Future diabetes risk can be predicted by the number of abnormal oral glucose tolerance test values during pregnancy

Abstract

AbstractAimTo quantify the future risk of type 2 diabetes (T2D) in women with gestational diabetes (GD) based on baseline metabolic characteristics and the number of abnormal values during a 3‐hour 100‐g oral glucose tolerance test (OGTT).Materials and MethodsWe conducted a population‐based retrospective cohort study of 10 023 pregnant women who underwent testing for GD in a large health maintenance organization in Israel using a 100‐g OGTT. Glucose values were obtained at four time points, 0, 60, 120 and 180 minutes.ResultsWe identified 9939 women who met the study criteria. Median follow‐up was 3.25 (interquartile range 1.5‐5.1; maximum 10.1) years. Using women without GD as reference, women with GD were at an increased risk of future T2D (hazard ratio [HR] 5.33 [95% confidence interval {CI} 3.86‐7.34]). This risk increased with a greater number of abnormal OGTT values, with the highest risk seen in women with four abnormal values (HR 16.67 [95% CI 7.94‐35.01]). In a multivariate model, a higher number of abnormal values, Arab ethnicity, higher body mass index, triglycerides and prepregnancy glucose were significantly associated with increased risk. Future T2D risk was also affected by the type of OGTT abnormality; an abnormal fasting value had the greatest risk, whereas an abnormal 3‐hour value had the lowest risk (HR 3.61 [95% CI 2.42‐5.38] vs. 1.50 [95% CI 0.93‐2.43], respectively).ConclusionsGD is a heterogenous disease, with varying degrees of glucose intolerance and subsequent T2D risk. Targeting interventions to women at the highest risk may help to improve postpartum adherence and effective long‐term follow‐up strategies.