Using Wearable Sensors To Understand Low Blood Sugar in Type 1 Diabetes (Wear WOLF)

Assessment of Impaired Counterregulatory Hormones and Cardiovascular Risk Using Modern Wearable Sensors in People Living With Type 1 Diabetes.

This is a single-site study using wearable sensor technology (CGM and smartwatch) to better explain low blood sugars in patients living with type 1 diabetes.

Up to 20 participants with T1D will wear a continuous glucose monitor (CGM) and a smartwatch to collect information about hypoglycemia (low blood sugar), heart rate variability (HRV), and sleep for 4 weeks. The main goal is to create a hypoglycemia risk score using wearable sensor metrics that can be easily applied to all patients with T1D to identify those at greater risk of hypoglycemia.

Study Overview

• Status: Not yet recruiting
• Conditions: Type 1 Diabetes Mellitus
• Intervention / Treatment: Procedure: Hyperglycemic clamp

Detailed Description

This is a single-site study using wearable sensor technology (continuous glucose monitor [CGM] and smartwatch actigraphy) to stratify hypoglycemia and cardiovascular risk in patients living with type 1 diabetes.

To carry out this research, 20 local participants with Type 1 Diabetes (T1D) will wear CGM and smartwatches to quantify hypoglycemia, heart rate variability (HRV), and sleep actigraphy for 4 weeks. These data will be correlated with counterregulatory hormone levels collected during hyperinsulinemic-hypoglycemic (HHC) clamp. The goal is to create a hypoglycemia risk score using wearable sensor metrics that can be easily applied to all patients with T1D to identify those with impaired counter-regulation in the clinical setting (Aim 1). How hypoglycemia exposure impacts cardiometabolic health in T1D will also be explored.

Participants will complete ambulatory blood pressure monitoring (ABPM), flow mediated dilation (FMD), reactive hyperemia-peripheral artery tonometry (RH-PAT), HRV assessment via wearable smartwatch, and serum inflammatory and coagulation evaluation before and after hyperinsulinemic-hypoglycemic clamp to investigate the effect of hypoglycemia on these cardiovascular (CV) risk factors (Aim 2,3). Subjects will be monitored for 4 weeks prior, and 1 week after hypoglycemic clamp.

• Study Type: Interventional
• Enrollment (Estimated): 20
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Program Manager; Phone Number: 858-246-2169; Email: t1dresearch@health.ucsd.edu

Study Locations

• United States
  • California
    • La Jolla, California, United States, 92037
      • University of California, San Diego - ACTRI
      • Contact: Program Manager; Phone Number: 858-246-2169; Email: t1dresearch@health.ucsd.edu
      • Principal Investigator: Robert Thomas, MD, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Men and women between the ages of 18 and 75 years old, inclusive, at the time of screening;
2. Females of non-childbearing potential must be ≥ 1 year post-menopausal or documented as being surgically sterile. Females of childbearing potential must agree to use two methods of contraception during the entire study;
3. Diagnosed with Type 1 diabetes >2-year duration based on clinical history or as defined by the current American Diabetes Association (ADA) criteria;
4. Using hybrid closed loop, standard pump, or multiple daily injections;
5. Able to use a Continuous Glucose Monitoring (CGM) device;
6. A1c > 7% and ≤ 10%:
7. eGFR ≥ 60 mL/min/1.73m²;
8. BMI 18.5-35.0 kg/m2 ;
9. Able to provide written informed consent approved by an Institutional Review Board (IRB).

Exclusion Criteria:

1. History or evidence of clinically significant disorder or condition that, in the opinion of the Investigator, would pose a risk to subject safety or interfere with the study evaluation, procedures, or completion;
2. History of pancreatitis, medullary thyroid carcinoma or liver disease:
3. Clinically significant diagnosis of anemia (Hemoglobin < 9 g/dl at screening);
4. Body Mass Index (BMI) < 18.5 kg/m2 and/or weight <50kg;
5. Body Mass Index (BMI) > 35 kg/m2;
6. Whole blood donation of 1 pint (500 mL) within 8 weeks prior to Screening. Donations of plasma, packed RBCs, platelets or quantities less than 500 mL are allowed at investigator discretion;
7. Current or recent (within 1 month of screening) use of diabetes medications other than insulin; (examples include GLP-1, RA, SGLT-2i, Pramlintide, Metformin);
8. Women who are pregnant or lactating/breastfeeding;
9. Unable or unwilling to follow the study protocol or who are non-compliant with screening appointments or study visits;
10. Any other condition(s) that might reduce the chance of obtaining study data, or that might cause safety concerns, or that might compromise the ability to give truly informed consent;
11. Severe hypoglycemic events or DKA within 3 months;
12. Currently using beta-blockers;
13. Adrenal insufficiency diagnosis.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: Wearable Sensor Arm; The intervention is the hyperglycemic clamp. All participants will complete the clamp.	Procedure: Hyperglycemic clamp; A continuous infusion of 20% dextrose will be maintained throughout the procedure, while a variable rate of insulin infusion will be used to control participants blood glucose level.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Hypoglycemic Clamp Epinephrine Response	The change in epinephrine from the start of the clamp to the end as measured in pg/mL.	160 Minutes

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
CGM Time In Range	Percent time between 70-180 mg/dL as measured by continuous glucose monitor.	4 weeks
CGM Time Below Range	Percent time <70 mg/dL as measured by continuous glucose monitor.	4 weeks
Peripheral Artery Tonometry	Change in peripheral artery tonometry as measured by Endo-PAT score.	4 weeks
Brachial Flow Mediated Dilation	Change in brachial artery vasodilation as measured by flow mediated dilation.	4 weeks

Collaborators and Investigators

• Sponsor: University of California, San Diego
• Collaborators: National Institutes of Health (NIH)
• Investigators: Principal Investigator: Robert Thomas, MD, PhD, UC San Diego

Study record dates

Study Major Dates

• Study Start (Estimated): February 1, 2025
• Primary Completion (Estimated): March 31, 2026
• Study Completion (Estimated): June 30, 2026

Study Registration Dates

• First Submitted: December 6, 2024
• First Submitted That Met QC Criteria: December 6, 2024
• First Posted (Estimated): December 10, 2024

Study Record Updates

• Last Update Posted (Estimated): December 10, 2024
• Last Update Submitted That Met QC Criteria: December 6, 2024
• Last Verified: December 1, 2024

More Information

Terms related to this study

• Keywords: Type 1 Diabetes; T1D; Type 1
• Additional Relevant MeSH Terms: Endocrine System Diseases; Metabolic Diseases; Autoimmune Diseases; Immune System Diseases; Glucose Metabolism Disorders; Diabetes Mellitus; Diabetes Mellitus, Type 1
• Other Study ID Numbers: 810845

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: As the funding for this project is coming from an NIH K12 grant, the data is being used as preliminary data for a K23 submission, so there may not be enough information available to be meaningfully shared.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No