Unmeasurable Hemoglobin A1c due to Extreme Hyperglycemia in High-performance Liquid Chromatography Method: A Case Report

Abstract

BACKGROUND: Hemoglobin A1c (HbA1c), which is one of the important parameters considered when judging the degree of glucose concentrations during the preceding 8–12 weeks, is used as the standard assessment of glycemic control in patients with diabetes. However, some measurement principles may cause errors in HbA1c measurement. CASE REPORT: A 49-year-old male patient with hyperglycemic hyperosmotic syndrome had an extreme high blood glucose level of 2,161 mg/dL and an HbA1c level that was not measurable due to a large amount of labile HbA1c. Many institutions measure HbA1c by high-performance liquid chromatography (HPLC). We measure HbA1c using ARKRAY HA-8190V (ion-exchange HPLC) and report National Glycohemoglobin Standardization Program (NGSP) (%). HbA1c was not measurable in this case, so we requested glycated albumin measurement as a substitute which revealed an extreme abnormal value of 64.5%. HPLC analysis revealed a large #C peak, which appeared to be labile HbA1c, before the HbA1c peak. The patient was treated with insulin therapy, and the HbA1c was measurable and was 14.1% a day after the glucose level was controlled. CONCLUSION: The report emphasiz of HbA1c measurements in situations of extreme hyperglycemia.