Infliximab does not contribute to long-term weight gain in IBD patients

Treatment with infliximab does not lead to a general long-term weight gain in patients with inflammatory bowel disease (IBD), claims a study.

“Weight gain among patients treated with antitumour necrosis factor-alpha (anti-TNF-α) therapies is unlikely to be due to an effect from anti-TNF-α therapy,” the researchers said.

“Although previous studies report unintended weight gain as a concerning problem with anti-TNF-α medications, we cannot confirm these results,” they added.

Patients who initiated therapy with infliximab were enrolled in this nationwide observational study utilizing Danish national health registries. The researchers followed changes in weight during induction therapy (0‒90 days) and maintenance therapy (91‒270 days). A multilevel mixed-effects linear regression model was used to analyse the association between infliximab use and weight gain.

A total of 851 patients with Crohn’s disease (CD) and ulcerative colitis (UC) who initiated infliximab therapy were included. Most of them did not gain weight in the long term while on maintenance therapy. [Am J Gastroenterol 2022;117:777-784]

Women with CD who were underweight at the start of treatment had an average weight gain of 7.5 kg. Men and women with CD and UC with normal or increased body mass index gained an average weight of <2 kg during maintenance therapy.

Moreover, underweight men with CD and UC had a weight gain of 2.9 kg (95 percent confidence interval [CI], 2.1‒3.6) and 2.9 kg (95 percent CI, 1.9‒3.9), respectively, in the first 90 days. However, neither of these groups had statistically significant weight gain during the maintenance period. Notably, <3 percent of patients gained weight >10 percent of their baseline body weight during the study period.

“Among the IBD population, it has been previously hypothesized that weight gain on anti-TNF-α therapy may be multifactorial, with a component of weight gain from the medication itself, in addition to improved nutritional status as the medication heals the gastrointestinal tract and patients are able to both consume more calories and better absorb nutrients,” the researchers said.

“Our findings, however, do not suggest that infliximab contributes to long-term weight gain,” they added.

Information regarding weight change on anti-TNF-α therapy among patients with IBD are limited. A post hoc analysis of the ACCENT I, ACCENT II, ACT I, and SONIC trials revealed several factors associated with weight gain, including race, elevated C-reactive protein, dose, low haematocrit and albumin, and sex. [Inflamm Bowel Dis 2020;26:125-131]

Of note, the findings of the present study contradicted those of smaller studies of patients with other autoimmune conditions, which showed an increase in weight on anti-TNF-α therapy compared with nonanti-TNF-α therapy. [Clin Rheumatol 2008;27:795-797; Arthritis Res Ther 2010;12:R197; Dermatol Ther 2011;24:446-451]

“Although additional studies with larger cohorts of patients are recommended, including those with patients on other anti-TNF-α medications and other biologics, these data are reassuring that anti-TNF-α therapies do not cause significant weight gain with long-term administration,” the researchers said.