Placental expression of glucose transporters GLUT-1, GLUT-3, GLUT-8 and GLUT-12 in pregnancies complicated by gestational and type 1 diabetes mellitus.

AIM The aim of the present study was to evaluate the placental expression of glucose transporters GLUT-1, GLUT-3, GLUT-8 and GLUT-12 in term pregnancies complicated by well-controlled gestational (GDM) and type 1 pregestational diabetes mellitus (PGDM). MATERIALS AND METHODS A total of 103 placental samples were obtained from patients diagnosed with GDM (n=60), PGDM (n=20) and a non-diabetic control group (n=23). Computer-assisted quantitative morphometry of stained placental sections was performed to determine the expression of selected GLUT proteins. RESULTS Immunohistochemical techniques used for the identification of GLUT-1, GLUT-3, GLUT-8 and GLUT-12 revealed the presence of all glucose transporters in the placental tissue. Morphometric evaluation performed for the vascular density-matched placental samples demonstrated a significant increase in the expression of GLUT-1 protein in patients with PGDM as compared to GDM and control groups (p<.05). With regard to the expression of the other GLUT isoforms, no statistically significant differences were observed between patients from the diabetic and control populations. Positive correlations between fetal birth-weight and the expression of GLUT-1 protein in the PGDM group (rho=.463, p<.05) and GLUT-12 in the control group (rho=.481, p<.05) were noted. CONCLUSIONS In term pregnancies complicated by well-controlled GDM/PGDM expression of transporters GLUT-3, GLUT-8 and GLUT-12 in the placenta remains unaffected. Increased expression of GLUT-1 among women with type 1 PGDM may contribute to higher rate of macrosomic fetuses in this population.