For the past several decades, glycated hemoglobin (also called hemoglobin A1c, HbA1c, or simply A1C) has been considered the gold standard for assessing overall glycemic control. However, this test has well-known shortcomings; conditions that alter the life span or glycation of red blood cells can render A1C a less reliable, or even wholly unreliable, indicator of a person’s actual glycemic status (1). Indeed, the frequency of potentially misleading laboratory A1C results is increasingly recognized (2). With the advent of glucose-sensing technology, a new tool has arrived that allows for determination of an individual’s overall glycemic control independent of the presence or absence of comorbidities that would render a laboratory A1C value unreliable.
Reports provided by current glucose-sensing technology devices provide a value for “estimated A1C” (3) or, alternatively, “glucose management indicator” (GMI). However, there are several major shortcomings with these...
