Is there a a formula to go by, such as–for every pound I lose, I have one less unit of levemir, or some thing like that?
There is a “theory” that your Total Daily Dose (TDD) of insulin is generally proportional to your bodyweight. A common starting TDD is 0.5 * bodyweight (in kg) which roughly means your TDD is your weight in lbs divided by 4. Everyone is different, my TDD is more like 80-90 units (more than this formula predicts) but this will give you a basic idea. What this means is that losing 4 lbs should reduce your TDD by a unit and since the guidelines is a 50/50 basal/bolus ratio this means that your basal would drop by a half unit.
These are rough measures, and in practice the 0.5/kg guidelines may not apply to you and you may notice absolutely no difference with in basal requirements with weigth loss.
Like Brian said, there’s a “theory” - I’ve generally had to just go with trial and error. I’ve lost 50+ pounds in the last year. Sometimes I’d lose 5 pounds in a week for a couple of weeks and start having lows left and right. Then I may go 3 months straight only losing .2-.5 pounds a week and stay steady.
More or less as I started having lows in the middle of the night, I knew to titrate back by a unit or two and give it a couple of days to see how that worked out. And if I still woke up with lows, to dial it back some more.
It’s frustrating. I’m hoping with the CGM I’ll have an easier time of being able to titrate my basal doses as I can see what’s going on at night rather than relying on waking up in a cold sweat to know that “whups. It’s time to dial it back again.”
If you don’t have access to a CGM, and plan on losing a significant amount of weight, or are particularly insulin sensitive, you might just do intermittent basal rate testing by doing 3am BG checks now and then as you lose weight.
I consider the TDD “theory” to be a useful rule of thumb if followed with a generous dose of YDMV.
Thank you all for your help
When I have lost weight in the the past, insulin reductions often produced momentum to reduce further. In other words, the act of cutting back doses seemed to me to produce more action from the remaining portion of the dose. For me, when losing weight and reducing insulin, less is indeed more.
Formulas are generally not helpful in my opinion but taking notes daily on what’s working well and what’s not, what you’re eating, the doses you’re taking, and the results of those things helps tremendously to keep track during times of changes
Now that you say that, I think I remember that happening to me a few times…
I sure would like the answer to this!
Insulin dose formulae based on TDD are not terribly useful (IMHO) because TDD includes bolus insulin and this is completely dependent on carbohydrate intake. Formulae for estimating basal doses are less subject to these variables. The figures I have seen (which apply to Type1s without significant insulin resistance) are:
Daily Basal = 0.2 - 0.5 x bodyweight (in Kg).
That’s still quite a big range. However, if you know your current basal dose you should be able to guestimate by how much it might drop for a given weight loss. Of course it will also depend on how you lose weight. If you undertake a regular exercise program this in itself will decrease your basal insulin requirements independent of any resulting weight loss.