Translating the A1C Assay Into Estimated Average Glucose Values

Certainty in science went out of fashion early last century following Heisenberg's postulates. We now see ranges and confidence intervals around any given mode, mean, or median. Truth, in short, is a dependent variable. Yet the American Diabetes Association (ADA) seems to be set on recommending the introduction of an estimated average glucose (eAG) value based on A1C levels, as an ADA Web site carries the formula for conversion of A1C to eAG. However, three factors have led representatives of 18 professional organizations in the U.K. to reject the introduction of this same eAG conversion based on current evidence (1). These representatives, including the current two authors, are concerned with the validity of the basic …