Insulin Sensitivity Factor¶

ISF, also called insulin correction factor (ICF), refers to the amount of blood glucose in mmol/L (or mg/dL, depending on your settings) one unit of insulin can neutralize.

Example: Bill has a 1:4 ISF (this is also written in shorthand as an ISF of 4 mmol/L/U (72 mg/dL/U)). This means 1 U of rapid insulin will bring Bill's sugar down by 4 mmol/L (72 mg/dL).

Like basal rates, ISF is not used verbatim by Trio but is modified over time as data on the patient is collected. Still, setting ISF as close to accurate as possible is important for Trio to function well.

Settings¶

It is safe to transfer your ISF from your pump settings. Note that almost all issues when starting with Trio are a result of an improperly set ISF. If you find you have lows with corrections, or you have SMB/UAM on and the application provides too much insulin at any time, resulting in a rollercoaster pattern, your ISF is likely to blame.

There are a few ways you can work to adjust your ISF. The easiest method is simply bringing yourself to a higher glucose with a glucose tab or choosing a time when you are "stuck" higher than your target, then correcting based on your ISF. If you are higher than your target after 4 hours, make your ISF more aggressive by DECREASING the value. If you are lower than your target after 4 hours, make your ISF less aggressive by INCREASING the value.

You may also find Autotune helpful in identifying when to adjust your ISF and determine whether it is too high or low based on the trend in its changes. Look to changing your profile value to the autotune value when Autotune stabilizes to ensure safety limiters aren't preventing any additional needed change.