BONE-DENSITY AND BIOCHEMICAL PARAMETERS O F BONE-MINERAL METABOLISM AND ACID LOAD IN PRETERM INFANTS

To assess the effect of feeding a preterm formula containing hydrolyse d protein on bone mineralisation and calcium (Ca), phosphorus (P) and acid-base metabolism, we compared radial bone mineral content and bioc hemical parameters of bone mineral and acid-base metabolism in prematu re infants (birth weight 1507 +/- 210g; gestational age 32.7 +/- 2.0 w eeks) fed either formula with a conventional, whey-based protein prepa ration (ConF; n = 20) or an identical preparation except for its prote in being a hydrolysate (PH; n = 19). The patients were examined within one week after reaching full enteral. nutrition and, whenever possibl e, 14 days later. While serum and urine parameters of Ca and P metabol ism were within the normal range in the vast majority of cases, bone d ensity was low in view of intrauterine mineral accretion and showed no increase over time, consistent with radiological signs of mild to mod erate osteopenia pre sent in all patients re-examined. In infants fed PH an increased renal acid excretion with low urine pH, and higher val ues for P in serum and urine together with a lower alkaline phosphatas e were observed only transiently. We conclude that feeding of a PH to preterm infants has no effect of clinical relevance concerning bone mi neral content, biochemical parameters of bone metabolism, or net acid excretion.