Aims: To study the prediction of abnormal glucose tolerance (AGT), diabetes mellitus (DM), hypertension (HT) and metabolic syndrome (MetS) among Chinese women using glycemic indices in the mid-trimester of pregnancy.
Methods: A cohort of Chinese women who had had either normal glucose tolerance or gestational diabetes mellitus (GDM) during a pregnancy were assessed at a median of 8 and 15 years post-delivery. All women underwent a 50-g glucose challenge test (GCT) and a 75-g oral glucose tolerance test in the mid-trimester of the index pregnancy. A receiver operating characteristic curve was used to assess the prediction of AGT, DM, HT and MetS.
Results: All glycemic indices were significant predictors of AGT and DM, and the 2-h plasma glucose (PG) and GCT were predictive of HT, at both 8 and 15 years post-delivery. MetS can only be predicted by the fasting plasma glucose (FPG) and was confined to 15 years post-delivery. After adjustment for confounding variables, all glycemic indices were still independent predictors of AGT and DM at both 8 and 15 years post-delivery, except for FPG in predicting DM at 8 years, while only the 2-h PG remains an independent predictor of HT at 15 years. The optimal cut-off values for FPG, 2-h PG and GCT are 4.2 mmol/L, 7.2 mmol/L and 7.7 mmol/L, respectively; all are lower than the current cut-off thresholds for the screening and diagnosis of GDM.
Conclusions: Women who had a glycemic level below the criteria for a positive screening test and below the diagnostic threshold for GDM still have a significant cardiometabolic risk.