How to dose insulin for carb ratios and corrections
When a doctor diagnoses insulin-dependent diabetes, you’ll quickly learn that accurate carbohydrate counting and correct mealtime insulin dosing and higher blood sugar levels are both critical to effective diabetes management.
But terms like “insulin-to-carb ratio” and “correction factor” can be confusing, especially if you’ve just been diagnosed with the disease.
This article explains how insulin works when eating food and how to dose insulin to keep blood sugar within limits.
All humans need insulin to live. It helps digest the glucose (sugar) found in most foods, including:
- any food to which sugar is added during processing
All carbohydrates are broken down into glucose which is ultimately converted into energy that fuels the brain and body.
As this sugar moves from the bloodstream into the cells, it raises your blood sugar levels.
In people without diabetes, the body automatically adapts to this cycle on natural autopilot.
For people with diabetes, the insulin-producing cells in the pancreas don’t make insulin the way they do in people without the condition. This means that people with diabetes must manage this functionality of insulin to regulate glucose levels themselves.
People with type 2 diabetes (T2DM) may not need insulin treatment because lifestyle changes can manage the condition.
This is not the case for type 1 diabetes (T1D). T1D is an autoimmune disease. People with T1D need treatment with insulin by injection or with a diabetes machine because their body can’t do it on its own.
People using insulin pumps rely solely on rapid-acting insulin for their bolus insulin and basal insulin. The insulin pump releases a very small amount of insulin in constant increments throughout the day, mimicking a human pancreas.
People who do not use an insulin pump can inject insulin several times a day. This could mean taking one or two injections of long-acting insulin a day, either with a vial and syringe or a plastic pre-filled insulin pen.
This is in addition to their fast-acting insulin, which can also be taken in syringe and vial form or with an insulin pen.
An insulin-to-carb (I:C) ratio is the amount of rapid-acting insulin needed to essentially “cover” the number of carbohydrates a person eats or drinks.
While many people tend to focus on calories when discussing food labels and nutrition information, those living with diabetes who need insulin often look first at the carb count on the labels. nutritional.
Everyone’s I:C ratio varies. This is because everyone’s diabetes is different. But as an example, an I:C ratio might look like this:
Always discuss with your diabetes care team what your blood sugar goal should be. These healthcare professionals can help you determine your ideal I:C ratio based on many factors, including:
- activity level and lifestyle
- insulin sensitivity
Simply calculating your I:C ratio for a meal does not take into account your insulin correction factor. This number indicates how much 1 unit of rapid-acting insulin will lower your blood sugar.
For example, if you’re dosing insulin for a particular amount of carbs, you’ll want to take less insulin for those carbs if your blood sugar is below 70 mg/dL.
You would also need additional insulin above the I:C ratio if you have higher blood sugar at that time.
Correction factors are like I:C ratios in that they can vary individually and even by time of day. This is all part of discussing with your diabetes care team to determine what might be the best rates for your needs.
To get a rough estimate of your I:C ratio, divide the number 500 by your total daily dose (TDD) of insulin, which includes both long-acting insulin and rapid-acting insulin. This is called the “rule of 500”.
To roughly calculate your correction factor, take the number 1800 and divide it by your TDD. This is called the “1800 rule”.
Remember to always work with your healthcare team to refine your I:C ratio and correction factor.
Most insulin pumps now perform this calculation automatically when recommending a bolus of insulin. However, for people taking multiple daily injections, manual calculation of these numbers is necessary for all meals, snacks and drinks.
The insulin to carb ratio and the correction factor are important tools to have in your diabetes tool belt. They can help you better manage your diabetes and blood sugar so you feel better.
The insulin to carb ratio and correction factor may change over time. They depend on many things, including lifestyle, diet, life circumstances, weight, gender, age, and health goals.
Always work with your doctor and healthcare team to determine your most appropriate insulin-to-carb ratio and correction factor.