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TIR or Hba1c?

MeiChanski

Well-Known Member
Messages
2,990
Location
Warwickshire
Type of diabetes
Type 1
Treatment type
Insulin
Hello friends,

There has been quite a debate on social media about HCP’s emphasis on getting a better hba1c. Since I’ve been pumping and seeing higher numbers, I was worried about having a higher hba1c. But after reading, apparently since I’m getting less hypos, my hba1c will go up but my TIR (time in range) is a better indicator or representation of my management. My TIR has increased from 40-60% (with multiple hypos that dragged my hba1c down) on MDI to 80-85% on a pump. So has anyone come across their diabetes team talking about TIR values instead of hba1c?
 

Mei, for obvious reasons, this wouldn't have been something applicable to me, however, even if nobody else has been discussing TIR with their health teams (although I doubt that's the case), there is absolutely nothing to stop you bringing it up for discussion.

If I am interpreting your message well enough, a shift from 40-60% to 80-85% of time in range is quite seismic and should be recognised - even if you have to point it out to them. Well done to you.
 
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My team list look at a1c but given that CGMs and apps give TIR I think it matters...
 
I tried to discuss it because I have huge swings. I'm not on a CGM (glue allergies!) so I spent the fortnight before my appointment doing a lot of testing to show the consultant.

Don't know why I bothered. Just looked at hba1c despite the fact it had gone up 10 points and despite the fact that it's still a reflection of hypos vs hypers

She said 'it's the best result today'. It was my worst result since diagnosis.
 
My consultant has been more interested in my time in range and the median line since I started wearing the Libre. Never mentions HBA1C I always have to ask the result.
 
TIR more important to me and my Consultant .. hes young and has a good knowledge of up to date research and lit out there. .....of course HBA is important but not a stand alone measure .
 
Very interested in this discussion. Since getting the Libre a year ago I chose to use the TIR measure on the reader as an indicator of how well I'm doing - it seemed to me to be the obvious measure to use. So I was pleased to listen to a presentation given by Dr Pratik Choudhary, (Senior Lecturer and Consultant, King’s College London) at a Diabetes UK "Tech and Type 1 conference" last November where, amongst other very informative things, he talks about this topic. (The conference is still available to view on: or search on Diabetes UK website).
So I tried to have a discussion with my own Consultant on this when I saw him in December and he was still banging on about HbA1c - which was a bit disappointing. However in the follow up letter to my GP he did then recall the TIR discussion and how this was looking for me - so I was more impressed. Last week I met with the DSN in his team and TIR was definitely a key topic. I'm starting on the Omnipod pump next week after 38 years of MDI (very exciting) and using the TIR on my Libre is seen as a good indicator of how well the pump take-on is going.
My view is that HbA1c has been the best indicator for clinicians for many years now so it is difficult for people to change their view quickly. It is only since the use of CGM and FGM has begun to become more widespread, that TIR data has been available and, right now, the benefit of this is being realised. The main benefit of course is that TIR is available instantly to the patient (and to the medical team) at any time removing the need for blood samples and laboratory analysis that is required for HbA1c. The future is TIR !
 
TIR is vastly superior to HbA1c.

Anyone can have a great A1c score while plotting a glucose profile like the Himalayan skyline. In my opinion it’s a pretty poor diagnostic measure and just as limited as an indicator of control.
 
Focusing on TIR may be the best way to improve a very high Hba1c. Using a very high Hba1c and number of A&E visits as a filter may be the best way to decide who to focus on so as to optimise the limited time a consultant has.
 
I used to have A1c up in the 70's before getting the Libre and using TIR to check my control over many weeks. Since using the TIR measure my HbA1c is dowm at 51 and staying there. Hence why I say TIR is important because it gives me, the patient, the ability to manage my overall control in real time and not waiting for an HbA1c measure that is 3 months too late.
 
Thank you for everyone’s response. I saw the GP nurse today and my bloods were taken two weeks ago. I had Dexcom (TIR was around 70%) for a month and my pump for around a month (rocky start and quite high at the start). I was 6.0% because of hypos and now my hba1c is 7.2% but my TIR is very good. It’ll be interesting to see my team again in March and my consultant in July to discuss TIR rather than focusing on hba1c. I’m hopeful my hba1c will come down with stable BGs and less hypos. I feel hba1c doesn’t capture your management very well and TIR is much better in telling your management. As we know hypos and highs can drag down or increase your hba1c and it doesn’t show your time spent being in range.
 
I think if you can plot enough data that you can predict a1c. I think tir is a good way to help a person steer towards controlling their a1c, but I’m not sure everyone can actually do it.

Why can’t they? Emotions, food, commitment, social pressures, illness, failures,... and there are more reasons (some days I like to blame aliens). Everyone has their own issues. It takes a lot of effort to stay in control, or tir.

I spoke with my doctor last year about what I do to stay where I’m at with control. I said it’s tiring. She said I’m doing it very well, but she could not do what I do.
 
Here’s another question if you’re going to analyze tir. How big is your range? If the range is too big, that’s really not going to stear an a1c. You could be in the range, but plotting numbers all over the place.

From the data above, 70 to 180 mg/dL is quite a big range. My own personal “dream range” is 70 to 99 mg/dL, and if I do that I can steer an a1c.
 
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My pump does 3.9 to 10.0 (which is your 70-180mg) on auto mode but it aims for 6.7. For me it aims between 5.5-9.5, if it predicts a low at 3.9 it’ll suspend auto basal and it’ll do auto basal to correct a 10.0. Ideally, I’d like to be between 4.8-6.6 but unfortunately due to being a woman, stress and sometimes being impatient that is difficult to aim but not impossible. I also had a few bad experiences in the past due to severe hypos. Levels at 5.0-5.5 gives me more time to intervene if there is an oncoming hypo. I feel more energetic and happier with more stable sugars in my TIR. Whether I face complications later, I wouldn’t know. But I know for definite that hypos were not doing me any good - memory loss/short term memory, depression and living life in fear.
 
Between Aug 19 and Feb 20 my A1c went from 38 to 42 and my DSN said that was an improvement. I suspect I was dropping low overnight without waking and my days were spent chasing my tail with readings going from low to high then back again as I attempted corrections too early. Now I’m trying to wait 4hrs between meals and corrections I’m finding my TIR is improving slowly.
 
My endo looks at both.At my last doctors appointment my A1C was 32 (5.1%) , my TIR was 99% between 3.6-8.9 (65-160) and 96% between 3.6-7.8 (65-140). With a SD of 1.1 (20)

I am very happy with that as a normal persons range is mostly 3.6-7.8 (65-140)! It means I am averaging a BG level of 5.6 (100) and not having extreme highs and lows to do so.

Right now my TIR is 97% for the last two weeks and 98% for the last 30 days.
 
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I learnt in a recent diabetic conference, that for a much safer chance of not developing complications, a diabetic must stay in the range of 4 - 10 for a minimum of 70%. The risks of complications such as retinopathy increase dramatically if this control is not maintained.
I've just returned from my Diabetic clinic with the results of my first true HbA1/C with my new 670g pump and am very pleased with the figure as well as what my pump predicted. Firstly my calculated that my HbA1/C would be 6.3 and secondly my blood sugar test turned out to be 6.1 or 43mmol/mol which equated to 86% TIR.
I must say that my pump has performed admirably after I removed a few hiccups with It.
 
Jim Lahey said:
TIR is vastly superior to HbA1c.

Anyone can have a great A1c score while plotting a glucose profile like the Himalayan skyline. In my opinion it’s a pretty poor diagnostic measure and just as limited as an indicator of control.
Click to expand...

I agree. It's that 'average' thing again, a worked out meaningless number that probably nobody in the survey, even hit.
 
hi there, I am 75 years old & only had type 1 for 7 years; I would like to reduce myH1A1c sccore but tit takes 3 hours for my insulin to kick in & therefore my sugar level gets quite high in the interim. how long should it take to kick in. I am on Apidra again after having tried Fiasp; on the booklet on Fiasp it says it has to be taken 0 - 1 minute before eating; it still took 3 hours.
Any explanations or help would be appreciated thanks
 
That is absolutely amazing. No matter how hard I try the best I can manage is 65% between 3.9 and 7.7 which is my Target Range. Around 6% is below 3.9. The estimated A1C by Libre is 46. But the blood test at the hospital came up with 52 which the consultant said is more accurate and good enough. You just can’t win!
 
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