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Insulin Resistance and Type 1 Diabetes

May 4, 2022

Although the advent of insulin has saved countless lives throughout the past 100 years, it’s not exactly a cure for diabetes. Diabetes still requires a lot of energy, knowledge, and perseverance to manage. Insulin must be taken at the optimal time before a meal, in the right location on the body, and the insulin itself must be stored properly to function. When you add other layers of difficulty such as insulin resistance, it makes diabetes management even more challenging.

I often find myself saying to others with diabetes that I only want high blood sugars for good reasons – such as eating a delicious food that probably had more carbs than I originally thought, or the adrenaline from playing a competitive sport. To me, insulin resistance seems like a frustrating reason for high blood sugars, as is a bad infusion set, insulin that got too warm, etc. Here is some information on what insulin resistance is, how it happens, and what you can do to reduce your insulin resistance to help you minimize high blood sugars for less fun reasons than yummy foods.

What is insulin resistance?

Insulin resistance is when the cells in the body have a reduced response to insulin and is considered the hallmark in diagnosing type 2 diabetes.1 It has been shown in recent research that people with type 1 diabetes develop insulin resistance over time, possibly related to the use of what is called exogenous insulin (insulin that comes from outside the body). We also know that many people have what has been termed “double diabetes,” where the individual has both insulin resistance and a lack of the ability to make insulin.

What are some of the causes of insulin resistance?

There are some times in life where insulin resistance is normal such as puberty, pregnancy, and during use of steroids. Luckily, these are all temporary and when the hormones or steroids are out of the system, insulin resistance should go back to normal. For people with diabetes using insulin therapy, there is unfortunately no end in sight for the need of insulin use, and newer studies suggest that using insulin that is not endogenous (made by your own body) causes insulin resistance.

For those of us who require exogenous insulin to live, extra insulin collects in our body which causes the cells to adapt and reduce the number of receptors for insulin.1 This in turn increases the amount of insulin needed, which can further lead to having excess insulin and further reduction in receptors. Other causes of increased insulin resistance include weight gain, physical inactivity, high triglycerides, defects on the insulin receptors of cells, stress on the body, chronic inflammation, and genetic predisposition, among others.2

What effects does insulin resistance have on the body?

When someone with diabetes has insulin resistance it can cause the following:1,3

  1. Increase in insulin needs
  2. Challenges with meeting glycemic targets
  3. Weight gain
  4. Increased risk for cardiovascular complications
  5. Elevated risk for mortality

Another challenge that insulin resistance causes is the increased cost and burden on the person with diabetes. According to a survey completed by the American Diabetes Association in 2018, 25% of people in the U.S. have rationed due to the challenge of the increased cost of insulin.1 Although this is not something we are able to immediately change, encouraging payers and politicians to ensure adequate coverage of diabetes treatment could help. You can refer to the Diabetes Patient Advocacy Coalition for more information on getting involved.

How to measure insulin resistance:

Measuring insulin sensitivity or resistance used to involve “euglycemic clamp” studies in which people are put on IV’s and insulin and glucose are infused to keep the blood glucose at a normal level.4 This is very costly, invasive, and time consuming. Unfortunately, you cannot determine insulin resistance based on how much insulin someone with type 1 diabetes is taking compared to their body weight.

There are some calculations that you can do to determine a person’s insulin resistance or sensitivity, but none of them are considered standard, and research to validate the various formulas that have been studied is still ongoing. As a person with diabetes, noticing that you need more insulin for meals, corrections, or basal rates is a good indication that your insulin resistance is increasing.

How to reduce insulin resistance or improve insulin sensitivity:

As with all topics diabetes-related, there is not a simple answer to this, but there are some actions that have helped people with T1D improve their insulin sensitivity, such as:

  • Increasing exercise
  • Losing weight (if overweight)
  • Using an insulin pump vs. injections
  • Low carbohydrate diet
  • Medications such as metformin*

*There have been many studies looking at Metformin use for increasing insulin sensitivity for people with T1D, and the results show that it helps people reduce BMI, insulin dose, and lipid levels, but the HbA1c reduction is only temporary.5 There are also many people who experience gastrointestinal side effects, such as diarrhea, that make it less than desirable as an additional medication. Other medications for type 2 diabetes, such as SGLT-2 Inhibitors and GLP-1 Agonists can help with weight loss, which could help with insulin resistance, but studies are still ongoing.

In Conclusion

The cyclical challenges in insulin resistance for people with type 1 diabetes, or diabetes that requires insulin, can be extremely frustrating. The good news is that there are some modifiable factors that you can utilize to reduce your risks. Here are some resources to help you increase your exercise with T1D:


  1. The Causes of Insulin Resistance in Type 1 Diabetes Mellitus: Is There a Place for Quaternary Prevention?
  2. Insulin Resistance-Associated Genetic Variants in Type 1 Diabetes
  3. Insulin Resistance and Risk of Major Vascular Events and All-Cause Mortality in Type 1 Diabetes: A 10-Year Follow-up Study
  4. Estimated insulin sensitivity in Type 1 diabetes adults using clinical and research biomarkers
  5. A Review of Insulin Resistance in Type 1 Diabetes: Is There a Place for Adjunctive Metformin?

Written and clinically reviewed by Marissa Town, RN, BSN, CDCES