Hemoglobin A₁ and Serum Glucose Concentrations

Excerpt

To the editor: Conventional wisdom has it that hemoglobin (Hb)A₁ reflects average glycemia during the preceding several weeks in diabetic patients (1). We believe that data from our diabetic outpatient clinic support the assertion by Boden and colleagues (2) that HbA₁ levels are disproportionately representative of high rather than average glucose concentrations.

Through 1 year we measured HbA₁ by column chromatography (3) in 63 diabetic patients on a total of 192 occasions. Each sample was assayed twice and the mean obtained. Figure 1 shows these HbA₁ values in relation to the corresponding fasting serum glucose levels. For higher levels of