Plasma concentrations of the carboxyterminal propeptide of type I procollagen (PICP) in preterm neonates from birth to term

Carboxyterminal propeptide of type I procollagen (PICP), a marker of bone f ormation, has not yet been studied in preterm infants. In this study, PICP concentrations were measured longitudinally for 12 wk after birth using the ELISA technique in 43 preterm infants with a gestational age (GA) ranging from 24-29 wk and in 35 preterm infants with a GA ranging from 30-34 wk. PI CP values in these preterm infants were higher than in children and adults. In cord plasma of preterm infants there was a significant gender differenc e, with higher PICP concentrations in male infants. A characteristic longit udinal pattern with an initial decrease during the first 3 postnatal days f ollowed by a rapid increase from d 7 to d 28 was seen in both groups. Regar ding the individual gestational ages, all preterm infants attained maximum PICP concentrations around 36 wk postmenstrual age. Multiple regression ana lysis revealed cord plasma PICP concentrations were significantly associate d with GA, birth weight, sex, and IGF-I. A significant correlation between PICP concentrations and GA was seen at wk 1-4 and between PICP concentratio ns and protein intake at wk 1. Body weight and energy intake were shown to exert a significant effect on the PICP concentrations at 2 wk. The collecte d data in preterm infants may serve further studies evaluating PICP as a ma rker for bone formation and growth in very low birth weight premature infan ts.