Biologic Agents Are Associated with Excessive Weight Gain in Children with Inflammatory Bowel Disease

Trajectory of body mass index and obesity in children with Crohn's disease compared to healthy children

BACKGROUND

There is increasing recognition that children with Crohn's Disease (CD) can develop obesity.

METHODS

Using the RISK Study, an inception cohort of pediatric CD participants, and Bone Mineral Density in Childhood Study (BMDCS), a longitudinal cohort of healthy children, multivariable linear mixed effects, generalized linear mixed effects, and logistic regression models were used to evaluate factors associated with change in body mass index z-score (BMIZ), obesity, and excessive weight gain, respectively.

RESULTS

1029 CD participants (625 exposed to antitumor necrosis factor (anti-TNF) therapy) and 1880 healthy children were included. Change in BMIZ was higher in CD exposed to anti-TNF as compared to CD unexposed to anti-TNF and the healthy reference group. Sex, age, baseline BMIZ, C-reactive protein, anti-TNF, and steroids were associated with changes in BMIZ in CD. CD exposed (odds ratio [OR] 4.81, confidence interval [CI] 4.00-5.78) and unexposed (OR 3.14, CI 2.62-3.76) had a greater likelihood of becoming obese versus the healthy reference group. While the prevalence of obesity was higher at baseline in the healthy reference group (21.3%) versus CD participants (8.5% exposed vs. 11.1% unexposed), rates of obesity were similar by the end of follow-up (21.4% healthy vs. 20.3% exposed vs. 22.5% unexposed). Anti-TNF therapy was an independent risk factor for the development of obesity and excessive weight gain in CD participants.

CONCLUSIONS

Patients with CD have dynamic changes in BMIZ over time, and while for most, this is restorative, for some, this can lead to obesity and excessive weight gain. It is important to understand the factors that may lead to these changes, including anti-TNF therapy. Counseling of patients and early lifestyle intervention may be necessary.

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.

Metabolic Dysfunction-Associated Fatty Liver Disease in Taiwanese Patients with Inflammatory Bowel Disease: A Study in Patients with Clinical Remission

The prevalence of inflammatory bowel disease (IBD) has increased worldwide. The prevalence of metabolic dysfunction associated fatty liver disease (MAFLD) has also risen. However, there is limited research on the connection between MAFLD and IBD in the Asian population. This study aims to analyze the prevalence and clinical significance of MAFLD in Taiwanese IBD patients with clinical remission. We retrospectively analyzed IBD patients who received transient elastography for liver fibrosis and controlled attenuation parameter evaluation for liver steatosis. This study enrolled 120 patients with IBD, including 45 Crohn's disease (CD) and 75 ulcerative colitis (UC). MAFLD prevalence in IBD was 29.2%. Patients with MAFLD had a shorter disease duration (2.8 years vs. 5.3 years, p = 0.017), higher alanine aminotransferase levels (24 U/L vs. 17 U/L, p = 0.003), a lower estimated glomerular filtration rate (91.37 mL/min/1.73 m2 vs. 103.92 mL/min/1.73 m2, p = 0.004), and higher γ-glutamyl transferase (γ-GT) (24 mg/dL vs. 13 mg/dL, p < 0.001). The prevalence of significant fibrosis in IBD with MAFLD was 17.1%. Significant fibrosis was found in older age (58.5 years vs. 40 years, p = 0.004) and the high type 2 diabetes mellitus proportion (50.0% vs. 10.3%, p = 0.049). A trend of longer disease duration was found in significant fibrosis (4.9 years vs. 1.6 years, p = 0.051). The prevalence of MALFD in IBD was 29.2%. and 17.1% of them had significant fibrosis. In addition to the intestinal manifestation, the study findings remind clinicians that they should be aware of the possibility of hepatic complications for IBD patients.

Compound heterozygous variants in OTULIN are associated with fulminant atypical late-onset ORAS

Autoinflammatory diseases are a heterogenous group of disorders defined by fever and systemic inflammation suggesting involvement of genes regulating innate immune responses. Patients with homozygous loss-of-function variants in the OTU-deubiquitinase OTULIN suffer from neonatal-onset OTULIN-related autoinflammatory syndrome (ORAS) characterized by fever, panniculitis, diarrhea, and arthritis. Here, we describe an atypical form of ORAS with distinct clinical manifestation of the disease caused by two new compound heterozygous variants (c.258G>A (p.M86I)/c.500G>C (p.W167S)) in the OTULIN gene in a 7-year-old affected by a life-threatening autoinflammatory episode with sterile abscess formation. On the molecular level, we find binding of OTULIN to linear ubiquitin to be compromised by both variants; however, protein stability and catalytic activity is most affected by OTULIN variant p.W167S. These molecular changes together lead to increased levels of linear ubiquitin linkages in patient-derived cells triggering the disease. Our data indicate that the spectrum of ORAS patients is more diverse than previously thought and, thus, supposedly asymptomatic individuals might also be affected. Based on our results, we propose to subdivide the ORAS into classical and atypical entities.

Nonalcoholic Fatty Liver Disease Is Common in IBD Patients However Progression to Hepatic Fibrosis by Noninvasive Markers Is Rare

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disorder in western countries and an increasing cause of end-stage liver disease and hepatocellular carcinoma. NAFLD is known to coexist in patients with inflammatory bowel disease (IBD). This study aims to examine the prevalence of NAFLD, as well as trends in NAFLD-associated fibrosis, in a well-characterized IBD cohort utilizing a validated noninvasive test.

METHODS

We conducted a single-center retrospective chart review of patients at a large academic IBD center between 2007 and 2017. Patients with IBD and concurrent hepatic steatosis were identified. Charts were reviewed for baseline characteristics and laboratory data in order to calculate and trend NAFLD progression over time by a noninvasive marker, the NAFLD fibrosis score (NFS).

RESULTS

Of 207 patients with IBD and concurrent NAFLD, NFS was able to be calculated for 138 patients at index diagnosis. A subsequent NFS was able to be calculated at 5-year follow-up for 56 patients. Over 5 years, 9 patients (16%) had worsening in NFS category, 4 patients (7%) had improvement in NFS category, and the remaining 43 patients (77%) stayed within their index NFS category.

CONCLUSIONS

IBD patients with NAFLD tend to have stable liver disease over 4-6 years, and the risk of liver disease progression is low. This is the first study to document the progression of NAFLD by noninvasive testing over time.

The impact of anti-TNFα agents on weight-related changes: new insights from a real-world pharmacovigilance study using the FDA adverse event reporting system (FAERS) database

INTRODUCTION

Studies in patients with immune-mediated inflammatory diseases (IMIDs) have inconsistently suggested that anti-TNFα therapy may be associated with excessive weight gain.

AREAS COVERED

We performed a nested case/non-case analysis to investigate the anti-TNF-α inhibitor-associated body-changes in the US Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) database. The risk was expressed as a measure of disproportionality using the reporting odds ratio (ROR) while adjusting for sex, drugs known to cause weight gain and reporter type. We also performed a time-to-onset (TTO) analysis of body weight-related events.

RESULTS

Infliximab was the most commonly involved TNF-α inhibitor in body weight-related changes, reaching an aROR of 1.42 (95%CI:1. 26; 1.59). An increased risk was especially found in patients affected by rheumatic disorders, both in the adult and pediatric population. The median TTO after the start of anti- TNFα therapy was about 6-7 months for both children and adults.

CONCLUSIONS

Given the potential effect of these agents on the excess weight gain in IMIDs patients, continuous attention for this side effect with appropriate counseling regarding lifestyle modifications are warranted, especially in those at high risk for obesity.

Body composition profile of children and adolescent patients with inflammatory bowel disease

BACKGROUND AND AIMS

Children with inflammatory bowel disease (IBD) generally show an alteration in their fat and soft tissue mass contents. These alterations may influence disease severity and increase the risk of post-operative complications.

METHODS

This is a retrospective cross-sectional study of patients with IBD, diagnosed and followed up between 2013 and 2018, in Jeddah, Saudi Arabia, who had dual-energy x-ray absorptiometry (DXA) scans for bone density evaluation. Obesity was defined based on fat mass index (FMI) and myopenia based on appendicular skeletal muscle mass (SMMa).

RESULTS

This study incorporated 95 child and adolescent patients (52% female) with IBD: 59 with Crohn's disease (CD) and 36 with ulcerative colitis (UC), mean age 11.8 ± 3.3 years and mean duration of illness 1.8 ± 1.9 years. The most common disease phenotype and behaviour for CD patients were ileocolonic (57.6%) and non-stricturing and non-penetrating (76.3%). Of UC patients, 75% had extensive disease (pancolitis). Body composition profile in the total IBD cohort was classified as normal in 49.5%, obese in 26.3%, myopenic in 23.2% and myopenic-obese in 1.1%. The use of biological therapy was identified as a negative predictor for both obesity (OR = 7.0, 95% CI: 1.3-37.9, P = .02) and myopenia (OR = 0.11, 95% CI:0.02-0.47, P = .003), and female gender was shown to predict myopenia (OR = 3.5, 95% CI: 1.0-11.8, P = .04).

CONCLUSIONS

Saudi Arabian children with IBD showed comparable body composition profiles to adult patients with IBD. Biological therapy was associated with a decreased incidence of both obesity and myopenia, and female gender was found to predict myopenia.

Changes in Anthropometric Parameters After Anti-TNFα Therapy in Inflammatory Bowel Disease: A Systematic Review and Meta-analysis

Background

Tumour necrosis factor (TNF)-α inhibitors have been widely used for the treatment of moderate-to-severe inflammatory bowel disease (IBD). TNFα also plays an important role in the regulation of weight homeostasis and metabolism and has been linked to variations in anthropometric responses. This relationship in patients with IBD has yet to be determined.

Objectives

Our objective was to evaluate the effects of TNFα inhibitors on changes in anthropometric measures in both adults and children with IBD through a systematic review and meta-analysis.

Methods

Multiple database searches identified studies involving children and adults with IBD and treated with TNFα inhibitors and reporting at least one primary outcome measure. Where possible, data were combined for meta-analysis. The primary outcomes included weight, body mass index (BMI), waist circumference, height, height/velocity, and fat and lean mass. Secondary outcomes included surrogate markers of disease activity. A random-effects model was used to estimate the standardised mean difference (SMD).

Results

In total, 23 cohort studies (total 1167 participants) met the inclusion criteria. Meta-analysis was performed on 13 of these studies. In children, 6–29.3 months of anti-TNFα therapy had a small but statistically significant effect on weight (SMD 0.31; 95% confidence interval [CI] 0.12–0.49; P = 0.001) with a mean gain in z score of 0.30 (standard error [SE] 0.12). In adults, 2–22.4 months of treatment had a moderate effect on BMI (SMD 0.72; 95% CI 0.17–1.26; P = 0.010; mean gain 1.23 kg/m²; SE 0.21). A small but statistically significant increase in BMI z score was found in children (SMD 0.28; 95% CI 0.03–0.53; P = 0.026; mean change 0.31 ± standard deviation [SD] 0.14) after 12–29.3 months of therapy. A meta-analysis of four studies found a negligible but statistically significant increase in height (SMD 0.16; 95% CI 0.06–0.26; P = 0.002; mean change 0.17 z score [SE 0.05]). A negligible effect on fat mass (SMD 0.24; 95% CI −0.19–0.66; P = 0.272) was found in a meta-analysis of five studies. Of note, despite the high heterogeneity among the studies that addressed the issue, these results were also consistently supported by findings from studies not included in the meta-analysis and reviewed in the systematic review. Unfortunately, a lack of data meant we were unable to perform moderator analysis on observed heterogeneity.

Conclusion

Anti-TNFα treatment appears to be associated with an increase in body weight, BMI, and other anthropometric parameters. Given the differing courses of IBD between children and adults, this association should be considered before initiating biologics for undernourished, overweight, and obese patients.

Registration: PROSPERO registration number CRD42020163079.

Electronic supplementary material

The online version of this article (10.1007/s40259-020-00444-9) contains supplementary material, which is available to authorized users.

Assessment of Body Weight Changes in Patients with Inflammatory Bowel Diseases Initiating Biologic Therapy: A Prospective Cohort Study

BACKGROUND

Prior studies have inconsistently suggested that biologic therapy may be associated with weight gain in inflammatory bowel disease patients (IBD). Our aim was to compare weight gain across different biologic therapy classes with distinct mechanisms of action.

METHODS

This prospective cohort study recruited patients with moderate to severe IBD initiating outpatient biologic therapy with anti-TNF (infliximab, adalimumab), vedolizumab, or ustekinumab. Weight measurements were performed at weeks 0, 14, 30, and 54. Changes in weight between baseline and each of the follow-up visits were modeled as a continuous variable, and multivariate regression assessed the independent effect of therapeutic class on this outcome.

RESULTS

Our study enrolled 269 patients (163 CD, 106 UC) initiating biologic therapy [99 anti-TNF (37%), 122 vedolizumab (45%), 48 ustekinumab (18%)]. From baseline, the weight significantly increased at week 14 with a mean of 0.36 kg (± 3.8 kg, p = 0.004) and continued to increase compared to baseline with 0.96 kg (± 3.9 kg, p < 0.001) and 1.29 kg (± 4.2 kg, p < 0.001) at week 30 and 54, respectively. On univariate and multivariable analysis, no significant differences between any of the biologic therapies for weight gain were seen at any time point (weight gain anti-TNF: 0.31 kg, 1.06 kg, 1.33 kg; VDZ: 0.30 kg, 0.83 kg, 1.10 kg; UST: 0.63 kg, 1.21 kg, 2.31 kg at wk 14, wk 30, and wk 54, respectively). None of the disease activity parameters showed any statistical association with weight gain.

CONCLUSION

There was no difference in weight gain among the different biologic therapeutic classes.

Rapid weight gain in infliximab treated Crohn's disease patients is sustained over time: real-life data over 12 months

BACKGROUND

Infliximab (IFX) is used in active Crohn's disease for induction and maintenance of remission. There are scanty data on weight gain in IBD-patients under anti-TNF treatment. We investigated changes in weight and blood chemistry in anti-TNF-naïve Crohn's disease patients during their first course of IFX.

METHODS

Retrospective analysis of 110 patients (77 men, 33 women) aged 34 years (range 14-73), 54 with luminal and 56 with fistulising disease, given at least 3 infusions of IFX (range 3-11). Data regarding body weight, height, C-reactive protein (CRP), haemoglobin and S-albumin at baseline, before the third infusion, at three months and at 12 months were collected.

RESULTS

At 6 weeks, 65 (59%) increased in weight, 73% and 76% at three and 12 months, respectively. There was an increase in median weight (1.7 kg, IQR = 3.1 kg) and BMI (0.5 kg/m², IQR = 1.2 kg/m²) at 6 weeks, which persisted at three and 12 months (all p < .001). There was no difference between men and women. Young patients, patients with underweight or fistulising disease increased most in weight. Disease activity assessed by PGA and SES-CD decreased at all time points (p < .05). Increases in weight and BMI correlated with an increase in serum albumin and a decrease in CRP.

CONCLUSION

Approximately 60% of Crohn's disease patients experience weight gain within the first six weeks of infliximab treatment. The weight increment correlates with improvements in inflammatory markers and disease activity. The causes of weight gain may be related to treatment induced metabolic changes and reduced inflammatory burden.

Weight gain in patients with severe atopic dermatitis treated with dupilumab: a cohort study

BACKGROUND

Dupilumab, targeting the interleukin-4α receptor and inhibiting the action of interleukin-4 and interleukin-13, was recently approved for treatment of moderate to severe atopic dermatitis. There is limited data on long-term effects and safety among patients with severe atopic dermatitis treated with dupilumab. Weight gain was observed among patients treated with dupilumab in our clinic. The aim was to describe weight change in a cohort study of patients with severe atopic dermatitis treated with dupilumab from baseline to follow-up after 12 months, and to analyze if weight change was associated with effect of treatment, reported appetite, and/or disturbed night sleep due to itching.

METHODS

All patients with atopic dermatitis receiving systemic treatment at the Unit of Dermatology, Karolinska University Hospital, have been registered and monitored consecutively since January 2017. This cohort constituted all patients who started treatment on dupilumab or methotrexate between 10 January 2017 and 30 June 2019 with at least 6 months of follow-up within the study period. The following variables were monitored at start of and during treatment: Eczema Severity Score Index, Patient-Oriented Eczema Measure, visual analogue scale for pruritus 10 cm, Montgomery-Åsberg Depression Rating Scale, Dermatology Life Quality Index, and weight. Data analyses were performed using two-sample Wilcoxon-Mann-Whitney rank-sum test, or the Wilcoxon matched-pairs sign-rank test with a p-value < 0.05 considered as statistically significant.

RESULTS

Patients treated with dupilumab (n = 12) gained weight (mean 6.1 kg, range [0.1-18.0], p = 0.002) after 1 year on treatment. The majority of patients showed a good response to treatment with dupilumab (n = 11); at follow-up at 6, 9, or 12 months, they reached EASI-90 (n = 6), EASI-75 (n = 4), or EASI-50 (n = 1). There was no significant association between weight gain and treatment response, reported appetite, or disturbed night-sleep due to itch. Patients treated with methotrexate showed no significant weight change (n = 8).

CONCLUSIONS

To our knowledge, this is the first report on a possible association between weight gain and dupilumab treatment; the extent of the association is yet to be seen, as is the mechanism behind this finding.

Impact of TNF-α Inhibitors on Body Weight and BMI: A Systematic Review and Meta-Analysis

Objective

The aim of this systematic review and meta-analysis of longitudinal studies was to ascertain to effects of TNF-α inhibitor therapy on body weight and BMI.

Methods

Three databases (PubMed, OVID, and EMBASE) were systematically searched from inception to August 2018. We identified prospective, retrospective, and randomized controlled studies in adults with immune-mediated inflammatory diseases treated with TNF-α inhibitors based on pre-specified inclusion criteria. A random-effects model was used to estimate standardised mean change (SMCC).

Results

Twenty-six longitudinal studies with a total of 1,245 participants were included in the meta-analysis. We found evidence for a small increase in body weight (SMCC = 0.24, p = .0006, 95% CI [0.10, 0.37]) and in BMI (SMCC = 0.26, p < .0001, 95% CI [0.13, 0.39]). On average, patients gained 0.90kg (SD = 5.13) under infliximab, 2.34kg (D = 5.65) under etanercept and 2.27kg (SD = 4.69) during treatment with adalimumab within the duration of the respective studies (4–104 weeks).

Conclusion

Our results yield further support the for the view that TNF-α inhibitors increase body weight and BMI as a potential side effect. Modulating cytokine signaling could be a future therapeutic mechanism to treat disorders associated with weight changes such as anorexia nervosa.

Understanding the Cause of Weight Gain in Patients With IBD on Anti-TNF Medications

This article investigates the factors that are associated with weight gain in patients on anti–tumor necrosis factor (anti-TNF) medications. What remains unanswered is whether remission of disease activity, the anti-TNF medications themselves, or both are responsible for abnormal weight gain in patients with inflammatory bowel disease.

Therapeutic Drug Monitoring and Outcome of Infliximab Therapy in Pediatric Onset Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) with pediatric onset has become more prevalent during past decades. Thus, the number of patients with moderate to severe disease subtype treated with antagonists to tumor necrosis factor alpha (TNFα) has concurrently risen. Most pediatric patients initially respond to these drugs but will need dose escalation during the first year of therapy. As pediatric data regarding therapeutic drug monitoring during therapy with TNFα-blocker adalimumab are sparse, this review focuses on the literature on therapeutic drug monitoring of infliximab and how it may guide management.

Gender Differences and Other Factors Associated with Weight Gain Following Initiation of Infliximab: A Post Hoc Analysis of Clinical Trials

BACKGROUND

In our clinical practice, women often report excess weight gain with infliximab (IFX) use. There are currently no studies investigating weight gain after antitumor necrosis factor therapy in patients with inflammatory bowel disease. The objective of this study was to evaluate the association of clinical factors, with a particular focus on sex and weight gain in patients with moderate to severe Crohn's disease (CD) or ulcerative colitis (UC) initiating IFX.

METHODS

Data was extracted from ACCENT I, ACCENT II, ACT 1, and SONIC; included patients received IFX for induction or maintenance of remission of CD or UC. Patients treated with azathioprine (IFX 0 mg/kg) were included as controls. Baseline demographics, clinical characteristics, and weight at each follow-up for the study duration were collected. In addition to descriptive statistics, adjusted mixed effects models were used to test the association between clinical variables and weight gain.

RESULTS

There were 1273 patients included for analysis; the majority was white (91%), with CD (81%), and half of patients (50%) were women. Upon univariate analysis, IFX dose, African American race, diagnosis of CD, elevated C-reactive protein, and low hematocrit and albumin were associated with weight gain (P < 0.001). Upon adjusted analysis, sex was significantly associated with weight gain (P = 0.009), with women experiencing a lower percentage increase from baseline weight than men (3.9% increase vs 4.3% increase).

CONCLUSIONS

When starting IFX, those with markers of severe disease and with a diagnosis of CD are likely to gain more weight. Adjusting for confounding variables, women actually gain less weight than men after IFX treatment, although this difference is not clinically relevant.

High body mass index is not associated with increased treatment failure in infliximab treated pediatric patients with inflammatory bowel disease

Background and Aim

While weight gain during infliximab therapy in inflammatory bowel disease (IBD) is common, there has been limited research evaluating its impact on infliximab efficacy.

Methods

Primary aims of this study were to determine the frequency of excess weight gain (body mass index [BMI] > 25 kg/m²) in children with IBD on maintenance infliximab and evaluate the impact on infliximab dosing, serum trough levels, and treatment failure. Secondary aims were to determine differences in weight gain, treatment characteristics, and clinical/biochemical variables between patients with therapeutic and subtherapeutic maintenance therapy trough levels. We performed a retrospective study of 253 pediatric IBD (75.1% Crohn's disease, 23.3% ulcerative colitis, 1.6% IBD-unclassified) patients on infliximab followed at BC Children's Hospital between January 2013 and January 2018.

Results

Median age at infliximab initiation was 13.9 years, median length of follow up was 56.9 months, and 55.7% were males; 10.3% of the cohort demonstrated excess weight gain (7.5% overweight, 2.8% obese). Average mg/kg dosing was not statistically different between groups (normal, overweight, and obese: 6.7, 6.4, and 6.7 mg/kg, respectively, P = 0.52). Median BMI of patients with therapeutic and subtherapeutic trough levels was similar at 19.9 kg/m² (interquartile range [IQR], 17.3-23.8) and 19.7 kg/m² (IQR, 17.4-21.9), respectively. BMI had no effect on secondary loss of response to infliximab, with no significant difference between normal and high BMI subgroups (13.4 vs. 16.7%, P = 0.9).

Conclusions

In a subgroup of pediatric IBD patients on maintenance infliximab, excess weight gain was not associated with higher weight-based dosing, lower serum trough levels, or increased risk of treatment failure.

Pediatric inflammatory bowel disease: continuous lessons for adult inflammatory bowel disease

PURPOSE OF REVIEW

Prospective and inception inflammatory bowel disease (IBD) cohorts offer excellent opportunities to develop risk stratification strategies, use relevant tissue to explore the biology of IBD progression, and study the natural history of IBD in the era of biological therapy. Adult IBD care can learn important lessons from recent pediatric IBD studies.

RECENT FINDINGS

A recent multicenter inception cohort of pediatric IBD patients examining genetic, serologic, and microbiome data at diagnosis has been able to create a model for prediction of disease complications, describe compositional changes in gut microbiota associated with disease severity, identify markers of intestinal fibrosis, and confirm how important early life environmental exposures affect disease severity and phenotype. Analysis of gene and protein expression in mucosal samples has been shown to offer both diagnostic information about differentiation of ulcerative colitis (UC) vs. crohn's disease as well as implications for treatment efficacy. Important developments in treatment of growth failure with antitumor necrosis factor therapy, the effect of oral medication noncompliance, and dietary IBD therapy are outlined.

SUMMARY

Pediatric IBD research has been focusing on better phenotyping at diagnosis, and development of molecular signatures of future disease behavior by using relevant intestinal tissue rather than blood. This has moved IBD from being a heterogeneous group of diseases with an unknown disease course to a better-defined condition in which patients are accurately risk stratified and treated based on individualized distinct biological and clinical information.

Does Obesity Influence the Risk of Clostridium difficile Infection Among Patients with Ulcerative Colitis?

BACKGROUND

Patients with ulcerative colitis (UC) are at an increased risk of Clostridium difficile infection (CDI) compared with the general population. Recent data suggest that obesity also increases the risk of CDI.

AIMS

To examine whether obesity influences the risk of CDI among patients with UC.

STUDY

We conducted a retrospective cross-sectional study of UC patients seen in gastroenterology clinic between January 1, 2014, and December 31, 2015. Records were reviewed for patients with the diagnosis of UC prior to 2014, and the first diagnosis of CDI between January 1, 2014, and December 31, 2015. Using body mass index (BMI), patients were classified into underweight (BMI < 18.5), normal weight (18.5 ≤ BMI < 25), overweight (25 ≤ BMI < 30), and obese (BMI ≥ 30). Age-adjusted and multivariate logistic regression was performed including gender, tobacco use, UC disease duration, medication exposure, and vitamin D deficiency.

RESULTS

Of the 636 patients with UC, 114 (18%) were obese, 232 (36%) overweight, 274 (43%) normal weight, and 16 (2.5%) underweight. Nineteen patients (3.0%) developed CDI during the study period. CDI risk was not associated with BMI (OR 0.90, 95% CI 0.79-1.02). Compared to normal weight patients, risk of CDI was not influenced by being obese (multivariate OR 0.63, 95% CI 0.15-2.58), overweight (multivariate OR 0.33, 95% CI 0.08-1.30), or underweight (multivariate OR 2.98, 95% CI 0.45-19.83). CDI was associated with ever use of TNF therapy (multivariate OR 6.09, 95% CI 2.07-17.93) but not vedolizumab (multivariate OR 0.76, 95% CI 0.08-7.36).

CONCLUSIONS

Obesity does not appear to be associated with the risk of C. difficile infection among patients with UC.