Sarah Howard (nee Tackett) has dedicated her career to supporting the T1D community ever since she was diagnosed with T1D while in college in May 2013. Since then, she has worked for various diabetes organizations, focusing on research, advocacy, and community-building efforts for people with T1D and their loved ones. Sarah is currently the Senior Manager of Marketing at T1D Exchange.
It is a little useful if I look at the deviation on my blood sugar range. However, it is very useful if I have a good time-in-range but have not looked at how variable my sugars are
I put “a little useful.” A1c is a helpful benchmark, but doesn’t really inform specific insulin dose adjustments like my pump/CGM reports do. I was happy to recently get my A1c down to 6.8% with fewer lows after years in the mid 7% range. This is about a year after switching to Tandem/Dexcom with Control IQ.
A little useful – mostly because doctors seem to view it as the holy grail, at least in my experience. However, I feel that CGM data (time in range, standard deviation, and average glucose) make A1C an obsolete measurement. If you’re using a CGM, A1C isn’t going to tell you anything you don’t already know.
I answered “a little useful” as HbA1c is a helpful benchmark, but TIR (Time in Range) is MUCH more informative in my humble opinion. (HbA1c does tell you when your blood glucose levels were high or low, only an ‘average’ of what they’ve been over the previous 3 months.)
I put “other” because I am not sure how accurate it is? I find that my A1c varies greatly from my Dexcom 30, 60, and 90 day averages. For example, my A1c will be 5.4 while by Dexcom averages indicate the A1c should be more like 6.1. Not sure why there is such a discrepancy?
As I’ve noted previously, I have a CGM and depend more on GMI, TIR, StdDev, and COV; I can adjust these for today, the last week, the last month for current status. A1c is in the mix and used, but is too reflective for essential value. For those without CGM, though, it has much more meaning.
I track my results using an Excel spreadsheet and make adjustments based on that data. I find the A1c a good confirmation that I am making the right adjustments, but I would not be able to make adjustments based on A1c alone.
While I find the A1C number “useful”, I do not make any changes to my routine based upon my A1C. However, having said that, If my A1C had gone high, I would have taken a closer look at my meal plan, exercise and insulin basals and boluses.
Luckily, I’ve maintained my exercise and meal plans, and have kept my A1C’s at acceptable levels.
Day to day data, charts and numbers affect my daily routine very much.
Having a CGM has removed the benefits from the A1c measurement as a tool to a large extent… Still helpful in terms of knowing whether the CGM is providing accurate data, or not…
I like to know my reasoning regarding basal rates have been good because it shows in my A1Cs. Also with my bonuses and diet. By staying in touch with my dr with what I’m doing, my A1Cs stay under 7.
As other have said, my CGM data are far more useful for managing BGs. Also, A1cs underestimate my BGs because of another health condition that makes my RBCs “younger” than they should be. However, my pump supplies provider seems to believe they need to send an A1c number to Medicare so I get it measured anyway when I have my other blood tests done.
TIR is far more useful. I use the Tandem X2 BIQ and Dexcom 6. Every time I look at my pump (I use it as my receiver) I see if I am “flatlining” – which is good news. Since I have (and prefer) BIQ, if need be I can use temp basal to tweak for the time being. I think that the A1C being just an average isn’t all that informative. Let’s say the goal for A1C is 5. If you bg’s run 5, 5 and 5 your A1C is 5. But if yor bg’s run 0, 5, and 10 your A1C is still 5.
I consider A1c an average over 3 months, nothing more. I like to see my average over the last week as an indicator of how any changes I have made are working.
Time in range and a look at overall patterns are both more important for my daily and long-term management.
A1c remains a quick question for non-endocrinologists to ask.
A1c has very little value if you are using a continuous glucose monitor. The cgm gives actual blood glucose values, whereas A1c is a rough estimate with high variability between people. But, A1c is a one test that is easy to do at a clinic. It still has little value.
Time in range based on a range of 70 to 180 is worthless as it is based on the assumption that an A1C of 7.0 is “good control.” Doctors should be honest with their patients and encourage them to achieve an A1C under 5.0 and yes, that is achievable without hypos.
Being a T1D for almost 38 years, the A1C was the gold standard until TIR & AGP came on the scene. Interestingly enough, my A1C brings with it constant dissatisfaction & unspoken guilt as opposed to my TIR. I know how hard I work and am very proud of the high 85% I average per 10 day Dexcom session. No complications so I guess I am doing pretty good despite a 6.8 average A1C
My A1C is never accurate. For over 20 years I’ve been geting a Fructosamine drawn as well and my Endo says that is much more accurate based on my BS readings. That seems to correlate better with my TIR.
I said not at all but that is because I use CGM full time and use the average BG on CGM, which is used to generate the GMI (glucose management indicator) as a better indicator.
Reply to Marsha Miller; My last 3 Endo’s in 3 different states have always ordered Fructosamine Levels when seeing that my A1C didn’t jive with my pump data and sensor info. Fructosamine just measures a 2 week analysis vs 90 days for A1C. I’ve been told I have a certain protein attached to my blood that affects the 90 day test. The 2 week test has always been more accurate for me.
Because I use a closed loop pump system with CGM, I depend more on the “Time in Range” than A1c. A1cs are averages and if I have a lot of lows and highs, the A1c result is not a measure of control.
A1C is just an average over 90 days, so it is NOT an accurate way to measure BG control. However, due to inaccuracies in CGM readings, Time in Range (TIR), Standard Deviation (SD) needs to be combined with A1C (since its not derived from CGM technology) to determine accurate measure of control.
A1C is an indicator of an indicator of blood glucose over time. Just because the only tool doctors have is a sledge hammer doesn’t mean they should use it every time we patients have a screw loose. I look forward to the day when CGM reports completely replace A1C tests for type 1 diabetics.
It is a little useful if I look at the deviation on my blood sugar range. However, it is very useful if I have a good time-in-range but have not looked at how variable my sugars are
I put “a little useful.” A1c is a helpful benchmark, but doesn’t really inform specific insulin dose adjustments like my pump/CGM reports do. I was happy to recently get my A1c down to 6.8% with fewer lows after years in the mid 7% range. This is about a year after switching to Tandem/Dexcom with Control IQ.
A little. And certainly not as God-awesome as the TV commercials touting CGM’s for everybody. Bah humbug for them. 🤢🤢🤢
Time in range is much more useful to me.
It’s useful in assessing management, but not in making changes to my routine.
Being able to call up a thirty-day summary on my pump is more useful.
Very understates CGM importance! My trial 780g keeps me between 108 & 116 regardless where my evening begins
Time in range and standard deviation is much more accurate and helpful
A little useful – mostly because doctors seem to view it as the holy grail, at least in my experience. However, I feel that CGM data (time in range, standard deviation, and average glucose) make A1C an obsolete measurement. If you’re using a CGM, A1C isn’t going to tell you anything you don’t already know.
so many doctors need re-training!
I answered “a little useful” as HbA1c is a helpful benchmark, but TIR (Time in Range) is MUCH more informative in my humble opinion. (HbA1c does tell you when your blood glucose levels were high or low, only an ‘average’ of what they’ve been over the previous 3 months.)
I put “other” because I am not sure how accurate it is? I find that my A1c varies greatly from my Dexcom 30, 60, and 90 day averages. For example, my A1c will be 5.4 while by Dexcom averages indicate the A1c should be more like 6.1. Not sure why there is such a discrepancy?
Medicare requires A1c at my clinic. It’s a nuisance to go to the lab for a blood draw. Time in range is a much more helpful measurement to me.
As I’ve noted previously, I have a CGM and depend more on GMI, TIR, StdDev, and COV; I can adjust these for today, the last week, the last month for current status. A1c is in the mix and used, but is too reflective for essential value. For those without CGM, though, it has much more meaning.
I prefer TIR for decision making on tweaks and adjustments to all dosing. It’s much more helpful.
A1c is nice, but Time in Range is more useful.
I track my results using an Excel spreadsheet and make adjustments based on that data. I find the A1c a good confirmation that I am making the right adjustments, but I would not be able to make adjustments based on A1c alone.
My Dr and I look at time in range!
While I find the A1C number “useful”, I do not make any changes to my routine based upon my A1C. However, having said that, If my A1C had gone high, I would have taken a closer look at my meal plan, exercise and insulin basals and boluses.
Luckily, I’ve maintained my exercise and meal plans, and have kept my A1C’s at acceptable levels.
Day to day data, charts and numbers affect my daily routine very much.
Having a CGM has removed the benefits from the A1c measurement as a tool to a large extent… Still helpful in terms of knowing whether the CGM is providing accurate data, or not…
I like to know my reasoning regarding basal rates have been good because it shows in my A1Cs. Also with my bonuses and diet. By staying in touch with my dr with what I’m doing, my A1Cs stay under 7.
As other have said, my CGM data are far more useful for managing BGs. Also, A1cs underestimate my BGs because of another health condition that makes my RBCs “younger” than they should be. However, my pump supplies provider seems to believe they need to send an A1c number to Medicare so I get it measured anyway when I have my other blood tests done.
I suspect the CGM measures will soon be regarded as a far better tool to measure control
TIR is far more useful. I use the Tandem X2 BIQ and Dexcom 6. Every time I look at my pump (I use it as my receiver) I see if I am “flatlining” – which is good news. Since I have (and prefer) BIQ, if need be I can use temp basal to tweak for the time being. I think that the A1C being just an average isn’t all that informative. Let’s say the goal for A1C is 5. If you bg’s run 5, 5 and 5 your A1C is 5. But if yor bg’s run 0, 5, and 10 your A1C is still 5.
If your bg is 0, you are likely dead. I get it- it is an average.
Past performance is not a guarantee of future results. Useful but only to help confirm what is working or not working.
A1c is one of several tools. So are Time-in-range, average, standard deviation, and morning BG.
I think time in range is more useful than A1c.
Overall A1C does not affect how I make changes. Other factors like time in range and standard deviation actually is more helpful.
I consider A1c an average over 3 months, nothing more. I like to see my average over the last week as an indicator of how any changes I have made are working.
Time in range and a look at overall patterns are both more important for my daily and long-term management.
A1c remains a quick question for non-endocrinologists to ask.
A1c has very little value if you are using a continuous glucose monitor. The cgm gives actual blood glucose values, whereas A1c is a rough estimate with high variability between people. But, A1c is a one test that is easy to do at a clinic. It still has little value.
I find HA1c useful as a calibration of my other measurements and vice versa.
A1c “average” is of little help. TIR and standard deviation is far more useful when considering any changes.
A1C along with time in range are very usefull.
Time in range based on a range of 70 to 180 is worthless as it is based on the assumption that an A1C of 7.0 is “good control.” Doctors should be honest with their patients and encourage them to achieve an A1C under 5.0 and yes, that is achievable without hypos.
😮
That would not be achievable for me. Too many hypos. Hypos kill brain cells.
Being a T1D for almost 38 years, the A1C was the gold standard until TIR & AGP came on the scene. Interestingly enough, my A1C brings with it constant dissatisfaction & unspoken guilt as opposed to my TIR. I know how hard I work and am very proud of the high 85% I average per 10 day Dexcom session. No complications so I guess I am doing pretty good despite a 6.8 average A1C
My A1C is never accurate. For over 20 years I’ve been geting a Fructosamine drawn as well and my Endo says that is much more accurate based on my BS readings. That seems to correlate better with my TIR.
I have never heard of fructosamine. What is that?
I’m on Dexcom with Tandem CIQ and I’ve about eliminated all Hypos so my latest A1c of 5.4 seems like a Cure to me. Just working on SD and TIR now.
The a1C is part of it. Time in range, deviation, and yeah elimination of hypoglycemia.
I said not at all but that is because I use CGM full time and use the average BG on CGM, which is used to generate the GMI (glucose management indicator) as a better indicator.
Reply to Marsha Miller; My last 3 Endo’s in 3 different states have always ordered Fructosamine Levels when seeing that my A1C didn’t jive with my pump data and sensor info. Fructosamine just measures a 2 week analysis vs 90 days for A1C. I’ve been told I have a certain protein attached to my blood that affects the 90 day test. The 2 week test has always been more accurate for me.
TIR seems to be more useful
A1C is nice and all, but TIR is much more valuable to me.
Because I use a closed loop pump system with CGM, I depend more on the “Time in Range” than A1c. A1cs are averages and if I have a lot of lows and highs, the A1c result is not a measure of control.
I also like to know time in range
A1C is just an average over 90 days, so it is NOT an accurate way to measure BG control. However, due to inaccuracies in CGM readings, Time in Range (TIR), Standard Deviation (SD) needs to be combined with A1C (since its not derived from CGM technology) to determine accurate measure of control.
A1C is an indicator of an indicator of blood glucose over time. Just because the only tool doctors have is a sledge hammer doesn’t mean they should use it every time we patients have a screw loose. I look forward to the day when CGM reports completely replace A1C tests for type 1 diabetics.