Assessment of bone health in preterm infants through quantitative ultrasound and biochemical markers.

Objective: To assess bone status in preterm infants with quantitative ultrasound and to search for biochemical markers of bone health. Methods: Metacarpus bone transmission time (mcBTT) was prospectively performed during hospitalization, together with biochemical and clinical outcomes analysis. Results: 154 patients were studied. At 3rd week of life mcBTT positively correlated with serum phosphate. Urinary excretion of calcium and phosphate were assessed in a subgroup of 55 patients: on day 21 mcBTT positively correlated with phosphaturia, negatively with calciuria. Gestational age (GA), weight and length at 3rd week and at 36 weeks of GA correlated positively with mcBTT. We found negative correlation between mcBTT at 3rd week and days of parenteral nutrition, mechanical ventilation period and days to reach 1800 g. Conclusions: Serum phosphate, phosphaturia and calciuria correlate most with mcBTT. Further studies are necessary to verify the possible influence of early bone status on future bone health.