Tuesday, April 12, 2016

HbA1c RESULTS CALLED INTO QUESTION.


IS THE HbA1c TEST A RELIABLE INDICATOR OF AVERAGE BLOOD GLUCOSE OVER THE PAST THREE MONTHS?

If you read my summary post from twelve days ago, you saw the picture I took of my test results from my home HbA1c test.  Watching what I ate and fasting a HECK of a lot of days in the first three months of the year, I still got a reading of 5.2%, which is equivalent to an average blood glucose of 103 mg/dl.

I was so upset when I saw that number!  How could it be true?  The answer is, it couldn't be true.


I went to the interwebs to check on the reliablility of this test and found several articles that showed that the results are skewed, either higher or lower, based on the patient's history of anemia and/or iron deficiency.

I have had anemia and/or iron deficiency since childhood. Even now, when blood tests are done, I am lacking in red blood cells.  Sometimes I take a supplement and that helps, and sometimes I just don't worry about it.

The article that I felt was the most clear was this one written by Dr. Chris Kesser.  In the article, he says this:

"Sugar has a tendency to stick to stuff. Anyone that has cooked with sugar can tell you that. In our bodies, sugar also sticks – especially to proteins. The theory behind the A1c test is that our red blood cells live an average of three months, so if we measure the amount of sugar stuck to these cells (which is what the hemoglobin A1c test does), it will give us an idea of how much sugar has been in the blood over the previous three months. The number reported in the A1c test result (i.e. 5.2) indicates the percentage of hemoglobin that has become glycated (stuck to sugar)."

However, people with low red blood cells get inaccurate results.  He continues:

"This confused me early in my practice. I was testing blood sugar in three different ways for all new patients: fasting blood glucose, post-meal blood sugar (with a glucometer) and A1c. And I was surprised to see people with completely normal fasting and post-meal blood sugars, and A1c levels of >5.4%."

You can read the rest of Dr. Kesser's article to learn how he changed his procedures and no longer uses the HbA1c as the determining factor when he checks the progress of his patients. For myself, I decided to check my blood glucose nine times per day over a one week time frame to see if it was true that my BG was rising so high after eating as to cause me to have an average blood glucose of 103 mg/dl, or 5.2%.

I tested my blood glucose right before each of my three daily meals.  I also tested one hour after beginning each meal, and again two hours after beginning each meal.  Of the seven days, I fasted only twice, from dinner one day until breakfast two days later, which made the duration of those two fasts 36 hours each.  On the first day that I fasted, I did check my BG nine times.  The second day that I fasted, I only checked it twice, because I could see from the last fasting day that there is barely any fluctuation when you are not eating at all.  On that second fasting day, I filled in estimates of what I considered to be reasonable numbers.

Here is a chart (click to enlarge it if necessary) that shows my results for this past week:




My TRUE average blood glucose over these 63 readings was 80 mg/dl or 4.4%.  And this is with me eating the same way that I was during my challenge, and even with me only fasting twice that week, when I was fasting three, four, or five times per week in the last half of the challenge, which would probably mean that my HbA1c should have been even lower than 4.4%.

My highest reading was 98 mg/dl or 5.0% (two hours after eating a meal) and my lowest reading was 68 mg/dl or 4.0% (the morning after a 36-hour fast).

My conclusion is that, had the HbA1c test been accurate, I would have gotten a reading somewhere in the neighborhood of 4.4%, not 5.2%.

Now that I have proved this to myself, I am going to go back to not checking my blood glucose as often.  I will check it now and then, and possibly when I eat a food I am not sure of to see if I can tolerate it.

In one of the diabetes Facebook groups that I belonged to last summer, I mentioned that I did not often check my BG.  The other diabetics were outraged and told me I had to test nine times per day or more every day for the rest of my life!  When I explained that I am perfectly controlled with diet and that I am on no diabetic drugs or insulin, they didn't care.  They felt that I was taking my disease lightly and it was an insult to all the diabetics that test multiple times per day.  They threatened me with blindness, nerve damage and amputations if I did not test every day.

At one point, I had made the mistake of saying that it was too expensive to do all that testing.  That's when the you-know-what really hit the fan!  They wondered what I cared most about, my disease or my money.

Well, since my diabetes is perfectly controlled with diet (and exercise), I care about the money.  If it ever becomes evident that I am no longer controlled, then I will spend the money.  For now, I will use that money to buy a nice steak!

Keep an eye out for my next personal challenge, which will center around body composition.

Onward and Downward!

4 comments:

  1. Yay that you were able to reach a satisfactory conclusion on the HbA1c matter!
    Did you do any weight training this week? If so - how did you find your strength?

    oooh ~ I'm eager to hear about your next your next challenge (I'd missed that sentence on first read through, due to nodding in agreement about the steak ;-) Can you share it a week or so before you begin, in case anyone wants to join you?

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    1. Hi, Tracy!

      I have done weight training and HIIT (High Intensity Interval Training) on the treadmill on Wednesdays since starting, and then HIIT again on Sundays. I was traveling yesterday and missed my regular day, but I'm going later today to catch up. I did have to back off on the weight a little to get going again, but I'm assuming I will catch up.

      I do know that the challenge will not be starting in the next few days because I just took a short trip to visit family out of state and it involved lots of restaurant meals. I'm afraid I slightly threw caution to the wind near the end of the trip and I did gain a few pounds (probably water weight) and a few inches (ditto). I want to get right back to where I was when the other challenge stopped and then start fresh. I am fasting to get back there, no matter how many days it takes!

      My next challenge is going to involve body composition. I have not decided on the exact rules yet, but it will include weight and body fat percentage, but NOT blood glucose, since that appears to be under control as long as I eat properly.

      I tend to say, "I'm starting right now before I can change my mind!" When I start, it will be something like fasting on any day that my weight is over 136 pounds OR my body composition is over 30%. Those were my original goals, and I think I should stay there to allow my body to adjust to that before pushing it any farther down in body fat percentage. I think maybe a month would be a good time to stay level, and then set a new goal. Of course, if I lose more during that time, I will not attempt to gain it back to stay level; I will just not force it to go down. Even before my recent trip, I'm still pretty fluffy with 30% body fat, and I would like to take off a few more pounds of fat if my body will allow it.

      I also need time for my loose skin to tighten up before I lose any more fat.

      Before the new challenge starts, I need to lose 1 1/4" from around my waist and 1/8" from around my neck. That will put me back where I was at the end of the last challenge that ended on April 1, 2016. With fasting, I think I can do it in a few days.

      How are things going with you?

      Rebecca

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  2. Thank you for sending me your link to your amazing research...

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