Impact of Inflammatory Bowel Disease on Growth in Children

Source: De Freitas MB, Poulsen GJ, Jess T, et al. Anthropometric trajectories in children prior to development of inflammatory bowel disease. JAMA Netw Open. 2025;8(1):e2455158; doi: 10.1001/jamanetworkopen.2024.55158.Investigators from Aalborg University, Copenhagen, Denmark, conducted a retrospective cohort study to assess growth trajectories in the years before and after a diagnosis of inflammatory bowel disease (IBD) in children. For the study, they reviewed data in the Danish National Child Health Register (DNCHR), which includes birth and childhood anthropometric measurements on Danish children. Other national registries were used to identify a cohort of patients, born between 1997 and 2015, who were diagnosed with IBD between the ages of 5–18 years. The cohort was subdivided into groups diagnosed with Crohn’s disease (CD) and ulcerative colitis (UC). Children without accurate measurements at birth, school entrance, and/or other ages were excluded. Danish growth charts and a random sample of anthropometric measurements from 100,000 children born during the same period were used to develop normative growth data for height, weight, and BMI by age and sex. Growth parameters for patients in the IBD cohort during the 10 years prior and 3 years after diagnosis were mapped onto these growth curves and z-scores for weight, height, and BMI calculated. Altered growth among those with IBD was assessed by identifying point-estimated z-scores for each parameter for which the 95% confidence interval [CI] did not include 0.Among a population of 916,133 children with valid growth data, 1,522 diagnosed with IBD were identified, including 851 (55.9%) with CD and 671 (44.1%) with UC. The mean age of diagnosis for those in the IBD cohort was 14.3 years. Overall, changes in weight gain were noted up to 4 years before diagnosis of IBD, with a mean weight z-score of -0.07 g (95% CI, -0.13, -0.01). A significant decrease in height was not noted until 1 year prior to diagnosis (mean, -0.14 cm; 95% CI, -0.20, -0.07), and significant alteration in BMI was observed starting 3 years prior to diagnosis (mean, -0.27; 95% CI, -0.34, -0.20). Much of the altered growth among children in the IBD cohort was due to changes among those with CD. In patients diagnosed with CD, significant impairment in weight was seen 3 years prior to diagnosis, height 1 year prior to diagnosis, and BMI 3 years before diagnosis. For those with UC, significant changes in weight and BMI were seen only in the final year before diagnosis. After diagnosis, growth impairment persisted for up to 3 years in those with CD and 1 year in patients with UC. Growth impairment recurred in those with UC beginning 3 years after diagnosis.The authors conclude that impaired nutritional status is apparent up to 3–4 years prior to diagnosis of IBD in children.Dr Doolittle has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device.The current study results heighten practitioner awareness of the diagnosis of IBD among children based on anthropometric data. Using a large database, the current investigators demonstrated that several growth parameters, such as weight gain, height, and BMI, were statistically lower than average. The particular strength of this study is that it demonstrates subtle growth changes even several years prior to diagnosis. The implication of the study results is that practitioners need to consider more aggressive investigation in the setting of lower growth parameters.While the current study results are helpful, the differential diagnosis of decreased anthropometric trajectories is broad and includes much more common diagnoses, such as eating disorders and depression. The prevalence of eating disorders among women is 5.5% to 17.9%; the prevalence of adolescent depression is 8% and dysthymia 4%.1,2 By contrast, the prevalence of IBD is 84.3 per 100,000.3 Even celiac disease is much more common, with an estimated prevalence of 1%.4What is even more challenging is that the reported differences, while statistically significant, may not be clinically relevant. For example, changes in weight gain 4 years prior to diagnosis were -0.07g (95% CI, -0.13, -0.01). This is a subtle difference that likely would be overlooked by even the most vigilant of parents and practitioners. Perhaps the real takeaway from this study is that even subtle changes in weight and growth should prompt more detailed history taking. Is the child depressed? Is the child having adequate calorie intake? If yes, then the practitioner may pursue a more involved evaluation.A decrease in growth parameters is evident among children with IBD, even several years prior to diagnosis. (See AAP Grand Rounds. 2022;48[6]:65.)5Perhaps the second study “takeaway” is the importance of continued nutritional and anthropometric monitoring after the diagnosis and treatment of IBD in children. The effect of medical therapy on growth, in fact, was not ascertained in the current study.