Pediatric intestinal failure: Predictors of metabolic bone disease.

PURPOSE: The purpose of this study was to identify risk factors for the development of metabolic bone disease (MBD) in pediatric intestinal failure (IF).

METHODS

A retrospective single-center study of 36 pediatric IF patients who were screened for MBD was performed. Bone mineral density (BMD) was measured using dual-energy X-ray absorptiometry (DXA). Simple regression analysis was initially performed to screen predictors, followed by multivariate step-wise linear regression analysis to identify risk factors of MBD.

RESULTS

Mean lumbar spine BMD Z-score was -1.16 ± 1.32, and 50.0% of patients had a BMD Z-score less than -1.0. Deficiency of 25-hydroxyvitamin-D (25-OHD <30 ng/ml) was present in the 63.8% of patients, while 25.0% had hyperparathyroidism (intact parathyroid hormone (PTH)>55 pg/ml). Seven patients (19.4%) had bone pain, of which 4 (11.1%) suffered a pathologic fracture. Using multivariate analysis, parenteral nutrition (PN) duration predicted decreased BMD (B=-0.132, p=0.006). Serum 25-OHD nonsignificantly correlated with BMD Z-score (B=0.024, p=0.092). Interestingly, repeat DXA after increasing vitamin D supplementation showed no improvement in BMD Z-score (-1.18 ± 1.49 vs -1.36 ± 1.47, p=0.199).

CONCLUSIONS

Pediatric IF is associated with a significant risk of MBD, which is predicted by the duration of PN-dependence. These findings underscore the importance of BMD monitoring. Better therapies for treating IF-associated MBD are needed.