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Study of In Vivo Glucose Metabolism in High-fat Diet-fed Mice Using Oral Glucose Tolerance Test OGTT and Insulin Tolerance Test ITT
Published on: January 7, 2018
Feasibility, Acceptability, and Validity of Home Continuous Glucose Monitoring-Based Oral Glucose Tolerance Test in
Adriana Rodriguez Gonzalez1,2, Caleb Harrison1,2, Brianna Hewitt1,2
1Center for Pediatric Research in Obesity and Metabolism and Division of Pediatric Endocrinology, Diabetes, and Metabolism, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, USA.
Context:
Home-based approaches to type 2 diabetes (T2D) screening in youth may facilitate early diagnosis.
Objective:
This work aimed to evaluate feasibility, acceptability, and validity of a continuous glucose monitoring (CGM)-based oral glucose tolerance test (OGTT).
Methods:
A prospective observational study was conducted at a pediatric clinical and translational research center. Participants were youth aged 8 to 18 years with overweight/obesity and prediabetes-range glycated hemoglobin A1c (HbA1c), fasting glucose, or 2-hour glucose on OGTT, and/or one or more guideline-based T2D risk factors. Participants completed two 75 g 2-hour OGTT 1) at the research center using serum samples (research-OGTT), and 2) at home using blinded CGM (home-OGTT). Feasibility: Percentage with valid home-OGTT data (date/time reported, transmitter returned). Acceptability: Survey and interview responses. Validity: Sensitivity, specificity, positive- and negative predictive value (PPV, NPV) of home- vs research-OGTT dysglycemia (fasting ≥100 mg/dL; 2-hour ≥140 mg/dL).
Results:
Thirty-nine youth (54% female; 33% Black, 8% Hispanic/Latinx, 13% multiracial, 46% non-Hispanic White; age 14.6 ± 2.0 years; mean body mass index 37.0 ± 6.7 kg/m2) participated. HbA1c was 5.7% ± 0.4%, fasting glucose 85.7 ± 8.0 mg/dL, and 2-hour glucose 115.9 ± 25.9 mg/dL. Thirty (77%) had valid home-OGTT data. Acceptability was high (92% excellent/great, 8% neutral). Due to higher average values on home-OGTT, sensitivity and NPV were high (≥80%), while specificity (fasting: 10%; 2-hour: 25%) and PPV (fasting: 3.6%, 2-hour: 18.2%) were low.
Conclusion:
Home-OGTT was acceptable, but strategies to precisely capture glucose ingestion timing could improve feasibility. Alternate dysglycemia thresholds may need to be defined prior to using CGM as a method for T2D screening in youth.
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