Relationships of Umbilical and Maternal Adiponectin, Resistin and Osteoprotegerin to Maternaland Newborn Anthropometric Characteristics

Abstract

Introduction. Adiponectin, resistin and osteoprotegerin (OPG) are cytokines expressed in the adipose tissue. Pregnancy is associated with gradually increased maternal levels of these molecules, also detected in significant amounts in umbilical cord blood serum samples. Aim, patients and methods. To establish the relationships of maternal and umbilical adiponectin, resistin and OPG levels to both maternal and fetal anthropometric measurements and insulin sensitivity, 28 mother-newborn pairs were enrolled in the study. Blood samples were collected in a fasting state, after delivery, and serum insulin, C-peptide, sex hormone-binding globulin, adipocytokines, OPG and bone specific alkaline phosphatase (BAP) were measured. Results. Compared to maternal values, umbilical serum adiponectin levels were about 3-fold higher; additionally, significantly higher resistin and lower OPG levels were observed. Stratification of umbilical and maternal adiponectin levels according to tertiles of birth body weight demonstrated significantly lower maternal adiponectin levels by tertiles of neonatal body weight. No relationships were noticed between infant birth weight and maternal or umbilical serum resistin and OPG, respectively. Umbilical resistin was significantly associated to both maternal resistin and umbilical adiponectin. Multiple regression analysis showed that maternal BMI, umbilical insulin, C-peptide and resistin explained 71.83% of umbilical serum adiponectin variability. Umbilical resistin was independently predicted by umbilical adiponectin, umbilical C-peptide and maternal BMI, and the model explained 81.49% of umbilical resistin levels. Conclusions. In human, umbilical serum adiponectin and resistin levels are significantly higher compared to adults. These adipokines may mediate the effects of maternal body mass on fetal development. The biology of the OPG/RANKL cytokine system in fetuses and newborns needs further research.