What is insulin resistance?
Insulin resistance is when your body’s cells don’t respond properly to the hormone insulin. So instead of keeping your blood sugar levels stable and within a healthy range, your blood sugar levels can rise.
Insulin resistance isn’t the same as diabetes. It can affect people with and without diabetes and at any age but is more common during puberty, pregnancy and menopause.
If you don’t have diabetes, insulin resistance can increase your risk of diabetes and lead to diabetes if your pancreas isn’t able to produce enough insulin to overcome the resistance and keep your blood sugar levels within a healthy blood sugar range. So you may then be at risk of prediabetes, type 2 diabetes or gestational diabetes (during pregnancy).
If you have any type of diabetes including type 1 diabetes, you can develop insulin resistance – including resistance to insulin you give yourself, through injections or an insulin pump.
Having insulin resistance if you live with diabetes usually means you’ll need a larger amount of insulin or medications that lower your blood sugar levels to help you stay within your blood glucose target range.
What is insulin sensitivity?
You may hear your healthcare professional talk about having a low sensitivity to insulin. It’s the same thing as having insulin resistance. It means your body needs more insulin because your body is less responsive to it.
If you are insulin resistant and are taking insulin you need higher doses of insulin for the same amount of carbohydrate.
This might be your carbohydrate ratio, for example:
- 1 insulin unit to 10g carbs = higher sensitivity
- 1 insulin unit to 5g carbs = (insulin resistant) lower sensitivity
Causes of insulin resistance
You are more likely to have insulin resistance if you have too much fat stored in and around your liver and pancreas, and high blood fats such as high triglycerides, or cholesterol. Insulin resistance is linked to living with overweight or obesity, but it can affect some people of a healthy weight or BMI.
The exact cause of insulin resistance isn’t fully understood and may be different from person to person.
How your body makes, uses or responds to insulin can change over time. It can be affected by hormones to the type and amount of exercise you do.
What is severe insulin resistance?
There is also something called severe insulin resistance which is rare and occurs in people whose bodies respond least well to insulin. It often means people have very high levels of insulin in the body, which can lead to other problems such as gaining weight and having high levels of fats in the body.
What causes severe insulin resistance?
Insulin resistance is often linked to living with obesity. But some other conditions such as polycystic ovary syndrome (PCOS) can cause insulin resistance and sometimes severe insulin resistance.
Rare conditions causing severe insulin resistance include insulin receptor mutations, insulin receptor antibodies and lipodystrophy (abnormal fat distribution).
Symptoms of insulin resistance
You may not have any symptoms of insulin resistance, but symptoms can include tiredness, difficulty concentrating and hunger.
If you have diabetes and notice that your blood sugar levels or HbA1c are increasing this may indicate insulin is not working effectively.
If you are at risk of type 2 or gestational diabetes, it is important to look out for the signs and symptoms of diabetes as this may indicate that insulin isn’t working effectively and early diagnosis of diabetes is very important to reduce the risk of complications.
Treatment for insulin resistance
For people living with overweight or obesity, weight loss can be one way to help improve how your body uses insulin whatever type of diabetes you have. Increasing activity levels can also help.
Some people with type 2 diabetes who improve how their body makes and uses insulin through weight loss may be able to put their diabetes into remission.
The ReTUNE study shows that some people of lower body weights with type 2 diabetes may also be able to put their diabetes into remission through weight loss.
If you manage diabetes with insulin
If you inject insulin as a treatment for your diabetes and have insulin resistance, it does not mean you are resistant to that specific brand or type of insulin. But you may need to increase the doses or use higher doses to cover the same amount of carbohydrate.
To help make the insulin more effective again, your healthcare team might also suggest that you need to start other medications such as Metformin alongside your insulin. Metformin can be prescribed to help reduce insulin resistance whether you have type 1 or type 2 diabetes.
Treatment for severe insulin resistance
Weight loss, healthy eating and exercise and the medications metformin and pioglitazone can improve insulin resistance and severe insulin resistance.
Some people with severe insulin resistance need specialised therapies including metreleptin therapy, immunosuppression, highly concentrated insulin therapy or a combination of the three.
You can ask your healthcare team for more information on insulin resistance.
You can also find further information and support on the National Severe Insulin Resistance Service website. They provide a multidisciplinary service for adults and children with severe insulin resistance, lipodystrophy or both throughout England. The service gets funding from NHS England. Patients from Wales, Scotland and Northern Ireland can also be seen if Health Board funding is approved.
