Maternal serum resistin concentrations in gestational diabetes mellitus and normal pregnancies

To investigate changes in maternal serum resistin levels during pregnancy and postpartum and clarify their relationship to insulin resistance.

Thirty normal pregnant women were compared to 30 women diagnosed with gestational diabetes mellitus (GDM). Serum resistin levels were collected at the time of glucose challenge test (26-28 weeks), at 38 gestational weeks and at the third postpartum day and measured with enzyme immunoassay. Correlation of resistin to the homeostatic model assessment-insulin resistance (HOMA-IR) was performed.

Maternal serum resistin levels at 38 weeks were significantly higher in pregnant women with GDM compared to the control group (0.28 vs 0.21 ng/mL, P = 0.02) and the same was true for the immediate puerperium (0.25 vs 0.19 ng/mL, P = 0.03). A significant increase in resistin levels was observed in GDM women from 26-28 weeks to 38 weeks (0.21 vs 0.28 ng/mL, P = 0.02), but not in controls. A decrease in serum resistin levels was noted in both the GDM and control groups, at 38 weeks and the immediate postpartum period, but this decrease did not reach statistical significance in either of the two groups. Resistin levels were positively correlated to HOMA-IR at 26-28 weeks of gestation (r = +0.253, P = 0.05).

GDM is associated with increased resistin serum levels in term pregnancy as well as postpartum. Resistin is positively correlated to HOMA-IR at 26-28 weeks of gestation. A reduction in maternal resistin after delivery indicates a significant placental or fetal contribution in the production of resistin.