A plus B equals confusing A1c

(I’m about to talk about my A1c without actually sharing my A1c because I don’t like to share specific numbers. Hopefully it will still make sense because I need a little advice or stories of similar experience.)

This summer has included quite a bit of travel and recently increasing amounts of stress. There is no good correction factor to lower a stress induced high BG value, so I have been running consistently higher than I would prefer.

I have gobs of pictures of Dexcom graphs saved on my computer and I keep an eye on the averages stored on my VerioIQ meter. I don’t download my full Dexcom results until right before an appointment because I use an old laptop that takes about 15 minutes to start up (the ONLY reason I still have it is for the CGM download).

I took a look at the averages (and standard deviations) in Diasend and the Dexcom report, and plugged it into the Estimated Average Glucose widget on the ADA site. I knew I wasn’t going to be happy with the results, but I wanted to go into my appointment prepared for the news. It appeared that my A1c was going to be at least a point and a half higher than it was three months ago.

I was really upset and considered canceling the appointment. However, I made a deal with “someone” who had been putting off a necessary appointment of her own that if I would go, she would go to her appointment as well.

My endocrinologist came in the room and we made a little small talk. My vitamin D levels are still low, which makes sense considering I can’t remember to take the pills. I’m pretty sure she is pregnant but at that “you can’t ask in case you are wrong” stage so I awkwardly avoided that topic. She asked how I was feeling and I told her that I was nervous about my lab results.

My A1c came back a full point lower than I expected. I told her that it didn’t match my averages. If it didn’t match my meter results, that could be easily explainable. As many times as I can test per day (8-10) there still are not enough data points for a comparison, but a CGM should give a more reasonable estimate considering I wear it 24/7.

She looked at the print outs from my devices. Just when she thought she could identify a pattern that needed to be adjusted, she would change her mind and notice that the problem wasn’t actually consistent. Argh! No changes to the pump settings.

At least we came up with a plan. When I get my labs done next, we are also going to measure my fructosamine level. The thought is that I might have something related to my red blood cells or hemoglobin levels that is artificially lowering my A1c (even though my full RBC count in my lab report is normal?).

At that point I remembered to ask her about my other recent frustration – the repeated moderate ketones with normal blood sugar results and significant stomach pain. Unfortunately, she was stumped by the ketones too. I am getting moderate ketones according to the blood ketone meters, but negative/trace ketones on the Ketostix.

I told her I hadn’t been calling the office when it happens because I was not sure what they could do. She agreed and said that their recommendations would only be regarding avoiding DKA – which is clearly not what is happening. She couldn’t explain why they are showing up in my blood and not “other places” either and she is not really familiar with the blood ketone meter. Her plan is for me to test for ketones periodically when I am feeling fine to see if the meter is off, if the ketones are related to the stomach pain, or some other reason yet to be determined.

I know I asked the ketone question before (twice) but I didn’t mention the “only in the blood” part? Has anyone experienced having moderate ketones in a blood test but negative ketones on a urine test? I know the blood tests are supposed to be more time sensitive, but would they also be more accurate? If they are moderate on the blood test, shouldn’t something show up on the urine test, even if it is delayed? Remember, my bg levels have never been over 130 with a flat line on the Dexcom when this is happening.

And the fructosamine… anyone have experience with an artificially lowered A1c? Were you anemic or any other similar red blood cell issue? I understand that a bg meter is not going to give me an exact match but am I wrong to assume a CGM should be closer? The estimations were off by a full point!

(I should add that I have an enlarged spleen. It has been thoroughly studied for cause and the official result is that… I have an enlarged spleen.)

Dr. Google was no help, the endocrinologist is stumped, anyone out there have any ideas?


  • a1c’s are only accurate in 100% completely healthy people. So a fructosamine is a good step 🙂 But remember that it’s only measuring a 1 month average, not 3. That’s what a the baby-momma’s should get too every 6 weeks.

    I have no good ideas with the ketones. Which is weird, because I usually know everything 😉 Good luck!!!

  • My A1c always comes back lower. I have slightly low iron and my endo feels that I have abnormal hemoglobin, but she’s not really worried about it. It’s only a problem when others doctors ask what my A1c is and can’t understand the concept that a lab test result could be wrong.

    Moving on…are your urine ketone strips expired? Were they in a bottle that was open more than 30 days? Humid? Old or expired ketone strips can give a false negative.

    • The ketone strips have been doing this from the very beginning. As much as I would like to store them in the bathroom (ha!) they are stored with the rest of my diabetes supplies away from the humidity.

  • I think it’s great that you don’t post numbers. It can be triggering for others and have negative effects. Kudos to you!

  • I’m sorry that I can’t really offer much in terms of advice. My A1c never is what I expect … except that it’s always higher, not lower. I’ve had a few fructosamine tests and they always seem to jive with the A1c. And as for ketones, I very rarely show any even when sick. I’d be curious as to what would be causing them for you since your BG isn’t high at the time right? I hope you can find the culprit to both your confusions!

  • Haemoglobin variants are the first cause of anomalous A1c results that spring to mind. Some interesting reading about how these variants affect the results from different methods is here: http://www.ngsp.org/interf.asp A quick PubMed search on Haemoglobin variants and A1c will probably turn some stuff up too.

    As for the ketones, I assume that you’ve excluded low carb eating as a cause. I went too low carb pre-pregnancy (in pursuit of the lowest A1c possible!) and woke with ketones every day until I fixed it.

    • I wish (except that I don’t!) that low carb eating was the cause. I am eating between 100 and 200 carbs each day. 🙂

  • Just re-read the “only in the blood” part about the ketones. Only thought there is that if you drink a lot of fluids, the ketones will be significantly diluted in your urine compared to the blood level. Could certainly be enough to account for the moderate bs trace difference.

  • I am not a doctor … Just a nerd who reads too much … But i have a theory about your low A1C … From what I have learned an A1C is the measuring of the amount of hemoglobin that gets attached to your red blood cells … And red blood cells live on average about 3 months … Now if your red blood cells are dying earlier then 3 months then less hemoglobin will be able to attach to it … Which then leads to a lower A1C reading … And there seem to be couple reasons this might happen … According to wikipedia this can be caused by an infection … But like I already said I am not a doctor … But the fact that you have an enlarged spleen makes me wonder about a possible infection.

    Good luck and God Bless

  • Hmmmm……….I got nothin’ 🙁 Except I know that ketones can show up in anyone’s urine (w/ or w/o D) — usually a sign of dehydration….but NO urine ketones and MOD blood ketones…. ?????? That being said, there does seem to be an interesting correlation between the fact that the A1c seemed “off” (A1c = BLOOD) AND BLOOD ketones are positive.

    All that being said, I did a quick Google consult of my own and learned about this stuff…beta-hydroxybutyrate. It’s type of ketone. I read that urine ketone testing only detects acetoacetate and acetone, and not this other stuff. So, based on your description, we’re left to conclude that the ketones you’re seeing on the blood meter, but not on urine dips, must be this particular type of ketone.

    I do have 1 question, though…why were you testing them? Did you have symptoms that were bothering you?

    So, ANYWAY,…that ketone appears to show up most commonly in 3 scenarios — DKA, Alcoholic Acidosis, and Starvation.



    And,”someone” has an appt on 8/29 🙂

  • I think I might have Tweeted you about this, but I had the SAME THING happen with my A1c earlier this month. All records and data I had indicated I’d be at least 1.5% higher than my A1c came back. My A1c actually came back the lowest it’s ever been – and I can’t for the life of me figure out why; nor can my doctor. (I’m not anemic)

    I’ll be getting a fructosamine test at my next visit.

    Hey, at least you aren’t alone – I have weird A1c results now too, apparently.

  • Hey Sara. Just had to chime in about the strange a1c result. I have the opposite problem — my a1c always comes back at least 1 point higher than my CGM averages would indicate. And it’s soooo frustrating, never getting the results I’m hoping for.

    Might be onto something with the spleen issue. I don’t have a spleen (ruptured and removed at age 2) and the docs used to tell me that could cause my red blood cells to stick around longer than usual, therefore accumulating more sugar before they are removed. It seems that my adult docs usually just view this explanation as an excuse and don’t give it much credence … also frustrating!

    So I’m wondering if your spleen could be overactive and causing the opposite problem. An enlarged spleen is a sign that you body is fighting something. Do you know if yours is typically enlarged? Are your a1c’s always lower than you would expect, or is this a fluke?

    My endo has also ordered a fructosamine test for my next labs, so I’ll be curious to see how they look. Will be interesting to see how both of our tests turn out!

    Good luck and thanks so much for sharing this!

  • I’m a little late to the party, but just thought I’d chime in with my increasing distrust of technology. I had my A1C measured 2 weeks apart– first with a POC test, then with an IV lab draw. There was a 0.6% difference! And it’s not like I went from 10.2 to 10.8 (in which case, .6 doesn’t mean crap if you’re that high). Sometimes things are just….off.

    Good luck figuring the other stuff out, though!

  • Hmmm. I don’t really have any solid info either. But I have had a lot of times where I was expecting up and it went down, and where I was expecting down and it went up. Seems like I could never figure it right.

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