GESTATIONAL DIABETES - ANTEPARTUM CHARACTERISTICS THAT PREDICT POSTPARTUM GLUCOSE-INTOLERANCE AND TYPE-2 DIABETES IN LATINO WOMEN

We examined antepartum clinical characteristics along with measures of glucose tolerance, insulin sensitivity pancreatic beta-cell function, and body composition in Latino women with gestational diabetes mellit us (GDM) for their ability to predict type 2 diabetes or impaired gluc ose tolerance (IGT) within 6 months after delivery. A total of 122 isl et cell antibody-negative women underwent oral and intravenous glucose tolerance tests (OGTT; IVGTT), hyperinsulinemic-euglycemic clamps, an d measurement of body fat between 29 and 36 weeks' gestation and retur ned between 1 and 6 months postpartum for a 75-g OGTT. Logistic regres sion analysis was used to examine the relationship between antepartum variables and glucose tolerance status postpartum. At postpartum testi ng, 40% of the cohort had normal glucose tolerance, 50% had IGT, and 1 0% had diabetes by American Diabetes Association criteria. Independent antepartum predictors of postpartum diabetes were the 30-min incremen tal insulin:glucose ratio during a 75-g OGTT (P = 0.0002) and the tota l area under the diagnostic 100-g glucose tolerance curve (P = 0.003). Independent predictors of postpartum IGT were a low first-phase IVGTT insulin response (P = 0.0001), a diagnosis of GDM before 22 weeks' ge station (P = 0.003), and weight gain between prepregnancy and the post partum examination (P = 0.03). All subjects had low insulin sensitivit y during late pregnancy, but neither glucose clamp nor minimal model m easures of insulin sensitivity in the 3rd trimester were associated wi th the risk of IGT or diabetes within 6 months' postpartum. These resu lts high-light the importance of pancreatic P-cen dysfunction, detecta ble under conditions of marked insulin resistance in late pregnancy, t o predict abnormalities of glucose tolerance soon after delivery in pr egnancies complicated by GDM. Moreover, the association of postpartum IGT with weight gain and an early gestational age at diagnosis of GDM suggests a role for chronic insulin resistance in mediating hyperglyce mia outside the 3rd trimester in women with such a P-cen defect.