Medication News & Update
The glycohemoglobin test or more commonly now referenced as the A1C value gives a picture of the patients average blood glucose levels over the last 120 days. However, the last 30 days contribute more to the value than do the previous 90-120 days. Therefore if significant changes in plasma glucose levels occur within the last 30 days it can contribute meaningfully to the A1C value.
The Diabetes Control and Complications Trial (DCCT) one of the benchmark diabetes trials within the past few years provides the greatest amount of data relating these two values. They developed or showed a linear relationship in that trial of A1C values to mean plasma glucose(MPG) levels. That relationship can be expressed mathematically as:
MPG = (35.6 x A1c) -77.3
the calculated value is approximate see the reference table below do the math and compare. ?use the percent as a whole number not 0.06 in your calculation.
AIC mg/dl glucose level Calculated
4 65 65.1
5 100 100.7
6 135 136.3
7 170 171.9
8 205 207.5
9 240 243.1
10 275 278.7
11 310 314.3
12 345 349.9
Each 1% change in A1c value represents a change of approximately 35mg/dl
These values and the relationship apply only to methods used to determine the A1C which are traceable to the DCCT reference.