Circulating osteoprotegerin and sRANKL concentrations in the perinatal period at term. The impact of intrauterine growth restriction.
BACKGROUND
Intrauterine growth restriction (IUGR) has been associated with low bone mass in infancy and increased risk for osteoporosis development in adult life. Osteoprotegerin (OPG) and receptor activator of nuclear factor-kappaB ligand (RANKL) are main determinants of bone resorption.


OBJECTIVE
To investigate OPG and soluble RANKL (sRANKL) concentrations in maternal, fetal and neonatal serum of IUGR patients and appropriate for gestational age (AGA) pregnancies. Additionally, plasma intact parathormone (PTH) concentrations were evaluated.


METHODS
Circulating OPG, sRANKL and PTH concentrations were measured in 40 mothers and their singleton full-term fetuses-neonates (AGA: n = 20, and IUGR: n =20) on postnatal days 1 (N1) and 4 (N4).


RESULTS
No significant differences in OPG, sRANKL or PTH concentrations were observed between AGA and IUGR groups. In both groups, maternal OPG concentrations were elevated compared with fetal, and N1 and N4 concentrations (p < or = 0.045 in all cases). N4 sRANKL concentrations were elevated compared with maternal, fetal and N1 ones (p < or = 0.01 in all cases). Fetal and N1 sRANKL concentrations correlated positively with PTH levels (r = 0.642, p = 0.024 and r = 0.584, p = 0.046, respectively).


CONCLUSIONS
The lack of a difference in circulating OPG, sRANKL or PTH concentrations between IUGR cases and AGA controls suggests that the low bone mass of IUGR infants may not be related to higher bone resorption rates. The increased maternal, compared with fetal/neonatal, OPG concentrations may suggest their placental origin. The lower OPG and higher sRANKL concentrations in fetuses and neonates could represent high bone resorption rates.
Second Department of Obstetrics and Gynecology, Athens University Medical School, Athens, Greece. amalpu@aretaieio.uoa.gr
Despina D
DD
Briana
Maria
M
Boutsikou
Stavroula
S
Baka
Demetrios
D
Hassiakos
Demetrios
D
Gourgiotis
Ariadne
A
Malamitsi-Puchner
D000328:Adult; D001724:Birth Weight; D005260:Female; D005312:Fetal Blood / Q000378:metabolism*; D005317:Fetal Growth Retardation / Q000097:blood*; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn / Q000097:blood*; D008297:Male; D008431:Maternal-Fetal Exchange / Q000502:physiology; D053244:Osteoprotegerin / Q000097:blood*; D010281:Parathyroid Hormone / Q000097:blood; D011247:Pregnancy / Q000097:blood*; D053245:RANK Ligand / Q000097:blood*
D053244:Osteoprotegerin; D010281:Parathyroid Hormone; D053245:RANK Ligand; C506030:TNFRSF11B protein, human; C505688:TNFSF11 protein, human