Influence of Antenatal Glucocorticosteroid Exposure on Osteoprotegerin and Receptor Activator of Nuclear Factor κB Ligand Levels in Newborn Infants

Abstract

Background/Aims: The physiologic relevance of osteoprotegerin (OPG) and the receptor activator of nuclear factor κB ligand (RANKL) in the preterm neonate is unknown. The aim of this study was to examine the effects of prematurity on OPG and RANKL concentrations at birth and to investigate in particular whether antenatal corticosteroid (ACS) exposure affects serum OPG and RANKL levels in premature neonates. Methods: Quantitative determination (enzyme immunoassay) of serum OPG and RANKL at 24 postnatal hours was performed in 47 healthy term neonates, 43 preterm newborns not exposed to ACS, and 55 preterm infants exposed to ACS. Results: OPG in the ACS-exposed preterm group (median 5.13 pmol/l, range 1.62-15.12) was significantly higher compared to preterm neonates not exposed to ACS (median 4.52 pmol/l, range 0.86-8.98, p < 0.05) and to unexposed term neonates (median 4.47 pmol/l, range 2.70-10.72, p < 0.05). Conversely, there was no difference in RANKL levels between the study groups. OPG and RANKL values were also similar between term and preterm neonates not exposed to ACS. Conclusions: Preterm neonates exposed to ACS have higher serum levels of OPG, while premature neonates not exposed to ACS have serum OPG and RANKL levels similar to those measured in healthy term neonates.