What is insulin resistance?

The body’s resistance to insulin does not necessarily mean someone has diabetes. However, insulin resistance does increase the risk for developing the disease, as well as other health conditions.

The hormone insulin, made by the pancreas, helps control the amount of sugar (glucose) in the blood. With insulin resistance, the body builds up a tolerance to insulin, making the hormone less effective. Glucose cannot enter the cells as easily, so it builds up in the blood. Untreated high blood sugar increases the risk of developing prediabetes and type 2 diabetes. It can even cause heart disease, nerve damage, vision problems, and kidney failure.

The cause of insulin resistance is still being studied. However, experts believe obesity, especially too much fat in the abdomen and around the organs, is a main cause of insulin resistance. This is especially true for men with a waist measurement of 40 inches or more, and for women with a waist measurement of 35 inches or more.

According to the National Institute of Diabetes and Digestive and Kidney Diseases, not getting enough physical activity is linked to insulin resistance. Regular physical activity causes changes that allow the body to better keep blood glucose levels balanced. A family history of type 2 diabetes also can raise the risk of insulin resistance. Additionally, older people are more prone to insulin resistance, according to the American Diabetes Association.

Insulin resistance usually has no symptoms. Blood tests can determine if someone has prediabetes or diabetes, but there is no single test for diagnosing insulin resistance. When sugar levels are consistently high, an individual may notice certain symptoms. These include increased thirst, tiredness, frequent urination, blurred vision, and tingling in the feet. This may be a sign of diabetes.

Eating healthier foods and losing weight can help reverse insulin resistance, according to the National Institute of Diabetes and Digestive and Kidney Diseases. These lifestyle changes also can prevent or delay type 2 diabetes in people who have prediabetes.

No medications are specifically approved to treat insulin resistance. Yet diabetes medications like metformin and thiazolidinediones, or TZDs, are insulin sensitizers that lower blood sugar, at least in part, by reducing insulin resistance.