To Study The Changes Of Selenium Concentration In Blood And Placenta And The Damage Of Histomorphology Of The Placentas In Gestational Diabetes Mellitus

Objective:To study the changes of Selenium Concentration in Blood and Placenta and to explore the relationship between the Selenium Concentration in Blood and Placenta and damage of histomorphology of the placentas in Gestational Diabetes Mellitus (GDM). Methods:We measured the selenium concentration in blood and placenta by 2,3-diaminonapaphthalene and glutathione peroxidase (GSH-Px) activity by a 5,5'-dithionbis (2-nitrobenzoic acid) direct method in blood in 30 women with GDM (GDM group) and 30 normal pregnant women (control group). Furthermore, the features of the placentas (10 from control group and 10 from GDM group) pathologic changes were observed microscopically. Results: (1) The selenium average levels of maternal blood , placental tissue and the activity of GSH-Px were lower in GDM group (0.0620±0.0224㎎/L)(0.4854±0.8570㎎/㎏) (68.20±15.91)U than that in the control group (0.0783±0.0209㎎/L),(0.5473±0.8416㎎/㎏)(80.36±12.68)U (P<0.01).(2)There was a significant positive correlation between the selenium concentration and GSH-Px activity in blood in the pregnant women (r=0.714, P<0.001). (3) There was a positive correlation between blood and placental selenium concentrations in GDM group (r=0.639, P<0.001). On the other hand, there was not correlation in women with normal pregnancies. (4) Placentas obtained from women with GDM had swelling of villi, thickening of trunk villus small artery wall, narrowing of lumen , increasing number of syncytial sprouts ,proliferating cytotrophoblasts and thickening of vasculo-syncytial membrane (VSM) under light microscopy. Placentas from control group did not show the pathologic changes as mentioned above. Conclusions: (1)The lower level of selenium in blood and placenta is possible interrelated gestational diabetes mellitus.(2) The GDM patients had lower GSH-Px levels in blood. Thus, lower GSH-Px levels in blood may contribute to the pathogenesis of GDM. (3)As selenium constitutes the active part of GSH-Px, these results suggest that the placental selenium deficiency may lead to reduced placental GSH-Px activity and the antioxidative defence may have been defective which may be associated with the damage of histomorphology of the placentas in GDM.