Prospective Test Performance of Nonfasting Biomarkers to Identify Dysglycemia in Children and Adolescents

Introduction: Test performance screening measures for dysglycemia have not been evaluated prospectively in youth. This study evaluated the prospective test performance of random glucose (RG), 1-hour nonfasting glucose challenge test (1-h GCT), Hemoglobin A1c (HbA1c), fructosamine (FA), and 1,5-Anhydroglucitol (1,5-AG) for identifying dysglycemia. Methods: Youth ages 8-17 years with overweight or obesity (body mass index, BMI, >= 85th percentile) without known diabetes completed nonfasting tests at baseline (n=176) and returned an average of 1.1 years later for two formal fasting 2-hour oral glucose tolerance tests. Outcomes included glucose-defined dysglycemia (fasting plasma glucose >= 100 mg/dL or 2-hour plasma glucose >= 140 mg/dL) or elevated HbA1c (>= 5.7%). Longitudinal test performance was evaluated using receiver operating characteristic (ROC) curves and calculation of area under the curve (AUC). Results: Glucose-defined dysglycemia, elevated HbA1c, and either dysglycemia or elevated HbA1c were present in 15 (8.5%), 11 (6.3%), and 23 (13.1%) participants at baseline, and 16 (9.1%), 18 (10.3%), and 28 (15.9%) participants at follow-up. For prediction of glucose-defined dysglycemia at follow-up, RG, 1-h GCT, and HbA1c had similar performance (0.68 (95% CI 0.55-0.80), 0.76 (95% CI 0.64-0.89), and 0.70 (95% CI 0.56-0.84)), while FA and 1,5-AG performed poorly. For prediction of HbA1c at follow-up, baseline HbA1c had strong performance (AUC 0.93 (95% CI 0.88-0.98)), RG had moderate performance (AUC 0.67 (0.54-0.79)), while 1-h GCT, FA, and 1,5-AG performed poorly. Conclusion: HbA1c and nonfasting glucose tests had reasonable longitudinal discrimination identifying adolescents at risk for dysglycemia, but performance depended on outcome definition.

Automated summary

This study evaluated the prospective test performance of different screening measures for identifying dysglycemia in youth. The results showed that HbA1c and nonfasting glucose tests had reasonable longitudinal discrimination in identifying adolescents at risk for dysglycemia, but their performance depended on the definition of the outcome.