Abstract: Abstract Objective The aim of the present study was to determine the plasma osteoprotegerin (OPG) levels in pregnant women with gestational diabetes mellitus (GDM) or with normal glucose tolerance (NGT) during their mid-late pregnancy, and to investigate the relationship between OPG and its involved factors. Method In this study, 65 women with GDM and 65 women with NGT were enrolled. Blood samples of each participant were collected during the 24-28 weeks of gestation using the EDTA anticoagulation tube, then centrifuged at 3000 × g for 5 min and collected the plasma. The samples of plasma were stored at -20 ℃ until use. Plasma concentration of OPG was measured by enzyme linked immunosorbent assay (ELISA). We also measured the level of fasting plasma glucose (FPG), fasting insulin (FINS), glycated hemoglobin (HbA1c), lipid, high-sensitivity C-reactive protein (hs-CRP), blood cell count, and calculated the homeostasis model assessment of beta-cell function (HOMA-B) and insulin resistance (HOMA-IR). Results The levels of plasma OPG were not significantly different between women with GDM and NGT. In the group of NGT, OPG levels were positively correlated with FINS (r=0.335, P=0.012)，HOMA-IR (r=0.363, P=0.006), platelet count (r=0.333, P=0.009) and negatively related with apolipoprotein B (r=-0.254, P=0.043), but in GDM group, the relation between OPG and the biomarker mentioned above was not found. Conclusion: OPG may be involved in insulin resistance and inflammation during the pregnancy in women with NGT, but the aforementioned effects of OPG were not obvious in the group of GDM, which may be caused by the reason that other stronger factors in the pathogenesis of GDM have masked the role of OPG.

Key words: osteoprotegerin , gestational diabetes mellitus , fasting insulin