Clinical trial NCT04972955: Predicting Dysglycemia in Individuals With Gestational Diabetes Immediately Postpartum Using Continuous Glucose Monitoring
Official title: Predicting Dysglycemia in Individuals With Gestational Diabetes Immediately Postpartum Using Continuous Glucose Monitoring
Study type: OBSERVATIONAL
Overall status: RECRUITING
Conditions: Gestational Diabetes
Prediabetes; Complicating Pregnancy
Type 2 Diabetes
Pregnancy Related
Glucose Metabolism Disorders
Metabolic Disease
Endocrine System Diseases
Keywords: Gestational Diabetes
Pregnancy
Prediabetes
Prospective Cohort Study
Type 2 Diabetes
CGM
Continuous Glucose Monitoring
Flash Glucose Monitoring
Screening
Lead sponsor: University of Manitoba
Sponsor class: OTHER
First posted: 2021-07-22
Enrollment: 240
Sex: FEMALE
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: People who are currently pregnant and have been diagnosed with gestational diabetes during the current pregnancy

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 continuous glucose monitoring immediately postpartum to estimate the risk of maternal dysglycemia postpartum.

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 people 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. 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. Continuous 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) and 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. Continuous glucose monitoring gives a detailed picture of glycemic excursions throughout the day including both fasting and postprandial states.

There are currently no published studies examining the use of continuous glucose monitoring postpartum. Furthermore, no studies have examined continuous glucose monitoring's potential role in diagnosis of maternal dysglycemia postpartum. There is an unmet need to improve postpartum screening for individuals with gestational diabetes so that high risk individuals do not miss the opportunity for early treatment. To address this, the investigators will perform a study examining the use of continuous 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.

Eligibility criteria: 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) or have an HbA1c of 6.0-6.4% during pregnancy
* 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 (\<27 weeks gestation BMI of ≥25 kg/m2 or ≥27 weeks gestation predicted BMI of ≥ 25 kg/m2 using (current weight in kg - 10kg)/height in meters2)
* 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

Primary outcomes:
measure: The diagnostic accuracy of CGM as a screening test for postpartum dysglycemia.
timeFrame: 1-14 days postpartum; 4-6 months postpartum
Secondary outcomes:
measure: New diagnosis of maternal diabetes or prediabetes based on HbA1c alone, and a combination of the 75-gram OGTT and the HbA1c.
timeFrame: 4-6 months postpartum
measure: Acceptability of CGM based on an acceptability questionnaires after device return and after final testing.
timeFrame: 15-17 days postpartum; 4-6 months postpartum
measure: Dyslipidemia at time of postpartum bloodwork.
timeFrame: 4-6 months postpartum
measure: Glycemic variability reflected by coefficients of variation and standard deviations of blood glucose data.
timeFrame: 1-14 days postpartum; 4-6 months postpartum
measure: Cardiometabolic and related health outcomes diagnosed by regular healthcare team.
timeFrame: 1, 2 and 5 years postpartum
measure: Cost component analysis of CGM vs. 75g OGTT.
timeFrame: 4-6 months to 5 years postpartum
Other outcomes:
Locations:
city: Calgary
country: Canada
facility: University of Calgary
state: Alberta
city: Winnipeg
country: Canada
facility: University of Manitoba
state: Manitoba
city: Toronto
country: Canada
facility: Mount Sinai Hospital
state: Ontario
city: Quebec City
country: Canada
facility: Universite Laval
state: Quebec
Study officials:
affiliation: University of Manitoba
name: Jennifer Yamamoto, MD
role: PRINCIPAL_INVESTIGATOR
References:
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