Hi Mike
@mikeysaurus, welcome also from me. I have Tresiba as my basal and find it great for me; I'm only 5 yrs into this D malarkey so still wrestling with the ever-changing behaviour of my D. But I have learnt a few "things", some from trial and learning.
My immediate thought was how long have you been on Tresiba, how much was explained about it when you made the change to Tresiba and is your current dose right. Also, even though you've been T1 for a long time, what sort of Hospital based support are you currently getting for your D specifically, have you been on a DAFNE course recently and thus are you being kept up to date with changing methods and approaches?
Incidentally have you tried replacing your Tresiba and Trurapi pens or cartridges? In case the insulins you have in use is compromised?
But first: others here on the forum, regularly say get your basal right or your bolus is trying to do both jobs of covering for food and corrections as well as trying to manage background insulin requirements. I agree with that, its been my experience. There is a basal testing process, but this testing process was developed before the majority of those of us had any CGM and (I think most importantly) before Tresiba was in use. Tresiba is a relatively new insulin, particularly in UK and it is sufficiently different that the traditional ways of using basal might not be so relevant. So I don't find I need to use the traditional basal testing process, although there can be merit in understanding what your day by day basal needs seem to be. I'm retired, active, busy and don't have structured days of waking, working and weekends of recovery (or frantic time squeezing).
Tresiba is, as far as I know, the only basal that lasts some 40-48 hours. It's profile suggests it should take 2 hrs to get going, then release very evenly for the next 2 days. Today's Tresiba dose is topping up yesterday's dose which makes Tresiba both inflexible yet potentially extremely dependable. Inflexible, because a Tresiba dose change takes at least 2 days to become effective, better 3 days and needs 2 or 3 days to feel the change or see the outcome of that dose change on your CGM daily graph. Dependable (and reassuring) because once you know your Tresiba dose is right you don't keep adjusting it, you don't have to make that daily juggle between "should I adjust my basal or my bolus today?". You just lean on the certainty that Tresiba is doing it's job steadily in the background and thus look to your bolus. So, how do you know your Tresiba is right?
The harsh reality is that our background insulin requirements vary a lot during any one 24 hr period and vary from one day to the next. Those people on a pump can do a series of fasting tests, say in 8 hour blocks over several days. They can get a good sense of which parts of the day their body is getting glucose releases, triggered by a multitude of hormones including adrenaline and cortisol, then programme their pump to release different amounts of insulin every hour, every day. We, on MDI, don't have that luxury.
NB: As far as our body is concerned insulin is just ..... well .... insulin! Your body doesn't necessarily recognise what is home grown or delivered extraneously. Nor does it know that it was meant to be there for the food and is short acting, or has been engineered to be very long acting and help manage a glucose surge triggered by an emotion, or that heavy cold you have and don't yet know about (but will reveal itself tomorrow with the sore throat and streaming nose). If there is insulin available in your blood, your body will use it regardless of where it came from. So getting your background insulin right, day after day week after week is potentially a true challenge. [I ought to add that some people may well find some extraneous insulins suit individuals better than others - so we are lucky that we do have choices].
This is why, in my non-medical opinion, taking Tresiba needs a very different mindset to using other basals. I optimise my Tresiba daily dose to keep me very steady through the longest fasting part of my 24 hr day, from late evening to breakfast. Breakfast can be early or midday; my overnight fast can be 6 hours or over 14 hours. Of course Tresiba is also still releasing steadily while I'm awake and so whatever Tresiba is providing to my daytime party "is what it is". I can't accurately reconcile for that daytime background need and so must manage daytime insulin requirements with food, bolus and exercise/activity, aware that Tresiba is also at my party, quietly in the backround. The lifesaving tool in this juggling is my CGM. So much information, showing trends as well as the equivalence of spot checks from a finger prick test.
I optimise my Tresiba to give me decent horizontal graphs overnight. If a night gets interrupted from my norm - then that night graph may not be usable. So a late party, ending with a very late snack, doesn't count. But that different activity often gives me explanation for the consequent different night graph. I use exercise and/or bolus corrections to try and manipulate my BG ahead of the start of the long fast to be around 6-7 mmol/L. For me with no pancreas whatsover, if lower than 6 I can crash very quickly and although my CGM alerts will wake me up it's still an interrupted night's sleep! If my straight overnight graphs are steadily (and repeatedly) sloping down my Tresiba is too strong. If my overnight graphs are repeatedly rising, my Tresiba needs increasing.
Over a 12 month period I expect to tweak my Tresiba between winter and summer, then reverse that from summer to winter. My basal needs definitely change with the seasons: I need 7.5 units in summer and so far this winter I'm at 9 units. Because of the 48hr profile of Tresiba I won't change it for short overseas trips to a different climate. But I did change it a couple of years ago when I found myself in hospital for nearly 4 weeks and that period of enforced limited mobility, plus post op recovery, did noticeably show that my basal needs had changed.
Tresiba in 2022 was still sufficiently new in UK, that the pre-op advice for insulin dependent people was very wrong. I was told to stop my basal on the day of hospital admission and had to point out that the written advice from the Hospital's Endo dep't was out of date and inappropriate for my long lasting Tresiba. I have also found that Health Care Professionals (HCPs) don't have much awareness of quite basic differences between T1 and T2, never mind how different managing MDI can be between using Levermir or Tresiba as a basal insulin.
Sorry this is a long meander offering more insight in using Tresiba. You may already know all of this and it could be your body and your lifestyle just needs a fundamental review leading to different insulins. But only changing one thing at a time! Have you come across Gary Scheiner's book "Think Like A Pancreas"? I found it helpful.
