Trusted medical advice from the
American Academy of Family Physicians.

Insulin Resistance

What is insulin resistance?

Insulin resistance is a condition linked to prediabetes and type 2 diabetes. Insulin resistance means your body is unable to respond to the amount of the hormone insulin it is producing. Insulin is made by your pancreas, one of your body’s organs. It helps protect your body from getting too much sugar (glucose). Glucose gives you energy. However, too much sugar is harmful to your health.

Symptoms

Most people don’t realize they have insulin resistance until they have a blood test. Everyone has high blood sugar levels from time to time. However, when your body’s sugar level is consistently high, you may notice you are thirstier than usual, urinate more, are more tired, have blurred vision, and have some tingling on the bottom of your feet.

What causes insulin resistance?

Obesity (being significantly overweight and belly fat), an inactive lifestyle, and a diet high in carbohydrates are the primary causes of insulin resistance. Some women develop insulin resistance while they are pregnant. This is called gestational diabetes. Certain diseases are associated with insulin resistance. That includes heart disease, nonalcoholic fatty liver disease, and polycystic ovary syndrome.

Certain risk factors are associated with insulin resistance, including:

  • A family history of diabetes
  • A sedentary (not active) lifestyle
  • Race (especially if you are Black, Hispanic, or Native American)
  • Age (the older you get, the more your risk increases)
  • Hormones
  • Steroid use
  • Some medicines
  • Poor sleep habits
  • Smoking

How is insulin resistance diagnosed?

Your doctor will ask you questions about your symptoms, your personal and family medical history, evaluate your weight, and take your blood pressure. Diagnosing insulin resistance requires a blood test. This might be done through a small finger prick or by having a small needle inserted into a vein to take a sample of blood. You will often be required to fast (avoid eating or drinking anything except water) 8 hours before the test. The blood sample will be sent to a lab for testing. It will test your fasting blood sugar. Anything more than 100 mg/dL is an indication of insulin resistance. Your doctor also may have the lab check your cholesterol levels (from the same blood sample). People with insulin resistance often have high cholesterol.

Your doctor will also test your hemoglobin A1C level as part of the diagnostic workup. This is a similar blood test that offers the doctor a look at how your sugar levels have been during the past 3 months.

The American Academy of Family Physicians (AAFP) recommends blood glucose screening of all pregnant women for gestational diabetes after the 24th week of pregnancy. Also, the AAFP recommends blood glucose screening for adults age 40 to 70 years who are overweight or have obesity and may be at risk of heart disease.

Can insulin resistance be prevented or avoided?

You cannot prevent or avoid risk factors such as race, age, and a family medical history. You can take steps to reduce your insulin resistance by losing weight (even 10% can make a difference), exercising regularly, and eating a healthy diet. Choose healthy carbohydrates. For example, eat whole grain bread instead of white bread, drink water instead of soda, and reduce your intake of sugary foods.

If you have or have had gestational diabetes, insulin resistance typically goes away after you give birth. However, you are at greater risk of being diagnosed with type 2 diabetes when you are older. That should be a warning to change your diet and lifestyle early so that you can delay it for as long as possible.

Treatment

Diet, weight loss, and exercise can improve insulin resistance. However, most people need medicine as well. Your doctor may prescribe a medicine that works best for your health and lifestyle needs. If your insulin resistance leads to uncontrolled type 2 diabetes, you may need insulin (given through a pump or daily injection).

Living with insulin resistance

Living with insulin resistance requires lifestyle changes as well as regular use of prescription medicine. You will have to be more careful in making meal and snack choices, reading labels, and maintaining a lower weight. You also will have to commit to regular exercise and take your medicines as prescribed.

Questions to ask your doctor

  • Does insulin resistance always lead to diabetes?
  • If I watch what I eat at a young age, can I avoid insulin resistance when I am older?
  • Can thin people have insulin resistance?
  • Will insulin resistance make it harder for me to lose weight?

Resources

Centers for Disease Control and Prevention: Diabetes: Insulin Resistance and Diabetes

National Institutes of Health, MedlinePlus: Prediabetes

National Institutes of Health, National institute of Diabetes and Digestive and Kidney Diseases: Insulin Resistance & Prediabetes

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