News & Research

By: Tory Asfahani

The ADA- and EASD-sponsored study, ADAG (HbA1c Derived Average Glucose) is drawing to a close, and new data was presented at the EASD meeting held in Amsterdam last month.

The purpose of ADAG is to determine whether there is a correlation between HbA1c values and blood glucose measurements. From this data, the ADAG study group developed an easier to understand method of determining someone’s average glucose level over a period of time. Currently, we refer to someone’s HbA1c, usually represented as a percentage, to describe how well they are controlling their blood glucose over time. Both the ADA and EASD recommend that people with diabetes try to maintain an HbA1c level of less than 7 percent, but this number does not have a great deal of meaning to someone who measures their daily glucose levels in terms of mg/dL. The ADAG study will help to clarify this measurement for patients by calculating an estimated average glucose level (measured in mmol/L or mg/dL) which is validated across all types of diabetes, in people of different ages and ethnicities who have a wide range of A1C levels.

The study, which began recruiting patients at 11 clinical centers in 6 countries in April 2006, was able to demonstrate “a sufficiently tight correlation between HbA1c and an average glucose (AG) to provide an equation to translate HbA1c values into an estimated Average Glucose (eAG).” The study authors recommend adopting a new consensus statement, which calls for the HbA1c assay to be standardized worldwide using new methods, with laboratory values expressed as a percent HbA1c, or as eAG in mmol/L or mg/dL. All clinical guidelines should be expressed in these units. It is anticipated that, over time, providers will begin using eAG over HbA1c with their patients in clinical practice.