Just wanted to update here as I was seen by a research doc at UVA health. Long drive but worth it. She did research on both tandem and omnipod5 and feels by far the most important numbers are carb ratio first and foremost and it should vary with time of day as you see fit. Secondarily important is insulin sensitivity factor. She did not feel basal was as important which is not to say it has no importance just that she feels the other values are critical.
I found this interesting as I had asked some questions here and felt basals were of top importance. Just another perspective.
I also told her that for me, dialing those values in was an art and not a science. She agreed.
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My tandem pump was set t basal, carb ratio and ISF that was working well with MDI, but not so great with the pump. I increased basal by 0.1u and my weight by 15lbs. This helped somewhat, but using a couple of formulas using Todd to get u/carb and ISF has really done wonders.
I admit I don’t let C-IQ decrease meal bolus when BG is 90.
Do we really know how (if) weight is used in the automation?
I’ll admit increasing your weight seems counterintuitive. For example, basil .5, correction 1:50, carb 1:10 and actual weight 150 vs override weight of 225.
In my mind, if everything stays the same (basil, correction and carb)except weight, the automation would be more aggressive at a lower weight vs a higher weight(per pound it is taking more to accomplish the same for 150 vs 225).
I really don’t understand how the algorithm uses body weight, but some Tandem users actually enter a weight 100 or more pounds extra to fool the pump to give a lower and flatter BG line.
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Weight is used as a modifier in how fast it switches off when low and how long it stays off. It also alters the predictive action to when it thinks you might be going low or high.
So the more weight you tell it, the faster it reacts.
The theory is that more mass takes longer to react and will be more sluggish to changes in glucose. So the weight factor tries to compensate for that.
I enter 30 lbs heavier than I am, but the reality is if you want to run lower you can just take some lantus every day.
I take small doses of lantus just to keep my sites from crapping out. But it keeps me lower, around 100 during the night.
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I’m not on T:IQ, perhaps its different, but every other source I’ve heard from says setting basal rate 1st is THE most important. Would be interesting to know if your doc’s rationale for the comment. Perhaps you’ve got your basal already dialed in so well?
You have to remember that this is your doctor’s OPINION. It’s not fact. Just like what you read on the Internet from actual users is their opinion. And my personal opinion is certainly different than your doctor’s, but they’re welcome to think whatever they want. This training wasn’t part of med school. They might have a local area rep telling them things to get them interested or answer questions. There are some training modules available to them, but they’re not much different than the training modules they made current T:slim users watch when they did the Control-IQ software update. How much any endocrinologist chooses to know about how these systems work is purely based on how much effort and personal time they invest into learning it… Just like us. And since many (most?) of them aren’t diabetic, they don’t even have first-hand knowledge.
This is how most of medicine works. One doctor’s personal experience is different from another’s, so they develop different opinions. This is why you can find so many differing opinions and have such wide and varying experiences with different doctors.
In my opinion, they seem confused, and don’t understand the differences between the different semi-closed loop systems. Either that, or they’re just over-simplifying answers for patients. They KISS (keep it simple stupid) philosophy…
Since Control-IQ is making adjustments to your programmed basal rate, how can that not be critical? It’s not designed to figure out it’s own basals, like Medtronic and Omnipod, but rather just make adjustments. It’s what sets Control-IQ apart from the other systems, giving YOU more control over how it behaves.
Insulin on board also informs nearly every choice Control-IQ makes, whether to deliver extra insulin or withhold some. The amount of IOB displayed is a calculation of whatever insulin the pump has delivered that is in EXCESS of your programmed basal rate. If your basal isn’t correct, neither is your IOB. If your programmed basal rate is higher than true, you will have more IOB than Control-IQ knows, leaving you prone to lows. If it’s lower than true, then you will have less IOB than Control-IQ thinks, leaving you prone to stubborn highs.
I find the notion of having to bolus PERFECTLY amusing. If I was that good, I wouldn’t need Control-IQ in the first place! I also think this is a great way to put the blame back on the “noncompliant” patients when Control-IQ doesn’t behave, if they believe I:carb is so important. “Well, they must not be counting all the carbs correctly, no wonder BG is all over the place!” How our food affects BG is WAY more complicated than just how many carbs are in it. We don’t have a viable system yet to account for how protein and fat affect BG levels and insulin sensitivity, so how much weight can practically be applied to carb ratio alone? Of course, I don’t count carbs at all, but rather just “guesstimate” and dial up whatever dose I think is correct, so it’s a given my opinion will differ here.
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Similar for me. Been doing this since using Medtronic pump in late 1980s, after being initially trained to use food exchanges !
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This Endo at UVA Health in Charlottesville, VA is very qualified to comment as she has been lead? researcher on both Control IQ snd Omnipod 5 systems. Below is what the website has to say about her. I am just starting and our time was very limited but I have many more questions about the algorithm to ask.
Dr.is a member of the UVA Center for Diabetes technology in which she works closely with engineers and clinical researchers to translate technology to treatment options for diabetes. Dr. runs clinical trials on automated insulin delivery treatment options using insulin pumps and continuous glucose monitors.
She has lots more to say, I just found her comments interesting but don’t understand her reasoning yet! Hopefully future visits will flesh it out.
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