NCT06490874

Continuous Glucose Monitoring (CGM) Substudy of the DECIDE RCT

Continuous Glucose Monitoring Among Individuals With Gestational Diabetes Treated With Metformin Versus Insulin: Protocol for a Nested Prospective Cohort in the DECIDE RCT (DECIDE CGM)

• Status: Withdrawn
• Phase: —
• Study type: Observational
• Enrollment: 0 (actual)
• Sponsor: Ohio State University · Academic / Other
• Sex: Female
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

This is a nested multicenter prospective cohort conducted concurrently and in conjunction with the DECIDE two-arm, pragmatic non-inferiority comparative effectiveness Randomized Controlled Trial (RCT) (NCT06445946) of metformin versus insulin among individuals with Gestational diabetes mellitus (GDM) requiring pharmacotherapy for glycemic control. Continuous Glucose Monitoring (CGM)-derived glycemic metric in pregnancy and postpartum will be compared between individuals randomized to metformin versus insulin. In addition, the association between CGM metrics and adverse pregnancy outcomes will be examined. Finally, whether CGM metrics can accurately identify diabetes postpartum compared with an oral glucose tolerance test and hemoglobin A1c will be determined. A total of 300 (150 metformin, 150 insulin) pregnant individuals will be recruited with GDM who require pharmacotherapy to use a blinded CGM device (Dexcom, Inc, San Diego, CA) at two pregnancy (medication randomization, late third trimester) and three postpartum timepoints (delivery, \~6 weeks, and \~2 years).

Detailed description

Gestational diabetes mellitus (GDM) is the most frequent metabolic complication of pregnancy, and affects nearly 1 in 10 pregnant individuals in the U.S. annually. GDM increases the risks of both adverse pregnancy and postpartum outcomes for the affected individual and exposed offspring. Following a diagnosis of GDM, individuals are instructed to achieve glycemic control to decrease the risk of adverse pregnancy outcomes through monitoring of blood glucose, dietary modifications, and increased physical activity. However, \>1 in 4 individuals with GDM will not achieve targeted glycemic control with diet and behavior changes alone, and require pharmacotherapy. This is a multicenter prospective observational cohort nested in the DECIDE randomized controlled trial (NCT06445946). DECIDE is a two-arm, pragmatic non-inferiority comparative effectiveness RCT of metformin versus insulin to prevent adverse pregnancy outcomes and to confirm postpartum safety among individuals with GDM who require pharmacotherapy to achieve glycemic control. This trial will determine whether metformin is not inferior to insulin in reducing adverse pregnancy outcomes and is comparably safe for exposed pregnant individuals and their children. This substudy will be conducted concurrently and in conjunction with the parent study. A subset of 300 individuals (150 metformin, 150 insulin) will be enrolled in this substudy from the 1,572 individuals from the parent trial. Primary aim: To compare CGM-derived glycemic profiles (primary outcome: time in range of 63 to 140 mg/dL; secondary outcomes (mean glucose, coefficient of variation, and percentage of time below the target glucose range or above the target glucose range) in pregnancy between individuals with GDM randomized to metformin versus insulin. Secondary aims: To examine the association between CGM metrics and adverse pregnancy outcomes (large-for-gestational-age at birth, neonatal hypoglycemia, and hyperbilirubinemia, hypertensive disorder of pregnancy, preterm birth \<37 weeks, NICU admission, neonatal mechanical ventilation, neonatal oxygen support, neonatal respiratory distress syndrome). To examine whether CGM metrics can identify diabetes and postpartum cardiometabolic outcomes (prediabetes, type 2 diabetes, impaired glucose tolerance, impaired fasting glucose, hypertension, obesity, and cholesterol abnormalities) compared with an oral glucose tolerance test or hemoglobin A1c.

Conditions

• Gestational Diabetes Mellitus
• Pregnancy, High Risk

Interventions

Type	Name	Description
DEVICE	CGM device - Metformin group	Individuals randomized to metformin will be provided with a CGM device (Dexcom, Inc, San Diego, CA) to be worn for up to 10 days (minimum \>5 days) at two pregnancy (randomization to metformin or insulin, late third trimester \> 340/7 weeks) and three postpartum timepoints (immediately after delivery, \~6 weeks, and \~2 years).
DEVICE	CGM device - Insulin group	Individuals randomized to insulin will be provided with a CGM device (Dexcom, Inc, San Diego, CA) to be worn for up to 10 days (minimum \>5 days) at two pregnancy (randomization to metformin or insulin, late third trimester \> 340/7 weeks) and three postpartum timepoints (immediately after delivery, \~6 weeks, and \~2 years).

Timeline

• Start date: 2025-09-01
• Primary completion: 2029-12-01
• Completion: 2030-12-01
• First posted: 2024-07-08
• Last updated: 2025-10-28

Locations

4 sites across 1 country: United States

Regulatory

• FDA-regulated device study