SHBG in GDM maternal serum, placental tissues and umbilical cord serum expression changes and its significance

To compare the expression of sex hormone binding globulin (SHBG) in normal placental tissues and serum with placental tissues from patients with gestational diabetes mellitus (GDM) and to deduce the mechanism affecting placental SHBG in GDM.Enzyme-linked immunosorbent assay (ELISA) method were used to detect SHBG levels changes in normal and GDM maternal serum, umbilical cord serum and placental. We measured SHBG mRNA and protein using reverse-transcription polymerase chain reaction, and Western blotting, respectively, in normal and GDM placental tissues.In maternal serum, compared with the control group, GDM group: glucose, insulin increased, SHBG decreased. In the placenta, compared with the control group, GDM group: SHBG, SHBG mRNA and SHBG protein decreased. There is no correlation between placenta SHBG and maternal serum SHBG respectively in control and GDM group, but in GDM group maternal serum insulin and placenta SHBG are linear correlation.GDM serum and placental SHBG levels are reduced, hyperinsulinemia may lead to a reduction of SHBG in circulating blood, but also damage the placenta cells which led to placental synthesis and secretion of SHBG decrease.