Safety and Feasibility of an Insulin Sensitivity-Informed Bolus Calculator in Type 1 Diabetes

NCT03709108 | Completed

• 1 other identifier: 21040
• Study Type: interventional
• Target: 15
• Locations: 1 country
• Sites: 1

Brief Summary

This is a single-center randomized crossover trial. The investigators will target completion of 15 adults (age 18-65 years) with Type 1 Diabetes who use an insulin pump. After completion of the Screening Visit, each subject will participate in a 28-day at home Data Collection Period while using their personal insulin pump, a personal glucometer, a study CGM, and a study activity tracker (i.e., Fitbit). This data collection period may be extended to obtain to gather more days of quality data, if needed per principal investigator judgement. Once the data has been collected and processed, subjects will participate in two 24-hour admissions (Experimental and Control Admission) in a semi-controlled environment (i.e., hotel), performed in the assigned random order. During both admissions, subjects will use the personal insulin pump and glucometer, and a study CGM. The exercise session will consist of three 15-minute bouts of moderate-intensity exercise (i.e., stationary bicycle). Subjects will be provided a controlled dinner; the SI-informed bolus calculator will be used in the Experimental Admission while standard therapy will be used in the Control Admission. Subjects will then be observed overnight and discharged in the following morning.

Conditions

Type 1 Diabetes Mellitus

Keywords

Continuous Glucose Monitor; Insulin Sensitivity; Exercise

Outcome Measures

Primary Outcomes (1)

• Safety and feasibility of the SI-informed bolus calculator: Low Blood Glucose Index

  Safety and feasibility of the SI-informed bolus calculator as measured by overall and postprandial occurrence of hypoglycemia quantified using the Low Blood Glucose Index (LBGI) computed from CGM data. LBGI is a previously introduced glucose variability measure and strong predictor of severe hypoglycemia, designed to aggregate the frequency and extent of low blood glucose events into a single number. By this definition, a higher LBGI may indicate a large number of mild hypoglycemic events, a small number of significant events, or a combination of both. As a higher LBGI indicates higher exposure to hypoglycemia, LBGI is expected to be better (i.e., lower) when the optimized bolus calculator is used, as compared to standard therapy.

  LBGI will be assessed in the postprandial period following the controlled dinner meal (up to 4 hours following dinner) and overnight (e.g., from 11PM until 6AM), and will be compared between the two admissions.

Study Arms (2)

Experimental-Control

OTHER

Subjects randomized to this Arm would go through the Experimental Admission (SI-informed bolus calculator) first and Control Admission (regular bolus calculator) second

Other: SI-Informed Bolus Calculator

Control-Experimental

OTHER

Subjects randomized to this Arm would go through the Control Admission (regular bolus calculator) first and Experimental Admission (SI-informed bolus calculator) second

Other: SI-Informed Bolus Calculator

Interventions

SI-Informed Bolus Calculator OTHER

The SI-Informed Bolus Calculator will be used to dose the dinner meal insulin bolus during the Experimental Admission

Control-Experimental; Experimental-Control

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Type 1 diabetes for at least 12 months
• Current use of an insulin pump for at least 12 months
• Current or historical use of a CGM system for at least 6 months
• Age ≥18 to ≤65 years old
• HbA1c \<8.5% at screening; if HbA1c \<6.0% then total daily insulin must be ≥0.5 U/kg
• 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
• Willingness to use the same set of insulin therapy parameters (i.e., basal rate, insulin-to-carbohydrate ratio, correction factor) during both admissions
• Willingness to upload data during the study
• An understanding of and willingness to follow the protocol and sign the informed consent

You may not qualify if:

• Diabetes ketoacidosis (DKA) in the 6 months prior to enrollment
• Clinically significant electrocardiogram (ECG) found at Screening as determined by the study medical physician
• Severe hypoglycemia resulting in seizure or loss of consciousness in the 6 months prior to enrollment
• Currently being treated for a seizure disorder
• Coronary artery disease or heart failure, unless written clearance is received from a cardiologist or primary care provider and documentation of a negative stress test within the year
• History of cardiac arrhythmia (except for benign premature atrial contractions and benign premature ventricular contractions which are permitted)
• Cystic fibrosis
• Pregnancy, breast-feeding, or intention of becoming pregnant over time of study procedures
• Abnormal liver function test results (Transaminase \>2 times the upper limit of normal)
• Abnormal renal function test results (calculated GFR \<60 mL/min/1.73m2)
• Uncontrolled thyroid disease (TSH undetectable or \>10 mIU/L)
• 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 for either the subject or the subject's care companion
• Presence of a known adrenal disorder
• Active gastroparesis

Sponsors & Collaborators

• University of Virginia: lead
• Juvenile Diabetes Research Foundation: collaborator
• DexCom, Inc.: collaborator

Study Sites (1)

University of Virginia

Charlottesville, Virginia, 22908, United States

Location

Related Publications (1)

• Fabris C, Nass RM, Pinnata J, Carr KA, Koravi CLK, Barnett CL, Oliveri MC, Anderson SM, Chernavvsky DR, Breton MD. The Use of a Smart Bolus Calculator Informed by Real-time Insulin Sensitivity Assessments Reduces Postprandial Hypoglycemia Following an Aerobic Exercise Session in Individuals With Type 1 Diabetes. Diabetes Care. 2020 Apr;43(4):799-805. doi: 10.2337/dc19-1675. Epub 2020 Mar 6.

  PMID: 32144167 RESULT

MeSH Terms

Conditions

Diabetes Mellitus, Type 1; Insulin Resistance; Motor Activity

Condition Hierarchy (Ancestors)

Diabetes Mellitus; Glucose Metabolism Disorders; Metabolic Diseases; Nutritional and Metabolic Diseases; Endocrine System Diseases; Autoimmune Diseases; Immune System Diseases; Hyperinsulinism; Behavior

Study Officials

• Chiara Fabris, PhD

  University of Virginia

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: OTHER
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Research Associate

Study Record Dates

• First Submitted: October 8, 2018
• First Posted: October 17, 2018
• Study Start: November 19, 2018
• Primary Completion: March 31, 2019
• Study Completion: March 31, 2019
• Last Updated: July 17, 2024

Record last verified: 2024-07

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)