Biologic Agents Are Associated with Excessive Weight Gain in Children with Inflammatory Bowel Disease

Children with active inflammatory bowel disease (IBD) are frequently underweight. Anti-tumor necrosis factor (anti-TNF) agents may induce remission and restore growth. However, its use in other autoimmune diseases has been associated with excess weight gain. Our aim was to examine whether children with IBD could experience excess weight gain. A centralized diagnostic index identified pediatric IBD patients evaluated at our institution who received anti-TNF therapy for at least 1 year between August 1998 and December 2013. Anthropometric data were collected at time of anti-TNF initiation and annually. Excess weight gain was defined as Delta BMI SDS (standard deviation score) where patients were (1) reclassified from normal to overweight/obese, (2) overweight to obese, or (2) a final BMI SDS > 0 and Delta SDS > 0.5. During the study period, 268 children received anti-TNF therapy. Of these, 69 had sufficient follow-up for a median of 29.3 months. Median age at first anti-TNF dose was 12.8 years. At baseline, mean weight SDS was -0.7 (SD 1.4), while mean BMI SDS was -0.6 (1.3). Using baseline BMI SDS, 11.6% were overweight/obese. At last follow-up (LFU), however, the mean Delta BMI SDS was 0.50 (p < 0.0001). However, 10 (17%) patients had excess weight gain at LFU; 3 patients were reclassified from normal to obese, and 7 had a final BMI SDS > 0 and Delta SDS > 0.5. Pediatric patients with IBD may experience excess weight gain when treated with anti-TNF agents. Monitoring for this side effect is warranted.