A1c, HbA1c, A1C, or Hb1c

13 May

What do all of the above have in common?

Everything! They are the same thing called differently. People who have diabetes know exactly what their A1c value means for them, people without diabetes, less. However, this is an important figure that everyone in today’s society should at least find out some time or other, better sooner than later. It may tell you a lot more than you expected.

Hb1Ac (as the Germans call it) is glycated hemoglobin. Wikepedia explains it as:

a form of hemoglobin used primarily to identify the average plasma glucose concentration over prolonged periods of time. It is formed in a non-enzymatic pathway by hemoglobin’s normal exposure to high plasma levels of glucose. Glycation of hemoglobin has been associated with cardiovascular disease, nephropathy and retinopathy in diabetes mellitus. Monitoring the HbA1c in diabetic patients may improve treatment.

In the normal 120-day life span of the red blood cell, glucose molecules react with hemoglobin, forming glycated hemoglobin. In individuals with poorly controlled diabetes, the quantities of these glycated hemoglobins are much higher than in healthy people.

Once a hemoglobin molecule is glycated, it remains that way. A buildup of glycated hemoglobin within the red cell therefore reflects the average level of glucose to which the cell has been exposed during its life cycle. Measuring glycated hemoglobin assesses the effectiveness of therapy by monitoring long-term serum glucose regulation. The HbA1c level is proportional to average blood glucose concentration over the previous four weeks to three months. Some researchers state that the major proportion of its value is related to a rather shorter period of two to four weeks.

So long-winded explanation aside, that means that the value of your Hb1Ac will tell you whether you have had too much glucose (=sugar) in your blood or not over a period of time.

Someone without diabetes will probably have a Hb1Ac of somewhere around 5.0 (according to the articles I’ve read, this could be anywhere between 4.0 and 5.9).  Diabetics will have a higher Hb1Ac because their bodies aren’t producing enough insulin to carry the glucose out of the blood. However, with the help of medication and a sensible healthy diet or if you have borderline diabetes, just a sensible diet, one should try to strive for a good Hb1Ac reading. And what is a good reading?

Dr Richard K. Bernstein in his book, Diabetes Solution, believes that even those inflicted with diabetes are entitled to Hb1Acs of normal people. He is a Type 1 diabetic and has succeeded in bringing down his Hb1Ac to below 5 and has kept it that way. My doctor does not agree with this.

Many diabetes associations, including those in Germany, believe that those inflicted with diabetes are not able to and should not try to achieve Hb1Acs of normal people. To ensure that diabetes patients do not suffer the medical complications mentioned in the Wikipedia quote above, they advocate a Hb1Ac of under 7! At this level, you are considered quite safe from the above mentioned diseases. If you have your diabetes well under control then you would be in the 6 – 6.5 range. What about a lower value? An article on the Islets of Hope website explains: ‘The risk of loss of consciousness, insulin shock, seizure, coma, and death from hypoglycemia for a person with diabetes increases significantly when an HbA1c falls below 5.0.’  Ok, so by reasoning, if you want to and can get it to above 5, you should still be ok.

But wait, things get a little more complicated. In Blood Sugar 101, Janet Ruhl cites a study which found that Hb1Ac accurately predicts heart attack risk.

Persons with hemoglobin A1c concentrations less than 5% had the lowest rates of cardiovascular disease and mortality. An increase in hemoglobin A1c of 1 percentage point was associated with a relative risk for death from any cause of 1.24 (95% CI, 1.14 to 1.34; P < 0.001) in men and with a relative risk of 1.28 (CI, 1.06 to 1.32; P < 0.001) in women. These relative risks were independent of age, body mass index, waist-to-hip ratio, systolic blood pressure, serum cholesterol concentration, cigarette smoking, and history of cardiovascular disease.

So on the one hand, a diabetic should not reduce his Hb1Ac to below 5 because it could be dangerous but for every point above 5, you are increasing your risk of cardiovascular disease. You can’t win them all can you. I think the general conclusion to draw from all this is that if you are diabetic, you’ll want to try to ensure that your Hb1Ac is as good as you can get it (but do work with your doctor to achieve this)!

I found this great chart which tells you what kind of blood glucose you are averaging for your Hb1Ac value. This is useful. Now I know in what range I am going to have to keep my blood glucoses in order to achieve a Hb1Ac close to 6. A Hb1Ac of under 6 really seems impossible for me to reach at the moment judging by my blood glucose readings and the stuff I like to eat.

HbA1c (in %) average blood sugar in mg/dl average blood sugar in mmol/l
4,7 70 3,9
5,0 80 4,4
5,3 90 5,0
5,6 100 5,6
5,9 110 6,1
6,2 120 6,7
6,5 130 7,2
6,8 140 7,8
7,4 160 8,9
8,0 180 10
8,6 200 11,1
9,2 220 12,2
9,8 240 13,3
10,4 260 14,4
11,6 300 16,7

Source: Wikipedia – German site

I also found a site with a Hb1Ac tracker. This is a free printable chart which will help you achieve your Hb1Ac goals if you want something simple to record your daily glucose readings.

If you are more into tech-stuff, Sugar Stats offers an online diabetes management program. After you’ve read through the page, click on the link titled ‘See Plans and Pricing‘ (or go straight to it here) which will take you to a page with the free download. I’ve signed on to test it out.

Please note I have nothing to do with either of the above links – just happened to come across them today.

I can only conclude – Hb1Ac is a very important small number!


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