Evaluation of nonfasting tests to screen for childhood and adolescent dysglycemia

Abstract

OBJECTIVE - To assess performance of nonfasting tests to screen children for dysglycemia (prediabetes or diabetes). RESEARCH DESIGN AND METHODS - This was a cross-sectional study of 254 over-weight or obese (BMI ≥85th percentile) children aged 10-17 years. Subjects came for two visits to a clinical research unit. For visit one, they arrived fasting and a 2-h glucose tolerance test and HbA 1c and fructosamine testing were performed. For visit two, they arrived nonfasting and had a random plasma glucose, a 1-h 50-g nonfasting glucose challenge test (1-h GCT), and urine dipstick performed. The primary end point was dysglycemia (fasting plasma glucose ≥100 mg/dL or a 2-h postglucose ≥140 mg/dL). Test performance was assessed using receiver operating characteristic (ROC) curves and calculations of area under the ROC curve. RESULTS - Approximately one-half of children were female, 59% were white, and 30% were black. There were 99 (39%) cases of prediabetes and 3 (1.2%) cases of diabetes. Urine dipstick, HbA 1c (area under the curve [AUC] 0.54 [95% CI 0.47-0.61]), and fructosamine (AUC 0.55 [0.47-0.63]) displayed poor discrimination for identifying children with dysglycemia. Both random glucose (AUC 0.66 [0.60-0.73]) and 1-h GCT (AUC 0.68 [0.61-0.74]) had better levels of test discrimination than HbA 1c or fructosamine. CONCLUSIONS - HbA 1c had poor discrimination, which could lead to missed cases of dysglycemia in children. Random glucose or 1-h GCT may potentially be incorporated into clinical practice as initial screening tests for prediabetes or diabetes and for determining which children should undergo further definitive testing. © 2011 by the American Diabetes Association.