Likelihood of Subsequent Type 2 Diabetes Diagnosis Among Patients Diagnosed With Gestational Diabetes and a 50-Gram 1-Hour Glucose Test Value of 200 mg/dL or Greater [ID: 1379006

Abstract

INTRODUCTION: Patients with gestational diabetes mellitus (GDM) are at increased risk for lifelong type 2 diabetes mellitus (T2DM). We sought to identify whether a 1-hour 50-g glucose result of 200 mg/dL or greater increased likelihood of T2DM among individuals with GDM. METHODS: This was a retrospective cohort study at a single tertiary care site from 2011 to 2019. Participants were included if diagnosed and treated for GDM during pregnancy, at least 18 years of age, and had singleton pregnancy. Exclusion criteria were significant fetal anomalies or incomplete records. Participants with values of 200 mg/dL or greater were then grouped and compared to participants with a value less than 200 mg/dL. Primary outcome was diagnosis of T2DM within 5 or less years of pregnancy. T tests, χ2, Fisher’s exact, and logistic regression were utilized for statistical analyses. RESULTS: Seven hundred eight participants met inclusion criteria. Among these, 100 (14.1%) had a value of 200 mg/dL or greater on the 1-hour 50-g glucose test. Groups were similar, with the exception that those with a very elevated 1-hour glucose result were more likely to be publicly insured (32.0% versus 17.1%, P=.009), identify as non-Hispanic Black (19% versus 14.6%, P=.036), and likely to be married (28.0% versus 25.8%, P=.039). Of the 708 participants, 31 (31.0%) were found to have T2DM among those with 1 hour of 200 mg/dL or greater versus 93 (15.3%) of those with lower 1-hour glucose results (P<.001). After controlling for confounders, T2DM remained independently associated with 1-hour glucose of 200 mg/dL or greater (adjusted odds ratio 2.14, 95% CI 1.22–3.74). CONCLUSION: Elevated screening results (≥200 mg/dL) on the 1-hour 50-g glucose test predicts an increased likelihood for T2DM.