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HbA1C not correlating with blood glucose levels

Discussion in 'Type 2 Diabetes' started by Adam63, Jun 19, 2013.

  1. Adam63

    Adam63 · Active Member

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    My HbA1C levels have been 7.1 a year ago, then 6.6 (49 in new units) six months ago, then 6.7 (50 in new units), however, when I take my blood glucose I find I get many measurements over 8 and this morning it was 9.1. I have not changed my diet recently. I strictly avoid all foods with overt sugars (biscuits, cakes and so on). I am on 2000 mg of Metformin. I am already experiencing two conditions that are related to high blood glucose levels psoriasis and gum disease. I have had to have six visits to the dental hospital over the last year to treat periodontal disease that the consultant says is directly a result of my diabetes.

    It seems to me that either my blood glucose meter is consistently inaccurate - or there is some disconnect between the HbA1C levels and the spot test blood glucose.

    My GP says my diabetes is perfectly under control and will not give me any supplementary medicines, apparently because they don't want me to have hypos. That appears to me to be ridiculous. Also the GP just refuses to engage with me trying to discuss my blood glucose levels. Their view appears to be that I am needlessly worrying and should not take my blood glucose levels and accept that the HbA1C is the correct measurement.

    I would like to get my glucose levels down a bit further, as I am concerned about the long term damage. My mother is now almost blind due to diabetic related retinopathy, my younger brother (also diabetic) has had two heart attacks and had a slew of diabetic related conditions, so I want to avoid such problems.

    Is HbA1C an infallible guide to ones diabetic condition ? I know it can be useful in diagnosing diabetes, but the medical profession now seem to use it as a measurement of the severity of ones diabetic condition. It actually measures the proportion of glycosylated haemoglobin in ones blood (that is the relative amount of ones haemoglobin that has become glycosylated or "sugar bound" and thus ineffective as a carrier of oxygen). They seem to assume that this provides some measure of the ongoing blood glucose levels. It is however the amount of sugar in the bloodstream that is affecting our capillaries and producing problems.

    There seems to be a disconnect between these two measurements. In the last few years it seems to me that doctors have turned only to considering the HbA1C and are ignoring blood glucose levels, certainly in the case of Type 2 diabetes.

    Am I merely to accept the view of my doctor that my diabetes is well controlled ? I am the one who will suffer the consequences of elevated blood glucose levels in the years to come. It seems impossible to get into a dialogue with my doctors about this.
  2. hanadr

    hanadr · Expert

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    Blood glucose measured by a meter is not directly correllated to HbA1c. You need a conversion table. The one I generally use is labelled " Hb-A1c average blood glucose conversion table." just Google for it
    An Hba1c of 6.7% equates to an average blood glucoese of 9 over the previous 120 days. the 6.5% recomended by NICE equates to an average of 8.6
    since a non-diabetic has an average of little over 5, their Hb A1c will appear in the upper 4% s
    That's my personal target, but I often miss and end up in the 5%s
  3. Yorksman

    Yorksman Type 2 · Well-Known Member

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    They measure different things. Your meter measures the glucose levels in your blood plasma. HBA1c is a measurement of the number of red blood cells which have glucose bound to them, otherwise referred to as glycated haemoglobin. Glucose does not easily bind to red blood cells and whereas your the glucose in your plasma is rapidly up and down all the time, your HBA1c is much more steady.

    Many things bind, either easily or with difficulty to your red blood cells. Oxygen binds easily but not as easily as carbon monoxide which displaces the oxygen. Alcohol on the otherhand doesn't bind with the red cells and stays in the plasma.

    If you have permanently high levels of glucose in your plasma, you will get high levels of HBA1c eventually. Conversely, if you keep your plasma levels low permanently, your HBA1c levels will slowly decline. Red blood cells live 100 - 120 days and your HBA1c has a half life of 60 days so declines in a curve typically seen in radioactive decay:


    However, because you eat regularly, you are topping your plasma levels up which, in time, will top your hba1c levels up. There is a relationship between the two, but it's not linear and it's not obvious.
  4. LittleWolf

    LittleWolf · Well-Known Member

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    They certainly do not correlate. My GO is reluctant to diagnose me as my HbA1c is normal but I go as low as a 'Lo' reading and as high as 19 *shrug*

    I also have psoriasis and gum disease despite using 2 kinds of mouthwash 5 times a day and two kind six toothpaste plus Corsodyl gel 3 times a day. Because I'm not diagnosed they like to crack jokes insinuating its all my fault. 'Maybe I should lay off the sugar' >_>

    I'd just continue eating to your meter really. It's hard to do thing all by yourself but this forum is great. Have you checked out the Low Carb section?

    Sent from the Diabetes Forum App
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