13 Comments
If you wear a CGM, do you look at the Glucose Management Indicator (GMI) available in many CGM reports? If so, is your GMI typically higher than, lower than, or equal to your A1c?
You must be logged in to post a comment.
© 2023 T1D Exchange. All Rights Reserved.
I have never heard of GMI and the only thing anyone really needs to think of is Time In Range, you know like a non diabetic. A1C is even a hoax. I had a 4.4 A1C and my Endo had a cow. She said you are low way too much. TIME IN RANGE!
Medtronic does not include GMI reports in the various reports that can be viewed on the 770G or any of the previous pumps I have owned.
Mine is usually exactly what my 30 day eA1C is w the dex6
Sometimes Higher sometimes Lower. I pay more attention to TIR and SD.
I don’t even know what a CMI stands for, so you could at least explain what we’re supposed to be looking for??? I wear an Abbott Freestyle Libre and can follow graphs, charts, and history averages. But I still don’t know what a CMI is. You need to inform a senior with T1D what are looking for in answering the question.
Not ‘C’ but GMI as in Glucose – https://pubmed.ncbi.nlm.nih.gov/31821016/
I’ve never heard of the GMI until today. So, that also means I don’t know where to find it.
My GMI is usual higher by .7-.1 points. I tend to think perhaps it might be the variability effecting the numbers. My A1c last time was quite low and I believe it was my experience of more lows, albeit short duration. The CGM tells me the real story IMHO with Time in range, standard deviation and GMI. The pump algorithm shoots for a higher target than I have always used. In trying to achieve my usual lower target I have been experiencing more lows than I used to, which of course is not the goal. I am hoping someday the target number can be set by my doctor with the algorithm flexible to meet the target.
I occasionally look at my GMI. It is close to the A1c, but I don’t compare often.
My GMI is always lower than my A1c (since using Tandem control IQ) , my doctor says the GMI is more accurate as it tests every 5 minutes and there are many variables associated with the A1c as a 3 month average. My standard deviation is now low and I think that effects A1c, in the past I had low A1c but higher SD, which is not good.
I occasionally look at GMI. It’s usually pretty close. I compared my last A1c (7.6%) to the GMI calculation on my Medtronic Carelink Report two weeks prior (7.2%).
So GMI 0.4% lower. I feel like both measurements are helpful, but my CGM time in range and standard deviation capture my variability and provide a more meaningful reflection of how I feel on a daily basis and what changes I might try to improve (e.g., bolusing earlier before meals is big one for me).
I review all reports every two weeks or so. I look at all of it and use my Tandem reports to see how much the pump is reducing or increasing insulin needs to see if more adjustments are needed. My medical team and I look more at time in range and standard deviation as those really tell the complete picture. But for me most test results match my Dexcom reports.
My HbA1c has always been “artificially” low but endos never reacted much to this feeling of mine even after I showed them my CGM readings. It took a sports doctor to say “why don’t we actually do a test” and tested my fructosamine which gave a result consistent with my CGM. Don’t trust HbA1c, folks. This is an interesting read, too, and shows how disturbingly inaccurate HbA1c can be:
https://diabetes.medicinematters.com/glycemic-control/diagnosis/racial-and-individual-variability-in-hba1c-glucose-relationship/12448762