424: Performance of the fasting glucose value alone for diagnosing gestational diabetes and predicting neonatal adiposity

Abstract

OBJECTIVE: Gestational diabetes (GDM) results in short and longterm offspring morbidity, though diagnostic methodology remains controversial. Based on a dual-center (Cleveland and Oklahoma City) GDM treatment cohort, we previously reported fasting blood glucose (FBG) from the 3hr oral glucose tolerance test (OGTT) was the single best predictor of neonatal body fat at z30 d. In this study, we sought to determine the performance of FBG (predefined cut point of <95 and >95 mg/dL) for identifying GDM and characterizing neonatal (n=48) adiposity. STUDY DESIGN: From a retrospective cohort of 906 patients (Oklahoma City) undergoing 3hr OGTT between 2011-2014, receiver operating curve (ROC) analysis was used to calculate sensitivity and specificity with a FBG cut point of ≥ 95 mg/dl, (10% population prevalence of GDM based on ACOG 2-step method). Using this FBG cut point, we analyzed neonatal body composition (% fat, absolute fat (FM) and fat-free mass (FFM)) and infants with % fat >90th percentile (PEA POD®). RESULTS: ROC analysis revealed sensitivity and specificity of FBG ≥ 95 mg/dL (0.21 / 0.95) for the prediction of GDM. Infants from mothers with a FBG ≥ 95 mg/dL were fatter both in relative (18.7 vs. 14.9%; p<0.05) and absolute (803 vs. 543g; p<0.01) terms. Further, over 50% of infants from mothers with FBG >95 mg/dL had a % fat greater than the 90th % fat percentile. CONCLUSION: FBG ≥ 95 mg/dl carries poor sensitivity for the ACOG diagnosis of GDM in our population. However, infants of mothers with FGB ≥ 95mg/dl have significantly higher body fat. Current diagnostic criteria for GDM may inadequately capture fetuses at risk for increased neonatal adiposity. (Table Presented).