1174-P: Characterization of Glucose Levels in Pregnancy Measured by Blood Glucose Testing or CGM Monitoring after a 50-g Screening or a 75-g or 100-g OGTT
Authors: CARLSON ANDERS L. , BECK ROY , LI ZOEY , NORTON ELIZABETH , BERGENSTAL RICHARD M. , JOHNSON MARY L. , DUNNIGAN SEAN , BANFIELD MATTHEW , KRUMWIEDE KATIE J. , SIBAYAN JUDY , CALHOUN PETER , DURNWALD CELESTE 
Published: June 2023

Glucose challenge testing (GCT) is standard diagnostic approach for gestational diabetes (GDM). Using CGM glucose values to characterize glycemia during GCT is not well described. CGM and blood glucose (BG) values were matched with closest CGM value ±5 min of each reported BG time. GDM diagnosed by standard glucose thresholds for 50g GCT, 75g and 100g OGTTs. GCT (n=543, mean gestation 28 wks) showed mean±SD 1 hr BG of 117±28 mg/dL, while matched CGM mean BG was 126±36 mg/dL. The 1 hr BG was ≥135 mg/dL in 24% of GCT vs. 38% by CGM. OGTT (75g) (n=44, mean gestational age 28 wks) showed mean±SD fasting, 1 hr and 2 hr BG of 84±9 mg/dL, 156±33 mg/dL, and 119±26 mg/dL. OGTT (100g) (n=77, mean gestational age 29 wks) showed mean±SD fasting, 1 hr, 2 hr, and 3 hr BG of 82±9 mg/dL, 166±31 mg/dL, 137±27, and 101±27 mg/dL. CGM levels during GCT and both OGTT were similar but slightly higher for each time point; maximum glucose and glucose excursions were also similar between each test vs CGM. Those diagnosed with GDM had consistently higher CGM glucoses than those without GDM (Figure 1). CGM during GCT/OGTT demonstrates CGM correlates to BG, although consistently slightly higher for all 3 glucose tests, regardless of glucose load or timing of measurement. Correlating CGM values to obstetric outcomes would help further describe the role of CGM for diagnosing GDM and improving glucose metabolism in pregnancy.

Disclosure
A.L.Carlson: Advisory Panel; MannKind Corporation, Novo Nordisk, Research Support; Abbott Diabetes, Dexcom, Inc., Eli Lilly and Company, Medtronic, Novo Nordisk, Insulet Corporation, UnitedHealth Group, Sanofi. J.Sibayan: None. P.Calhoun: None. C.Durnwald: None. R.Beck: Consultant; Eli Lilly and Company, Novo Nordisk, Diasome, Insulet Corporation, Research Support; Tandem Diabetes Care, Inc., Beta Bionics, Inc., Dexcom, Inc., Bigfoot Biomedical, Inc., Medtronic, Ascensia Diabetes Care, Roche Diabetes Care, Eli Lilly and Company, Novo Nordisk. Z.Li: None. E.Norton: None. R.M.Bergenstal: Advisory Panel; Abbott Diabetes, Eli Lilly and Company, Medtronic, Novo Nordisk, Roche Diabetes Care, Zealand Pharma A/S, Consultant; Ascensia Diabetes Care, Bigfoot Biomedical, Inc., CeQur SA, Dexcom, Inc., Hygieia, Onduo LLC, Sanofi, Vertex Pharmaceuticals Incorporated, Research Support; Abbott Diabetes, Dexcom, Inc., Eli Lilly and Company, Insulet Corporation, Medtronic, Novo Nordisk, Sanofi, UnitedHealth Group. M.L.Johnson: Research Support; Abbott, Lilly, Insulet Corporation, NIH - National Institutes of Health, Patient-Centered Outcomes Research Institute, Novo Nordisk, Tandem Diabetes Care, Inc., Medtronic, Hemsley Charitable Trust, Jaeb Center for Health Research. S.Dunnigan: None. M.Banfield: None. K.J.Krumwiede: None.

Funding
The Leona M. and Harry B. Helmsley Charitable Trust; United Health Group