Integration of Continuous Glucose Monitoring With HbA1c to Improve the Detection of Prediabetes in Asian Individuals: Model Development Study

Background Glycated hemoglobin (HbA 1c ) is a convenient tool to evaluate glycemic status but its ability to detect individuals at risk for type 2 diabetes is limited. Objective Exploiting the glycemic variability captured in continuous glucose monitoring (CGM), we used a well-characterized Asian cohort study from Singapore to assess whether utilizing CGM features in a machine learning model can improve the detection of prediabetes as compared to using HbA 1c alone. Methods In this study, 406 nondiabetic Asian participants underwent an oral glucose tolerance test and had their fasting and 2-hour plasma glucose concentrations measured, together with HbA 1c , to classify them as with normoglycemia or prediabetes. They also wore a CGM sensor for 14 days. CGM profile features were extracted and prediction models were constructed with random subsampling validation to evaluate predictive efficacy. The use of CGM and HbA 1c data alone or in combination was assessed for the ability to correctly distinguish prediabetes from normoglycemia. Results In this cohort (N=406), 189 (46.6%) individuals had prediabetes. The majority of the cohort were women (n=236, 58.1%) and of Chinese ethnicity (n=267, 65.8%). Those with prediabetes were slightly older, heavier, and had higher glucose levels with more variability than the normoglycemia group. A 2-step approach was used where those with HbA 1c ≥5.7% were automatically categorized as having prediabetes; the model then focused on the prediction capability of the CGM features among individuals with HbA 1c <5.7%. The prediction models with CGM outperformed the benchmark for comparison defined by HbA 1c ≥5.7%, where they yielded an area under the receiver operating characteristic curve of 0.866‐0.876, with a lower specificity of 78%‐80% but a vastly improved sensitivity of 76%‐78%. Conclusions Adding CGM to HbA 1c in a 2-step approach greatly improved the sensitivity of detecting prediabetes in an Asian population. Given the benefits to optimizing lifestyle behaviors and its growing acceptability among the nondiabetic population, CGM is a promising alternative for type 2 diabetes mellitus risk screening.