Comparison of Biological Factors Affecting the Bone and Immuno Activity May of Breast Feeding and Formula Feeding During Infancy

Human milk is a complex biologic fluid that contains nutritional and protective factors such as Osteoprotegerin (OPG), at level that is 1000-fold higher than that found in normal human serum. Since OPG and Receptor activator of nuclear factor-kappa B ligand (RANKL) system are tightly involved in bone remodeling and immuno activity the present study was designated to evaluate the effect of breastfeeding on serum Soluble receptor activator of nuclear factor-kappa B ligand (sRANKL)/ OPG ratio in full term neonates in comparison with those of formula feeding full term neonates. In this cross-sectional study serum levels of OPG and sRANKL in 45 breastfed infants were compared with those of 44 formula-fed full term infants. The levels of serum OPG, sRANKL, were determined by standard techniques using enzyme-linked immunosorbent assay kits (ELISA methods). The serum levels of OPG were significantly higher in breastfed infants (P<0.001). No marked differences were observed between the serum levels of sRANKL in the two study groups (p=0.8). High OPG and level in serum of breastfed infants are important factors involved in remodeling of bone and immuno activity may prove superiority of breast feeding over formula feeding during infancy.