Issue 14

Clinical Question

Does obesity affect the likelihood of experiencing clinical remission, response or mucosal healing with infliximab (IFX) treatment?

Editor’s Bottom Line

Obesity does not appear to affect response to anti-TNF therapy in patients with IBD.

Reference

Singh S, Proudfoot J, Xu R and Sandborn WJ. Obesity and Response to Infliximab in Patients with Inflammatory Bowel Diseases: Pooled Analysis of Individual Participant Data from Clinical Trials.  Am J Gastroenterol. 2018;113:883–89. https://doi.org/10.1038/s41395-018-0104-x

Synopsis

Obesity has been associated with greater disease severity among the 10–15% of IBD patients with comorbid obesity. Additionally, observational studies have suggested that obesity can reduce response to therapies including anti-tumor necrosis factor-α (TNF) agents, in patients with rheumatic diseases, but similar studies have yielded inconsistent findings in patients with IBD. In this study, researchers conducted a pooled data analysis using information from 1,205 adults with IBD who participated in four pivotal clinical trials of IFX for IBD (ACCENT-I, SONIC, ACT-1, and ACT-2). Two studies included Crohn’s disease patients and two included ulcerative colitis patients. Researchers considered subjects with a body mass index (BMI) of 30 kg/m2 or greater as obese.

The primary outcome was clinical remission, defined as a Crohn’s disease activity index (CDAI) <150 or Mayo Score <3 at the time that endpoint was measured in the original studies. The authors also compared rates of clinical response and mucosal healing, and conducted multivariable logistic regression analyses controlling for sex, smoking status, disease activity, and concomitant prednisone and immunomodulator use.

Among all subjects, 14% were obese and the median BMI was 23.5 kg/m2 (range: 13–49.2). Approximately 32% were receiving concomitant steroids and 46% were receiving immunomodulators. Patients in the highest BMI quartile tended to be older, were more likely to be male, and had lower baseline disease activity scores. They were also more likely to receive concomitant prednisone.

Pooled analyses showed obese and non-obese patients were equally likely to experience clinical remission (54.4% and 55%, respectively). The likelihood of a clinical response was also similar for the highest vs. lowest BMI quartiles (adjusted odds ratio [aOR]: 0.84 [0.52–1.35]; P=0.45) as was the likelihood of mucosal healing (aOR: 1.13 [0.55–2.34]; P=0.95). Adjusting for potential confounding variables and for disease type and study design did not impact this relationship.

Details

Study Design: Pooled analysis of randomized controlled trials
Funding: American College of Gastroenterology, Crohn’s and Colitis Foundation, and National Institutes of Health.
Allocation: Randomized
Setting: Multicenter trial
Level of Evidence: 1a (Oxford Levels of Evidence)

The summary and conclusion in this issue of E-mentoring in IBD pertains to the manuscript(s) being reviewed, and should be considered in the context of what is already known surrounding the topic and incorporated into practice as deemed appropriate by the individual learner.