Basal Glucose on Tolerance Test During Pregnancy Predicts Impaired Fasting Glucose and Type 2 Diabetes Within 2 Months After Gestational Diabetes

Objectives: Postpartum mothers with gestational diabetes may remain with either type 2 diabetes mellitus, impaired glucose tolerance or impaired fasting glucose. Our aim in this study was to identify maternal variables that could predict 1 or more of these conditions. Methods: In 193 singleton pregnancies with gestational diabetes, we applied bivariate logistic regression and receiver-operating characteristic curves to data from the index glucose-challenge test that allowed the diagnosis of gestational diabetes. Results: Receiver-operating characteristic curves of fasting glucose from the index glucose-challenge test predicted impaired fasting glucose and type 2 diabetes mellitus combined, with a sensitivity of 100%, false-positive rate of 40.5%, area under the curve of 0.849, p=0.004 and positive predictive value 45%, and with a cutoff point of 4.7 mmol/L. Conclusions: At the time of diagnosis of gestational diabetes during pregnancy, a basal glucose level of >= 4.7 mmol/L on index glucose-challenge test indicates a 45% probability of either type 2 diabetes mellitus or impending diabetes early postpartum. (C) 2020 Canadian Diabetes Association.