The numbers are good but the A1c went up


My boy is on the 670G and his numbers are good, but he jumped from a 9 to a 12.9 A1c.
Due to the numbers the doctor was predicting a 7. Has anyone experienced this.
Numbers good but A1c went up.


What do you consider good numbers? His numbers are not good if his a1c is 13, which means his avg BG is well north of 320. Do you test his BG with a meter? If so, which meter and how frequently do you test and how close are the cgm readings from the fingerstick? You say his numbers are good, I’m assuming by good you mean between 90-130 most of the time because that is the range threshold of the 670, so something is drastically wrong. If his doc is looking at his cgm data and predicts a 7, but the blood test reveals a 13, you should be looking at all the data collection points(CGM accuracy). If his cgm does match the fingerstick and confirms the cgm data is correct, then get another a1c.

Thanks - He no longer pricks his finger to check his blood. He lets the CGM do that. All the doctors seem fine with that for some reason.

You cannot rely on the cgm readings by themselves . The Medtronic Guardian 3 sensor is not known for it’s accuracy. Without checking his BG with a meter, you have no idea what his BG is. The Medtronic 670 requires multiple calibrations a day. If you don’t calibrate the system, you get kicked out of auto mode and the transmitter will not give you any cgm readings. There’s no way to ignore the calibration requirement whether you’re in auto mode or not, unless he’s just making up numbers to calibrate with. This would explain why the cgm data is telling you his a1c is 7 when in actuality it is 13. Those doctors that are telling you it’s perfectly OK to not do fingersticks, are killing your kid. They know that pump requires calibrations during the day to keep the readings accurate.

I would suggest you do fingersticks to verify the accuracy of your son’s CGM. I use Dexcom G5 and find my fingerstick calibrations and CGM readings are rarely more than 10-12 points out so off so long as I calibrate 4 times a day. If his are off there could be an issue with the sensor lot, or other issues with the device - there are lots of discussions on the topic of Medtronic accuracy on this forum.
If the numbers are in range them out could be a testing issue - it doesn’t happen often but it’s a possibility.

How do I find Medtronic accuracy - discussions.

I don’t know that there are any specific discussions on the topic - I’ve just seen it mentioned in responses, so unfortunately you have to scroll through a search for “Medtronic.”

Hi Mark @cookmh, when you say “his numbers are good”, what numbers are you looking at? His self-recorded finger-stick numbers, or the summation of 25,000 readings from his Guardian? Also keep in mind that the testing laboratory may have made an error when performing or recording the Hg/HbA1c.

Curious too, that all your boy’s doctors have told him it is okay to bolus insulin based on Guardian readings; unlike the higher quality glucose sensors, the Guardian does not have a “non-adjunctive” classification or rating. Possible solutions, the doctors could prescribe a different glucose sensor - all sensors do not work for all people.

My experience tells me, that with diabetes, there is NOT a “one-size-fits-all” solution. Also, diabetes requires much, much more than attaching hardware to our bodies - we must feed them the proper information - pump-settings, carb counts, etc. - and use the information they feed us [ glucose readings, trends] intelligently.