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A1c and Dexcom averages

Discussion in 'Parents of Children with Type 1' started by BittysMom, Dec 11, 2013.

  1. BittysMom

    BittysMom Approved members

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    If A1c results are weighted more heavily to recent blood sugars, what averages when looking at Dexcom's software do you find align most with your A1c results? I'm assuming there is a disparity between the 90 day average and more recent averages... Thanks.
     
  2. nebby3

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    Good question. I'd like to know the answer too. But there is also the fact that A1Cs are not really averages. They measure glucose that attaches to blood cells above a certain level but lows don't unattach the glucose or negate highs. At least this is my understanding.
     
  3. missmakaliasmomma

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    I have actually heard the opposite... that lows do bring down a1c somewhat. My daughter's endo said it too. I believe her words were " a good a1c with a lot of lows balancing the highs isn't good either"

    I usually don't look at her avgs so can't really help with the actual question
     
  4. 4MyBoys

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    We don't have a Dexcom, bur my son uses the Medtronic CGM 24/7 and his actual A1C is always within 0.2 of his sensor's estimated A1C. Is that what you're wondering?
     
  5. MomofSweetOne

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    I would think it would depend on what happened in the time just prior to the A1C? The last A1C exactly matched the Dexcom average, but the A1C before that was about 0.4 higher than the Dexcom average. However, in two weeks before that A1C, she'd been ill and then on a rugged camping trip where we ran her BGs higher than typical to avoid lows. I figured that many higher numbers that close to the test were the cause of the discrepancy.

    For the next one, we'll have switched meter brands and I'm curious to see how that affects things. For the first few tests, we did both meters and they were typically 30ish points apart. I'm now seeing more wonky numbers than we've ever seen, and I wonder how much of it is the meter.:(
     
  6. swellman

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    Since we switched to the OneTouch Verio IQ quite some time ago our averages were pretty much within 0.2% points. Pretty spot on.
     
  7. nebby3

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    I have heard that from doctors too but it was on this site that I heard it is not an average and lows have no more effect than a number like 100. I guess it is a matter of who you want to believe :)
     
  8. Dave

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    Our last A1C was 5.7. The average on the dexcom was 110, so we should have been a little lower. This topic is also on the GLU site, which Im finding to be an excellent source of info also, just fyi.
     
  9. BittysMom

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    Which average on the Dex? 90 day? We see the Endo today, so I'll have my own anecdote a bit later.
     
  10. Brenda

    Brenda Junior Member

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    Probably my explanation is the one "on this site." I will explain it again, to the best of my ability.

    The A1c is essentially a measurement of how much glucose "sticks" to red blood cells. Glucose begins to "stick" when ones BG is 150 mg/dl. The higher the BG, the more glucose there is to stick. A red blood cell lives 90 days. From day 1 on, it slowly begins to die. Let's use a couple of examples for a person who, we will assume for this exercise, has a BG between 97 and 126 mg/dl for the 90 days before their A1c. Their A1c will be 6.0. If, on days 1-3, this person runs 200-300 mg/dl, his/her A1c might still be 6.0 (probably more like 6.008 rather than 6.0). But, if he/she is 97-126 for 87 days, 200-300 on days 88-90, the A1c is going to be higher (I do not know the exact figure, could be 6.3--math is not my thing).

    Despite what any endo says, including those I met when our daughter was much younger, lows DO NOT make one have a lower A1c because they do not kill the red blood cells faster or remove glucose from the cells.

    Like most people, I did not have a good understanding of this for the first 14 years Marissa had diabetes, then a couple of people explained it to me.

    Hope this makes sense.

    All that said, last year, the ADA (I think in its Standards of Care) determined that they wanted to move away from the A1c as a measurement of control, that they want to have something to reflect better the "average" of ones blood sugars. Not sure how/when they intend to do this because everyone is still reporting that they are getting A1cs done.
     
  11. nebby3

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    Thanks for the explanation, Brenda. So if glucose doesn't attach above 150, a non-D person with perfect numbers still has an A1C of 4 or 5ish, right? Is that because they go above 150 after meals? Or is there really no 0 and the lowest one could be is something like 4?

    It sounds like a CGM average could actually be a better measurement than an A1C since it reflects both highs and lows.
     
  12. BittysMom

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    So, our Dex averages were:

    (A1c today was 6.5)
    14 day 135
    30 day 142
    60 day 148
    90 day 147

    That seems to make sense.

    I guess there would be no specific day to look at even if the values of the averages were very different. I hear people refer to their cgm average and just always wondered how many days out they were referring to.
     
  13. missmakaliasmomma

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    Yes, there's no 0. And I'm pretty sure a very good a1c for a nonD is high 4s to low 5s. Mine was 5 a few months ago. I have no idea if I go up to 150 after a meal because I won't waste my daughter's test strips on that, I'll only test myself if I feel low.
     

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