Does Obesity Have an Effect on Patients With IBD Receiving Biologic Treatments?

Obesity is not associated with outcomes like hospitalization or serious infection in patients with IBD who receive biologics.

Obesity is not associated with hospitalization, surgical procedures, or serious infections among patients with inflammatory bowel disease (IBD) who were newly prescribed biologic therapy, according to a study in the American Journal of Gastroenterology.

Researchers developed a multicenter electronic health record (EHR)-based cohort of patients with IBD. The cohort included adult patients aged 18 years and older who were newly prescribed biologic agents (tumor necrosis factor [TNF]-α antagonists, vedolizumab, or ustekinumab), those who had a 1-year follow-up within the health system, and those whose weight and height were recorded within 3 months of initiation of a biologic agent.

The study participants were characterized as normal (body mass index [BMI] 18.5-24.9 kg/m2), overweight (BMI 25.0-29.9 kg/m2), or obese (BMI ≥30 kg/m2). The primary outcomes were risk for all-cause hospitalization and IBD-related abdomino-pelvic operations.

A total of 3038 patients with IBD (31.1% with ulcerative colitis [UC]) were included, of whom 1764 (mean age, 38 years; men, 46%) had normal BMI, 858 (mean age, 45 years; men, 61%) were overweight, and 416 (mean age, 47 years; men, 48%) were obese. A majority of participants were new users of TNF-α antagonists (76.3%).

Of the cohort, 22.9% of patients required hospitalization within 1 year of initiating new biologic therapy. Univariable analysis showed that the 1-year risk of all-cause hospitalization was comparable among patients who had a normal BMI (23.4%), those who were overweight (21.8%), and those with obesity (23.3%). According to Cox proportional hazard analysis, obesity (adjusted hazard ratio [aHR], 0.90; 95% CI, 0.72-1.13) and overweight status (aHR, 0.91; 95% CI, 0.76-1.08) were not associated with an increased risk for hospitalization vs normal BMI.

About 3.3% of patients required an operation within a year of beginning a new biologic agent. Univariable analysis demonstrated that the 1-year operative risk was comparable among patients with normal BMI (3.5%), those who were overweight (3.4%), and those with obesity (2.4%; P = .54). Cox proportional hazard analysis showed that obesity (aHR, 0.62; 95% CI, 0.31-1.22) and overweight status (aHR, 1.05; 95% CI, 0.67-1.65) were not associated with the risk for IBD-related operation vs normal BMI, after adjustment for demographic, clinical, and treatment characteristics.

Within 1 year of initiating use of a biologic agent, 5.8% of patients were hospitalized with a serious infection. Univariable analysis revealed that the 1-year risk for serious infections was comparable among patients with normal BMI (5.6%), those who were overweight (5.7%), and those with obesity (6.7%; P = .67). According to Cox proportional hazard analysis, obesity (aHR, 1.11; 95% CI, 0.73-1.71) and overweight status (aHR, 0.97; 95% CI, 0.69-1.37) were not associated with the risk for serious infections vs normal BMI, after adjustment for demographic, clinical, and treatment characteristics.

The findings were comparable in stratified analysis according to Crohn disease vs UC and TNF-α antagonists vs non-TNF-α antagonists.

Study limitations include an inability to obtain detailed disease characteristics, including disease distribution, behavior, duration, and clinical and endoscopic disease activity indexes, which may be important confounders. Also, the analysis was based on medication prescription data, and BMI was used to reflect obesity.

“Our data provide reassuring evidence that obesity does not negatively modify patients’ clinical course and obesity does not increase risk of infections with biologics, suggesting early aggressive immunosuppressive therapy can be safely used if necessary,” the researchers commented.

Disclosure: Some of the study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.

References:

Gu P, Luo J, Kim J, et al. Effect of obesity on risk of hospitalization, surgery, and serious infection in biologic-treated patients with inflammatory bowel diseases: a CA-IBD cohort study. Am J Gastroenterol. 2022;117(10):1639-1647. doi:10.14309/ajg.000000000000185