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

CT-based body composition parameters predict the loss of response to infliximab in patients with Crohn's disease

OBJECTIVE

Infliximab is a first-line biologic agent for the treatment of Crohn's disease (CD), in which loss of response (LOR) remains a challenge in the treatment of patients with CD. The study aimed to explore the association between body composition parameters and LOR to infliximab in CD patients.

METHODS

118 patients with CD admitted to the First Affiliated Hospital of Wenzhou Medical University and treated with infliximab from June 2015 to December 2021 were retrospectively enrolled. The body composition of patients was analyzed by computed tomography (CT). The primary outcome measure was the one-year LOR. Patients were divided into the Remission group and the LOR group to analyze the association between body composition parameters and the LOR to infliximab.

RESULTS

The rate of sarcopenia in the LOR group was higher than in the Remission group (83.7% vs. 60.0%, P=0.008). Multivariate analysis showed that females had a lower risk of sarcopenia than males (OR=0.30, 95% CI 0.11-0.81, P =0.017); BMI was significantly associated with sarcopenia (OR=0.68, 95% CI 0.56-0.83, P <0.001); L1 CD and L2 CD had a lower risk of sarcopenia than L3 CD (OR=0.29, 95% CI 0.10-0.83, P =0.021; OR=0.25, 95% CI 0.07-0.87, P=0.028).

CONCLUSIONS

Sarcopenia was identified as a risk factor for developing LOR in infliximab-treated patients.

A High Visceral-to-Skeletal Muscle Area Ratio on Cross-Sectional Imaging Is Associated With Failure of Standard Ustekinumab Doses: A Multicenter Study

INTRODUCTION

Anti-interleukin 12/23 agents have shown greater durability in response compared with anti-tumor necrosis factor α agents. Data on the association between body composition (BC) or body mass index (BMI) and ustekinumab's therapeutic response is limited. We aimed to evaluate the impact of BC on time to failing standard doses of ustekinumab in patients with Crohn's disease (CD).

METHOD

Patients with CD aged 16 years and older from 2 tertiary centers were studied retrospectively. Included patients had abdominal imaging within 6 months of ustekinumab induction and were followed until April 30, 2022. An experienced abdominal radiologist blinded to the clinical information measured the area of visceral fat area and skeletal muscle area at the mid L3 vertebral level, with values corrected for height 2 to derive respective indices (visceral fat index [VFI], skeletal muscle index [SMI]) and the VFI:SMI ratio.

RESULTS

Ninety-nine patients met inclusion criteria. The mean age at ustekinumab induction was 46.6 (±1.6) years. The median BMI (interquartile range) was 26.5 (22.6-30.8). Twenty-four patients (24.2%) did not respond or lost response to standard doses of ustekinumab over the follow-up duration. A younger age (hazard ratio 0.96, 95% confidence interval 0.94-0.99, P = 0.01) and a VFI:SMI ratio >1.6 (hazard ratio 4.65, 95% confidence interval 1.73-12.45, P = 0.002) were both associated with a shorter time to failing ustekinumab at standard doses on multivariate analysis. BMI, notably, had no association with the primary outcome.

DISCUSSION

A high VFI:SMI ratio is associated with an increased risk of failing standard doses of ustekinumab. BC measurements derived from cross-sectional imaging at the start of ustekinumab therapy is a useful indicator for therapeutic durability.

Visceral Adiposity Independently Predicts Time to Flare in Inflammatory Bowel Disease but Body Mass Index Does Not

BACKGROUND

Obesity is associated with progression of inflammatory bowel disease (IBD). Visceral adiposity may be a more meaningful measure of obesity compared with traditional measures such as body mass index (BMI). This study compared visceral adiposity vs BMI as predictors of time to IBD flare among patients with Crohn's disease and ulcerative colitis.

METHODS

This was a retrospective cohort study. IBD patients were included if they had a colonoscopy and computed tomography (CT) scan within a 30-day window of an IBD flare. They were followed for 6 months or until their next flare. The primary exposure was the ratio of visceral adipose tissue to subcutaneous adipose tissue (VAT:SAT) obtained from CT imaging. BMI was calculated at the time of index CT scan.

RESULTS

A total of 100 Crohn's disease and 100 ulcerative colitis patients were included. The median age was 43 (interquartile range, 31-58) years, 39% had disease duration of 10 years or more, and 14% had severe disease activity on endoscopic examination. Overall, 23% of the cohort flared with median time to flare 90 (interquartile range, 67-117) days. Higher VAT:SAT was associated with shorter time to IBD flare (hazard ratio of 4.8 for VAT:SAT ≥1.0 vs VAT:SAT ratio <1.0), whereas higher BMI was not associated with shorter time to flare (hazard ratio of 0.73 for BMI ≥25 kg/m2 vs BMI <25 kg/m2). The relationship between increased VAT:SAT and shorter time to flare appeared stronger for Crohn's than for ulcerative colitis.

CONCLUSIONS

Visceral adiposity was associated with decreased time to IBD flare, but BMI was not. Future studies could test whether interventions that decrease visceral adiposity will improve IBD disease activity.

Clinical importance of weight gain and associated factors in patients with moderate to severe ulcerative colitis: results from the MOSAIK cohort in Korea

BACKGROUND

Many patients with ulcerative colitis (UC) gain weight after treatment. However, the clinical significance of weight gain in these patients remains unclear. This study aimed to evaluate body weight changes after treatment in patients newly diagnosed with moderate-to-severe UC and their effects on patients' prognosis.

METHODS

The change in weight between diagnosis and 1 year after treatment in 212 patients enrolled in the MOSAIK cohort (mean age, 40 years; males, 60%) was analyzed. Significant weight gain was defined as a weight increase of ≥ 5% from the baseline at 1 year. Factors associated with significant weight gain and the effect of significant weight gain on the risk of major adverse outcomes (clinical relapse, hospitalization, and new use of steroids or biologics) during a follow-up period of 20 months were evaluated.

RESULTS

Mean weight gain at 1 year was 1.7 ± 4.2 kg. The proportion of overweight/obese patients increased by 9.0% from 37.9% to 46.9%. Thirty-two percent had significant weight gain; extensive colitis at diagnosis was the only factor associated with significant weight gain (odds ratio 6.5, 95% confidence interval 1.4-31.0, p = 0.006). In multivariable analysis, significant weight gain was not associated with the risk of major adverse outcomes. Weight loss symptoms at diagnosis were associated with an increased risk for new steroid use after 1 year.

CONCLUSIONS

Approximately one-third of patients with moderate-to-severe UC had significant weight gain after 1 year of treatment. However, significant weight gain was not associated with the patient's prognosis.

Patients With Inflammatory Bowel Diseases and Higher Visceral Adipose Tissue Burden May Benefit From Higher Infliximab Concentrations to Achieve Remission

INTRODUCTION

In patients with inflammatory bowel diseases (IBDs), high visceral adipose tissue (VAT) burden is associated with a lower response to infliximab, potentially through alterations in volume distribution and/or clearance. Differences in VAT may also explain the heterogeneity in target trough levels of infliximab associated with favorable outcomes. The aim of this study was to assess whether VAT burden may be associated with infliximab cutoffs associated with efficacy in patients with IBD.

METHODS

We conducted a prospective cross-sectional study of patients with IBD receiving maintenance infliximab therapy. We measured baseline body composition parameters (Lunar iDXA), disease activity, trough levels of infliximab, and biomarkers. The primary outcome was steroid-free deep remission. The secondary outcome was endoscopic remission within 8 weeks of infliximab level measurement.

RESULTS

Overall, 142 patients were enrolled. The optimal trough levels of infliximab cutoffs associated with steroid-free deep remission and endoscopic remission were 3.9 mcg/mL (Youden Index [J]: 0.52) for patients in the lowest 2 VAT % quartiles (<1.2%) while optimal infliximab level cutoffs associated with steroid-free deep remission for those patients in the highest 2 VAT % quartiles was 15.3 mcg/mL (J: 0.63). In a multivariable analysis, only VAT % and infliximab level remained independently associated with steroid-free deep remission (odds ratio per % of VAT: 0.3 [95% confidence interval: 0.17-0.64], P < 0.001 and odds ratio per μg/mL: 1.11 [95% confidence interval: 1.05-1.19], P < 0.001).

DISCUSSION

The results may suggest that patients with higher visceral adipose tissue burden may benefit from achieving higher infliximab levels to achieve remission.

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.

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.

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

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

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.

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

BACKGROUND AND AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Visceral Adipose Tissue Volumetrics Inform Odds of Treatment Response and Risk of Subsequent Surgery in IBD Patients Starting Antitumor Necrosis Factor Therapy

BACKGROUND

Data describing the effect of obesity on antitumor necrosis factor (anti-TNF) treatment response are inconsistent. Visceral adipose tissue (VAT) is a superior marker of adiposity to body mass index. However, its effect on treatment response is unclear. We aimed to evaluate the effect of VAT on anti-TNF treatment response.

METHODS

Inflammatory bowel disease (IBD) patients starting anti-TNF agents between January 1, 2009, and July 31, 2019, were included. 3-dimensional measurements of VAT volume and visceral fat index (visceral:subcutaneous adipose tissue ratio; VFI) were obtained from computed tomography (CT) scans. Subjects were categorized by predefined volume cutoffs (<1500cm3, 1500-2999cm3, ≥3000cm3) and VFI (<0.33, 0.33-0.66, ≥0.67). Primary outcomes included a composite treatment response end point at 6 and 12 months. Secondary outcomes were surgery at 6 and 12 months. Multivariable logistic regression was used to calculate adjusted odds ratio (aOR) and 95% confidence interval (CI).

RESULTS

The final cohort included 176 patients. No significant differences in treatment response at 6 months was observed. At 12 months, compared with volume <1500cm3, patients with volume 1500-2999cm3 had higher odds of response (aOR, 3.52; 95% CI, 1.16-10.71; P = .023), whereas volume ≥3000cm3 did not. Compared with VFI<0.33, VFI ≥0.67 had higher odds of surgery at 6 (aOR, 48.22; 95% CI, 4.73-491.57; P = .023) and 12 months (aOR, 20.94; 95% CI, 3.14-139.67; P = .004). Post hoc analysis suggested VAT may affect drug pharmacokinetics.

CONCLUSIONS

We found VAT volume is associated with anti-TNF treatment response in a nondose dependent manner, and VFI may inform risk of surgery after anti-TNF initiation. If confirmed by prospective studies, VAT volumetrics are potentially useful biomarkers to inform IBD treatment decisions.

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.

Impact of Obesity on Response to Biologic Therapies in Patients with Inflammatory Bowel Diseases

Approximately 20-40% of patients with inflammatory bowel disease (IBD) are obese. Obesity is associated with inferior outcomes in patients with IBD, with lower rates of achieving remission, poor quality of life, and higher burden of unplanned healthcare utilization. Multiple cohort studies in patients with immune-mediated inflammatory diseases, including IBD, treated with biologic agents like tumor necrosis factor-α antagonists have suggested that obesity is associated with inferior response to biologic therapy. This may be related to the negative impact of obesity on the pharmacokinetics of biologic agents. Pharmacokinetic studies of multiple biologic agents have demonstrated that high body weight is associated with more rapid clearance and a higher volume of distribution of biologic agents, which leads to low trough concentrations. Randomized trials in patients with psoriasis and psoriatic arthritis treated with biologic agents suggest that diet- or lifestyle-induced weight loss is associated with improved response to therapy. This provides an opportunity to explore intentional weight loss as adjunctive therapy in obese patients with IBD. However, diet and lifestyle interventions for weight loss are hard to implement in patients with IBD; hence, long-term therapy with weight-loss agents (such as with phentermine-topiramate, naltrexone-bupropion) is attractive as adjunctive therapy in obese patients with IBD.

Bioelectrical impedance analysis-based nomogram construction for predicting secondary loss of response to infliximab in bio-naïve Crohn's disease patients

BACKGROUND

Infliximab is emerging as the first-line therapy for Crohn's disease (CD); however, the rate of secondary loss of response (SLR) can exceed 50%. This study aimed to construct a nomogram based on bioelectrical impedance analysis (BIA) indexes and laboratory markers to predict SLR to infliximab in biologically naïve CD patients.

METHODS

Data of 136 biologically naïve CD patients treated between September 2019 and March 2021 were retrospectively retrieved. BIA-based body composition parameters and laboratory markers were obtained before the infliximab therapy. Predictor selection was conducted using the least absolute shrinkage and selection operator (LASSO) and univariate logistic regression. The nomogram was developed using multivariable logistic regression, and internal validation was made by ten-fold cross-validation.

RESULTS

SLR occurred in 51% of the CD patients during 54 weeks. The nomogram predictors included hemoglobin, albumin, serum iron, and BIA scores. The nomogram showed significant discrimination (area under the curve [AUC], 0.920; 95% confidence interval, 0.873-0.967) and calibration (mean error = 0.012). Decision curve analysis (DCA) indicated that the nomogram provided net clinical benefit when the risk probability was between 2% and 83%. Internal validation assessment of the nomogram robustness found an AUC of 0.904 and an accuracy of 0.841.

CONCLUSIONS

This BIA-based body composition parameters- and laboratory markers-based novel nomogram could act as a predictive tool to evaluate SLR to infliximab therapy, crucial for optimizing treatment strategies and switching biologics in CD.

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.