Objective: We investigated circulating markers of bone turnover before and during systemic glucocorticoid treatment in paediatric patients with inflammatory bowel disease (IBD).
Methods: Twenty-two children (mean age, 12.3 years) with IBD necessitating peroral steroid therapy were studied, with special reference to bone formation and resorption markers amino-terminal type I collagen propeptide (PINP) and carboxyterminal telopeptide of type I collagen (ICTP) respectively. In addition, GH-related IGF-I and sex hormone-binding protein (SHBG) were measured. Bone markers were analyzed at the initiation of the glucocorticoid treatment, at 2 and 5 weeks thereafter and at 1 month following the withdrawal of the steroid. Control group comprised 22 IBD patients in remission.
Results: PINP and IGF-I were already lower before glucocorticoid treatment serum in children with active IBD as compared with control children with IBD in remission (median PINP 271 vs 535 microg/l, P<0.05; IGF-I 23 vs 29 nmol/l, P<0.05). After 2 weeks of glucocorticoid treatment serum PINP levels had declined further, from 271 to 163 microg/l (P<0.001), serum ICTP from 14.2 to 9.6 microg/l (P<0.001), and SHBG from 54 to 35 nmol/l (P<0.001) respectively. By contrast, serum IGF-I increased from 23 to 37 nmol/l (P<0.001). One month after the withdrawal of the glucocorticoid, all bone markers restored to levels similar to the controls.
Conclusions: Bone formation in children with active IBD appears compromised and systemic glucocorticoid treatment further suppresses bone turnover. After the cessation of the glucocorticoid the bone markers show immediate improvement.