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USS Virginia Closed-Loop for Overnight Control in Type 1 Diabetes

Unified Safety System (USS) Virginia Closed-Loop Versus Sensor Augmented Pump Therapy for Overnight Control in Type 1 Diabetes

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT02131766
Enrollment
33
Registered
2014-05-06
Start date
2014-06-30
Completion date
2015-03-31
Last updated
2020-04-16

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Diabetes Mellitus

Keywords

Diabetes Mellitus, Type 1, Artificial Pancreas Project (APP), Diabetes Assistant (DiAs), Closed-Loop Control (CLC)

Brief summary

The purpose of this study is to use the USS Virginia Closed-Loop system for overnight insulin delivery in adults with Type 1 Diabetes (T1DM) in an outpatient setting to evaluate the system's ability to significantly improve blood glucose levels. This protocol will test the feasibility of bedside closed-loop control - an approach comprised of standard sensor-augmented pump therapy during the day using off-the-shelf devices and overnight closed-loop control using experimental devices in an outpatient setting. The rationale for this study is as follows: we anticipate that closed-loop control may ultimately be adopted by patients with T1DM in a selective manner. Patient may choose to start using these systems for overnight control only, e.g. to alleviate the well documented fear of hypoglycemia while asleep. To test this paradigm of bedside closed-loop control, subjects will be studied with continuous glucose monitoring (CGM)-augmented usual pump therapy during the day followed by overnight use of USS Virginia Closed Loop Control.

Detailed description

The subject will participate in both the Experimental and the Control Admissions. The order of the two admissions will be randomized. During the Control Admission at home, the subject will use the study insulin pump along with a continuous glucose monitor receiver. During the Experimental Admission, the subject will be the research house/hotel where the subject will be in control of the DiAs. Participation in this study will require 5 study visits over 11-14 weeks.

Interventions

DEVICEDiAs

DiAs is the central component of our system. It is a standard cell phone running on an Android operating system. The cell phone has been changed to prevent from (1) using it as a phone or browser, (2) changing the volume (3) accidentally shutting it off. The cell phone runs an algorithm and is connected to work with the insulin pump and continuous glucose monitor to help keep the blood sugar in a desired range and help avoid hypoglycemia during the night.

Insulin pump plus CGM.

Sponsors

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
CollaboratorNIH
University of Virginia
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
21 Years to 65 Years
Healthy volunteers
No

Inclusion criteria

1. Clinical diagnosis, based on investigator assessment, of type 1 diabetes for at least one year and using insulin for at least 1 year and an insulin pump for at least 6 months \- Criteria for documented hyperglycemia (at least 1 must be met): i. Fasting glucose ≥126 mg/dL ii. Two-hour Oral Glucose Tolerance Test (OGTT) glucose ≥200 mg/dL iii. HbA1c ≥6.5% documented iv. Random glucose ≥200 mg/dL with symptoms v. No data at diagnosis is available but the participant has a convincing history of hyperglycemia consistent with diabetes. \- Criteria for requiring insulin at diagnosis (1 must be met): i. Participant required insulin at diagnosis and continually thereafter ii. Participant did not start insulin at diagnosis but upon investigator review likely needed insulin (significant hyperglycemia that did not respond to oral agents) and did require insulin eventually and used continually iii. Participant did not start insulin at diagnosis but continued to be hyperglycemic, had positive islet cell antibodies - consistent with latent autoimmune diabetes in adults (LADA) and did require insulin eventually and used continually 2. Age ≥21 to \<65 years 3. HbA1c \<10.0% 4. For females, not currently known to be pregnant If female and sexually active, must agree to use a form of contraception to prevent pregnancy while a participant in the study. A negative urine pregnancy test will be required for all premenopausal women who are not surgically sterile. Subjects who become pregnant will be discontinued from the study. 5. Demonstration of proper mental status and cognition for the study 6. Currently using insulin-to-carbohydrate ratio to calculate meal bolus sizes 7. Ability to access the Internet and upload CGM data via the DexCom company software during the data collection period. 8. Willingness to remain within approximately 30 miles radius of study site during the day time hours of Visit 4. 9. An understanding of and willingness to follow the protocol and sign the informed consent Additional Inclusion Criteria for UVA subjects only who participate in the 5 days at-home portion * Availability of a significant other or family member committed to participating in all training activities, knowledgeable at all times of the participant's location, and being present and available to provide assistance when system is being used at night * Commitment to maintaining uninterrupted availability via cell phone and avoiding any overnight travel for the duration of the period of time using the closed-loop system at home. * Access to internet and cell phone service at home

Exclusion criteria

1. Admission for diabetic ketoacidosis in the 12 months prior to enrollment 2. Severe hypoglycemia resulting in seizure or loss of consciousness in the 12 months prior to enrollment 3. History of a seizure disorder (except hypoglycemic seizure), unless written clearance is received from a neurologist 4. Coronary artery disease or heart failure, unless written clearance is received from a cardiologist 5. Cystic fibrosis 6. A known medical condition that in the judgment of the investigator might interfere with the completion of the protocol such as the following examples: * Inpatient psychiatric treatment in the past 6 months * Presence of a known adrenal disorder * Abnormal liver function test results (Transaminase \>2 times the upper limit of normal); testing required for subjects taking medications known to affect liver function or with diseases known to affect liver function * Abnormal renal function test results (calculated GFR \<60 mL/min/1.73m2); testing required for subjects with diabetes duration of greater than 5 years post onset of puberty * Active gastroparesis * If on antihypertensive, thyroid, anti-depressant or lipid lowering medication, lack of stability on the medication for the past 2 months prior to enrollment in the study * Uncontrolled thyroid disease (TSH undetectable or \>10 mlU/L); testing required within three months prior to admission for subjects with a goiter, positive antibodies, or who are on thyroid hormone replacement, and within one year otherwise * Abuse of alcohol or recreational drugs * Infectious process not anticipated to resolve prior to study procedures (e.g. meningitis, pneumonia, osteomyelitis). * Uncontrolled arterial hypertension (Resting diastolic blood pressure \>90 mmHg and/or systolic blood pressure \>160 mmHg). * Oral steroids * Uncontrolled microvascular complications such as current active proliferative diabetic retinopathy defined as proliferative retinopathy requiring treatment (e.g. laser therapy) in the past 12 months. 7. A recent injury to body or limb, muscular disorder, use of any medication, any carcinogenic disease, or other significant medical disorder if that injury, medication or disease in the judgment of the investigator will affect the completion of the protocol 8. Basal Rates \<0.01 units/hour. 9. Current use of the following drugs and supplements: * Acetaminophen * Any medication being taken to lower blood glucose, such as Pramlintide, Metformin, glucagon-like peptide (GLP)-1 Analogs such as Liraglutide, and nutraceuticals intended to lower blood glucose * Beta blockers * Any other medication that the investigator believes is a contraindication to the subject's participation

Design outcomes

Primary

MeasureTime frameDescription
USS Virginia Time Within Target40 hoursAssess the effect size of USS Virginia in increasing time within target (70-180 mg/dL) over a 24-hour period with closed-loop control overnight (23:00 to 07:00) as compared to sensor-augmented pump alone.

Secondary

MeasureTime frameDescription
Overnight Target Range40 hoursAssess time spent within target range of 80-140 mg/dl overnight with USS Virginia Closed Loop compared to sensor-augmented pump therapy alone
Decreased Overnight Hypoglycemia40 hoursAssess the effect of USS Virginia Closed Loop System to decrease hypoglycemia overnight compared to sensor-augmented pump therapy alone
Morning Glucose Levels40 hoursAssess the distribution of wake-up glucose levels at 07:00 achieved by USS Virginia Closed Loop vs. to sensor-augmented pump therapy alone;

Countries

Italy, United States

Participant flow

Pre-assignment details

These results for 40 participants who completed the trial represent the combined results from participants at UVA, Mt. Sinai and Mayo Clinic (NCT02131766) combined with participants at University of Padua in Italy (NCT02008188).

Participants by arm

ArmCount
USS Virginia Closed Loop Control vs SAP
This is a cross-over trial in which each subject participates in two phases: USS Virginia Closed Loop Control (CLC) and Sensor Augmented Pump Therapy (SAP) and is randomized to order. During CLC: The subject will be admitted to the research house/hotel and will be discharged after 5 nights. The DiAs (CLC controller) will be initiated by 11:00 PM and will be discontinued before breakfast. During SAP: The subject will wear the continuous glucose monitor with the study insulin pump for a full 7 day period (approximately 7 consecutive 24 hour periods). The subject will follow their usual regimen. A limited number of UVA and UPadova subjects will be asked to wear the DiAs at home for 5 days at the conclusion of research house admission.
40
Total40

Withdrawals & dropouts

PeriodReasonFG000
Overall StudyWithdrawal by Subject4

Baseline characteristics

CharacteristicUSS Virginia Closed Loop Control vs SAP
Age, Continuous45.5 years
STANDARD_DEVIATION 9.5
Region of Enrollment
Italy
12 participants
Region of Enrollment
United States
28 participants
Sex: Female, Male
Female
22 Participants
Sex: Female, Male
Male
18 Participants

Adverse events

Event typeEG000
affected / at risk
deaths
Total, all-cause mortality
— / —
other
Total, other adverse events
1 / 40
serious
Total, serious adverse events
0 / 40

Outcome results

Primary

USS Virginia Time Within Target

Assess the effect size of USS Virginia in increasing time within target (70-180 mg/dL) over a 24-hour period with closed-loop control overnight (23:00 to 07:00) as compared to sensor-augmented pump alone.

Time frame: 40 hours

Population: Cross-over trial with same subjects participating in both arms for a total of 40 subjects.

ArmMeasureValue (MEAN)Dispersion
USS Virginia Closed Loop ControlUSS Virginia Time Within Target78.3 percentage of time spent in rangeStandard Deviation 10.2
Sensor Augmented Pump TherapyUSS Virginia Time Within Target71.4 percentage of time spent in rangeStandard Deviation 11.6
Secondary

Decreased Overnight Hypoglycemia

Assess the effect of USS Virginia Closed Loop System to decrease hypoglycemia overnight compared to sensor-augmented pump therapy alone

Time frame: 40 hours

Population: Cross-over trial with a total of 40 participants

ArmMeasureValue (MEAN)Dispersion
USS Virginia Closed Loop ControlDecreased Overnight Hypoglycemia0.9 percentage of time overnightStandard Deviation 1.5
Sensor Augmented Pump TherapyDecreased Overnight Hypoglycemia3.2 percentage of time overnightStandard Deviation 3.4
Secondary

Morning Glucose Levels

Assess the distribution of wake-up glucose levels at 07:00 achieved by USS Virginia Closed Loop vs. to sensor-augmented pump therapy alone;

Time frame: 40 hours

Population: Cross-over trial with a total of 40 participants

ArmMeasureValue (MEAN)Dispersion
USS Virginia Closed Loop ControlMorning Glucose Levels123.7 mg/dLStandard Deviation 17.8
Sensor Augmented Pump TherapyMorning Glucose Levels145.3 mg/dLStandard Deviation 31
Secondary

Overnight Target Range

Assess time spent within target range of 80-140 mg/dl overnight with USS Virginia Closed Loop compared to sensor-augmented pump therapy alone

Time frame: 40 hours

Population: Cross-over trial for a total of 40 participants

ArmMeasureValue (MEAN)Dispersion
USS Virginia Closed Loop ControlOvernight Target Range61.1 percentage of time overnightStandard Deviation 20.6
Sensor Augmented Pump TherapyOvernight Target Range39.6 percentage of time overnightStandard Deviation 18.3

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026