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It is very important to keep my A1c normal, but I wish hypoglycemia did not help to lower it!
TIR is much more important to me.
It is still a comprehensive measurement that gives feedback on glycemic control. I agree that Time in Range is useful too. But both are recent developments within my life time.
Time in range and the standard deviation have become much more important to me. But especially important is the percentage of the time I am in the hypoglycemic range, That’s a little like the time you are exposed to covid–you want to keep it as small as possible. Zero is ideal. How to do it? That’s another very, very long story.
A1C used to be the standard. Mine was at 5.1 but you know what that means? I am WAY low too much. Time in Range is now the gold standards.
Along with time in range and SD, these are about equal. I aim for less than 6.0 with 95%+ time in range with no lows.
Time in range is as important if not more so
It is important because it is important to my doctors. I like the time in range information my flash CGM gives me the best because I have very high and very low swings most of the time.
I put somewhat important. It used to be very important, but now I am more contentious of my time in range as it is more accurate.
To me, both A1C and TIR are equally most important. They accomplish different things but added together provide a great benefit both for me and for my doctor.
Both time in range and A1c are important indicators. If your TIR is good generally your A1c is good. TIR can help reduce the wild hypo-hyper swings.
It’s important to me to reach my goal, but changing my A1C day to day is impossible. I work on individual tests on some aspects of diabetes care and long-term aspects. Affect long-term by repeating short term.
My Abbott Freestyle Libre gives me time in range and averages by the day, week. 2 weeks and month. It also tells you how many highs and lows or in range numbers you have had. My Dr. still wants lab A1Cs along with all of the other tests that require fasting. I hate fasting labs!!!!
Since I have a Dexcom G6, I have found an actual A1C number to be fairly unimportant. I think TIR is a better indicator of blood glucose management. I can manipulate my A1C just by donating blood a couple of weeks before, but I can’t manipulate my TIR as easily.
I tend to run a bit higher in my A1c than my blood sugar average would suggest so I pay more attention to Time in Range.
Glad to see TIR as weighing as, or more heavily for a good many of us. A1C is an *average* not a *mean,* which means that you can get a splendid A1C by crashing low every few days. That’s why they used to yell at us for having one that’s too LOW, back in the day, as well as too high. “You can only get that number by going hypo–stop doing that!” With CGMs it’s much easier to avoid that, focus on TIR instead. I still find it somewhat useful just as a kind of way marker–as when I broke through the < 6 AIC barrier a year ago, yippee! But only did that (safely) by maintaining an >80% TIR.
I agree with the majority of those leaving comments – A1C is important, but TIR is a much more informative and actionable metric.
A1c will simply be a reflection of what your TIR and SD numbers are.
TIR is the more important indicator to me than A1C.
I agree that TIR is much more important but care about A1C because one can have a 100% TIR running on the high side of the range and still not maximize the A1C. (But one can have a fabulous A1C while having too many lows.)
Most important to me is TBR (Time BELOW Range). After that, A1C. This combo analysis addresses A1C’s that are deceptive due to excessive lows, and TIR’s that are deceptive due to hovering around 160.
When l initially got the MEDTRONIC system my a1C rose a bit but it stopped the extremely lower levels I experienced from work/life. Since I stopped utilizing the CGM I’ve had a few lower than “safe” levels so while I expect an improved a1C there are those risks, and yes I’ll tend to snack for specific tasks to prevent those drops. With a CGM I’d vote for the “time in range,” but l now have to use the a1C.
Now with CGM availability, A1c is far less important. My doctor doesn’t always order A1cS any more.
I find TIR far more significant. A1c is an average that doesn’t accurately reflect my daily life.
I believe that time in range is much more important.
The comments from others are very informative. Time in range does appear to be more important than A1C. I thought it was important because my doctor performs the test and asks the questions.
The A1C gives the long view of what I did on a daily basis. I like the accountability. I have a CGM not connected with my pump. I’m waiting to get one that can be connected, so I’ll have a “Closed Loop” system (better known as an artificial PANCREAS!!!)
I said unimportant but that is only part of the answer. I look at my GMI (A1c estimate from CGM data) every week. I look at the average glucose, not the population average for correlation of mean glucose with percent of hemoglobin with a glucose molecule stuck to it in a particular position of that molecule, which is what the A1c actually is. It is the population average applied to the individual. The GMI (glucose management indicator , that is, an A1c generated from CGM data) is your actual average BG level compared to the measured A1c of a population of people using CGM. GMI with a modern system where you use it nearly all the time is more accurate for you. 30% of people have a measured A1c that is 0.4% or more different than the GMI. Many endorsed time in range. I use this daily, set a goal that is tough and try to meet it. It requires me to avoid post meal hyperglycemia, and hypoglycemia, to meet it (90% or better between 70-180). TIR is a better indicator for day to day, allows time below range (hypoglycemia) which is a critical safety indicator. I want both- the A1c-GMI is what has been correlated to risk of complications over time in studies, countless times. It turns out that applying TIR retrospectively to the Diabetes Control and Complications trial showed TIR with fingersticks predicted as well as A1c. Actually, these are highly correlated with each other, but the TIR is more complete. GMI discussed more here: Glucose Management Indicator (GMI): A New Term for Estimating A1C From Continuous Glucose Monitoring Richard M. Bergenstal, Roy W. Beck, Kelly L. Close, George Grunberger, David B. Sacks, Aaron Kowalski, Adam S. Brown, Lutz Heinemann, Grazia Aleppo, Donna B. Ryan, Tonya D. Riddlesworth and William T. Cefalu Diabetes Care 2018 Nov; 41 (11): 2275-2280. https://doi.org/10.2337/dc18-1581 BTW- I am sorry this new format does not allow posting images. A picture (often for me a graph or table) can be worth a thousand words…
Somewhat important. The A1C is just an average over several weeks so if BGs widely swing very high and very low and trend towards more lows, your A1C looks great, but your control and time in range is horrible. Time-in-Range and Standard Deviation of TIR is much more important.
I said A1c is very important because it’s one of the tools used to help manage diabetes and anything that helps is very important in my opinion. However A1c alone can be misleading, you can have a high A1c and be having serious lows, but if your highs are high enough and often enough they can cancel out those lows. To really understand you need to go below the surface. I would say time in range would be more helpful and therefor more important, but without a CGM there won’t be enough data to get reliable time in range info. Personally, I feel that the graphs from my CGM & pump data are the MOST important to me, this is where I see the trends, the real numbers behind my A1c and time in range, this is the data that informs my decisions on treatment changes.