Discrepancies Between Reported Self-Monitored Blood Glucose Results and Point-of-Care Hemoglobin A1c in Children with Diabetes: Lessons to Be Learned

BACKGROUND: The hemoglobin A1c (HbA1c) assay is considered the gold standard for assessing glycemic control in children and adolescents with type 1 diabetes mellitus (T1DM). In recent years, point-of-care (POC) testing has been more commonly used in the outpatient clinic. However, despite its popularity, little is known about the accuracy of the POC methods in children. PATIENTS AND METHODS: In this case series, we describe seven children-six with T1DM and one with type 2 diabetes mellitus-who had major discrepancies between measured POC HbA1c via A1cNow+(®) (Bayer Healthcare Metrika, Sunnyvale, CA) and self-monitored blood glucose records. RESULTS: In six subjects, the discrepancy was explained by the presence of the hemoglobin S trait, and an additional subject had the hemoglobin C trait. CONCLUSIONS: This report demonstrates that as with all laboratory tests, the HbA1c test is subject to limitations, particularly in children with hemoglobin variants. Increased awareness regarding these limitations among healthcare professionals is paramount, especially with the increased use of the HbA1c POC method in the medical community. Failure to recognize these limitations can lead to unnecessary medical, financial, and social interventions that could have profound impact on the patient-doctor relationship.