Long-term Effects of Flash Glucose Monitoring System in Patients With Gestational Diabetes

Study Overview
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Brief Summary
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The purpose of this study is to report the glycemic control effect and clinical safety and effectiveness of mother and fetus when using a continuous glucose monitoring system (CGM) [Freestyle Libre] for a long period of time compared to self monitoring blood glucose(SMBG) in gestational diabetes patients.

Detailed Description
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The investigators plan to conduct a randomized clinical trial among patients with Gestational Diabetes Mellitus (GDM). The intervention group will use Continuous Glucose Monitoring (CGM) throughout the study period, scanning four or more times per day. The control group will be instructed to perform Self-Monitoring Blood Glucose (SMBG), also four or more times per day. Eligible participants are those within 24 to 30 weeks of gestation (Visit 0). These subjects will undergo a 1-week run-in period, during which they will wear a retrospective CGM device and perform SMBG four or more times daily as a part of the screening process (Visit 1). Following the run-in period, subjects will be randomly assigned to either the CGM group (using the Freestyle Libre device) or the Control group (using SMBG). Members of the control group will be asked to perform SMBG four or more times daily, while those in the CGM group will be instructed to scan their CGM four or more times per day. Participants will have clinic visits at intervals ranging from 2 to 4 weeks, the frequency of which will be determined at the discretion of the attending physician (Visits 2, 2', 2'', 2''', 2'''). Upon reaching gestational age 34-35 weeks (Visit 3), members of the control group will begin to wear a retrospective CGM device until they reach gestational age 36 weeks (Visit 4). After 6-12 weeks from delivery, subjects will be asked to visit the clinic again and undergo a 75g Oral Glucose Tolerance Test (OGTT) (Visit 5). For the purposes of data analysis and outcome determination, the most recent 1-week CGM data collected at Visit 4 will be used for both groups.

Official Title
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Long-term Effects of Flash Glucose Monitoring System in Patients With Gestational Diabetes

Conditions
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Gestational Diabetes Mellitus in Pregnancy

Intervention / Treatment
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* Device: CareSens N (iSENS)
* Device: Freestyle Libre (Abbott)


Participation Criteria
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Eligibility Criteria
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[Inclusion Criteria] 19-40 aged female Gestational diabetes diagnosed at 24 to 28 weeks of pregnancy screening (stage 1 or stage 2 approach) 2-1.Screening one-step approach (75g oral glucose tolerance test, diagnosed when one or more of the following) Fasting blood glucose 92 mg/dL or higher Blood glucose 180 mg/dL or higher 1 hour after glucose loading Blood glucose of 153 mg/dL or higher 2 hours after glucose loading 2-2. Screening two-step approach (50 g oral glucose tolerance test then,100g oral glucose tolerance test) If the blood glucose level is 140 mg/dL or higher for 1 hour after the 50g oral glucose tolerance test, 100g oral glucose tolerance test 2 or more of the following Fasting blood glucose 95mg/dL or higher Blood glucose 180mg/dL or higher 1 hour after glucose loading Blood glucose of 155 mg/dL or higher 2 hours after glucose loading Blood glucose of 140 mg/dL or higher 3 hours after glucose loading Singleton Pregnancy [Exclusion Criteria] - pregestational diabetes (Overt diabetes) Diabetes Before Pregnancy At least one of the following at the first prenatal visit Fasting blood glucose 126mg/dL or higher Random blood glucose 200mg/dL or higher

Ages Eligible for Study
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Minimum Age: 19 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Supportive Care
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: randomized, parallel, open labeled study
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: SMBG arm<br>Self Monitoring of Blood Glucose group | Device: CareSens N (iSENS)<br>* Control group is asked to perform SMBG (4 times or more per day).<br>|
| Experimental: CGMS arm<br>Continuous glucose monitoring system, CGM | Device: Freestyle Libre (Abbott)<br>* CGM group is asked to scan CGM (4 times or more per day).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 63-140 mg/dL Time in Range | 63-140 mg/dL Time in Range evaluated for 1 week before Visit4 visit | at visit 4(gestational age 36weeks) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| AbA1C (%) | HbA1C evaluated at visit 4 | at visit 4(gestational age 36weeks) | 
| Glycated Albumin(g/dL) | Glycated Albumin evaluated at visit 4 | at visit 4(gestational age 36weeks) | 
| >180 mg/dL Time in Range | >180 mg/dL Time in Range evaluated for 1 week before Visit4 | 1 week before Visit4 (gestational age 36weeks) | 
| >140 mg/dL Time in Range | >140 mg/dL Time in Range evaluated for 1 week before Visit4 | 1 week before Visit4 (gestational age 36weeks) | 
| >120 mg/dL Time in Range | >120 mg/dL Time in Range evaluated for 1 week before Visit4 | 1 week before Visit4 (gestational age 36weeks) | 
| <63mg/dL Time in Range | <63mg/dL Time in Range evaluated for 1 week before Visit4 | 1 week before Visit4 (gestational age 36weeks) | 
| <54mg/dL Time in Range | <54mg/dL Time in Range evaluated for 1 week before Visit4 | 1 week before Visit4 (gestational age 36weeks) | 
| 63-120mg/dL Time in Range | 63-120mg/dL Time in Range evaluated for 1 week before Visit4 | 1 week before Visit4 (gestational age 36weeks) | 
| Night time Blood glucose (0AM-6AM) 63-94 mg/dL Time in Range | Night time Blood glucose (0AM-6AM) 63-94 mg/dL Time in Range evaluated for 1 week before Visit4 | 1 week before Visit4 (gestational age 36weeks) | 
| Night time Blood glucose (0AM-6AM) ≥95 mg/dL Time in Range | Night time Blood glucose (0AM-6AM) ≥95 mg/dL Time in Range evaluated for 1 week before Visit4 | 1 week before Visit4 (gestational age 36weeks) | 
| Night time Blood glucose (0AM-6AM) <63 mg/dL Time in Range | Night time Blood glucose (0AM-6AM) <63 mg/dL Time in Range evaluated for 1 week before Visit4 | 1 week before Visit4 (gestational age 36weeks) | 
| Night time Blood glucose (0AM-6AM) <54 mg/dL Time in Range | Night time Blood glucose (0AM-6AM) <54 mg/dL Time in Range evaluated for 1 week before Visit4 | 1 week before Visit4 (gestational age 36weeks) | 
| Overall average blood glucose level | Overall average blood glucose level evaluated for 1week before visit4 | 1 week before Visit4 (gestational age 36weeks) | 
| Overall average Night time Blood glucose (0AM-6AM) level | Overall average Night time Blood glucose (0AM-6AM) level evaluated for 1week before visit4 | 1 week before Visit4 (gestational age 36weeks) | 
| Overall average During the day time blood glucose (6AM-12PM) level | Overall average During the day time blood glucose (6AM-12PM) level evaluated for 1week before visit4 | 1 week before Visit4 (gestational age 36weeks) | 
| Frequency of severe hypoglycemia(Hypoglycemia requiring help from others) | Frequency of severe hypoglycemia during the study period hyperglycemia requiring help from others) | From visit 1 to visit 4(Gestational age 25-31 weeks to Gestational age 36 week) | 
| glucose variability | glucose variability evaluated for 1week before visit4 (MAGE,SD,CV) | 1 week before Visit4(gestational age 36weeks) | 
| rate of insulin treatment | rate of insulin treatment | From visit 1 to visit 4 (Gestational age 25-31 weeks to Gestational age 36 week) | 
| Estimation A1c of continuous blood glucose measurement for 1 week before Visit4 visit | Estimation A1c of continuous blood glucose measurement for 1 week before Visit4 visit | 1 week before Visit4(Gestational age 36 week) | 
| Total daily insulin requirements (evaluated at every visit) | Total daily insulin requirements (evaluated at every visit) | From visit 1 to visit 4(Gestational age 25-31 weeks to Gestational age 36 week) | 
| Satisfaction Questionnaire | Satisfaction Questionnaire(DTSQ) ,Score: min0  max 48, higher scores mean a better outcome | Visit 1 (Gestational age 25-31 weeks) , Visit 4 (Gestational age 36 week) | 
| C-section rate | C-section rate | during the study period (Gestational age 25-31 weeks to Pospartum 6-12 weeks) | 
| preeclampsia rate | preeclampsia rate | during the study period (Gestational age 25-31 weeks to Pospartum 6-12 weeks) | 
| preeclampsia or gestational hypertension rate | preeclampsia or gestational hypertension rate | during the study period (Gestational age 25-31 weeks to Pospartum 6-12 weeks) | 
| the rate of preterm birth | the rate of preterm birth | during the study period (Gestational age 25-31 weeks to Pospartum 6-12 weeks) | 
| Weight gain during the study period | Weight gain during the study period | during the study period (Gestational age 25-31 weeks to Pospartum 6-12 weeks) | 
| Average daily blood glucose measurements during the study period | Freestyle Libre scans, SMBG | during the study period (Gestational age 25-31 weeks to Pospartum 6-12 weeks) | 
| Changes in Microbiome | Changes in Microbiome | during the study period (Gestational age 25-31 weeks to Pospartum 6-12 weeks) | 
| Rate of transition to type 2 diabetes | Rate of transition to type 2 diabetes | at post partum (6-12 weeks after delivery) | 
| Rate of transition to Glucose intolerance (prediabetes and/or diabetes) | Rate of transition to Glucose intolerance (prediabetes and/or diabetes) | at post partum (6-12 weeks after delivery) | 
| Rate of transition to Impaired fasting glucose (IFG) and/or diabetes | Rate of transition to Impaired fasting glucose (IFG) and/or diabetes | at post partum (6-12 weeks after delivery) | 
| Rate of transition to Impaired fasting glucose (IGT) and/or diabetes | Rate of transition to Impaired fasting glucose (IGT) and/or diabetes | at post partum (6-12 weeks after delivery) | 
| 75g OGTT hourly blood glucose | 75g OGTT hourly blood glucose | at post partum (6-12 weeks after delivery) | 
| hemoglobinA1C | hemoglobinA1C | at post partum (6-12 weeks after delivery) | 
| glycated albumin | glycated albumin | at post partum (6-12 weeks after delivery) | 
| Insulin resistance index (HOMA-IR) | HOMA-IR (no unit, higher score means a worse outcome) | at post partum (6-12 weeks after delivery) | 
| Insulin resistance index (Matsuda index) | Matsuda index (no unit, higher score means a better outcome) | at post partum (6-12 weeks after delivery) | 
| Insulin secretion ability index (HOMA-beta) | HOMA-beta(no unit, higher score means a better outcome) | at post partum (6-12 weeks after delivery) | 
| Insulin secretion ability index (Insulinogenic index) | Insulinogenic index(no unit, higher score means a better outcome) | at post partum (6-12 weeks after delivery) | 
| Insulin Composite index(Oral disposition index) | Oral disposition index(no unit, higher score means a better outcome) | at post partum (6-12 weeks after delivery) | 
| Insulin Composite index(disposition index) | disposition index(no unit, higher score means a better outcome) | at post partum (6-12 weeks after delivery) | 
| weight change | weight change | at post partum (6-12 weeks after delivery) | 
| Change in Bioelectric impedance analysis (BIA) | Change in Bioelectric impedance analysis (BIA) | at post partum (6-12 weeks after delivery) | 
| fetal: childbirth weight | fetal: childbirth weight | at Delivery | 
| fetal: Macrosomia ( > 4000 g) | fetal: Macrosomia ( > 4000 g) | at Delivery | 
| fetal:Large for gestational age ( > 90th percentile for age) | fetal:Large for gestational age ( > 90th percentile for age) | at Delivery | 
| fetal:Small for gestational age ( < 10th percentile for age) | fetal:Small for gestational age ( < 10th percentile for age) | at Delivery | 
| fetal:Neonatal glucose level | fetal:Neonatal glucose level | at Delivery | 
| fetal:NICU admission | fetal:NICU admission | at Delivery | 
| fetal:birth trauma (including shoulderdystocia, clavicle fracture or Erb's palsy) | fetal:birth trauma (including shoulderdystocia, clavicle fracture or Erb's palsy) | at Delivery | 
| fetal:Pre-term birth | fetal:Pre-term birth | at Delivery | 
| fetal:Apgar score | score: min 0   max 10, higher scores mean a better outcome | at Delivery | 
| fetal:Meconium aspiration | fetal:Meconium aspiration | at Delivery |