@Jag1 I am curious about this too, although I can’t believe just the act of keeping low BG levels causes a higher mortality. Unless you go “too low” and I’m not sure they have a complete answer on what that too low is. But if you have a TIR at a higher percent and you don’t hardly ever drop below 55 how could it be harmful? Unless at some point you drop too low, pass out and die. But I would strongly suspect the people that venture into dangerous hypo range more often are more likely poorly controlled. (not always someones fault)
But I just ran across someone that had a 5.9 A1c and just got a cgm and while her doctor and her thought she was doing really good it turns out she was having huge peaks and drops…so now she is working on better control.
CGM’s are relatively newer and really newer for a much wider amount of people. The UK information would not be very many people with CGM’s. The UK is priding themselves on giving Libres to 17% of Type 1 diabetics, with kids at the top of the list. It can be very hard to get a cgm there, you literally have to be considered poorly controlled.
So any UK study could have a huge amount of people with peaks and valleys because when you finger stick you have a tendency to check before you eat, when you first rise and go to bed. So an A1c can hide that data. And the UK study was 2003-2006 with follow up 2007-2012. That’s significant as I was still misdiagnosed in 2010 and I had a pcp telling me that I couldn’t be a type 1 because medications worked some on me. So knowledge was severely lacking even 10 years ago. They also mentioned that less variability seemed to play a role in mitigating risk.
Cgm’s being widely used by a bigger range of people is more of a recent US thing, although some countries are working on supplying them to more people, So there is not a lot of available data on lower A1c’s with a good TIR attached to it. But with the years advancement, extra tools and knowledge, you can look at how many more Joslyn long term diabetics there are now versus even a few years ago.
We are probably the new data they will use to help try to figure it out.
EDITED to add dates and variablity quoted in study.