title: Gestational age, sex and maternal parity correlate with bone turnover in premature infants.
abstract: Factors affecting bone turnover in premature infants are not entirely clear but certainly are different from those influencing bones of adults and children. To identify fetal and maternal factors that might influence bone turnover, we prospectively studied 50 infants (30 preterm and 20 full-term) born at Ain Shams University Obstetric Hospital in Cairo, Egypt. Maternal parity and medical history and infant's weight, gestational age, gender and anthropometrical measurements were recorded. Cord blood samples were collected and serum type I collagen C-terminal propeptide (PICP) was assessed as a marker for fetal bone formation. First morning urine samples were collected and pyridinoline cross-links of collagen (Pyd) were measured as an index for bone resorption. Serum PICP was higher in premature infants when compared with full-term infants (73.30 +/- 15.1 versus 64.3 +/- 14.7, p = 0.022) and was higher in male premature infants when compared with females (81.64 +/- 9.06 versus 66.0 +/- 15.7, p = 0.018). In a multiple regression model using PICP as the dependent variable and controlling for different infant and maternal conditions, PICP significantly correlated with infant gender (r = 8.26 +/- 4.1, p = 0.05) maternal parity (r = -2.106 +/- 0.99, p = 0.041) and diabetes (r = 22.488 +/- 8.73, p = 0.041). Urine Pyd tended to increase in premature infants (612 +/- 308 versus 434 +/- 146, p = 0.057) and correlated significantly with gestational age (r = -63.93 +/- 19.55, p = 0.002). Therefore, bone formation (PICP) is influenced by fetal age and gender, as well as maternal parity and diabetes. Bone resorption (Pyd) is mostly dependent on gestational age only. Further in-depth studies are needed to enrich management of this vulnerable population.
authors.affiliation: Neonatalogy Department, the George Washington University & the Children's National Medical Center, Washington DC 20037, USA. haly@mfa.gwu.edu
authors.forename: Hany
authors.initials: H
authors.lastname: Aly
authors.forename: Mohamed F
authors.initials: MF
authors.lastname: Moustafa
authors.forename: Hanna A
authors.initials: HA
authors.lastname: Amer
authors.forename: Sahar
authors.initials: S
authors.lastname: Hassanein
authors.forename: Christine
authors.initials: C
authors.lastname: Keeves
authors.forename: Kantilal
authors.initials: K
authors.lastname: Patel
mesh_terms: D000596:Amino Acids / Q000494:pharmacology; D000818:Animals; D001724:Birth Weight; D001862:Bone Resorption; D001842:Bone and Bones / Q000378:metabolism; D003094:Collagen / Q000737:chemistry; D005260:Female; D005312:Fetal Blood / Q000378:metabolism*; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D010298:Parity; D010446:Peptide Fragments / Q000097:blood; D011347:Procollagen / Q000097:blood; D012044:Regression Analysis; D012737:Sex Factors; D013997:Time Factors
chemical_list: D000596:Amino Acids; D010446:Peptide Fragments; D011347:Procollagen; C042813:procollagen type I carboxy terminal peptide; C015484:pyridinoline; D003094:Collagen