What is insulin resistance?
People with insulin resistance have cells throughout their bodies that don’t use insulin effectively. This means the cells have trouble absorbing glucose, which causes a buildup of sugar in their blood.
It’s not entirely clear why some people develop insulin resistance and others don’t. A sedentary lifestyle and being overweight increases the chance of developing prediabetes and type 2 diabetes.
The effects of insulin resistance
Insulin resistance typically doesn’t trigger any noticeable symptoms. You could be insulin resistant for years without knowing, especially if your blood glucose levels aren’t checked. The American Diabetes Association (ADA) estimates that nearly 70 percent of individuals with insulin resistance and prediabetes will go on to develop type 2 diabetes if significant lifestyle changes aren’t made.
Some people with insulin resistance may develop a skin condition known as acanthosis nigricans. This condition creates dark patches often on the back of the neck, groin, and armpits. Some experts believe it may be caused by a buildup of insulin within skin cells. There’s no cure for acanthosis nigricans, but if caused by a specific condition, treatment may allow for some of your natural skin color to return.
Since insulin resistance increases your risk for progressing to diabetes, you may not notice right away if you develop type 2 diabetes. That’s why if you have prediabetes it’s important to have close follow up with your doctor. They will routinely monitor your blood sugar so that diabetes can be recognized as soon as possible.
Classic diabetes symptoms can include:
- extreme thirst or hunger
- feeling hungry even after a meal
- frequent or increased urination
- tingling sensations in your hands or feet
- feeling more tired than usual
- frequent infections
- evidence in blood work
If you don’t have obvious symptoms, your insulin resistance and prediabetes, or diabetes, are usually detected with a blood draw.
One way to diagnose prediabetes or diabetes is with an A1C test. This test measures your average blood sugar over the past two to three months.
- An A1C under 5.7 percent is considered normal.
- An A1C between 5.7 and 6.4 percent is diagnostic for prediabetes.
- An A1C equal to or above 6.5 percent is diagnostic for diabetes.
Your doctor may want to reconfirm this test on another day. However, depending on the lab where you have your blood drawn, these numbers could vary anywhere from 0.1 to 0.2 percent.
Fasting blood glucose test
A fasting blood glucose test is taken after not eating or drinking for at least eight hours. It provides your fasting blood sugar level.
A high level may require a second test a few days later to confirm the reading. If both tests show elevated levels of blood glucose, you may be diagnosed with prediabetes or diabetes.
- Fasting blood sugar levels under 100 milligrams/deciliter (mg/dL) are considered normal.
- Levels between 100 and 125 mg/dL are diagnostic for prediabetes.
- Levels equal to or greater than 126 mg/dL are diagnostic for diabetes.
Again, depending on the lab, these numbers could vary up to 3 mg/dL points in the cutoff numbers.
Glucose tolerance testing
According to the ADA, a two-hour glucose tolerance test may be another way to diagnose prediabetes or diabetes. A blood glucose level is drawn before the test begins. A premeasured sugary drink is then given, and the blood glucose level is checked again in two hours.
- A blood sugar level after two hours of less than 140 mg/dL is considered normal.
- A result between 140 mg/dL and 199 mg/dL is considered prediabetes.
- A blood sugar level of 200mg/dL or higher is considered diabetes.
Random blood draws
Random blood sugar tests are most useful if you’re having significant symptoms of diabetes. A blood sugar result over 200 mg/dL will confirm diabetes. However, the ADA doesn’t currently recommend that random blood glucose tests be used for routine screening of diabetes or for identifying individuals with prediabetes.
When you should get tested
Testing for diabetes should begin at about age 40, along with the usual tests for cholesterol and other markers of health. Ideally, you can get tested at your annual physical exam or preventive screening with your primary doctor.
Testing at a younger age may be recommended if you:
- live a sedentary lifestyle
- have low “good cholesterol” (HDL) level or high triglyceride levels
- have a parent or sibling with diabetes
- are American Indian, African-American, Latino, Asian-American, or Pacific Islander
- have high blood pressure (140/90 mm Hg or above)
- have signs of insulin resistance
- were diagnosed with gestational diabetes (a temporary condition that causes diabetes to develop only while pregnant)
- had a baby who weighed more than 9 pounds
Even if your test comes back in the normal range, you should have your blood glucose levels checked at least every two to three years.
Children and young adults between the ages of 10 to 18 may also benefit from diabetes screening if they are overweight and have two or more of the above risk factors for diabetes.
Preventing insulin resistance problems
If you have prediabetes, you may be able to prevent diabetes by exercising 30 minutes at least five days a week and eating a balanced diet. Losing weight, even just 7 percent of your body weight, can also lower your risk of developing diabetes. Making good lifestyle choices is the best way to get your blood glucose levels in the desired range.
It’s important to remember that a diagnosis of insulin resistance and prediabetes is a warning. You can often reverse this condition with healthy lifestyle changes.