A R T I C L E

Sliding Scale Insulin

Sliding scale insulin therapy is a method commonly used to manage blood glucose levels in people with diabetes. It involves adjusting insulin doses based on current blood sugar readings, providing a flexible, reactive approach to control. However, its effectiveness and safety have been debated, as it may not address long-term glycemic control adequately.

What is Sliding Scale Insulin?

Sliding scale insulin is a technique used to determine how many units of insulin to give before each meal based on your current blood glucose value. 

It is an uncommon technique among people who have had type 1 because it isn't very accurate and can lead to an increased risk of hyper- and hypoglycemia. 

However, a sliding scale technique is still used for some patients who have recently been diagnosed since it is relatively simple that isn't as complicated as doing full carbohydrate counts with insulin ratios. 

How to Use a Sliding Scale

First, your doctor or another licensed healthcare professional will provide you with a scale to use that indicates how many units of insulin to give based on your blood glucose. Each sliding scale is different and they are often customized for each patient, so it is not okay to use just any scale that you may find on the internet or elsewhere. If your doctor wants you to use this technique, they will provide you with a scale to use. 

The simplest scales will have two columns, one displaying blood glucose ranges and the other indicating how many units of insulin to give. The image to the right is an example of a sliding scale. 

Using a sliding scale is relatively simple. The first step is to check your blood glucose using a meter or a CGM. Then looking through the blood glucose column on the table and find the range in which your current blood glucose falls.

For example, if your current blood glucose was 238, then you would use the 201 - 250 range. If your blood glucose was 65, then you'd use the ≤70 (less than 70) range. If your blood glucose was 323, then you'd use the ≥300 (greater than 300) range. 

Once you have found the range in which your blood glucose falls, move across to the insulin column where it will tell you how many units of insulin to give. For example, if your blood glucose falls in the 71 - 100 range, then you give 4 units of insulin. If your blood glucose falls in the 251 - 300 range, then you give 12 units of insulin. 

Your doctor will instruct you on how many times per day to use your sliding scale and administer insulin. Frequently, they will tell you to use it before each meal (breakfast, lunch, and dinner) and sometimes once before bed (or around 10pm).

If you would like to practice using a sliding scale, scroll to the bottom of this page to view some practice problems with answers and explanations. 

More Complicated Sliding Scales

One of the key advantages of using sliding scale insulin is that it is pretty simple to use, but because your activity levels and food intake change throughout the day, your doctor may provide you with a sliding scale that separates the insulin doses by meal or time of day like the one below. 

When using a sliding scale like this, you still find the column with your blood glucose range, but now you use a different column of insulin units for each meal or time of day. This helps give you a little more control over your dosage that using just one scale every time. 

Pros and Cons of Sliding Scale Insulin

Sliding scale insulin is not very commonly used anymore, and people who have had type 1 diabetes for a long period of time will almost ever use it. In fact, some studies have called it an "antiquated" tool that is "stuck in the past". That being said, here are the pros and cons to using sliding scale insulin. 

Pros

Cons

Conclusions

Sliding scale insulin is a tool that has some limited advantages in rare cases, but it is not something that should be used for long periods of time or by someone who has the ability to use more accurate dose calculation methods (such as carb counting). It is not something that you should try unless your doctors or healthcare provider has instructed you to do so and has taught you how to use it safely. 

Practice Problems — Set 1

Use the sliding scale on the right to calculate how many units of insulin to give based on the blood glucose provided. The answers are provided in a drop down below. 

Click to show answers

Practice Problems — Set 2

Use the sliding scale below to calculate how many units of insulin to give based on the blood glucose and meal/time of day provided. The answers are provided in a drop down below. 

Click to show answers

Sources and Further Reading