The role of growth hormone and insulin-like growth factor-1 in Crohn's disease: implications for therapeutic use of human growth hormone in pediatric patients.

PURPOSE OF REVIEW: This review evaluates the role of the growth hormone (GH) and insulin-like growth factor (IGF) in influencing linear growth in pediatric Crohn's disease. It also examines the current evidence concerning the use of recombinant human growth hormone (rhGH) as a potential therapy in achieving optimal growth and inducing mucosal healing for pediatric Crohn's disease.

RECENT FINDINGS: Current treatment strategies for Crohn's disease including antitumor necrosis factor-α (TNF-α) therapy have been demonstrated to improve growth velocity, but linear growth deficits persist despite optimization of therapy. By complex mechanisms, including the reduction of levels of IGF-1 and induction of systemic and hepatic GH resistance, cytokines such as TNF-α and interleukin-6 (IL-6), commonly elevated in active Crohn's disease, are important as mediators of linear growth delay. Recent evidence suggests that rhGH therapy is effective in improving short-term linear growth for a selected group of patients but of limited benefit as a therapy for improving mucosal disease and reducing clinical disease activity.

SUMMARY: Crohn's disease interacts with the GH-IGF-1 axis in important ways. Recent studies evaluating rhGH use in pediatric Crohn's disease have demonstrated some efficacy in reversing persistent linear growth delay but limited benefits in terms of improving mucosal disease and clinical disease activity. Larger studies of adequate power are needed to confirm a true benefit in terms of growth, to examine a potential benefit with regard to modification of disease activity, and to evaluate long-term risks.