Objective: The purpose of this study was to investigate the insulin sensitivity and visceral fatness in women with previous gestational diabetes mellitus (GDM), who are prone to develop type 2 diabetes.
Research design and methods: A 75-g oral glucose tolerance test (OGTT) performed 1 year postpartum identified 21 GAD(-) women with previous GDM and impaired glucose tolerance (GDM-IGT). Sixty age- and BMI-matched women with normal glucose tolerance (GDM-NGT) were selected by 1:3 matching to the GDM-IGT group. Another 18 women with normal glucose metabolism during a previous pregnancy and no family history of diabetes were recruited as the normal control group. Age and BMI matching was performed using a range of +/-1.0 years and +/-1.0 kg/m(2), respectively. Total body fat was measured by tetrapolar bioelectrical impedance, and visceral fat was determined using a single cut of a computed tomography scan. Insulin sensitivity was determined by the minimal model technique using the frequently sampled intravenous glucose tolerance test.
Results: One year postpartum, visceral fat was greater in the GDM-IGT group than in the age- and BMI-matched GDM-NGT or normal control groups. The insulin sensitivity index was lower in the GDM-IGT group than in the GDM-NGT or normal control groups. beta-Cell function, as measured by the acute insulin response to glucose, was also lower in GDM-IGT.
Conclusions: High body fat content, especially visceral fat content, and a low insulin response to glucose seem to contribute simultaneously to the development of impaired glucose metabolism in Korean women with previous GDM.