PREDISPOSE: Predicting Dysglycemia in Individuals With Gestational Diabetes Immediately Postpartum Using Flash Glucose Monitoring

Sponsor

University of Calgary (Other)

Overall Status

Not yet recruiting

CT.gov ID

NCT04972955

Collaborator

(none)

240

Enrollment

Anticipated Duration (Months)

Study Details

Study Description

Brief Summary

Gestational diabetes is one of the most common medical disorders in pregnancy and is a major risk factor for the postpartum development of dysglycemia. Despite the high risk of developing dysglycemia, 50-80% of women with gestational diabetes are not receiving testing within a year postpartum. The investigators will conduct a prospective cohort study to examine the use of flash glucose monitoring immediately postpartum to estimate the risk of maternal dysglycemia postpartum.

Condition or Disease	Intervention/Treatment	Phase
Gestational Diabetes Prediabetes; Complicating Pregnancy Type 2 Diabetes Pregnancy Related Glucose Metabolism Disorders Metabolic Disease Endocrine System Diseases	Device: Freestyle Libre 2

Detailed Description

Gestational diabetes is one of the most common medical disorders in pregnancy and affects up to 18% of pregnancies. It is associated with an increased risk of both maternal and neonatal complications. Importantly, gestational diabetes is a major risk factor for the postpartum development of pre-diabetes or type 2 diabetes (together referred to as dysglycemia). Specifically, half of women with gestational diabetes will develop dysglycemia within 10 years of delivery. Despite the high risk of developing dysglycemia, 50-80% of women with recent gestational diabetes are not receiving testing within a year postpartum.

There are likely many factors contributing to this low screening rate. These include individual factors such as socioeconomic status and maternal age, as well as the nature of the guideline recommended test itself. The Diabetes Canada 2018 Clinical Practice Guidelines recommend screening for maternal dysglycemia between "6 weeks to 6 months postpartum" with a 75g oral glucose tolerance test (OGTT). This recommendation is based on expert opinion. While the 75g OGTT is thought to be the "gold-standard" for screening for dysglycemia postpartum, it has many pitfalls. First, the OGTT is widely disliked by women as it is time consuming and inconvenient. It requires consuming a sugary drink in addition to two separate venipunctures. Second, the 75g OGTT is notoriously unreproducible. Third, when including the direct medical costs, transportation costs, and the indirect time costs, it is estimated that the 75g OGTT costs $108/woman screened. Finally, it takes only a "snap shot" of a woman's glucose and insulin response with only two measurements over two-hours.

Emerging technologies are changing the landscape of diabetes care. Flash glucose monitoring (Freestyle Libre 2) is one such technology. People easily insert a small cannula just under the skin using an applicator. While the device is in place, it measures interstitial glucose concentrations every 15 minutes. It is a small disc (~size of a quarter) that is placed by a research assistant and removed by the participant. It can be worn during typical daily activities such as sleeping, showering, and exercising. The sensor can store up to 8 hours of glucose readings in 15-minute intervals. People scan the sensor using a smartphone or reader to upload glucose readings to the Freestyle Libre 2 app, which can be viewed by a clinician and/or researcher. Flash glucose monitoring gives a detailed picture of glycemic excursions throughout the day including both fasting and postprandial states.

There are currently no studies examining the use of flash glucose monitoring postpartum. Furthermore, no studies have examined flash glucose monitoring's potential role in diagnosis of maternal dysglycemia. There is an unmet need to improve postpartum screening for women with gestational diabetes so that high risk women do not miss the opportunity for early treatment. To address this, the investigators will perform a study examining the use of flash glucose monitoring immediately postpartum to estimate the risk of maternal dysglycemia postpartum. This is an observational study which aims to see if CGM can be used to diagnose diabetes. The CGM device in this study will be used for diagnosis and not as an intervention.

Study Design

Study Type:

Observational

Anticipated Enrollment :

240 participants

Observational Model:

Cohort

Time Perspective:

Prospective

Official Title:

Predicting Dysglycemia in Individuals With Gestational Diabetes Immediately Postpartum Using Flash Glucose Monitoring

Anticipated Study Start Date :

Sep 1, 2022

Anticipated Primary Completion Date :

Feb 1, 2025

Anticipated Study Completion Date :

Feb 1, 2028

Arms and Interventions

Arm	Intervention/Treatment
Pregnant women diagnosed with gestational diabetes Pregnant women who have been diagnosed with gestational diabetes during the current pregnancy	Device: Freestyle Libre 2 Participants will wear a flash glucose monitoring device, the Freestyle Libre 2, for two weeks following delivery.

Arm

Intervention/Treatment

Pregnant women diagnosed with gestational diabetes

Pregnant women who have been diagnosed with gestational diabetes during the current pregnancy

Device: Freestyle Libre 2

Participants will wear a flash glucose monitoring device, the Freestyle Libre 2, for two weeks following delivery.

Outcome Measures

Primary Outcome Measures

New diagnosis of maternal diabetes based on 75g OGTT [4-6 months postpartum]
Maternal diabetes defined as fasting plasma glucose ≥ 7.0mmol/L or 2-hour plasma glucose of ≥ 11.1 mmol/L
New diagnosis of maternal prediabetes based on 75g OGTT [4-6 months postpartum]
Maternal prediabetes defined as fasting plasma glucose 6.1-6.9 mmol/L or 2-hour plasma glucose of 7.8-11.0 mmol/L

Secondary Outcome Measures

New diagnosis of maternal diabetes based on postpartum HbA1c [4-6 months postpartum]
Diabetes is defined as HbA1c ≥ 6.5%
New diagnosis of maternal prediabetes based on postpartum HbA1c [4-6 months postpartum]
Prediabetes is defined as HbA1c 6.0-6.4%
Acceptability of testing using the device based on an acceptability questionnaire [15-17 days postpartum; 4-6 months postpartum]
The Acceptability Questionnaire for the Freestyle Libre 2 Postpartum will be completed at two points throughout the study. Scores can range between 7 and 60, with a higher score indicating a worse outcome.
Glycemic variability reflected by coefficients of variation and standard deviations of blood glucose data [Delivery to 2 weeks postpartum]
Blood glucose data will be collected using the Freestyle Libre 2 flash glucose monitoring system
New diagnosis of type 2 diabetes [1, 2 and 5 years postpartum]
Information on new type 2 diabetes diagnoses will be obtained through administrative provincial databases
Cost component analysis of CGM vs. 75g OGTT [4-6 months to 5 years postpartum]
Costs of assessing blood glucose via CGM versus lab-derived OGTT results will be compared.

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years and Older

Sexes Eligible for Study:

Female

Accepts Healthy Volunteers:

Inclusion Criteria:

Pregnant individuals age 18 and older
Diagnosed with gestational diabetes by the Diabetes Canada guidelines (including both the preferred or alternate testing approaches)
Have any of the following: have an elevated fasting glucose (≥ 5.3 mmol/L) on the diagnostic 75g OGTT in pregnancy; required insulin or metformin for treatment during pregnancy; body mass index (BMI) ≥ 25kg/m2, yes/no)
Planned in-hospital delivery
Able to provide informed consent
Willingness to use the study device and complete assessments
Have access to email in order to complete participant questionnaire through REDCap

Exclusion Criteria:

Non-gestational diabetes (i.e. pre-existing diabetes)
Planned x-ray, MRI or CT within 3 weeks postpartum
Has an implantable medical device (ex. pacemaker)
On medications known to affect glucose metabolism (for example glucocorticoids, metformin etc.)
On medications which may interfere with the Freestyle Libre 2 accuracy (for example Vitamin C >1000mg/day)
Unable to speak and understand French or English
Unable to consent or declined informed consent