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When evaluating your T1D, is your A1c or your time in range more important to you?
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A1c is what it is. TIR can be manipulated by changing the parameters.
While it wasn’t stated, I felt it was implied 70-180 was considered the range.
If my time in range is good, I know my A1C will be good as well. The fallacy in relying solely on your A1C is that you can be swinging high and low wildly and still have a decent A1C.
This is a loaded question – Ideally, I would have a low A1C and 100% time in range. But, if the time in range is very wide such as 70-200 it becomes pointless. Also, a low A1C with little time in range could indicate a lack of control.
So if I am usually in range, I probably have an acceptable A1c. If not my range needs an edit. I guess I could be at the high end of my range and have an A1c above 7or higher.
I answered Both however A1c can be spot on but TIR really is more determinative to Control
Time in range doesn’t tell the entire story on management, especially without average glucose. You could be at 179 level and have a high A1C or be at 71 the entire time and be borderline low all the time and still be in range 100% of the time. A1C while weighted for the last 30 days of the 90 period measured gives at better look at management control in general. I think it is important to use all the tools to manage the best(and safest) control.
Those same extremes could also result in an admirable a1c……since it is an average.
I view them both as important. The goal is to keep my A1c below 6, and my time in range above 85%, preferably in the 90’s%. They must both remain good numbers, depending upon our goals.
Here is how I evaluated the question. If I am judging how much sugar is attached to my red blood cells on average, then A1C is the measure that is important. Why? Because, as we all know, too much sugar in your blood cells hardens arteries, and too much potassium and other minerals floating around in your blood (rather than in your cells) wreaks havoc too.
So, I don’t even consider my TIR because my most important metric is my blood sugar at this moment. If high, I need to consider how to bring it down to 80. If low (below 65), I need treat to 80. If I focus on the here and now, I can better manage what the future is going to look like and my TIR is spot on.
I monitor my control daily, TIR on a weekly basis and use the A1c as a confirmation that I have been doing ok for the last 90 days.
The problem with TIR as defined by the ADA is that up to 180 gm/dl is not a physiologic number, it is indeed pathologic which we should not be normalizing. Most normal people will not go above 140 after a carb heavy meal, and will stay there only temporarily.
They are equally important.
A1C used to be all we had, pretty much, but as an **average** it conceals as much as it reveals. You can get a pretty low A1C as a result of having a lot of severe hypos, which is why Endo’s used to yell at us for getting that number too LOW. But since the advent of CGM we can look at the whole graph over the same time period and see whether hypos are a factor or not. Back in the day TIR didn’t even exist, but now that it does it gives us a much more complete picture of how we’re doing. A1C is only secondary in terms of how much information it’s really adding to that picture.
I think a lower a1C with very few episodes of hypoglycemia would prevent a lot of diabetic complications. And admittedly a large number of lows would skew that number (while indicating the glucose removal from the blood, but not consider if any damage from short-term highs), so a “time in range” is important. My alarms are set 70-130, I’m there almost 70% of the time with 3% lows (Medtronic), while at that generic 70-180 I’m there in the 90 percentile. These all influence the a1C, influencing the risk to our body.
If I could be guaranteed an a1C 9.7 I’d die happy and healthy I wouldn’t worry, but that’s not the case. And regardless I personally feel to work so hard for a good a1C and still smoke, eat extremely unhealthily not be active almost seems hypocritical because damage from any reason is still damage. Neuropathy, cardiovascular problems, eye damage are present in both diabetic and non-diabetic members in my family. To me means there’s a probable tendency towards that: so my goal is to cause as much trouble and prevent health problems that at the same time.
The A1C is a measurable metric. If you have a low A1C (5’s, 6’s, 7’s) you ‘most likely’ have good time in range. Since an A1C is a more ‘measurable metric, it provides you the data to work towards improvement. (IMO)
If my A1c is reasonable, then time in range is more important to me. If my A1c shows as high, then that becomes more important to me.
Selected A1c only because TIR has always exceeded physician’s target
I manage, hour-to-hour and day-to-day, using time in range. I evaluate the long-term effect using A1c.
I think both are important tools, I think if you have an A1c in the mid 6’s and a TIR in 90% that would be fantastic, granted maybe hard, but I try for that and look at both daily.
I put time-in-range, however the A1c is a close second. I certainly don’t want to average around 140 even though my time in range is 100%.
The basic question incorrectly pre-supposes significant emotional import. I reject the premise entirely.
There are 3 measurements that are needed to monitor T1D control. They are all important for good control. Time in Range is the primary measure. A1C and Standard Deviation can be good, but good TIR prevents complications and dangerous medical events. A1C is equally important because it is NOT dependent on any technology. However, horrible control with lots of lows can result in a deceiving low/good A1C. Standard Deviation(SD) is important because it shows how much your BG swings up and down from the average. Continuous SD and TIR are only available with CGMs, so are dependent on accuracy and how often worn. All 3 measures give a more accurate picture
I look at men BG on CGM for 1 month and time in range, I set a goal of > 90%. A1c does not mean much to me, I put more weight on GMI (A1c from CGM) because it is more accurate for the individual
A1C is the hammer of diabetes tools. It has been around for a long time and has been surpassed by many better options.