Perinatal sclerostin concentrations in abnormal fetal growth: the impact of gestational diabetes

Objective: To prospectively evaluate maternal and cord blood concentrations of sclerostin - an osteocyte-secreted factor, inhibiting osteoblast differentiation and bone formation and associated with adverse metabolism - in pregnancies with normal and abnormal fetal growth. Methods: Plasma sclerostin concentrations were determined by ELISA in 80 maternal and 80 cord blood samples from asymmetric intrauterine-growth-restricted (IUGR, n = 30), large-for-gestational-age (LGA, n = 30), and appropriate-for-gestational-age (AGA, n = 20) singleton full-term pregnancies. Fourteen out of 30 mothers with LGA offspring presented with gestational diabetes mellitus (GDM). Results: Maternal and fetal sclerostin concentrations did not differ among LGA, IUGR, and AGA groups. Fetal concentrations were higher than maternal. In LGA group, maternal concentrations were elevated in cases of GDM (b = 13.009, 95%CI 1.425-24.593, p = .029). In a combined group and the IUGR group, maternal concentrations were elevated in older mothers (b = 0.788, 95%CI 0.190-1.385, p = .010, and b = 0.740, 95%CI 0.042-1.438, p = .039, respectively). Conclusions: Maternal and fetal sclerostin concentrations may not be differentially regulated in pregnancies complicated by abnormal fetal growth. Circulating maternal levels are higher in cases of GDM, probably implying reduced bone formation. Sclerostin up-regulation with aging may be one of the molecular pathways responsible for the observed age-related decline in bone synthesis, leading to accelerated bone loss in humans.