Predicting Dysglycemia in Individuals With Gestational Diabetes Immediately Postpartum Using Continuous Glucose Monitoring
- Conditions
- Gestational DiabetesPregnancy RelatedPrediabetes; Complicating PregnancyType 2 DiabetesGlucose Metabolism DisordersMetabolic DiseaseEndocrine System Diseases
- Interventions
- Device: Freestyle Libre 2
- Registration Number
- NCT04972955
- Lead Sponsor
- University of Manitoba
- 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.
Recruitment & Eligibility
- Status
- RECRUITING
- Sex
- Female
- Target Recruitment
- 240
- 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
- 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
Study & Design
- Study Type
- OBSERVATIONAL
- Study Design
- Not specified
- Arm && Interventions
Group Intervention Description Pregnant women diagnosed with gestational diabetes Freestyle Libre 2 Pregnant individuals who have been diagnosed with gestational diabetes during the current pregnancy
- Primary Outcome Measures
Name Time Method The diagnostic accuracy of CGM as a screening test for postpartum dysglycemia. 1-14 days postpartum; 4-6 months postpartum Diagnostic accuracy will be measured as sensitivity, specificity, positive likelihood ratio and negative likelihood ratio.
- Secondary Outcome Measures
Name Time Method New diagnosis of maternal diabetes or prediabetes based on HbA1c alone, and a combination of the 75-gram OGTT and the HbA1c. 4-6 months postpartum Diabetes or prediabetes based on the postpartum 75-gram OGTT will be evaluated as fasting plasma glucose ≥7.0 mmol/L or 2-hour plasma glucose of ≥11.1 mmol/L or fasting plasma glucose 6.1-6.9 mmol/L or 2-hour plasma glucose of 7.8-11.1 mmol/L, respectively. Diabetes or prediabetes based on the postpartum HbA1c will be evaluated as ≥6.5 and ≥6.0%, respectively. Diabetes and prediabetes will be analyzed separately and together.
Acceptability of CGM based on an acceptability questionnaires after device return and after final testing. 15-17 days postpartum; 4-6 months postpartum The Acceptability Questionnaires for the Freestyle Libre 2 Postpartum will be completed at two points throughout the study. "Strongly agree/painless" and "agree/almost painless" will be considered as "rated favorably" in planned analyses.
Dyslipidemia at time of postpartum bloodwork. 4-6 months postpartum Dyslipidemia is defined as abnormal levels of lipids in the bloodstream, which elevate cardiovascular risk. Lactation state will be recorded given impacts on lipid levels.
Glycemic variability reflected by coefficients of variation and standard deviations of blood glucose data. 1-14 days postpartum; 4-6 months postpartum Blood glucose data will be collected using the Freestyle Libre 2 continuous glucose monitoring system.
Cardiometabolic and related health outcomes diagnosed by regular healthcare team. 1, 2 and 5 years postpartum Information on dysglycemia, hypertension, cardiovascular disease, and additional health outcomes will be obtained through administrative provincial databases and chart review.
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.
Trial Locations
- Locations (4)
University of Calgary
🇨🇦Calgary, Alberta, Canada
University of Manitoba
🇨🇦Winnipeg, Manitoba, Canada
Mount Sinai Hospital
🇨🇦Toronto, Ontario, Canada
Universite Laval
🇨🇦Quebec City, Quebec, Canada