Closed-loop Insulin Delivery In Type 1 Diabetes Pregnancies (CIRCUIT) (CIRCUIT)

February 12, 2024 updated by: Lois Donovan, University of Calgary

Closed-loop Insulin Delivery by Glucose Responsive Computer Algorithms In Type 1 Diabetes Pregnancies (CIRCUIT)

This trial will assess the efficacy of the Tandem t:slim X2 insulin pump with Control IQ technology compared with standard insulin delivery plus CGM in pregnant women with type 1 diabetes.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Pregnant women with type 1 diabetes (T1D) require normal or near normal glucose in order to reduce the risks of birth defects, stillbirth, increased birthweight, neonatal hypoglycemia, neonatal death, preterm delivery and preeclampsia. Reducing maternal glucose is extremely difficult due to an increased risk of maternal hypoglycemia. Only 14% of T1D pregnancies achieve pregnancy guideline recommended glucose control, leading to complications related to high maternal glucose exposure in roughly half of newborns.

Maintaining recommended maternal glucose levels during pregnancy reduces the risk of adverse neonatal outcomes to those similar in pregnancies unaffected by T1D. Most insulin pumps in use today are open-loop systems, which means that the user must program the pump to deliver a pre-set amount of insulin. These insulin delivery methods (MDI and open-loop pumps) are usually inadequate to achieve the optimal glucose control necessary for T1D pregnancies and they impart a large time, effort and emotional burden.

Closed-loop systems have been found to be effective in improving glucose control outside of pregnancy when studied in children and adults. A new hybrid closed-loop system, the Tandem t:slim X2 insulin pump with Control IQ technology, recently became commercially available. Trials have demonstrated the efficacy of the Control IQ algorithm for non-pregnant adults and children. Pregnant women were not included in these trials.

The investigators propose the first randomized controlled trial to evaluate the Tandem t:slim X2 insulin pump with Control IQ technology versus standard insulin delivery (MDI or pump) and CGM in pregnant women with T1D. In this trial, the investigators will assess the efficacy of the Tandem t:slim X2 insulin pump with Control IQ technology compared with standard insulin delivery plus CGM in pregnant women with type 1 diabetes.

We are grateful to Tandem Diabetes Care and Dexcom for in-kind donations to this investigator initiated study.

Study Type

Interventional

Enrollment (Estimated)

90

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • Australia
      • Campbelltown, Australia, 2560
      • Camperdown, Australia
      • Garran, Australia
        • Not yet recruiting
        • Canberra Hospital
        • Contact:
          • Christopher Nolan
      • Parkville, Australia
      • Westmead, Australia
  • Canada
    • Alberta
      • Calgary, Alberta, Canada, T2T 5C7
        • Recruiting
        • University of Calgary
        • Contact:
        • Principal Investigator:
          • Lois Donovan, MD
        • Contact:
    • British Columbia
    • Manitoba
    • Ontario
      • London, Ontario, Canada, N6C 2R5
      • Toronto, Ontario, Canada, M5T 3L9
        • Recruiting
        • Mount Sinai Hospital
        • Contact:
      • Toronto, Ontario, Canada, M4N 3M5
    • Quebec

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

16 years to 43 years (Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Between 18 and 45 years of age (inclusive)
  • A diagnosis of type 1 diabetes, as defined by Diabetes Canada, for at least 12 months
  • A viable singleton pregnancy confirmed by ultrasound, less than 14 weeks gestation
  • Currently on intensive insulin therapy (≥ 3 injections, or Continuous subcutaneous insulin infusion (CSII)
  • Willingness to use the study devices throughout the trial
  • A1c ≥ 6.5% and <10% measured any time during pregnancy prior to enrollment
  • Able to provide informed consent
  • Have access to email

Exclusion Criteria:

  • Non-type 1 diabetes
  • Current treatment with drugs known to interfere with glucose metabolism as judged by the investigator such as high dose systemic corticosteroids
  • Known or suspected allergy to insulin
  • Women with nephropathy (estimated glomerular filtration rate [eGFR] <45), severe autonomic neuropathy, uncontrolled gastroparesis or severe proliferative retinopathy, as judged by the investigator, that is likely to interfere with the normal conduct of the study and interpretation of study results
  • Total daily insulin dose <8 or >250 units/day at screening
  • Severe visual or hearing impairment, as judged by the investigator to impact treatment compliance
  • Unable to communicate effectively in English or French as judged by the investigator
  • Current use of Tandem Control IQ, DIY looping system, 670G in Auto Mode, or alternate closed-loop system as judged by the investigator
  • Any reason judged by the investigator that would likely interfere with the normal conduct of the study and interpretation of study results

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Tandem t:slim X2 insulin pump with Control IQ technology plus CGM
Participants randomized to the intervention group will be fitted with the Tandem t:slim X2 insulin pump with Control IQ technology and Dexcom G6 Continuous Glucose Monitor.
Device: Tandem t:slim X2 insulin pump with Control IQ technology
The intervention group will be fitted with the Tandem t:slim X2 insulin pump with Control IQ technology during pregnancy.
No Intervention: Standard insulin delivery (multiple daily injections (MDI) or pump) and CGM
Participants randomized to the control group will be fitted with the Dexcom G6 Continuous Glucose Monitor. They will continue to use standard insulin delivery (MDI or pump) and CGM.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Glycemic control as reflected by percent glucose time-in-range
Time Frame: 16 weeks until 34 weeks gestation
Time in range (3.5 to 7.8 mmol/L) per day assessed by CGM glucose measurement
16 weeks until 34 weeks gestation

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Percent time spent above target range per day (+/-SD)
Time Frame: 16 weeks gestation until delivery of neonate
Glucose above target range defined as glucose >7.8 mmol/L; Blood glucose will be assessed using CGM data
16 weeks gestation until delivery of neonate
Percent time spent below target range per day (+/-SD)
Time Frame: 16 weeks gestation until delivery of neonate
Glucose below target range defined as glucose < 3.5 mmol/L; Blood glucose will be assessed using CGM data
16 weeks gestation until delivery of neonate
Mean blood glucose measurement at 24 and 34 weeks (+/-SD)
Time Frame: 24 and 34 weeks gestation
Blood glucose measured in mmol/L and assessed using CGM data
24 and 34 weeks gestation
Proportion of participants who experience maternal hypoglycemic events
Time Frame: 16 weeks gestation until delivery of neonate
Maternal hypoglycemic events defined as ≥15 minutes with CGM glucose <3.5 mmol/L [level 1] or <2.8 mmol/L [level 2]; Blood glucose will be assessed using CGM data
16 weeks gestation until delivery of neonate
Glycemic variability reflected by the coefficients of variation and standard deviations of CGM data
Time Frame: 16 weeks gestation until delivery of neonate
Blood glucose measured in mmol/L and assessed using CGM data
16 weeks gestation until delivery of neonate
Diabetes-related distress to the participant
Time Frame: 7-13 weeks + 6 days gestation, 24 weeks gestation, 34 weeks gestation, 6 weeks postpartum
Diabetes-related distress will be assessed four times during the study using the Diabetes Distress Screening Scale (DDSS17)
7-13 weeks + 6 days gestation, 24 weeks gestation, 34 weeks gestation, 6 weeks postpartum
Fear of hypoglycemia
Time Frame: 7-13 weeks + 6 days gestation, 24 weeks gestation, 34 weeks gestation, 6 weeks postpartum
Fear of hypoglycemia will be assessed four times during the study using the Hypoglycemia Fear Survey Questionnaire II (HFSQ II)
7-13 weeks + 6 days gestation, 24 weeks gestation, 34 weeks gestation, 6 weeks postpartum
Fear of hyperglycemia
Time Frame: 7-13 weeks + 6 days gestation, 24 weeks gestation, 34 weeks gestation, 6 weeks postpartum
Fear of hyperglycemia will be assessed four times during the study using the g. Hyperglycemia Fear in Pregnancy Survey
7-13 weeks + 6 days gestation, 24 weeks gestation, 34 weeks gestation, 6 weeks postpartum
Sleep quality
Time Frame: 7-13 weeks + 6 days gestation, 24 weeks gestation, 34 weeks gestation, 6 weeks postpartum
Sleep quality will be assessed at four times during the study using the Modified Pittsburgh Sleep Quality Index (PSQI)
7-13 weeks + 6 days gestation, 24 weeks gestation, 34 weeks gestation, 6 weeks postpartum
Health-related quality of life
Time Frame: 7-13 weeks + 6 days gestation, 24 weeks gestation, 34 weeks gestation, 6 weeks postpartum
Health-related quality of life will be assessed four times during the study using the Euro Quality of life questionnaire (EQ-5D-5L)
7-13 weeks + 6 days gestation, 24 weeks gestation, 34 weeks gestation, 6 weeks postpartum
Work productivity
Time Frame: 7-13 weeks + 6 days gestation, 24 weeks gestation, 34 weeks gestation, 6 weeks postpartum
Work productivity will be assessed four times during the study using the Work Productivity and Activity Impairment survey
7-13 weeks + 6 days gestation, 24 weeks gestation, 34 weeks gestation, 6 weeks postpartum
Diabetes-related distress to the partners
Time Frame: 7-13 weeks + 6 days gestation, 24 weeks gestation, 34 weeks gestation, 6 weeks postpartum
Diabetes-related distress to the partners will be assessed four times during the study using the Partner Diabetes Distress Scale
7-13 weeks + 6 days gestation, 24 weeks gestation, 34 weeks gestation, 6 weeks postpartum
Proportion of participants who experience preeclampsia events
Time Frame: 16 weeks gestation until delivery of neonate

Preeclampsia is defined as pregnancy ≥20 wks gestation with SBP ≥140mmHg and/or DBP ≥90 mmHg on ≥2 occasions a minimum of 6 hrs apart and new-onset of proteinuria (defined as urinary excretion ≥0.3g protein on a 24-hr urine specimen, or ≥ 2+ by urinary dipstick, or ≥30mg protein/mmol of urinary creatinine by spot testing) OR ≥1 of the following adverse conditions:

  • Eclampsia (Seizures in pregnancy)
  • Elevated liver function tests (Increased AST and/or ALT >70 IU/L)
  • Decreased platelet count <100 x 109/L
  • Elevated serum creatinine (>80 μmol/L)
  • Small for gestational age infant (birth weight <10th percentile)
16 weeks gestation until delivery of neonate
Proportion of participants who experience gestational hypertension events
Time Frame: 16 weeks gestation until delivery of neonate
Gestational hypertension is defined as a woman ≥20 weeks gestation with a systolic blood pressure of ≥140 mm Hg and/or a diastolic blood pressure ≥90 mm Hg on ≥2 occasions a minimum of 6 hours apart without proteinuria
16 weeks gestation until delivery of neonate
Proportion of participants who experience worsening chronic hypertension events
Time Frame: 16 weeks gestation until delivery of neonate
Chronic hypertension is defined as hypertension that is present at <20 weeks gestation or pre-pregnancy
16 weeks gestation until delivery of neonate
Proportion of participants who have caesarean deliveries
Time Frame: 16 weeks gestation until delivery of neonate
16 weeks gestation until delivery of neonate
Proportion of participants who experience preterm births
Time Frame: Delivery of neonate to 6 weeks postpartum
Preterm birth defined as birth occurring <37 weeks gestation
Delivery of neonate to 6 weeks postpartum
Proportion of babies born large for gestational age (>90th percentile)
Time Frame: Delivery of neonate
Delivery of neonate
Proportion of babies born small for gestational age (<10th percentile)
Time Frame: Delivery of neonate
Delivery of neonate
Mean neonatal birthweight (+/-SD)
Time Frame: Delivery of neonate
Birthweight measured in kilograms
Delivery of neonate
Comparison of birthweight z-score
Time Frame: Delivery of neonate
Delivery of neonate
Proportion of babies born with neonatal hypoglycemia
Time Frame: Delivery of neonate
Delivery of neonate
Proportion of neonates admitted to intensive care unit admission
Time Frame: Delivery of neonate to 6 weeks postpartum
Admission to neonatal intensive care unit admission defined as admission of 24 hours or more
Delivery of neonate to 6 weeks postpartum
Proportion of participants who experienced pregnancy loss or miscarriage (< 20 weeks, stillbirth ≥20 weeks, neonatal loss up to 28 days)
Time Frame: 7-13 weeks until delivery of neonate + up to 28 days
7-13 weeks until delivery of neonate + up to 28 days
Proportion of participants who experience episodes of severe hypoglycemia
Time Frame: 7-13 weeks + 6 days gestation until delivery of neonate
Severe hypoglycemia defined as a hypoglycemic episode requiring assistance from another person.
7-13 weeks + 6 days gestation until delivery of neonate
Proportion of participants who experience episodes of diabetic ketoacidosis
Time Frame: 7-13 weeks + 6 days gestation until delivery of neonate
Diabetic ketoacidosis (DKA) is defined as an episode with elevated plasma ketones which can be categorized as possible DKA (mild/ self- treated [plasma ketones 0.6 - 1.5mmol/L], moderate/self-treated (plasma ketones > 1.5mmol/L which resolves without hospital admission), or capillary blood ketones >3.0 mol/L without an anion gap of > 15 with admission to hospital for another reason [i.e. prevention of DKA]) or confirmed DKA (severe, with either plasma ketones > 3.0mmol/L or positive serum ketones with an anion gap (Na -(CI+HC03) > 15 and requiring hospital admission for IV fluids and IV insulin to correct the abnormal metabolic state).
7-13 weeks + 6 days gestation until delivery of neonate
Proportion of participants who experience device-related adverse events
Time Frame: 7-13 weeks + 6 days gestation until delivery of neonate
Device-related adverse events include skin reactions and insulin delivery failures.
7-13 weeks + 6 days gestation until delivery of neonate

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Calgary

Investigators

  • Principal Investigator: Denice Feig, MD, Mount Sinai Hospital
  • Principal Investigator: Lois Donovan, MD, University of Calgary

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 15, 2021

Primary Completion (Estimated)

January 1, 2026

Study Completion (Estimated)

January 1, 2026

Study Registration Dates

First Submitted

April 28, 2021

First Submitted That Met QC Criteria

May 20, 2021

First Posted (Actual)

May 26, 2021

Study Record Updates

Last Update Posted (Actual)

February 13, 2024

Last Update Submitted That Met QC Criteria

February 12, 2024

Last Verified

February 1, 2024

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • REB20-1266

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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