Crohn’s disease is associated with altered body composition, such as low muscle mass, which can affect clinical outcomes. However, there are few studies regarding the effect of sarcopenia on prognosis of Crohn’s disease. In this study, we evaluated the body composition at the initial diagnosis of Crohn’s disease and analyzed the clinical meaning of sarcopenia.
We conducted a retrospective review of medical records of patients who were diagnosed as Crohn’s disease and underwent computed tomography within 3 months after diagnosis. Sarcopenia was defined as an L3 skeletal muscle index (SMI) of < 49 cm2/m2 for men and < 31 cm2/m2 for women. Outcomes such as need for hospitalization, surgery, use of steroids, immunomodulators and biologics were analyzed.
A total of 79 patients (male, 73.4%; mean age, 29.9 years) were included and 40 patients (51%) were diagnosed as sarcopenia. C-reactive protein (CRP) level was correlated with sarcopenia (
Approximately 50% of patients with newly diagnosed as Crohn’s disease had sarcopenia. CRP levels were higher in the sarcopenia group and SMI correlated with ESR, hemoglobin, and albumin. However, none of prognostic values were demonstrated.
Crohn’s disease (CD) is a chronic immune-mediated GI disorder that the incidence and prevalence are increasing worldwide [
Sarcopenia, affected by malnutrition, immobility, and chronic catabolic diseases has been reported as a key factor that is associated with morbidity, mortality in elderly people [
The aim of this study was to clarify the prevalence of sarcopenia among CD patients and reveal the predictive values of sarcopenia in impacts on prognostic outcomes.
The electronic medical records and radiology database were searched for patients with newly diagnosed as CD between March 2013 and March 2017 at Seoul National University Bundang Hospital. The inclusion criteria were as follows: ≥ 18 years old; diagnosis of CD based on clinical, endoscopic, radiological examination; availability of an accurate height, weight and CT data within 3 months after diagnosis. Subjects were excluded if: they had a medical history of having biologics, steroid or immunomodulators for other significant comorbidities except CD; they got a previous history of bowel surgery; they had cancer history or other chronic disease
L3 vertebral level at CT was used for segmentation of body composition [
To determine the associated factors with sarcopenia status in CD patients, the following variables were analyzed: age, sex, height, weight, smoking history, disease characterization according to the Montreal classification, laboratory test (serum CRP, ESR, albumin, hemoglobin, and vitamin D). Data obtained from dual-energy X-ray absorptiometry (GE Lunar Prodigy; Madison, WI, USA) was used to evaluate bone mineral density (BMD). The lowest BMD
The data of the patients were analyzed according to sarcopenia status using the Student
The study was conducted in accordance with the Declaration of Helsinki for the participation of human subjects in research. It was approved by the International Review Board (IRB) of Seoul National University Hospital (IRB No. B-1708-412-108). Written informed consents were obtained.
A total of 79 patients (male, 73.4%; mean age, 29.9 ± 11.3 years) were included and all of their ethnicity were Korean. Prevalence of sarcopenia was 51% (40 patients) according to Korean specific cutoff values. The baseline characteristics of patients with or without sarcopenia are compared in
Dual-energy X-ray absorptiometry was performed in 28 patients. Among them, patients with BMD
Correlation between SMI and clinical variables in patients with CD were shown
The present study examined the prevalence of sarcopenia among CD patients which was much higher than the prevalence in healthy aging adults [
Recent studies revealed that skeletal muscle volume is associated with age, sex, height, BMI, and serum CRP, albumin levels which could be considered to reflect chronic inflammation, malabsorption or intestinal deformities [
To demonstrate the prognostic value of sarcopenia, we performed time-to-first-event analysis such as operation, hospitalization, use of biologics, immunomodulators, and steroids. However, none of results showed statistically significance. Study by Adams et al. [
It is interesting that in a cumulative operation-free survival rate analysis by Bamba et al. [
The first strength of this study was that we enrolled newly diagnosed CD patients and attempted to evaluate the prognostic value of baseline status according to sarcopenia in initial setting of treatment start. Second, present study included commonly used medication in time-to-first-event analysis. It enables us to know that there were no association between sarcopenia and need for steroid, biologics or immunomodulators in follow-up period. The third strength is that the cutoff value of sarcopenia was specifically considered for ethnicity whereas cutoff of other previous study was not [
This study has a few limitations. First, this was a retrospective analysis and was from a single center. Owing to the absence of controls, it may have affected the results. However, following the international guidelines, a strategy of using medication for CD and decision for surgery is standardized in our tertiary care, university-affiliated hospital. Second, due to the retrospective nature of this study, patients without CT data within 3 months were excluded. Finally, we could not analyze the data of CDAI according to baseline sarcopenia status [
In conclusion, this study revealed that baseline status of sarcopenia is present in approximately 50% of patients with newly diagnosed CD. However, the sarcopenia status is not a prognostic factor for predicting need for surgery, hospitalization, initiation of steroids, immunomodulators, or biologics.
The authors received no financial support for the research, authorship, and/or publication of this article.
No potential conflict of interest relevant to this article was reported.
Conception and design: Lee CH, Yoon H. Data acquisition: Lee CH, Yoon H. Data analysis and interpretation: Lee CH, Yoon H. Drafting the manuscript: Lee CH Critical revision of the manuscript and supervision: all authors. Approval of final manuscript: all authors.
The skeletal muscle area (SMA) measured at the L3 vertebral level. The skeletal muscle index, which defines sarcopenia, is the SMA divided by the height squared. Purple is SMA measured in patients with CD without sarcopenia and blue is SMA measured in patients with CD with sarcopenia.
Time-to-first-event analysis by Kaplan-Meier methods in patients with or without sarcopenia: cumulative operation-free survival rate (A), hospitalization-free survival rate (B), biologics-free survival rate (C), immunomodulators-free survival rate (D), and corticosteroid-free survival rate (E).
Baseline Characteristics of Subjects Who Were Diagnosed as CD with and without Sarcopenia
Variable | No sarcopenia (n = 39) | Sarcopenia (n = 40) | |
---|---|---|---|
Demographic and clinical parameters | |||
Age (yr) | 32.0 ± 13.9 | 28.0 ± 7.8 | 0.118 |
Male sex | 24 (61.5) | 34 (85.0) | 0.018 |
Height (m) | 1.67 ± 0.08 | 1.72 ± 0.07 | 0.008 |
BMI (kg/m2) | 20.9 ± 3.2 | 19.7 ± 2.8 | 0.086 |
VFA (cm2) | 57.0 ± 49.9 | 41.4 ± 37.2 | 0.119 |
SFA (cm2) | 98.5 ± 64.8 | 68.3 ± 49.7 | 0.022 |
SMA (cm2) | 136.5 ± 35.0 | 124.3 ± 24.1 | 0.077 |
SMA/SFA | 3.6 ± 5.5 | 3.9 ± 4.8 | 0.827 |
SMA/VFA | 4.6 ± 4.6 | 6.2 ± 6.2 | 0.203 |
SMI (cm2/m2) | 48.5 ± 9.6 | 42.0 ± 6.1 | 0.001 |
Smoking, past/current | 14 (35.9) | 17 (42.5) | 0.548 |
Laboratory parameters | |||
CRP (mg/dL) | 2.4 ± 3.6 | 4.5 ± 5.6 | 0.044 |
ESR (mm/hr) | 30.3 ± 25.8 | 30.2 ± 22.0 | 0.983 |
Serum hemoglobin (mg/dL) | 12.6 ± 3.3 | 12.9 ± 2.2 | 0.569 |
Serum albumin (mg/dL) | 3.90 ± 0.72 | 3.93 ± 0.66 | 0.859 |
Vitamin D (ng/mL) | 14.9 ± 7.9 | 12.6 ± 5.9 | 0.163 |
Montreal classification | |||
Age at diagnosis | |||
A1 (< 17 yr) | 4 (10.3) | 3 (7.5) | 0.712 |
A2 (17–40 yr) | 29 (74.4) | 35 (87.5) | 0.137 |
A3 (> 40 yr) | 6 (15.4) | 2 (5.0) | 0.154 |
Location | |||
L1 (terminal ileum) | 12 (30.8) | 8 (20.0) | 0.271 |
L2 (colon) | 1 (2.6) | 0 | 0.494 |
L3 (ileocolon) | 26 (66.7) | 32 (80.0) | 0.180 |
L4 (upper GI) | 3 (7.7) | 6 (15.0) | 0.481 |
Behavior | |||
B1 (non stricturing) | 22 (56.4) | 21 (52.5) | 0.727 |
B2 (stricturing) | 6 (15.4) | 5 (12.5) | 0.711 |
B3 (penetrating) | 11 (28.2) | 14 (35.0) | 0.516 |
P (perianal disease) | 5 (12.8) | 17 (42.5) | 0.003 |
Value are presented as mean±SD or number (%).
VFA, visceral fat areas; SFA, subcutaneous fat areas; SMA, skeletal muscle areas; SMI, skeletal muscle index.
Correlations between SMI and Clinical Parameters
BMI | Height | Sex | Age | SFA | VFA | CRP | ESR | Hemoglobin | Albumin | Vitamin D | |
---|---|---|---|---|---|---|---|---|---|---|---|
SMI | 0.383 |
0.382 |
0.646 |
0.016 | 0.068 | 0.239 |
–0.201 | –0.320 |
0.271 |
0.350 |
0.053 |
BMI | 0.090 | 0.160 | 0.093 | 0.714 |
0.572 |
–0.093 | –0.145 | 0.265 |
0.240 |
0.017 | |
Height | 0.690 |
–0.113 | –0.116 | 0.126 | –0.005 | –0.237 |
0.274 |
0.346 |
–0.015 | ||
Sex | –0.075 | –0.192 | 0.127 | 0.026 | –0.327 |
0.327 |
0.301 |
–0.010 | |||
Age | 0.086 | 0.462 |
0.105 | –0.198 | 0.120 | –0.253 |
0.000 | ||||
SFA | 0.635 |
–0.163 | 0.003 | 0.137 | 0.166 | –0.023 | |||||
VFA | –0.034 | –0.117 | 0.342 |
0.192 | 0.082 | ||||||
CRP | 0.326 |
–0.047 | –0.378 |
–0.129 | |||||||
ESR | –0.351 |
–0.444 |
–0.273 |
||||||||
Hemoglobin | 0.411 |
0.116 | |||||||||
Albumin | 0.276 |
Correlation is significant at the 0.05 level (2-tailed).
Correlation is significant at the 0.01 level (2-tailed).
SMI, skeletal muscle index; SFA, subcutaneous fat areas; VFA, visceral fat areas.