obesity, exploring the pathophysiology and possible treatment modalities of this condition.

Differentiation Between Ulcerative Colitis and Crohn's Disease Using Abdominal Computed Tomography in Patients With First-Time Inflammatory Bowel Disease

Background Ulcerative colitis (UC) and Crohn's disease (CD) are classified as inflammatory bowel diseases (IBDs). However, they have different pathogeneses and treatment strategies and need to be differentiated. Purpose To determine the feasibility of differentiating UC from CD in patients with first-time IBD based on simple abdominal computed tomography (CT) findings. Methods We conducted a retrospective study of patients diagnosed with IBD for the first time at our hospital between January and December 2021. Age, sex, white blood cell count, albumin concentration, C-reactive protein concentration, visceral fat area, subcutaneous fat area, and psoas major volume were extracted and used to differentiate the two groups. Results Forty-three patients were selected. Their mean age was 35.60 ± 17.19 years, and 32 were male, while 11 were female. The visceral fat cross-sectional area was 51.80 cm2 for UC and 21.10 cm2 for CD (p < 0.01). The subcutaneous fat cross-sectional area was 108.30 cm2 for UC and 66.30 cm2 for CD (p = 0.049). The total protein concentration was 6.15 g/L for UC and 6.60 g/L for CD (p = 0.012). Receiver operating characteristic curve analysis of the visceral and subcutaneous fat cross-sectional areas showed areas under the curve, 95% confidence intervals, sensitivities, and specificities of 0.750 and 0.675, 0.603-0.897 and 0.507-0.844, 0.810 and 1.00, and 0.591 and 0.409, respectively, at cutoffs of 26.53 and 36.6 cm2. Conclusions  The visceral and subcutaneous fat cross-sectional areas determined with simple abdominal CT can differentiate UC from CD in patients with first-time IBD.

A novel nomogram integrating body composition and inflammatory-nutritional markers for predicting postoperative complications in patients with adhesive small bowel obstruction

Background

Postoperative complications in adhesive small bowel obstruction (ASBO) significantly escalate healthcare costs and prolong hospital stays. This study endeavors to construct a nomogram that synergizes computed tomography (CT) body composition data with inflammatory-nutritional markers to forecast postoperative complications in ASBO.

Methods

The study's internal cohort consisted of 190 ASBO patients recruited from October 2017 to November 2021, subsequently partitioned into training (n = 133) and internal validation (n = 57) groups at a 7:3 ratio. An additional external cohort comprised 52 patients. Body composition assessments were conducted at the third lumbar vertebral level utilizing CT images. Baseline characteristics alongside systemic inflammatory responses were meticulously documented. Through univariable and multivariable regression analyses, risk factors pertinent to postoperative complications were identified, culminating in the creation of a predictive nomogram. The nomogram's precision was appraised using the concordance index (C-index) and the area under the receiver operating characteristic (ROC) curve.

Results

Postoperative complications were observed in 65 (48.87%), 26 (45.61%), and 22 (42.31%) patients across the three cohorts, respectively. Multivariate analysis revealed that nutrition risk score (NRS), intestinal strangulation, skeletal muscle index (SMI), subcutaneous fat index (SFI), neutrophil-lymphocyte ratio (NLR), and lymphocyte-monocyte ratio (LMR) were independently predictive of postoperative complications. These preoperative indicators were integral to the nomogram's formulation. The model, amalgamating body composition and inflammatory-nutritional indices, demonstrated superior performance: the internal training set exhibited a 0.878 AUC (95% CI, 0.802-0.954), 0.755 accuracy, and 0.625 sensitivity; the internal validation set displayed a 0.831 AUC (95% CI, 0.675-0.986), 0.818 accuracy, and 0.812 sensitivity. In the external cohort, the model yielded an AUC of 0.886 (95% CI, 0.799-0.974), 0.808 accuracy, and 0.909 sensitivity. Calibration curves affirmed a strong concordance between predicted outcomes and actual events. Decision curve analysis substantiated that the model could confer benefits on patients with ASBO.

Conclusion

A rigorously developed and validated nomogram that incorporates body composition and inflammatory-nutritional indices proves to be a valuable tool for anticipating postoperative complications in ASBO patients, thus facilitating enhanced clinical decision-making.

Computed tomography-based body composition parameters can predict short-term prognosis in ulcerative colitis patients

OBJECTIVES

Emerging evidence suggests a potential relationship between body composition and short-term prognosis of ulcerative colitis (UC). Early and accurate assessment of rapid remission based on conventional therapy via abdominal computed tomography (CT) images has rarely been investigated. This study aimed to build a prediction model using CT-based body composition parameters for UC risk stratification.

METHODS

In total, 138 patients with abdominal CT images were enrolled. Eleven quantitative parameters related to body composition involving skeletal muscle mass, visceral adipose tissue (VAT), and subcutaneous adipose tissue (SAT) were measured and calculated using a semi-automated segmentation method. A prediction model was established with significant parameters using a multivariable logistic regression. The receiver operating characteristic (ROC) curve was plotted to evaluate prediction performance. Subgroup analyses were implemented to evaluate the diagnostic efficiency of the prediction model between different disease locations, centers, and CT scanners. The Delong test was used for statistical comparison of ROC curves.

RESULTS

VAT density, SAT density, gender, and visceral obesity were significantly statistically different between remission and invalidation groups (all p < 0.05). The accuracy, sensitivity, specificity, and area under the ROC curve (AUC) of the prediction model were 82.61%, 95.45%, 69.89%, and 0.855 (0.792-0.917), respectively. The positive predictive value and negative predictive value were 70.79% and 93.88%, respectively. No significant differences in the AUC of the prediction model were found in different subgroups (all p > 0.05).

CONCLUSIONS

The predicting model constructed with CT-based body composition parameters is a potential non-invasive approach for short-term prognosis identification and risk stratification. Additionally, VAT density was an independent predictor for escalating therapeutic regimens in UC cohorts.

CRITICAL RELEVANCE STATEMENT

The CT images were used for evaluating body composition and risk stratification of ulcerative colitis patients, and a potential non-invasive prediction model was constructed to identify non-responders with conventional therapy for making therapeutic regimens timely and accurately.

KEY POINTS

• CT-based prediction models help divide patients into invalidation and remission groups in UC. • Results of the subgroup analysis confirmed the stability of the prediction model with a high AUC (all > 0.820). • The visceral adipose tissue density was an independent predictor of bad short-term prognosis in UC.

Sarcopenia and treatment failure in inflammatory bowel disease: a systematic review and meta-analysis

BACKGROUND

The association between sarcopenia and treatment outcomes in inflammatory bowel disease (IBD) is currently a subject of controversy.

METHODS

A systematic search was performed of PubMed, Embase, Web of Science, and the Cochrane Library for studies published until April 2023. The quality assessment of each included study was performed using the Newcastle-Ottawa Scale.

RESULTS

Seventeen studies were included with 2,895 IBD patients. Sarcopenia exhibited an increased risk of treatment failure (OR=2.00, 95% CI: 1.43-2.79) and notably increased the need for surgery (OR=1.54,95%CI:1.06-2.23) as opposed to a pharmacologic treatment plan change (OR=1.19, 95% CI:0.71-2.01) among IBD patients. However, no significant association was found between sarcopenia and treatment failure in corticosteroid (OR=1.21, 95% CI: 0.55-2.64) or biologic agent (OR=1.65, 95% CI: 0.93-2.92) cohorts. Sarcopenia was also linked to elevated treatment failure risks in patients with Crohn's disease (OR=1.82, 95% CI: 1.15-2.90) and those diagnosed with ulcerative colitis (OR=2.55, 95% CI: 1.05-6.21), spanning both Asian (OR=1.88, 95% CI: 1.29-2.74) and non-Asian regions (OR=2.17, 95% CI: 1.48-3.18).

CONCLUSIONS

Sarcopenia was considered a novel marker for use in clinical practice to predict treatment failure, specifically, the need for surgery in IBD patients. This distinct cohort necessitates clinical attention and tailored care strategies.

Sarcopenia and frailty in inflammatory bowel disease: Emerging concepts and evidence

Sarcopenia is a condition marked by progressive loss of skeletal muscle mass and function while frailty is a multidimensional concept characterized by diminished physiological reserve and increased vulnerability to stressors. Both of these were previously considered as related to aging and shown to impact the quality of life and carry prognostic significance. Emerging data show that both sarcopenia and frailty carry similar relevance in chronic illness. Inflammatory bowel disease (IBD) is characterized by chronic inflammation of the gastrointestinal tract and malnourishment, both of which contribute to the development of sarcopenia by increasing protein breakdown and reducing protein synthesis. The coexistence of frailty further compounds the clinical complexity of IBD patients. Published evidence suggests a bidirectional association with IBD contributing to muscle wasting, while the resultant sarcopenia and frailty could further exacerbate the disease course. Sarcopenia and frailty are independently associated with adverse outcomes, including hospitalizations, increased surgical interventions, and surgical complications. As therapeutic strategies for IBD evolve, understanding the nuanced relationship between inflammatory bowel disease, sarcopenia, and frailty is crucial for devising holistic management. Comprehensive care should encompass not only disease-modifying therapies but also interventions targeting frailty and sarcopenia, as they have been shown to have a significant impact not only on the disease course but also on the quality of life. Future research could focus on further elucidating underlying mechanisms, simple screening strategies, and developing targeted interventions to improve the overall quality of life for individuals grappling with the complex interplay of IBD, sarcopenia, and frailty.

Research progress on the predictive role of sarcopenia in the course and prognosis of inflammatory bowel disease

Sarcopenia is a syndrome characterized by a progressive and extensive decrease in skeletal muscle quality and function. With the development of imaging technology in recent years, the understanding and research on the pathogenesis, diagnosis, and evaluation of sarcopenia have gradually improved. More than one-third of patients with inflammatory bowel disease (IBD) have sarcopenia (Ryan et al., 2019), and as a new and unique body composition evaluation index, it is critical for predicting the clinical course, prognosis and postoperative complications of patients with IBD. However, there are limited research summarizing the prevalence of sarcopenia among IBD. Furthermore, there is a scarcity of studies establishing the precise criteria for diagnosing sarcopenia in these patients. This article summarizes the evaluation of sarcopenia and its recent advancements in predicting the course and prognosis of IBD.

A bidirectional Mendelian randomization study of sarcopenia-related traits and inflammatory bowel diseases

Background

There is increasing evidence pointing to a close relationship between sarcopenia and inflammatory bowel disease. However, it remains unclear whether or in which direction causal relationships exist, because these associations could be confounded.

Methods

We conducted a two-sample bidirectional mendelian randomization analysis using data from European genome-wide association studies of the appendicular lean mass(n = 450,243), walking pace(n = 459,915), grip strength (left hand, n = 461,026; right hand, n = 461,089), inflammatory bowel disease (25,042 patients and 34,915 controls), ulcerative colitis (12,366 patients and 33,609 controls), and Crohn's disease (12,194 patients and 28,072 controls) to investigate the causal relationship between sarcopenia-related traits and inflammatory bowel disease and its subtypes on each other. The inverse-variance weighted method was used as the primary analysis method to assess the causality, and a comprehensive sensitivity test was conducted.

Results

Genetically predicted appendicular lean mass was significantly associated with inflammatory bowel disease (OR = 0.916, 95%CI: 0.853-0.984, P = 0.017), ulcerative colitis (OR =0.888, 95%CI: 0.813-0.971, P = 0.009), and Crohn's disease (OR = 0.905, 95%CI: 0.820-0.999, P = 0.049). Similar results also revealed that the usual walking pace was causally associated with Crohn's disease (OR = 0.467, 95%CI: 0.239-0.914, P = 0.026). Reverse mendelian randomization analysis results found that genetic susceptibility to inflammatory bowel disease, and Crohn's disease were associated with lower appendicular lean mass. A series of sensitivity analyses ensured the reliability of the present research results.

Conclusion

The mendelian randomization study supports a bidirectional causality between inflammatory bowel disease, Crohn's disease and appendicular lean mass, but no such bidirectional causal relationship was found in ulcerative colitis. In addition, genetically predicted usual walking pace may reduce the risk of Crohn's disease. These findings have clinical implications for sarcopenia and inflammatory bowel disease management.

Body composition parameters correlate with the endoscopic severity in Crohn's disease patients treated with infliximab

Background

The disease activity status and behavior of Crohn's disease (CD) can reflect the severity of the disease, and changes in body composition are common in CD patients.

Aims

The aim of this study was to investigate the relationship between body composition parameters and disease severity in CD patients treated with infliximab (IFX).

Methods

Patients with CD assessed with the simple endoscopic score (SES-CD) and were treated with IFX were retrospectively collected, and body composition parameters at the level of the 3rd lumbar vertebrae were calculated from computed tomography (CT) scans of the patients. The correlation of patients' body composition parameters with disease activity status and disease behavior was analyzed, and the diagnostic value of the relevant parameters was assessed using receiver operating characteristic (ROC) curves.

Results

A total of 106 patients were included in this study. There were significant differences in the subcutaneous adiposity index (SAI) (p = 0.010), the visceral adiposity index (VAI) (p < 0.001), the skeletal muscle mass index (SMI) (p < 0.001), and decreased skeletal muscle mass (p < 0.001) among patients with different activity status. After Spearman and multivariate regression analysis, SAI (p = 0.006 and p = 0.001), VAI (p < 0.001 and p < 0.001), and SMI (p < 0.001and p = 0.007) were identified as independent correlates of disease activity status (both disease activity and moderate-to-severe activity), with disease activity status independently positively correlated with SAI and SMI and independently negatively correlated with VAI. In determining the disease activity and moderate-to-severe activity status, SMI performed best relative to SAI and VAI, with areas under the ROC curve of 0.865 and 0.801, respectively. SAI (p = 0.015), SMI (p = 0.011) and decreased skeletal muscle mass (p = 0.027) were significantly different between different disease behavior groups (inflammatory disease behavior group, complex disease behavior group) but were not independent correlates (p > 0.05).

Conclusion

Body composition parameters of CD patients treated with IFX correlate with the endoscopic disease severity, and SMI can be used as a reliable indicator of disease activity status.

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.

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.

Body Composition of Patients Undergoing Radical Cystectomy for Bladder Cancer: Sarcopenia, Low Psoas Muscle Index, and Myosteatosis Are Independent Risk Factors for Mortality

Background: We assessed a wide array of body composition parameters to identify those most relevant as prognostic tools for patients undergoing radical cystectomy (RC) due to bladder cancer (BC). Methods: In this retrospective, single-center study, preoperative computed tomography (CT) scans of 657 patients were measured at the level of the 3rd lumbar vertebra (L3) to determine common body composition indices including sarcopenia, myosteatosis, psoas muscle index (PMI), subcutaneous and visceral fat index (SFI and VFI), visceral-to-subcutaneous fat ratio (VSR), and visceral obesity. Predictors of overall survival (OS) and cancer-specific survival (CSS) were identified in univariate and multivariate survival analysis. Results: Sarcopenia and a low PMI were independently associated with shorter OS (Sarcopenia: HR 1.30; 95% CI 1.02–1.66; p = 0.04 and a low PMI: HR 1.32; 95% CI 1.02–1.70; p = 0.03) and CSS (Sarcopenia: HR 1.64; 95% CI 1.19–2.25; p < 0.01 and a low PMI: HR 1.41; 95% CI 1.02–1.96; p = 0.04). Myosteatosis, measured as decreasing average Hounsfield units of skeletal muscle, was an independent risk factor for OS (HR 0.98; 95% CI 0.97–1.00; p = 0.01) and CSS (HR 0.98; 95% CI 0.96–1.00; p < 0.05). The assessed adipose tissue indices were not significant predictors for OS and CSS. Conclusions: Sarcopenia, a low PMI, and myosteatosis are independent predictors for OS and CSS in patients undergoing radical cystectomy for bladder cancer.

Sarcopenia is a negative predictive factor for endoscopic remission in patients with Crohn's disease treated with biologics

BACKGROUND

Sarcopenia has been associated with poor prognosis in chronic diseases.

AIMS

To investigate the role of sarcopenia in predicting clinical and endoscopic outcomes in patients with Crohn's disease (CD).

METHODS

Consecutive CD patients who started biologics between 2014 and 2020 and underwent abdominal magnetic resonance or computed tomography within 6 months from the beginning of the biological therapy were enroled. Sarcopenia was defined as Psoas Muscle Index (PMI) lower than 5.4 cm²/m² (men) and 3.56 cm²/m² (women). Univariate and multivariate analyses were used to evaluate whether sarcopenia could predict steroid-free clinical remission (SFCR), endoscopic remission (ER), hospitalisation and surgery after 12 months of therapy.

RESULTS

358 patients were included. Sarcopenia was found in 18.2% of patients, and it was associated with a lower rate of ER (14.8% vs 47.7%; p = 0.002) after 12 months of therapy, while it was not associated with SFCR (65.1% vs 70.1%; p = 0.435), hospitalisation (9.2% vs 7.8%; p = 0.801) and surgery (3.1% vs 6.1%; p = 0.549). Sarcopenia was identified as a predictor of lack of ER (odds ratio [OR]=5.2; p = 0.006), as well as smoking (OR=2.5; p = 0.028) and perianal disease (OR=2.6; p = 0.020).

CONCLUSION

Sarcopenia is a negative prognostic factor for ER in CD patients treated with biologics.

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.

Volumetric visceral fat machine learning phenotype on CT for differential diagnosis of inflammatory bowel disease

OBJECTIVES

To investigate whether volumetric visceral adipose tissue (VAT) features extracted using radiomics and three-dimensional convolutional neural network (3D-CNN) approach are effective in differentiating Crohn's disease (CD) and ulcerative colitis (UC).

METHODS

This retrospective study enrolled 316 patients (mean age, 36.25 ± 13.58 [standard deviation]; 219 men) with confirmed diagnosis of CD and UC who underwent CT enterography between 2012 and 2021. Volumetric VAT was semi-automatically segmented on the arterial phase images. Radiomics analysis was performed using principal component analysis (PCA) and the least absolute shrinkage and selection operator (LASSO) logistic regression algorithm. We developed a 3D-CNN model using VAT imaging data from the training cohort. Clinical covariates including age, sex, modified body mass index, and disease duration that impact VAT were added to the machine learning model for adjustment. The model's performance was evaluated on the testing cohort separating from the model's development process by its discrimination and clinical utility.

RESULTS

Volumetric VAT radiomics analysis with LASSO had the highest AUC value of 0.717 (95% CI, 0.614-0.820), though difference of diagnostic performance among the 3D-CNN model (AUC = 0.693; 95% CI, 0.587-0.798) and radiomics analysis with PCA (AUC = 0.662; 95% CI, 0.548-0.776) and LASSO have not reached statistical significance (all p > 0.05). The radiomics score was higher in UC than in CD on the testing cohort (mean ± SD, UC 0.29 ± 1.05 versus CD -0.60 ± 1.25; p < 0.001). The LASSO model with adjustment of clinical covariates reached an AUC of 0.775 (95%CI, 0.683-0.868).

CONCLUSION

The developed volumetric VAT-based radiomics and 3D-CNN models provided comparable and effective performance for the characterization of CD from UC.

KEY POINTS

• High-output feature data extracted from volumetric visceral adipose tissue on CT enterography had an effective diagnostic performance for differentiating Crohn's disease from ulcerative colitis. • With adjustment of clinical covariates that cause difference in volumetric visceral adipose tissue, adjusted clinical machine learning model reached stronger performance when distinguishing Crohn's disease patients from ulcerative colitis patients.

Body Composition in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is associated with body composition changes, which are associated with clinical prognosis, response to therapy, and quality of life in IBD patients. Therefore, it is critical to review the body composition distribution in IBD, summarize the potential factors affecting body composition distribution, and take steps to improve the body composition distribution of IBD patients as early as possible. In the current review, we searched PubMed via keywords 'inflammatory bowel disease', or 'IBD', or 'Crohn's disease', or 'CD', or 'ulcerative colitis', or 'UC', and 'body composition'. Malnutrition and sarcopenia are common in IBD patients and are associated with the clinical course, prognosis, and need for surgery. Disease activity, reduced nutrition intake, vitamin D deficiency, and intestinal dysbiosis are factors contributing to changed body composition. Early use of biological agents to induce remission is critical to improving body composition distribution in IBD patients, supplementation of vitamin D is also important, and moderate physical activity is recommended in IBD patients with clinical remission.

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.

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.

Body Composition as a Comorbidity-Independent Predictor of Survival following Nephroureterectomy for Urothelial Cancer of the Upper Urinary Tract

Radical nephroureterectomy (NUE) is the gold standard treatment for high-risk urothelial cancer of the upper urinary tract (UTUC). Besides sarcopenia and frailty, fat distribution is moving increasingly into focus. Components of body composition were assessed in patients undergoing NUE due to UTUC. The study cohort included 142 patients. By using CT-based measurements, the skeletal muscle index (SMI), subcutaneous adipose tissue index (SATI), and visceral adipose tissue index (VATI) were measured at the height of the third lumbar vertebra. Overall survival (OS) and cancer-specific survival (CSS) were estimated using univariable und multivariable Cox regression models. The prevalence of sarcopenia in the study population (n = 142) was 37%. OS and CSS were significantly reduced in sarcopenic patients. In the multivariable cox regression analysis, including age, ACE-27, T-stage, R-stage, LVI and necrosis, sarcopenia remained a significant risk factor of OS (HR, 1.77; 95% CI 1.02-3.07; p = 0.042) and CSS (HR, 2.17; 95% CI 1.18-3.99; p = 0.012). High visceral adipose tissue seems to be protective, although not statistically significant. Sarcopenia is a comorbidity-independent risk factor in patients who underwent NUE due to UTUC. Visceral fat represents a potentially protective factor. These results suggest that specific factors of body composition can be used for better risk stratification.

Sarcopenia Is More Prevalent Among Inflammatory Bowel Disease Patients Undergoing Surgery and Predicts Progression to Surgery Among Medically Treated Patients

BACKGROUND

Sarcopenia is common in inflammatory bowel disease (IBD); however, estimates of its prevalence and impact on clinical outcomes are variable. This study sought to compare the prevalence of sarcopenia in IBD patients starting new biologics vs patients undergoing IBD surgeries, and its association with common clinical predictors of nutritional status, adverse events, and clinical outcomes.

METHODS

This was a multicenter retrospective cohort study of IBD patients who had a computed tomography (CT) scan within 6 months prior to new biologic initiation (medical cohort) or IBD surgery (surgery cohort). The lowest sex-specific quartile of the total psoas area index at the L3 level defined sarcopenia. Prevalence and predictors of sarcopenia, performance of common clinical nutritional markers, and association with adverse events and clinical outcomes at 1 year were determined.

RESULTS

A total of 156 patients were included (48% medical cohort, 52% surgery cohort). Sarcopenia was more common in the surgery cohort (32% vs 16%; P < .02). In the medical cohort, sarcopenia predicted need for surgery at 1 year (odds ratio, 4.75; 95% confidence interval, 1.10-20.57; P = .04). Low albumin and body mass index (BMI) were associated with the presence of sarcopenia; however, 24% of sarcopenic patients had both normal BMI and albumin.

CONCLUSIONS

Sarcopenia is more prevalent among IBD patients undergoing surgery and predicts the need for surgery in patients starting new biologic therapy. Low albumin and BMI were similar between cohorts, suggesting a unique role for sarcopenia as a relevant clinical marker of lean muscle mass depletion for surgically and medically treated IBD patients.

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.

Sarcopenia in Inflammatory Bowel Diseases: Reviewing Past Work to Pave the Path for the Future

Purpose of the Review

Sarcopenia is the loss of muscle quantity and strength. It is highly prevalent in patients with inflammatory bowel disease (IBD) and is associated with periods of ongoing inflammation. This review will summarize the prior work in the field and highlight areas for future research.

Recent Findings

The presence of sarcopenia has been associated with adverse outcomes in different populations. Most recently, sarcopenia has been associated with adverse postoperative outcomes and an increased likelihood of surgery in IBD. Despite this, significant heterogeneity among these studies limits the ability to draw definitive conclusions.

Summary

The importance of sarcopenia in inflammatory bowel disease (IBD) is only beginning to be recognized. Future studies assessing it utility both as a risk stratification tool and a modifiable factor in IBD are needed.

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.

Correlation Among Body Composition Parameters and Long-Term Outcomes in Crohn's Disease After Anti-TNF Therapy

Background

The impact of the body composition on the pathophysiology and clinical course of Crohn's disease (CD) has not been fully elucidated.

Aims

To reveal the correlations among body composition and long-term outcomes in CD after anti-TNF therapy.

Methods

Ninety-one patients who received anti-TNF therapy as their first biologic treatment were enrolled. The skeletal muscle index (SMI), visceral and subcutaneous fat area (VFA, SFA), and the ratio of the VFA to SFA (mesenteric fat index; MFI) at the 3^rd lumbar level were measured using computed tomography (CT) imaging before the induction. The correlation among the body composition and outcomes were retrospectively analyzed.

Results

The 5-year cumulative secondary failure- and resection-free rates in patients with a low SMI (39.1% and 64.8%) were significantly lower than those with a high SMI (67.5% and 92.7%; p = 0.0071 and 0.0022, respectively). The 5-year cumulative secondary failure-free rate in the patients with low VF (45.0%) was significantly lower than that in those with high VF (77.6%; p = 0.016), and the 5-year cumulative resection-free rate in patients with a high MFI (68.9%) was significantly lower than that in those with a low MFI (83.0%; p = 0.031). Additionally, patients with low age and BMI had significantly lower cumulative secondary failure- and resection-free rates than those with high age and BMI (low age: 37.4% and 71.2%; high age: 70.7% and 88.9%; p = 0.0083 and 0.027, respectively) (low BMI: 27.2% and 64.8%; high BMI: 68.3% and 87.9%; p = 0.014 and 0.030, respectively), respectively. In the multivariate analyses, a low SMI was the only independent risk factor for secondary failure (hazard ratio [HR] 2.15, 95% confidence interval [CI] 1.04–4.44), while low age (HR 4.06, 95% CI 1.07–15.4), a low SMI (HR 4.19, 95% CI 1.01–17.3) and high MFI were risk factors for bowel resection (HR 4.31, 95% CI 1.36–13.7).

Conclusion

The skeletal muscle mass and ratio of visceral to subcutaneous fat were suggested to reflect the long-term clinical outcome and may be helpful as prognostic markers after anti-TNF therapy in CD.

Association Between Frailty or Sarcopenia and Adverse Outcomes in Inflammatory Bowel Disease: A Systematic Review

Background and Aims

Chronological age often guides the management of patients with inflammatory bowel disease (IBD). Frailty and sarcopenia, which are related but distinct entities that become increasingly prevalent with age, better predict nonsurgical and surgical outcomes in various chronic illnesses. We conducted a systematic review to assess the association between frailty or sarcopenia and adverse nonsurgical outcomes in adult patients with IBD.

Methods

Through a systematic literature review of 4 online databases (MEDLINE, EMBASE, Scopus, and CINAHL Plus), we identified 16 studies that focused on frailty or sarcopenia and nonsurgical outcomes in IBD. The Newcastle-Ottawa Scale was used to determine the quality of included studies.

Results

We identified 16 studies: 8 frailty-based and 8 sarcopenia-based studies (14 high-quality and 2 low-quality studies). All results were presented in a summarized narrative format. Frailty predicted all hospitalization-related outcomes (hospitalization, readmission, and length of stay) and mortality-related outcomes. The outcomes of therapeutic efficacy, need for therapy escalation, and infections had mixed results in relation to their association with frailty or sarcopenia. The data regarding sarcopenia and hospitalizations were also equivocal.

Conclusion

This systematic review supports the use of frailty indices to predict hospitalization- and mortality-related outcomes in adult patients with IBD. Future research should focus on identifying and validating frailty and sarcopenia tools in IBD to better help predict adverse clinical outcomes and response to therapy.

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.

Relationship between sarcopenia/myosteatosis and frailty in hospitalized patients with cirrhosis: a sex-stratified analysis

Background:

Previous studies have shown that sarcopenia appears to be a significant contributor to physical frailty among outpatients with cirrhosis. However, the evidence is scant regarding the relationship between sarcopenia and multi-dimensional frailty among inpatients. We aimed to investigate the potential contribution of sarcopenia to frailty in hospitalized patients with cirrhosis in a sex-dependent manner.

Methods:

This cohort enrolled consecutive cirrhotics. Muscle quantity and quality were assessed using the computed tomography-based skeletal muscle index (SMI) and intramuscular adipose tissue content, respectively. Frailty phenotype was clarified by a self-reported Frailty Index. Multiple linear regression determined the association between sarcopenia and frailty phenotype.

Results:

A total of 202 cirrhotic patients with 48.5% male were included. The median Frailty Index was 0.13, rendering 17.3% subjects as frail. Among the 16 frail men, 68.8% had sarcopenia and 62.5% exhibited myosteatosis. In contrast, among the 19 frail women, 26.3% had sarcopenia and 15.8% exhibited myosteatosis. Frail patients had a significantly lower median SMI (42.80 cm²/m²) compared with those with pre-frailty (48.23 cm²/m²) and with robust status (50.82 cm²/m²) in the male but not the female group. In male patients, multivariate linear regression implicated age (β = 0.330, p < 0.001), SMI (β = −0.260, p < 0.001), albumin (β = −0.245, p = 0.005), and sodium (β = −0.179, p = 0.037) as independent risk factors for frailty.

Conclusion:

Sarcopenia is associated with multi-dimensional frailty in male patients with cirrhosis. It is tempting to incorporate sex-specific intervention with the purpose of mitigating frailty among inpatients.

Inflammatory Bowel Diseases and Sarcopenia: The Role of Inflammation and Gut Microbiota in the Development of Muscle Failure

Sarcopenia represents a major health burden in industrialized country by reducing substantially the quality of life. Indeed, it is characterized by a progressive and generalized loss of muscle mass and function, leading to an increased risk of adverse outcomes and hospitalizations. Several factors are involved in the pathogenesis of sarcopenia, such as aging, inflammation, mitochondrial dysfunction, and insulin resistance. Recently, it has been reported that more than one third of inflammatory bowel disease (IBD) patients suffered from sarcopenia. Notably, the role of gut microbiota (GM) in developing muscle failure in IBD patient is a matter of increasing interest. It has been hypothesized that gut dysbiosis, that typically characterizes IBD, might alter the immune response and host metabolism, promoting a low-grade inflammation status able to up-regulate several molecular pathways related to sarcopenia. Therefore, we aim to describe the basis of IBD-related sarcopenia and provide the rationale for new potential therapeutic targets that may regulate the gut-muscle axis in IBD patients.

Sarcopenia assessed by computed tomography is associated with colectomy in patients with acute severe ulcerative colitis

BACKGROUND

Altered body composition is an important characteristic of malnutrition that may better reflect the clinical course. This study aimed to evaluate the prognostic role of sarcopenia by computed tomography (CT) on colectomy in acute severe ulcerative colitis (ASUC) during index hospitalization and follow-up.

METHODS

254 ASUC patients undergoing CT scans at admission were retrospectively included. Sarcopenia was assessed by the skeletal muscle index (SMI) with CT scans at L3, and patients with an SMI below the lowest sex-specific quartile were diagnosed with sarcopenia. Body mass index (BMI) < 18.5 kg/m² was defined as clinical malnutrition. Univariate and multivariate analyses were performed to determine the association between sarcopenia and colectomy.

RESULTS

The prevalence of sarcopenia in ASUC was 50.0%, and malnutrition was 25.2%. Among sarcopenic patients, 36.2% was malnutrition, 51.2% had normal BMI, 11.8% was overweight, and 0.8% was obese. During index hospitalization, 66.9% patients needed rescue therapy with 52.4% received medical rescue therapy and 14.6% received colectomy. During follow-up, 33.2% patients needed colectomy. Significantly more sarcopenic patients required colectomy (22.0% vs 7.1%, p = 0.001) and rescue therapy (81.9% vs 52.0%, p < 0.001) during index hospitalization and colectomy during follow-up (44.4% vs 23.7%, p = 0.001) than non-sarcopenic patients. However, BMI < 18.5 kg/m² was not related to the clinical course. In multivariate analyses, sarcopenia remained an independent risk factor for rescue therapy and colectomy during index hospitalization and colectomy during follow-up.

CONCLUSION

Sarcopenia rather than BMI was associated with clinical outcomes in ASUC and played an important role in predicting the need for colectomy.

Sarcopenia is a Predictor for Adverse Clinical Outcome in Pediatric Inflammatory Bowel Disease

OBJECTIVES

Inflammatory bowel disease (IBD) has a high impact on nutritional status. Sarcopenia is related to higher risk of surgery and rescue therapy in adults with IBD; however, comparable data in pediatric populations are scarce. We evaluated muscle mass as a predictor of disease outcome in pediatric IBD.

METHODS

All pediatric IBD patients who underwent magnetic resonance enterography (MRE) during 2008 to 2019 were included. Muscle mass was assessed by measuring the area of the psoas muscle at the upper level of L3 on MRE. The psoas area divided by the body surface area (BSA) yielded the psoas index. Clinical and radiological data, including disease location, activity, course, and medications were documented. The control group included non-IBD children who underwent an MR imaging study.

RESULTS

We enrolled 101 IBD patients, 69 (68.3%) with Crohn disease (CD) and 32 (31.7%) with ulcerative colitis (UC) (mean age 15.03 ± 3.27 years). The psoas index was significantly lower in the IBD patients compared with the 87 controls (326 vs 528, respectively, P < 0.001). Patients with a psoas index in the lowest quartile had significantly higher risk for biologic therapy (multivariate analysis, hazard ratio [HR] = 12.1, P = 0.046) and disease exacerbation (HR = 9, P = 0.047) independently of body mass index, compared with patients with a psoas index in the uppermost quartile.

CONCLUSIONS

Sarcopenia correlates with the radiological severity of pediatric IBD and serves as a predictor for adverse clinical disease outcome. Muscle mass measurement in MRE studies may serve as a possible marker for disease outcome in this population.