Differing hBa1c results

When I had a blood test as a matter of routine on 11 January for an operation they told me it was 8.5 (69). I was pretty horrified as since DAFNE a year ago it has been coming down and it had been 7.6 before that.

Had another blood test on 30 January, so 2-3 wks later, and it was 7.6!!

Something doesn't seem right, but I tend to believe the latest result given my daily readings more than the one before. And also it can't be possible to improve that much in 2 weeks?!

Anyone any ideas please?

I suppose its perfectly possible to have that kind of change within a 2 week period.........

Did you record noticeably lower readings in the 2 weeks prior to the latest test.....

The 8.6 may have been a finger blood test...who took that one after your operation......

No it wasn't a finger prick test...and if anything after the op what with recovering my readings were up and down so weren't noticeably lower no...I actually saw 8.5 written down on my records plus the nurse mentioned to me that it was high....I mean I don't like to doubt the result from the hospital....

I could forget it but if the 8.5 WAS incorrect it's not very good is it!

Did you record your readings over the two periods? Is there a noticeable difference between the 90-day average for the first period and the 90-day average for the second period? That would probably tell you what you want to know.

I believe that a two week period can have a crucial and disproportionate effect on HbA1c's especially if it is immediately before a blood test and is radically different from what is usual (either up or down). the HbA1c's are guides. It is not a pure science!

Interesting..not an exact science, but a 90 day average...just didnt think 2 weeks could provide such differing results. Will bear in mind for any similar future occasion.

Diane, I tried to find a document (or 2) to support my understanding that the previous two weeks can radically effect HbA1cs. Wikipedia (HbA1C) cites the Hemoglobin A1c Fact Sheet from Michigan Diabetes Research & Training Center (26/12/2007) "some researchers state that the major proportion of its (HbA1c) value is weighted towards the most recent 2-4 weeks." Further "internet" research came up with support for it being a guide and many sites indicate that it is an assessment of the glycated haemoglobin over a period lasting anything from 6-12 weeks. Some sites are very dogmatic and state without qualification that it is the average over 12 weeks. Most are not as absolute. My experience came from two episodes where I was quite sick and had BGs all over the place just prior to my regular blood test and Endocrinologist appointment As my HbA1c's are usually boringly consistent I was astonished when it came back... I was then told (by the Endocrinologist) not to worry but to have it done again in 6 weeks. It was then back to its usual value. Similarly, last Nov when I came back from overseas with a bacterial infection in the blood! Helen

Thanks for that Helen that is really interesting. I didn't realise that there were such differeing views on the test. If it is based on the 2 week thing then with my readings of 8.5 and 7.6, I would have expected the latter one to be higher, as 2 weeks prior to that I had an operation (having said that my readings weren't wildly up and down). Oh well! But thanks for that, that is really enlightening. I will stop panicking now.

I had my first clinic appointment this morning since doing DAFNE last July and my HB1AC is down from 84 to 55.

Excellent Rafa. Well done. That is a huge improvement and a great step towards avoiding the long term complications.