Hi Helmut

There are formulas that have used 5 days glucose measures to give an estimated glycated albumin (Look up Suzuki on pubmed). But I cannot see the reason why you would want to do it? HbA1c is an integration of net glucose exposure over the last ninety days (although significantly weighted to glycaemia over the last 2-4 weeks). Hence it tells you much more than a few glucose measurements alone can tell you, and by definition any guestimation of HbA1c from glucose measures will be flawed and highly variably. In what scenario would you want to do this?

You may, but just approximately.

Your answers are in: 

http://www.ngsp.org/A1ceAG.asp

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2999698/

Hope these are helpful!

Wisit

Timothy is right. It depends to much on the average survival time of erythrocytes (and therefore hemoglobin). For this reason this is not advised in the Netherlands

Hi Helmut in Osnabrueck;

well yes; the answer of Timothy summarizes the most important aspects. If it would be THAT simple to estimate HbA1c from Glucose alone, then, obviously, there would be no real need to measure the latter one, or? Read about the situation in African diabetics in my review, that is quite old, though.

good luck with your research

SR

Given the glycemic level is not in acute jeopardy, and is otherwise stable regardless if controlled or not, both glucose levels and A1c are complementary. 

It is a common practice to compare estimated A1c according to 2009 ADA matching table (glucose mean vs. A1c), and the measured A1c.

It is not uncommon, to have a discrepancy between estimated vs. measured A1c. In this case glycemia levels should determine to what extent our efforts should be in order to have good glycemic control, since:

1. If the case indicates low avidity of Hemoglobin to glucose (under-glycation) then efforts must aim at ameliorating hyperglycemia, regardless of near normal A1c. 

2. If it is a case of high avidity of hemoglobin to glucose levels (over-glycation) then efforts should focus on avoiding hypoglycemia even if A1c is higher than desired target.

BR

A1c and blood glucose measures are equally important, but they're both different in clinical practice.  a 56 year old lady with a long standing Type 2 Diab presented with a BG of 23 mmol/l and an A1c of 8.1%. Her Log bok shows uncontrolled Diabetes with severe hyper's in the past week. I wonder if A1c at this time might affect the treatment plan?! 

Hi Nadine,

Since A1c lags behind, Hyperglycemia becomes a leading factor and effector. A1c in this situation seems a mere bystander. (if sustain BG ~20 mmol, then A1c would be >13%, far higher than 8.1%).

I woder if you attribute this prominent rise in BG 23 mmol/L, to increasing glucose producrion from endogenous sources. If yes, then incretin mimetics are default companion to insulin, until BG drops and settle equivalent to respective recent A1c.Incretins potentially ensure curtailing insulin-induced weight gain which can perpetuate hyperglycemia.

BR

E.S. Kirkpatrick et al explain the limits of the relationship plasma average glucose and HbA1c, Clin Chem 2007: 53; 897-901

estimation of Hba1c from glucose is not accurate since A1c measure the average glucose conc. 3 months before therefore the best and accurate estmation is measuring directly  

I completely agree that it is not accurate.

http://www.ngsp.org/A1ceAG.asp

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2999698/

Best regards,

Wisit

I think it excellent question because if there a validated equation, would be helpfull to assess glycemic control using estimated hba1c in developing countries where hba1c not avaolable or not affordable especially no well stabished health insurance service .

there is equation for Patients with T2DM but Iam not sure of its validity

(Our hypothesis is that if patient obtain a FBG