Response of preterm infants to aluminum in parenteral nutrition.

Twenty-five preterm infants with birth weights (BW) 540 to 2280 g (20 with birth weight less than 1500 g) and gestational ages 24 to 37 weeks, were studied to determine the response to 2 levels of aluminum (Al) loading from currently unavoidable contamination of various components of parenteral nutrition (PN) solution. High Al loading group (H) received solutions with measured Al content of 306 +/- 16 micrograms/liter and low A1 loading group (L) received solutions with 144 +/- 16 micrograms A1/liter. Urine Al:Creatinine (Al:Cr) ratios (micrograms:mg) became elevated and significantly higher in H (1.6 +/- 0.38 vs 0.5 +/- 0.1, p less than 0.05) at the third sampling point (mean 19 days). Serum Al concentrations were highest at onset in both groups and stabilized with study but remained consistently higher than the normal median of 18 micrograms/liter. Calculated urine Al excretion were consistently low and were 34 +/- 6% vs 28 +/- 5% in the H and L groups, respectively. One infant in the L group who died 39 days after termination of above study showed the presence of A1 in bone trabeculae and the presence of excessive unmineralized osteoid along the trabeculae. We conclude that small preterm infants are able to increase urine Al excretion with increased Al load. However urine Al excretion is incomplete with bone deposition of Al and persistently elevated serum Al concentrations.