The impact of age, disease severity, and BMI on bone health and growth in children and young people with Crohn's disease

The objective of this study was to explore the correlation between paediatric Crohn's disease (CD) characteristics, bone health and growth parameters at diagnosis and follow‐up.Retrospective data was collected for 47 children aged 4–16 who were newly diagnosed with CD between January 2018 and December 2019. Mean follow‐up time was 2.5 years.Eleven (24%) children had growth delay at diagnosis, which persisted in 4 (44%) of 9 recorded children at follow‐up. Of the 35 children tested, 20 (57%) had inadequate Vitamin D levels (<50 mmol/L) at diagnosis. Thirty‐seven (79%) children had a dual‐energy X‐ray absorptiometry scan at diagnosis, with 20 of them having at least 1 low Z‐score. Children with poorer bone mineral density and bone mineral concentration Z‐scores for age had a younger age at diagnosis (p = .042 and p = .021), more severe disease (p = .04 and p = .029) and a lower BMI (p < .001) at diagnosis. Children diagnosed with CD ≥11 years had a lower‐than‐expected height velocity (p < .0001 and p < .001). Multivariate regression analysis demonstrated an older age of diagnosis was a significant predictor of a lower height velocity at follow‐up.Disease severity and age of diagnosis are important CD‐related factors that influence bone health and growth. Vitamin D is an accessible component that if optimised can improve all three factors. Monitoring and optimising each aspect systematically has the potential to enable children to achieve their bone health and growth potentials.