A High-accuracy and compliance-driven paradigm for pediatric type 2 diabetes screening based on simplified OGTT --- a multicenter study

The incidence of type 2 diabetes (T2D) in children is rising rapidly, yet many cases remain undetected. Conventional diagnostic tools, including fasting glucose, HbA1c, and the gold-standard oral glucose tolerance test (OGTT), have limitations and often show low compliance in pediatric populations. This study aimed to evaluate a simplified OGTT (s-OGTT) with adjusted capillary glucose cut-off values as a novel approach for screening and diagnosing T2D in children and adolescents. A total of 468 children from four clinical centers in China underwent s-OGTT with capillary glucose testing. Capillary glucose values were compared with venous glucose levels using Bland-Altman analysis. Sensitivity and specificity for diagnosing diabetes and prediabetes were assessed using receiver operating characteristic (ROC) curves. Capillary glucose levels showed a strong correlation with venous measurements. Based on gold-standard criteria, 37 children were diagnosed with diabetes, 41 with impaired fasting glucose (IFG), and 74 with impaired glucose tolerance (IGT). Using optimized capillary cut-offs tailored for point-of-care testing, the s-OGTT demonstrated excellent diagnostic performance and improved specificity compared with applying conventional venous-based thresholds directly: for diabetes based on fasting glucose (sensitivity 97.56%, specificity 98.40%), diabetes based on 2 h postload glucose (sensitivity 100.00%, specificity 99.67%), IFG (sensitivity 97.60%, specificity 98.30%), and IGT (sensitivity 88.89%, specificity 92.04%). Validation analyses confirmed high agreement between s-OGTT and venous results. The s-OGTT provides a reliable, accurate, and child-friendly approach for diagnosing diabetes and abnormal glucose tolerance. These optimized thresholds enhance diagnostic specificity and support its use for large-scale pediatric screening.