Continuous Glucose Monitors (CGM) for Type 2 Diabetes (T2D) Risk Evaluation

Feasibility and Acceptability of Home Use Continuous Glucose Monitors for Type 2 Diabetes Risk Evaluation in Youth

The purpose of this research study is to determine whether continuous glucose monitors (CGM) are a safe, effective, and acceptable way to evaluate type 2 diabetes risk in youth as compared to the standard 2-hour oral glucose tolerance test (OGTT).

This study will involve wearing a CGM, wearing a physical activity tracker, responding to surveys, and completing at-home glucose and mixed food challenge while wearing the CGM. Subjects will also be asked to complete an interview by phone or videoconference after wearing the CGM.

Study Overview

• Status: Completed
• Conditions: Insulin Resistance; PreDiabetes; Overweight and Obesity
• Intervention / Treatment: Device: CGM

Detailed Description

Youth-onset type 2 diabetes (T2D), an increasingly common and aggressive disease that disproportionately impacts racial and ethnic minorities, presents several diagnostic challenges. The rapid loss of glycemic control soon after T2D diagnosis makes early identification an important goal in pediatrics, and risk-based screening has been recommended for children for over two decades. However, the screening tests currently used in practice, including hemoglobin A1c (HbA1c), fasting glucose, and 2-hour oral glucose tolerance test (OGTT), have significant drawbacks. Real-time continuous glucose monitors (CGM) are promising new tools for risk stratification in individuals with dysglycemia. These patient-worn medical devices measure interstitial glucose every 5 minutes and offer glimpses into an individual's everyday life, which may include consumption of carbohydrates in amounts larger than that assessed in an OGTT, enhancing test sensitivity. Whether use of CGMs to evaluate type 2 diabetes risk in free-living youth is feasible and acceptable to patients and families is unknown. Assessment of CGM with standardized, but practical, home-based glucose and mixed-meal challenges is needed to determine facilitators and barriers to use of this technology-driven approach in clinical practice. Without advancement in the approach to screening for youth-onset T2D, there is ongoing risk of failure to understand which individuals are at highest risk for complications and could benefit the most from intervention early in the disease process.

In this single-arm prospective study, participants will attend one in-person study visit to complete 2-hour oral glucose tolerance test after overnight fast. Participants will wear a continuous glucose monitor and a wrist-worn actigraphy device for physical activity and sleep measurement for 10 days beginning on the day of the study visit, then return the monitors by mail. During the 10 day wear period, participants will respond to text message-based surveys to document food intake, physical activity, and sleep times and will complete two at-home challenges: 1) glucose challenge using study-provided glucose beverage that is identical to that they consume during clinical oral glucose tolerance test; and 2) food challenge with mixed carbohydrate/fat/protein-containing food of their choice. Glucose trends during these at-home challenges will be compared with oral glucose tolerance test obtained during the study visit. Individual interviews will be conducted upon completion of CGM wear to assess acceptability of the use of at-home glucose challenge and CGM wear as a strategy to evaluate diabetes risk in youth.

• Study Type: Interventional
• Enrollment (Actual): 40
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Pennsylvania
    • Pittsburgh, Pennsylvania, United States, 15224
      • Children's Hospital of Pittsburgh

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 8 years to 18 years (Child, Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Any gender, age 8-18 years
• Tanner 2 or higher pubertal development
• Overweight or obese (BMI ≥85th percentile for age/sex, or ≥ 25 kg/m2 for participants =18 years)
• A) No previously documented abnormal HbA1c or glucose but at higher risk for T2D based on race/ethnicity (Black, Hispanic, Asian, Native American, Pacific Islander), diagnosis with dyslipidemia, hypertension, polycystic ovary syndrome, presence of acanthosis nigricans, or first degree relative with T2D; or B) previously documented (within 6 months) HbA1c 5.7-7.0%, fasting glucose ≥100 mg/dL, or 2-hour plasma glucose on OGTT of ≥140 mg/dL
• Consent (adult subjects), parental/guardian permission (if applicable), assent (if applicable)
• Willingness to wear ActiGraph watch and CGM continuously for 10 day study duration

Exclusion Criteria:

• Current or recent (within 1 month) use of diabetes-related medication
• Current use of hydroxyurea (due to interference with CGM)
• Known type 1, cystic fibrosis-related, or medication-induced diabetes
• Potential subject unable to speak or read in English
• Severe cognitive impairment
• Current or previous pregnancy

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: CGM use for T2D risk evaluation; All participants will complete a standard 2-hour oral glucose tolerance test (OGTT), wear a CGM for 10 days, complete at-home glucose challenge, and provide qualitative feedback about their experiences with both OGTT and CGM use for risk evaluation.	Device: CGM; Participants will wear blinded Dexcom G6 Pro continuously for 10 days in their home environment. Two challenges will be completed at home: 1) glucose, using 1.75 g/kg (max 75g) glucose beverage provided by study team, and 2) mixed food, containing 50g carb as well as protein and fat content of participant's choice.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Feasibility of CGM Use to Determine Type 2 Diabetes Risk	Completeness of CGM data (≥ 80% of days with data)	10 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Acceptability of CGM Use for At-home T2D Risk Evaluation in Youth	Interview-based assessment. Participants rated their experience with CGM-OGTT using a Likert-like scale from 1-5 (1= terrible, 2=bad, 3=neutral, 4=good, 5=excellent). Acceptability was defined as a pre-specified threshold of ≥80% of participants providing a neutral or higher rating.	30 minutes
Sensitivity of At-home CGM-measured Glucose Challenge	Sensitivity of CGM-glucose 2 hours after at-home glucose beverage ingestion to predict OGTT-2h≥140 mg/dL	2 Hour Point of Home-OGTT
Specificity of At-home CGM-measured Glucose Challenge	Specificity of CGM-glucose 2 hours after at-home glucose beverage ingestion to predict OGTT-2h≥140 mg/dL	2 Hour Point of Home-OGTT
Positive Predictive Value of At-home, CGM-measured Glucose Challenge	Positive predictive value of CGM-glucose 2 hours after at-home glucose beverage ingestion to predict OGTT-2h≥140 mg/dL	2 Hour Point of Home-OGTT
Negative Predictive Value of At-home, CGM-measured Glucose Challenge	Negative predictive value of CGM-glucose 2 hours after at-home glucose beverage ingestion to predict OGTT-2h≥140 mg/dL	2 Hour Point of Home-OGTT
Sensitivity of At-home CGM-measured Fasting Glucose	Sensitivity of baseline CGM-glucose at the time of at-home glucose beverage ingestion to predict fasting OGTT ≥100 mg/dL	5 Minute Point of Home-OGTT
Specificity of At-home CGM-measured Fasting Glucose	Specificity of baseline CGM-glucose at the time of at-home glucose beverage ingestion to predict fasting OGTT ≥100 mg/dL	5 Minute Point of Home-OGTT
Positive Predictive Value of At-home CGM-measured Fasting Glucose	Positive predictive value of baseline CGM-glucose at the time of at-home glucose beverage ingestion to predict fasting OGTT ≥100 mg/dL	5 Minute Point of Home-OGTT
Negative Predictive Value of At-home CGM-measured Fasting Glucose	Negative predictive value of baseline CGM-glucose at the time of at-home glucose beverage ingestion to predict fasting OGTT ≥100 mg/dL	5 Minute Point of Home-OGTT

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Laboratory-measured HbA1c	HbA1c will be measured in the laboratory at baseline to investigate associations with CGM indices obtained during at-home glucose challenge.	Measured at Research Visit
Laboratory-measured Fasting Glucose	Fasting glucose will be measured in the laboratory at baseline to investigate associations with CGM indices obtained during at-home glucose challenge.	Start of Lab-OGTT
Laboratory-measured 2-hour Glucose	2-hour OGTT glucose will be measured in the laboratory at baseline to investigate associations with CGM indices obtained during at-home glucose challenge.	2 Hour Point of Lab-OGTT

Collaborators and Investigators

• Sponsor: Mary Ellen Vajravelu, MD
• Investigators: Principal Investigator: Mary Ellen Vajravelu, MD, MSHP, University of Pittsburgh

Study record dates

Study Major Dates

• Study Start (Actual): October 11, 2022
• Primary Completion (Actual): November 21, 2023
• Study Completion (Actual): December 14, 2023

Study Registration Dates

• First Submitted: May 25, 2022
• First Submitted That Met QC Criteria: May 31, 2022
• First Posted (Actual): June 3, 2022

Study Record Updates

• Last Update Posted (Actual): September 25, 2024
• Last Update Submitted That Met QC Criteria: August 30, 2024
• Last Verified: August 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Glucose Metabolism Disorders; Metabolic Diseases; Overnutrition; Nutrition Disorders; Body Weight; Hyperinsulinism; Insulin Resistance; Overweight
• Other Study ID Numbers: STUDY22030082

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: Yes