Carb Ratio (CR)¶

Highlights

CR can be transferred from your pump
Adjust your CR by performing a test meal experiment

CR refers to the amount of carbohydrates one unit of insulin is able to neutralize.

Bill has a CR of 10g/U. If Bill eats a meal containing 50g of carbs, how much insulin does Bill need for the entire meal?

Here is the formula you will need:

\[ \frac{grams\ of\ carb\ eaten}{C R} \]

Calculate Bill's Insulin Dose:

\[ \frac{50}{10}= \]

\[ 5\ units \]

Answer

Bill needs 5 units of insulin for his meal.

CR is not changed like basal rates or ISF. Your CR must be as accurate as possible for proper Trio function.

It is safe to transfer your CR from your pump settings. However, your settings may not be accurate if you are experiencing high peaks with meals or lows three hours afterward. If you have SMB/UAM on and are experiencing sharp drops, you may also need to optimize your ISF.

Testing/Adjusting Your Carb Ratio (CR)¶

Baseline Calculation¶

If your current carb ratio is close, but needs some testing and adjustment, skip to the next section.

If your current carb ratio is inaccurate or you are unsure where to even start, the adjustments in Trio are based on formulas developed by Walsh, et.al. and may help you find a starting point to then test or adjust your carb ratio.

Warning

This calculation is to be used as a starting point for testing and is not considered definitive or exact.

CR Testing¶

CR Adjustment¶

The standard way to adjust your CR is a test meal experiment, which can be done while not looping. Have a meal with a known amount of carbohydrates and bolus according to your current CR. Monitor your blood sugar at the three-hour mark; did you go high, low, or end up where you started prior to the meal? If you end up high, you can make your CR more aggressive by DECREASING the value. If you were low, make your CR less aggressive by INCREASING the value. You may also look to increase or decrease your adjustment factor if you have dynamic CR on.

How To Enter Your Carb Ratios (CR) Into Trio¶

Step 1¶

Enter the CR Profile screen

CR Profile Menu

Step 2¶

Tap the "Add Rate +" on the top right of the screen until you have the number of CRs you require. Then, edit each rate by tapping the arrow to the right of the CR.

Add Edit CR