Shall we start wth HbA1c? You might get yours in a plain number format or a percentage and it gives a reasonable indication of how well things have been going over the last 90 days. Or does it? An average, kind of, number based upon your blood glucose? Hmm. Perhaps if your BG is generally very stable and it's floating around in the happy zone for the majority of the time then your A1c might reflect that you're doing well. What happens if you're having several hypos per day, over treating them, and correcting several hypers per day? Lots of numbers such as 2, 3, 18 and 19 might be on your CGM/Flash/BG Meter and your time in the happy zone might be very infrequent yet your HbA1c might show that you're doing quite well with it's average BG offering. Clearly, you're not and that's why HbA1c alone can't be trusted to give an accurate picture of your diabetes management.
Time in Range seems like a better way of monitoring how well things are going. The picture is more detailed with this data. We can identify problem periods of time and change what we've been doing to reduce those instances. Time in Range data may just be one of the most simple yet brilliantly effective innovations in diabetes care in the last decade. I wonder how many of you have left a diabetes review with your HCP with the news of elevated HbA1c ringing in your ears? "It's too high, you need to get that under 8%... around 7%.... 6.5%?" and you nod and agree and off you trot, back to work or home, with absolutely no idea why your A1c is elevated. Perhaps it was that sandwich? or maybe your entire diet?! Oh no! "Keto, that'll solve it". Well, maybe.
Time in Range should help to stop the overreacting to HbA1c results. If it's a bit high, all that data can be looked through and if you leave notes on your CGM/Flash device app then it's even easier to identify what might have caused the hyper on that day.
Can TIR be problematic?
I'll wager that you've seen a few 100% TIR screenshots on your socials. Maybe you've reached the unicorn zone, too? It's a nice feeling even if it's not really that much better than a 90% or 80% TIR. Of course, 100% doesn't always tell the full story. If your TIR was at 100% over 90 days but your BG was between 8 mmol/l and 10 mmol/l in that period then your A1c would reflect a more sketchier management compared to the incredible management indicated by the 100% alone.
100% over 90 days is likely impossible for most but a high TIR might also indicate inaccurate CGM/Flash readings. I don't know of a single device which hasn't had accuracy questioned or complained about on social media. That includes me, I've made noises about inaccuracies dating back to 2017 and the issue is still a big one, six years later. Artificially inflated TIR might be noticed by a higher than expected HbA1c - just as the fictional blood glucose diaries of old proved, the wrong numbers from BG checks can be picked up when your A1c comes back at 11%
Also, numbers and targets and TIR can get a little overwhelming for some. Some feel an incredible sense of failure because their Time in Range is 69% and they've read that it needs to be 70% or better. That's such a shame because 69% TIR is probably pretty good! and 1% off your "goal" is such a small amount. 5% is a small amount, so is 10, yet not reaching that target number can deeply affect some.
Also! You're not a number. Your life is wonderfully unique to you and your diabetes will likely reflect just how much time and energy you have to manage it. In the late 1990s, during one of my infrequent diabetes reviews, a consultant decided that it would be motivating for me to know of the previous patient's HbA1c. The guy walked by me on his way out of the building. During my consultation, I found out what his first name is and his last HbA1c result. "X is doing brilliantly, his A1c is..." Can you imagine being offered that information at your next review? There would be uproar on socials and I'd be leading the roaring. In the 90s, I was less concerned but I responded sarcastically (Me! Sarcastic? No!). It left me feeling totally uncared about by that diabetes team. My hurt aside, the guy with the great A1c was also being viewed as a number! What a crap time to be a diabetic. Things are much better now. At least they should be for us all, as diabetes care has evolved hugely.
Back to the subject! It seems to me that HbA1c and TIR can be useful when viewed together. Alone they can be problematic and as much as HCPs and your peers might focus on those numbers, please remember that they are just numbers and not your wonderful unique diabetic self.
Sorry if this post was a bit "numbery" and boring.
BUY DIABETIC DAD A COFFEE HERE
GET MENTORING SUPPORT FROM DIABETIC DAD
Prefer PayPal?
