Healthy or Harmful? Measuring A1c in Seniors.
My hemoglobin A1c has always been higher than it should be on the basis of my daily blood glucose (BG) readings. I've spent about $500 on sensors for a continuous glucose monitor (CGM) to see if I was going high at unexpected times.
I showed a printout of a daily CGM chart to an endocrinologist whose knowledge I respect, and he said the most common cause of higher-than-expected A1c is having a meter that reads too low. And of course one calibrates the CGM with the meter. But I usually start to feel low when my meter says I'm below about 65. If that was really an 85, I shouldn't feel low.
And at my last blood draw, my Ultra read 82 and 86, for an average of 84. The lab value was 84.
Another explanation for higher-than-expected A1c is red blood cells that live longer than normal. I have no way of testing for this. Another is an abnormal hemoglobin. Outside research labs, there are no tests for this.
Then I read that if you have iron-deficiency anemia, your A1c will be higher than you expect. I've been taking senior vitamins, which don't contain iron, because high iron levels can contribute to heart attacks. I eat red meat, and the heme iron in red meat is absorbed better than the iron in vitamin pills. Also, I cook in iron skillets. I figured I was getting enough iron from these sources.
We did a ferritin test, which came out in the low half of normal. But just out of curiosity, for a month before my last A1c test, I used regular vitamin pills that contained iron.
Result: my A1c dropped from 5.8 to 5.2.
"Aha!" I thought. "I've solved the puzzle." Then I noticed that this test had been sent to the Mayo Clinic instead of being done at the local hospital. So was the change because the A1c was really lower, or was it because different labs get different results?
I called the local hospital lab to find out what method they used and if they knew what method Mayo uses. Different methods are affected in different ways by abnormal hemoglobins.
They wouldn't tell me because I'm a patient. Only a physician can receive this information, they said. I asked why, as this has nothing to do with patient privacy. "Because you might misinterpret the information," they said. "Ask your doctor."
This is ridiculous!
I've sometimes asked my doctor questions about lab tests and the doctor didn't understand what I was talking about. My GP couldn't answer my questions about LDL particle sizes and referred me to a cardiologist who he said was well read. The cardiologist wouldn't even listen to my questions. "I like to do things my way," he said.
How can we take care of our health if health-care people won't share knowledge with us? I think this is criminal.
High iron levels can lead to heart attacks. So if I keep taking iron-containing vitamins because I think I have low iron levels that are affecting the A1c but it turns out that it's just that the Mayo lab is using a different method, then this lack of knowledge sharing could cause me to have a heart attack.
If, on the basis of a falsely higher A1c, I keep trying to get it lower with increased drug dosages, I could have a lot of hypoglycemia, which is also harmful.
Is this policy of withholding information from patients health care or health harm?
I think it's causing harm.