Are the ADA Hemoglobin A_1c Criteria Relevant for the Diagnosis of Type 2 Diabetes in Youth?

Diagnostic criteria for diabetes in children have not been established with nearly the rigor as that employed in adults. Recently revised American Diabetes Association (ADA) criteria allowed utilization of hemoglobin A_1c (HbA1c) ≥6.5 % for diagnosis of diabetes. A recent series of pediatric studies appear to show that HbA1c has lower sensitivity than Fasting plasma glucose (FPG) or oral glucose tolerance test (OGTT). However, FPG and OGTT have themselves never been validated in children. Studies to validate diagnostic thresholds in children appear unlikely to take place. Thus, accepting the major ADA diagnostic criteria appears to be the best course of action for the pediatric community. One area in which correlation studies between HbA1c and FPG or OGTT might shed light is in the definition of criteria for intervention in ‘pre-diabetes,’ as the Diabetes Prevention Program Trial did not use HbA1c. However, such treatment, and the exact diagnostic thresholds at which it should be initiated in children, remains unproven.