Alteration of serum tumor necrosis factor-alpha level in gestational diabetes mellitus and correlation with insulin resistance

Objective To explore the dynamic of tumor necrosis factor-alpha(TNF-α)and its correlation with insulin resistance(IR)during different stages of gestational diabetes mellitus(GDM).Methods Thirty-two subjects with GDM and 31 cases of normal pregnant women nonnal glucose tolerance,NGT were enrolled in the study,serum TNF-α and insulin were determined by radioimmunoassay.The plasma glucose was measured by using glucose oxidase.Tests repeated for each group according different stages of prenatal 25~28 weeks,29~32 weeks,37~38 weeks and postpartum 6~8 weeks.IR was assessed by the homeostasis model of assessment for insulin resistance index(HOMA-IR).Results ① Serum TNF-α levels in GDM and NGT group rose with gestational age,and both significantly decreased at postpartum. ② Serum TNF-α levels in GDM of above-mentioned four stages respectively were(7.05±0.67)ng/L,(7.11±0.75)ng/L,(7.36±0.79)ng/L,(5.46±0.37)ng/L respectively.All significantly increased than those in the same stage group(t=7.81,7.05,7.15,P<0.01). ③ Maternal serum TNF-α levels were in positive correlation with HOMA-IR in GDM(r=0.571,P<0.05).Conclusions Serum TNF-α levels in GDM rose with gestational age,but significantly decreased at postpartum.The dynamic changes of serum TNF-α contribute to occurrence of insulin resistance.