Age-related Trajectory of Bone Density in Children with Intestinal Failure: A Longitudinal Retrospective Cohort Study

Background: Longitudinal changes in bone health in children with intestinal failure (IF) are unclear. We aimed to better understand the trajectory of bone mineral status over time in children with IF and identify clinical factors that influence the trajectory.

Methods: Clinical records of patients attending the Intestinal Rehabilitation Center of Cincinnati Children's Hospital Medical Center between 2012 and 2021 were reviewed. Children diagnosed with IF before age 3 years with at least two lumbar spine dual-energy x-ray absorptiometry scans were included. We abstracted information on medical history, parenteral nutrition, bone density, and growth. We calculated bone density z scores with and without adjustment for height z scores.

Results: Thirty-four children with IF met inclusion criteria. Children were shorter than average with a mean height z score of -1.5 ± 1.3. The mean bone density z score was -1.5 ± 1.3 with 25 of the cohort having a z score < -2.0. After height adjustment, the mean bone density z score was -0.42 ± 1.4 with 11% below -2.0. Most dual-energy x-ray absorptiometry scans (60%) had a feeding tube artifact. Bone density z scores increased slightly with age and lower parenteral nutrition dependency and were higher in scans without an artifact. Etiologies of IF, line infections, prematurity, and vitamin D status were not associated with height-adjusted bone density z scores.

Conclusion: Children with IF were shorter than expected for age. Deficits in bone mineral status were less common when adjusting for short stature. Etiologies of IF, prematurity, and vitamin D deficiency were not associated with bone density.