Biologic therapies are effective at inducing and maintaining remission in people with inflammatory bowel disease (IBD). Previous studies have associated TNF-a inhibitors with weight gain, however, it is unclear if this is a class-specific effect or a manifestation of good disease control. To clarify this issue, a retrospective study was undertaken to examine weight changes over time during therapy with different biologic agents.
Adult patients with IBD who received any biological therapy for at least 12 months, between 2008 and 2020, were identified at two specialised IBD services. Demographic, disease, and therapy-related data were examined. Weight change and patterns thereof were examined for each specific therapy and relationships amongst weight outcomes and various predictive factors explored.
Of 294 patients (156 females), 165 received Infliximab (IFX), 68 Adalimumab (ADA), 36 Vedolizumab (VDZ) and 25 Ustekinumab (UST). There was a statistically significant weight gain over time in the IFX and VDZ groups and more weight gain in the IFX vs ADA and VDZ vs ADA at most time points. Three weight trajectories were identified: around 95% of patients had small weight loss or a modest weight gain but 5% of patients, most of whom were on IFX had marked weight gain (24.3 kg). Having a baseline high BMI, being female, having an initiation CRP ≤ 5 or albumin > 35 reduced the odds of major weight gain.
Weight gain in biologic treated IBD patients appears to be associated with clinical factors (male gender, high CRP, low albumin) and therapy-specific factors.