LAS VEGAS – Higher body mass index among inflammatory bowel disease patients is independently associated with an increased risk of treatment failure and IBD-related surgery or hospitalization, a single-center, retrospective cohort study demonstrated.
“The problem of IBD and obesity is on the rise,” Soumya Kurnool said at the Crohn’s & Colitis Congress, a partnership of the Crohn’s & Colitis Foundation and the American Gastroenterological Association. “Today, 15%-40% of IBD patients are obese. This is significant because there is a decreased prevalence of remission and an increased risk of relapse in obese IBD patients. These patients also have a higher annual burden of hospitalization.”
She and her associates set out to evaluate the effect of obesity on response to biologic therapy in patients with ulcerative colitis (UC). They conducted a single-center, retrospective cohort study of biologic-treated adults with UC who started therapy during 2011-2016. The researchers excluded patients who had undergone a prior colectomy, as well as those who were underweight at the time of starting a biologic agent and those who had fewer than 6 months of follow-up data.
The primary outcome was time to treatment failure, defined as a composite of IBD-related surgery, hospitalization, and/or treatment modification. Secondary outcomes were time to IBD-related surgery and/or hospitalization and whether the patient achieved endoscopic remission within 1 year of starting biologic therapy. They conducted multivariate Cox proportional hazard analyses after adjusting for key confounders.
Ms. Kurnool reported results from 160 patients with a median age of 36 years. Half were male, and the mean follow-up was 24 months. The median BMI of the cohort was 24.3 kg/m2; 26% were overweight and 18% were obese. More than half of patients (55%) were on infliximab with weight-based dosing and 45% were on other fixed-dosing regimens, including 19% on vedolizumab. In terms of outcomes, 68% of patients experienced treatment failure. All who failed treatment underwent treatment modifications; 15% had IBD-related surgery, and 19% had IBD-related hospitalization.
After adjusting for age, sex, disease duration, prior hospitalization, prior anti-TNF therapy, steroid use, and albumin level, Ms. Kurnool and her associates found that every 1-kg/m2 increase in BMI was associated with a 4% higher risk of treatment failure (adjusted hazard ratio, 1.04), an 8% higher risk of surgery or hospitalization (adjusted HR, 1.08), and a 6% lower risk of achieving endoscopic remission (adjusted HR, 0.94).
“This increase in the risk of treatment failure and IBD-related surgery or hospitalization was consistent across strata of patients treated with infliximab and fixed-dosing regimens,” she said. “Based on these findings, physicians should consider proactive monitoring in obese patients treated with biologic agents.”
Ms. Kurnool reported having received a National Institutes of Health Short Term Training Grant from the University of California, San Diego.
*This story was updated on 3/26.
SOURCE: Kurnool S et al. Crohn’s & Colitis Congress, Clinical Abstract 24.