Gestational Diabetes Mellitus And Insulin Resistance

Objective1. To investigate the degree of insulin resistance (IR) of the gestational diabetic patients, the metabolic abnormalities of them, and the effect of these abnormalities on their fetal growth..2. To investigate the feasibility of screening gestational diabetes mellitus (GDM) by the 2-hour 75-g Oral glucose tolerance test(OGTT), in which capillary whole blood glucose (CBG) is detected replacing the venous plasma glucose(VPG).MethodsUsing 2-hour 75-g CBG-measured-OGTT for GDM screening and 2-hour 75-g VPG-measured-OGTT for GDM diagnosis. 35 pregnant women with GDM and 37 with gestational impaired glucose intolerance (GIGT) were recruited and served as Group A and Group B respectively. Women in both Group A and B were managed by Dietary control only and kept their CBG at appropriate level. 90 cases with normal pregnancy were served as control group (Group C). We measured and compared such parameters as blood glucose, blood insulin level and IR in 24~28 gestational weeks and at term, the function of pancreatic islet β-cell, the body mass index (BMI) of before-pregnancy and before-labour, weight gain in pregnancy and neonatal birth weight of three groups, and recorded their pregnancy outcomes. Results1. During 24~28 gestational weeks, the value of IR in Group A was more severe than that in Group B and Group C (P<0.05). There was no significant difference of the IR between Group B and Group C (P>0.05). At term, the IR in Group B became higher than that of Group C (P<0.05), While the IR in Group A was no more different to that in Group C (P>0.05).2. The function of pancreatic islet β-cell in decreasing order were Group C, Group B and Group A(P<0.05).3. Though there were no significant differences in the pregnancy outcomes among the three groups because of tight control of blood sugar by diet therapy alone, themean values of new birth weight in Group A is still higher than that in Group C . 4. The three CBG levels in the 2-hour 75-g CBG-measured-OGTT were respectivelycorrelated to the three VPG level in the VPG-measured-OGTT. Conclusions1. During 24-28 gestational weeks, The IR and metabolic abnormalities in GDM women are more severe compared with that in normal pregnancy. These severe IR probably accelerate their fetal growth. At term the IR in GDM women mitigates, it may result from the rapidly decline of placental function.2. It seems that diet alteration limit ly effects on reducing the rates of accelerated fetal growth and high new birth weight of the GDM pregnant women.3. The 2-hour 75-g CBG-measured-OGTT can be used to screen GDM duringpregnancy.