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

The Relationship Between Intramural Fat Accumulation and Sarcopenia on MR Enterography Exams in Patients with Crohn's Disease

Research on magnetic resonance enterography (MRE) and sarcopenia for assessing Crohn's disease (CD) is growing. Our study examined the connections between the presence of sarcopenia, intramural fat accumulation (IFA), and clinical, laboratory, and MRE findings.This retrospective study was conducted on 112 patients with suspected or diagnosed CD who underwent 3-tesla MRE. The study examined the correlation between sarcopenia-related parameters and MRE findings. Results of MRE exams and clinical and laboratory results were statistically analyzed. The Kruskal-Wallis, Pearson chi-square, and Fisher-Freeman-Halton tests were used for comparison.It was determined that patients with active inflammation on a chronic basis had more IFA than the others (p<0.001). There were positive relationships between IFA and intramural edema (p<0.001). There were positive correlations between IFA and high b-values and negative correlations with apparent diffusion coefficient values (p<0.05). Positively significant relationships were found between IFA and wall thickness, affected segment length, disease duration, and sedimentation values (p<0.05). Strong correlations were found between sarcopenia and the CD activity index as well as wall thickness (p<0.001/p=0.003). There was no significant relationship between steroid usage and other variables.The presence of IFA is associated with chronic inflammation. There was no clear relationship between steroid use and IFA. Our findings support the idea that sarcopenia is related to the activity of CD. Further comprehensive research is required on these subjects. · The usage of MR enterography for the management of CD is increasing day by day due to its advantages.. · There is a paucity of evidence regarding the relationship between sarcopenia and MR enterography findings in patients with CD.. · Intramural fat accumulation (IFA) is a sign of chronicity in patients with CD.. · The presence of IFA seems to be associated with active inflammation on a chronic basis.. · There was no clear relationship between steroid use and IFA.. · Algin O, Güneş YC, Cankurtaran RE et al. The Relationship Between Intramural Fat Accumulation and Sarcopenia on MR Enterography Exams in Patients with Crohn's Disease. Fortschr Röntgenstr 2024; DOI 10.1055/a-2330-8148.

Skeletal Muscle Mass Assessment in Pediatric Patients: Development of a Normative Equation and Assessment of Factors Associated With a Low Skeletal Muscle Mass in PICU Patients

OBJECTIVES

To develop an equation for defining a low skeletal muscle mass (SMM) in children and to investigate risk factors and outcomes associated with low SMM in critically ill pediatric patients.

DESIGN

Single-center retrospective pediatric cohorts, 2011-2018.

SETTING

Tertiary Emergency and Critical Care Center of Kyushu University Hospital in Japan.

PATIENTS

We studied two cohorts of pediatric patients 1-15 years old who underwent abdominal CT at the level of the third lumbar vertebra (L3). First a cohort of trauma patients presented to the emergency department in whom we developed an SMM regression equation. Second, a cohort of patients who had undergone abdominal CT within 3 days of PICU admission.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The equation for estimating normal SMM used sex, age, and weight. Low SMM was defined as less than 80% of normal. In the 112 patients in the PICU cohort, median (range) age was 68 (13-191) months, and 83 (74.1%) had underlying disease. There was low SMM in 54 patients (48.2%). Regarding associations, using odds ratio (OR) and 95% CI, we found that low dietary intake (OR 4.33 [95% CI, 1.37-13.70]; p = 0.013) and the presence of underlying disease (OR 7.44 [95% CI, 2.10-26.30]; p = 0.002) were independently associated with greater odds of low SMM. Low SMM, compared with normal SMM, was also associated with longer hospital stays (42.5 d vs. 20.5 d; p = 0.007; β, 1.59; 95% CI, 1.09-2.33; p = 0.016).

CONCLUSIONS

In this retrospective PICU cohort from a single center in Japan, we found that low SMM at PICU admission was present in almost half the cases. Low SMM, as defined by being less than 80% of the normal, was associated with greater odds of low dietary intake and underlying chronic disease. Furthermore, low SMM was associated with longer hospital stays.

Establishment of a quantitative assessment model and web-based calculation tool for the skeletal muscle index in children

BACKGROUND & AIMS

The skeletal muscle index (SMI) is widely used in adults. The reference values for SMI in children are inadequate and require validation in pediatric patients for clinical usefulness. Therefore, this study developed a quantitative assessment model for SMI in children using standard deviation (SD) curves and validated the model's utility and generalizability.

METHODS

We examined three compartments of the abdominal skeletal muscle region. SMI was calculated as skeletal muscle area divided by height squared for each compartment (PMI, psoas muscle index; PSMI, paraspinal muscle index; TSMI, total skeletal muscle index). The optimal model was generated using random grouping methods (training and testing), polynomial regression analysis, and the mean squared error evaluation methods. The generated model was validated with previously published SMI data and clinical data of patients with inflammatory bowel disease.

RESULTS

The data of 474 children were analyzed. The previously reported SMI reference values overlapped well with our model. In patients with inflammatory bowel disease, the mean (SD) Z-scores for SMI were low in boys (PMI, -1.15 [1.11]; PSMI, -1.31 [1.07]; TSMI, -0.84 [0.91]) and girls (PMI, -1.22 [1.08]; PSMI, -1.44 [1.19]; TSMI, -0.74 [1.16]). Furthermore, SMI was positively correlated with body weight, body mass index, and serum albumin level, a nutritional marker, and negatively correlated with erythrocyte sedimentation rate, an inflammatory marker.

CONCLUSION

We established a quantitative assessment model for SMI and validated the model's generalizability and clinical usefulness. We generated an easy-to-use calculation tool for Z-scores from skeletal muscle area obtained from computed tomography images, age, and height information; it has been made publicly available (http://square.umin.ac.jp/ped-muscle-calc/index.html).

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.

Systematic review: Sarcopenia in paediatric inflammatory bowel disease

BACKGROUND

Low skeletal muscle mass (MM) and deteriorated function (sarcopenia) can be a frequent complication in paediatric inflammatory bowel disease (IBD).

AIM

To conduct a systematic review of the paediatric IBD literature on skeletal muscle function and mass and identify interventions that could affect them.

METHODS

Systematic searches (EMBASE, Medline, Cochrane library central for registered control trials and Web of Science) were conducted using the terms 'lean body mass' (LM), 'fat free mass' (FFM) or 'MM' and 'IBD'.

RESULTS

Fourteenth studies were included, presenting data from 439 Crohn's disease (CD), 139 ulcerative colitis (UC) and 2 IBD-unclassified participants compared with healthy matched or unmatched groups or reference populations. Six out of 14 studies reported lower LM, whilst 7 studies observed lower MM and FFM in CD patients compared to healthy controls. Research in UC patients reported lower LM in 3 studies, lower MM in 3 studies and lower FFM in 4 studies. Three prospective studies measured the impact of enteral feeding and showed improvement on disease activity and LM or FFM, while one retrospective study did not show any impact on LM.

CONCLUSION

Despite the variety of experimental approaches and methods used to assess sarcopenia, most studies showed reduction in MM, LM and FFM in IBD. Nutritional intervention may have a positive effect on LM and FFM. Future research should focus on standardizing the terminology and methodologies used in assessing body composition and investigating sarcopenia in diseased and matched healthy control cohorts in adequately powered studies with a longitudinal design.

Magnetic Resonance Imaging Can Be Used to Assess Sarcopenia in Children with Newly Diagnosed Crohn's Disease

BACKGROUND

This study aimed to determine the proportion of patients with sarcopenia diagnosed by MRI and compare these results to bioelectrical impedance analysis (BIA).

METHODS

Children with newly diagnosed Crohn's disease (CD) who had MRI enterography (MRE) and BIA and had at least 12 months of follow-up were included. Total psoas muscle area (TPMA) and total paravertebral muscle (TPVM) were measured and compared to subjects' lean mass and the lean mass body index (LMBI) was assessed by BIA.

RESULTS

30 newly diagnosed children with CD were included (mean age 14.2 years, 53% male). Sarcopenia was found in 13 (43%) children; mean TPMA was 15.2 (1.1 SD) cm2 and TPVM 30.95 (1.7 SD) cm2. A highly positive correlation was shown for lean mass assessed by BIA and TPMA (0.706, p < 0.001) and TPVM (0.75, p < 0.001). Sarcopenia was more prevalent in boys (77% vs. 24%, p = 0.004), patients with the perianal disease (69% vs. 29%, p = 0.03), and children with sarcopenia were likely to receive anti-TNF (77% vs. 41%, p = 0.05). During the follow-up period, 16 (53%) children experienced a relapse. TPMA (HR 0.99, p = 0.018) and TPVM (HR 0.99, p = 0.031) values were statistically significant risk factors for relapse.

CONCLUSION

A high proportion of patients with CD have sarcopenia at the time of the diagnosis. There is a good correlation between muscle mass assessed by MRI and BIA. Because MRI is performed in a great proportion of newly diagnosed CD patients it can also be used to assess the presence of sarcopenia.

Body composition and musculoskeletal fitness: A cluster analysis for the identification of risk phenotypes for pediatric sarcopenia

BACKGROUND AND AIM

Sarcopenia is primarily a disease in older people characterized by reduced muscle mass and strength. Nevertheless, sarcopenia may, at least partially, have pediatric origins. The study aimed to identify risk phenotypes for sarcopenia in healthy young people using clustering analysis procedures based on body composition and musculoskeletal fitness.

METHODS

We conducted a cluster cross-sectional analysis of data from 529 youth aged 10-18 yr. Body composition was assessed using whole-body dual-energy x-ray absorptiometry (DXA), determining: lean body mass index (LBMI, kg/m2), fat body mass index (FBMI, kg/m2), abdominal FBMI (kg/m2), and lean body mass/fat body mass ratio (LBM/FBM); body mass index was also calculated (BMI, kg/m2). Musculoskeletal fitness was assessed using handgrip strength (kg) and vertical jump power (W) tests. Results were presented as absolute values and adjusted by body mass. Plank endurance (s) was also assessed. All variables were sex and age in years standardized (Z-score). LBMI or LBM/FBM ratio ≤ -1 SD were used to identify participants at risk for sarcopenia. Maturity was estimated as the years of distance from the peak height velocity (PHV) age.

RESULTS

Using the Z-score means for body composition and musculoskeletal fitness and having LBMI or LBM/FBM ratio as the categorical variables (at risk vs. not at risk), the cluster analyses indicated three homogeneous groups (phenotypes, P): P1, risk body composition and unfit; P2, non-risk body composition and non-fit, and P3, non-risk body composition and fit. With the LBMI as a categorical variable, the ANOVA models showed that the body composition and absolute values of musculoskeletal fitness were in P1 < P2 < P3 and the estimated PHV age of P1 > P3 in both sexes (p < 0.001). Having the LBM/FBM as a categorical variable, higher values of BMI, FBMI, and abdominal FBMI, and lower values of handgrip strength and vertical jump power both adjusted for body mass and plank endurance were observed in P1 than in P2 and/or P3 and the P2 than in the P3 in boys and girls (p < 0.001).

CONCLUSIONS

Two risk phenotypes for sarcopenia were identified in apparently healthy young people: I. a low LBMI phenotype with low BMI and II. a low LBM to FBM phenotype with high BMI and FBMI. In both risk phenotypes I and II, musculoskeletal fitness was low. For screening, we suggest using absolute measures of handgrip strength and vertical jump power in phenotype I and body mass adjusted measures of these markers, as well as the plank endurance time in phenotype II.

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

BACKGROUND

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Establishment and validation of reference values for abdominal skeletal muscle compartments in children

BACKGROUND & AIMS

Sarcopenia, resulting from skeletal muscle loss, is a serious concern in children, for whom nutrition and physical activity are essential for growth. In sarcopenia research, the skeletal muscle mass is often obtained from computed tomography (CT) cross-sectional images in both adults and children; however, the method of evaluating skeletal muscle using CT, especially the area range to be measured, has not yet been validated in children. The aim of this study is to establish reference values for three compartments of the abdominal skeletal muscle area (aSMA) obtained from cross-sectional CT images, and to validate the differences among them by assessing correlations with physical development.

METHODS

We conducted a single-centre, retrospective, cross-sectional study and included patients aged 1-17 years who underwent abdominal CT at Chiba University Hospital from 2007 to 2020. Patients with chronic diseases such as malignant tumours and inflammatory bowel disease were excluded from the analysis. aSMA was obtained from CT cross-sections at the lumbar L3-L4 intervertebral disc level by dividing it into three compartments: the psoas muscle area (PMA), paraspinal muscle area (PSMA), and total skeletal muscle area (TSMA). Quartile regression curves by sex and muscle compartment were generated using non-crossover and nonparametric regression quantile estimation. The correlation between each compartment of aSMA with height and weight was assessed using Spearman's rank correlation coefficient.

RESULTS

We analysed the abdominal CT images of 593 children (male: n = 335, female: n = 258) and generated curves predictive for the 5th, 25th, 50th, 75th, and 95th percentiles for each compartment of aSMA by sex. In patients aged 13 years and older, boys had significantly larger aSMA areas than girls in all three compartments. Among the three compartments, PSMA had the strongest correlation coefficient with height and weight for both boys and girls.

CONCLUSIONS

We generated quantile regression curves for three aSMA compartments obtained from cross-sectional CT images and established reference values in children. PSMA values were most strongly correlated with height and weight among the three aSMA compartments.

Body composition, physical activity, and quality of life in pediatric patients with inflammatory bowel disease on anti-TNF therapy-an observational follow-up study

BACKGROUND

Poor outcome of inflammatory bowel disease (IBD) is associated with malnutrition. Our aim was to compare body composition (BC) and physical activity (PA) between patients with IBD and healthy controls, and to assess the changes in BC, PA and health related quality of life (HRQoL) in children with IBD during anti-TNF therapy.

METHODS

32 children with IBD (21 with Crohn's disease (CD), (age: 15.2 ± 2.6 years, 9 male) and 11 with ulcerative colitis (UC), (age: 16.4 ± 2.2 years, 5 male) participated in this prospective, observational follow up study conducted at Semmelweis University, Hungary. As control population, 307 children (age: 14.3 ± 2.1) (mean ± SD) were included. We assessed BC via bioelectric impedance, PA and HRQoL by questionnaires at initiation of anti-TNF therapy, and at two and six months later. The general linear model and Friedman test were applied to track changes in each variable.

RESULTS

During follow-up, the fat-free mass Z score of children with CD increased significantly (-0.3 vs 0.1, p = 0.04), while the BC of patients with UC did not change. PA of CD patients was lower at baseline compared to healthy controls (1.1 vs. 2.4), but by the end of the follow up the difference disappeared.

CONCLUSIONS

The fat-free mass as well as PA of CD patients increased during the first six months of anti-TNF treatment. As malnutrition and inactivity affects children with IBD during an important physical and mental developmental period, encouraging them to engage in more physical activity, and monitoring nutritional status should be an important goal in patient care.

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.

Initial Abdominal CT and Laboratory Findings Prior to Diagnosis of Crohn's Disease in Children

PURPOSE

To identify initial abdominal computed tomography (CT) and laboratory findings prior to a diagnosis of Crohn's disease (CD) in children.

MATERIALS AND METHODS

In this retrospective study, patients (≤18 year-old) who were diagnosed with CD from 2004 to 2019 and had abdominal CT just prior to being diagnosed with CD were included in the CD group. Patients (≤18 years old) who were diagnosed with infectious enterocolitis from 2018 to 2019 and had undergone CT prior to being diagnosed with enterocolitis were included as a control group. We assessed the diagnostic performances of initial CT and laboratory findings for the diagnosis of CD using logistic regression and the area under the curve (AUC).

RESULTS

In total, 107 patients (50 CD patients, 57 control patients) were included, without an age difference between groups (median 13 years old vs. 11 years old, p=0.119). On univariate logistic regression analysis, multisegmental bowel involvement, mesenteric vessel engorgement, higher portal vein/aorta diameter ratio, longer liver longitudinal diameter, lower hemoglobin (≤12.5 g/dL), lower albumin (≤4 g/dL), and higher platelet (>320×10³/µL) levels were significant factors for CD. On multivariate analysis, multisegmental bowel involvement [odds ratio (OR) 111.6, 95% confidence interval (CI) 4.778-2605.925] and lower albumin levels (OR 0.9, 95% CI 0.891-0.993) were significant factors. When these two features were combined, the AUC value was 0.985 with a sensitivity of 96% and specificity of 100% for differentiating CD.

CONCLUSION

Multisegmental bowel involvement on CT and decreased albumin levels can help differentiate CD from infectious enterocolitis in children prior to a definite diagnosis of CD.

Imaging of Sarcopenia

Sarcopenia is currently underdiagnosed and undertreated, but this is expected to change because sarcopenia is now recognized with a specific diagnosis code that can be used for billing in some countries, as well as an expanding body of research on prevention, diagnosis, and management. This article focuses on practical issues of increasing interest by highlighting 3 hot topics fundamental to understanding sarcopenia in older adults: definitions and terminology, current diagnostic imaging techniques, and the emerging role of opportunistic computed tomography.

Sarcopenia in Children with Solid Organ Tumors: An Instrumental Era

Sarcopenia has recently been studied in both adults and children and was found to be a prognostic marker for adverse outcome in a variety of patient groups. Our research showed that sarcopenia is a relevant marker in predicting outcome in children with solid organ tumors, such as hepatoblastoma and neuroblastoma. This was especially true in very ill, high-risk groups. Children with cancer have a higher likelihood of ongoing loss of skeletal muscle mass due to a mismatch in energy intake and expenditure. Additionally, the effects of cancer therapy, hormonal alterations, chronic inflammation, multi-organ dysfunction, and a hypermetabolic state all contribute to a loss of skeletal muscle mass. Sarcopenia seems to be able to pinpoint this waste to a high degree in a new and objective way, making it an additional tool in predicting and improving outcome in children. This article focuses on the current state of sarcopenia in children with solid organ tumors. It details the pathophysiological mechanisms behind sarcopenia, highlighting the technical features of the available methods for measuring muscle mass, strength, and function, including artificial intelligence (AI)-based techniques. It also reviews the latest research on sarcopenia in children, focusing on children with solid organ tumors.

Association between Dietary Inflammatory Index and Sarcopenia in Crohn's Disease Patients

Background: Chronic inflammation is a pathophysiological cause of sarcopenia in Crohn’s disease (CD) patients. However, the potential impact of diet-related inflammation on sarcopenia has not yet been adequately investigated. We examined the associations between Dietary Inflammatory Index (DII) and sarcopenia in CD patients. Methods: A total of 140 CD patients from Ruijin Hospital in Shanghai were included in this cross-sectional study. DII scores were calculated from the dietary data collected using a validated food frequency questionnaire (FFQ). Sarcopenia was determined according to the Asian Working Group for Sarcopenia. Multivariable logistic regression analyses were performed to determine the association between DII and sarcopenia. Results: The mean DII score was 0.81 ± 2.13, ranging from −3.24 to 4.89. The overall prevalence of sarcopenia was 26.4%. The higher DII score significantly increased the risk of sarcopenia in CD patients (OR_Quartile4vs1: 9.59, 95% CI: 1.69, 54.42, p_trend = 0.031) in the multivariable model after adjusting for more potential confounders. Moreover, CD patients with a lower DII had a significantly higher appendicular skeletal muscle mass index (ASMI, OR_Quartile4vs1: 5.48, 95% CI: 1.51, 19.87, p_trend = 0.018) after adjusting for age, gender, BMI, smoking status and drinking status model. Yet, there were no significant differences between DII and ASMI after adjusting for more potential confounders. Additionally, no significant association was observed between DII and handgrip strength in the multivariable-adjusted models. Conclusions: Pro-inflammatory diet was associated with increased risk of sarcopenia in CD patients. CD patients should have a proper intake of energy and protein. These patients could also benefit from supplementation with enteral nutrition due to its anti-inflammatory potential.

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.