Using Higher Basal rates combined with Control IQ to get lower average glucose levels

I was wondering if anyone else sets a higher-than-needed basal rate on their Tandem pump since Control IQ will keep you from going too low? I find this allows me to have glucose levels lower than the preset 112 mg/dL on the pump, while also helping to fight the post-meal spikes faster.

I have set my daytime basal rates higher, but minimal increase to overnight rates.

The reason for minimal at night time is due to occasional CGM dropouts overnight, so lose the possibility of basal adjustments. So if really low, but pump has no CGM reading, it will use the set rate without reduction, leading to extreme low.


Seems like SLIGHTLY increased basal and SLIGHTLY reduced correction factor is the magic combination for Control-IQ.

I also run sleep mode around the clock for more aggressive basal adjustments.

Like @MM1, I’m much more liberal with daytime rates than nighttime ones. I seldom have Dexcom issues, but I’d like to be conscious if the pump is reverting to an inflated programmed basal.


I find that more insulin makes my sugars more volatile.
It’s a balancing act.
I know that if my sugars run in the 80s for extended periods, my liver tends to dump glucose then I’ll shoot up to 200.

I also have a pretty strong dawn phenomenon, which is basically the same thing only without the low sugars.

Some people can tolerate that, however my liver has a mind of its own. Mid 90s are my sweet spot.

Do you mean adjusting the correction factor to reduce insulin delivery, like adjusting from 1:20 to 1:30) or one that is smaller in number, like going from 1:30 to 1:20, that increases insulin delivery?

Describing the inverse relationship in the correction factor can get tricky. I sometimes use the terms, “more aggressive” or “less aggressive,” where more aggressive means more insulin and less aggressive means less insulin.

Interesting. What do you consider an extended period? Hours? Days?

I mean what I say literally. I try not to make people over-think or have to infer anything from my words. “Reduced correction factor” in my specific case means reducing the setting from 1:46 to 1:42.

I find this interesting, too. I don’t know the exact signaling pathway, but wonder if this is learned/reactive and wonder if it can be re-programmed?

I don’t notice any liver dump unless I hit the critical low line. I can revert from 60s easily without the rebound and can live all day in the 80s. But if I touch 55, the rest of the next coming day is going to be a stubborn nightmare.

I do get crazy spikes after my morning coffee, though. Maybe that just evacuates all my glycogen stores, forcing my liver to be more conservative with them for the rest of the day?

Sorry, it was ambiguous to me without your clarification.

I didn’t intend that to sound snarky. It’s a common misunderstanding, and I should probably learn to be more specific because I know it’s a common misunderstanding. But for the life of me, I honestly don’t understand why. Correction Factor is a very specific thing with a numerical value that can be moved up and down, why do so many assume there’s any deeper meaning than that?

To me “reduce” and “increase” only relate to a numerical value. I have no other understanding of those words. They’re specific instructions to add or subtract from the existing value. Now the educated can take that information and infer whether it makes the algorithm more or less aggressive… But the average diabetic doesn’t know that much about what their pump settings mean. If you speak of aggressiveness, they’ll ask you to break it down into a plain directive. “Number up or number down?”.

It’s like science and religion. You can talk about the same exact thing, but you’re answering very different questions: how vs. why, where only the first coincides directly to a numerical value.

Yes the correction factor thing is kind of a double negative.

My liver dumping thing happens if I’m under 80 for a few hours.
Or even low 80s. I didn’t know it was happening until I got cgm.
If I stay in high 80s at least I can stay very flat.
If I’m lower I’ll see it 80 82 84 81 then 100, 120 150 200. It’s fast and all while I’m not eating.
It’s really the only thing that could be happening

I think it is due to the inverse relationship between the correction factor and the amount of insulin that it calculates. My experience as an editor taught me that there’s a spectrum of meaning readers can take from any written material. What looks eminently clear to me doesn’t look the same to everyone. In this instance, a “for example” would have nailed down your intent.

I apologize for the meta digression but I thought your expertise with Tandem’s C-IQ deserved a clearer text. I regret irritating as I know my remarks can appear pedantic.


To get even more philosophical: I don’t think there is a direct pathway for a formula to enter the brain. At least not into mine. The way I store a formula is by creating examples on-the-fly and then let my brain condense it into a formula. Therefore it is always much easier for me to understand something if I am presented with both examples and formula. Often I communicate in examples only. It seems to be much easier for a lot of people to detect a pattern in examples and then to come up with a formula themselves instead of dealing with a formula directly. I assume that not everybody resorts to the ‘trick’ of generating examples on-the-fly.