Feasibility, Acceptability, and Validity of Home Continuous Glucose Monitoring-Based Oral Glucose Tolerance Test in Youth.

Abstract

Home-based approaches to type 2 diabetes (T2D) screening in youth may facilitate early diagnosis. This work aimed to evaluate feasibility, acceptability, and validity of a continuous glucose monitoring (CGM)-based oral glucose tolerance test (OGTT). 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). 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. 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.