To Örebro University

Background: Growth retardation is well described in childhood-onset inflammatory bowel disease (IBD).

Aims: To study if childhood-onset IBD is associated with reduced final adult height.

Methods: We identified 4201 individuals diagnosed with childhood-onset IBD 1990-2014 (Crohn's disease: n = 1640; ulcerative colitis: n = 2201 and IBD-unclassified = 360) in the Swedish National Patient Register.

Results: Patients with IBD attained a lower adult height compared to reference individuals (adjusted mean height difference [AMHD] -0.9 cm [95% CI -1.1 to -0.7]) and to their healthy siblings (AMHD -0.8 cm [-1.0 to -0.6]). Patients with Crohn's disease (CD) were slightly shorter than patients with ulcerative colitis (UC; -1.3 cm vs -0.6 cm). Lower adult height was more often seen in patients with pre-pubertal disease onset (AMHD -1.6 cm [-2.0 to -1.2]), and in patients with a more severe disease course (AMHD -1.9 cm, [-2.4 to -1.4]). Some 5.0% of CD and 4.3% of UC patients were classified as growth retarded vs 2.5% of matched reference individuals (OR 2.42 [95% CI 1.85-3.17] and 1.74 [1.36-2.22] respectively).

Conclusion: Patients with childhood-onset IBD on average attain a slightly lower adult height than their healthy peers. Adult height was more reduced in patients with pre-pubertal onset of disease and in those with a more severe disease course.