nsulin Resistance and β-cell Secretion in Women with Normal Glucose Tolerance and Gestational Diabetes Mellitus

Objective To investigate whether insulin secretion and resistance are different in normal glucose tolerant and gestational diabetes mellitus women during late pregnancy.Methods 40 gestational diabetes mellitus(GDM)patients(GDM group)were paired with 40 normal glucose tolerant pregnant patients(control group)according to age(±1yr),race,parity,gestational weeks(±1wk)and gravidity.The body mass index(BMI),waist/hip ratio(WHR),fasting plasma glucose(FPG),75 g OGTT 2h-postprandial glucose(2hPG),fasting insulin(FINS),2h-postprandial insulin(2hINS)in patients at 28～30 weeks of gestation in the two groups were measured.Insulin resistance was measured by homeostasis insulin resistance index(HOMA-IR),insulin secretion function was evaluated by homeostasis β-cell index(HBCI).The indexes mentioned above were compared between the two groups.Results(1)Compared with the control group,BMI atbooking,WHR at OGTT,FPG,2hPG,FINS、2hINS were significantly higher than those in GDM group(P0.05).(2)HOMA-IR transformed to logarithm in GDM group was significantly higher than that of control group(t=3.26,P=0.002).However,no significant differences in HBCI between two groups were found(P0.01).Conclusions GDM women in the third trimester have significant trend of great BMI and central obesity.GDM are additionally characterized by peripheral insulin resistance and persisting hyperinsulinemia states independent of defective beta-cell secretion.