Bone deficits in parenteral nutrition-dependent infants and children with intestinal failure are attenuated when accounting for slower growth.

OBJECTIVE: The aim of the present study was to determine whether bone mineral content (BMC) and density (BMD) of infants and children with parenteral nutrition (PN)-dependent intestinal failure (IF) is lower than healthy controls, and investigate potential causes of lower BMC and BMD.
METHODS: We performed a cross-sectional study comparing infants and children with PN-dependent IF with duos of age-, sex-, and race-matched controls. Lumbar spine BMC and BMD were measured by dual-energy x-ray absorptiometry, and serum cytokines, aluminum, insulin-like growth factor-1 (IGF-1), IGF-binding protein 3 (IGF-BP3), parathyroid hormone, 25-hydroxy vitamin D, and 1,25-dihydroxy vitamin D were measured. Generalized estimating equation models accounting for matching were used for comparisons.
RESULTS: BMC was 15% and BMD was 12% lower in IF participants than in controls (P ≤ 0.004). Group differences were attenuated to 3% and 7% and were not statistically significant (P = 0.40 and P = 0.07) when adjusted for length and weight; length- and weight-for-age were lower in IF than in control participants (12.5% vs 63%; 29.5% vs 54%, P ≤ 0.03). IF participants had higher serum aluminum (23 vs 7 μg/L, P < 0.0001), IGF-1 (97 vs 64 ng/mL, P = 0.04), and 25-hydroxy vitamin D concentrations (40 vs 30 ng/mL, P = 0.0005), and lower IGF-BP3 (1418 vs 1812 ng/mL, P < 0.0001) and parathyroid hormone concentrations (51 vs 98 pg/mL, P = 0.0002) than controls. There was no difference in serum cytokine concentrations (P ≥ 0.09).
CONCLUSIONS: Growth retardation is a significant problem for patients with PN-dependent IF. Additional investigation is needed to elucidate the cause and its effect on bone mass and density, especially the role of IGF-1 resistance and aluminum toxicity.