Continuous Glucose Monitors (CGM) for Type 2 Diabetes (T2D) Risk Evaluation
Condition: Overweight and Obesity; PreDiabetes; Insulin Resistance
MeSH terms: Overweight; Insulin Resistance
Study type: Interventional

Summary: 
      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.
    

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.
    

Intervention name(s): CGM
Intervention type(s): Device
Intervention description(s): 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.
Intervention model: Single Group Assignment
Intervention model description: Subjects will wear a continuous glucose monitor (CGM) to determine the feasibility and acceptability of the device to evaluate risk of youth developing Type 2 Diabetes (T2D).
Masking: None (Open Label)
Primary purpose: Diagnostic