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What Is Prediabetes?

People with prediabetes have glucose levels that are higher than normal but not high enough yet to indicate diabetes. The condition used to be called borderline diabetes. Most people with prediabetes don't have symptoms, but they are considered to be at high risk of developing heart disease.

Normally, your body produces a hormone called insulin to help your cells use the energy (glucose) found in food. With diabetes, either your body doesn't make enough insulin or doesn't efficiently use the insulin it does produce. When glucose builds up in the blood, it can damage the tiny blood vessels in the kidneys, heart, eyes, and nervous system.

With prediabetes, the subtle balance between glucose and insulin has been thrown off. The pancreas may not be able to produce enough insulin after a meal to "clear" the incoming glucose from the blood. Or cells may be insulin resistant. When cells are insulin resistant, they won't allow the insulin to escort glucose from the bloodstream into them. Too much glucose in the blood is also called high blood sugar or hyperglycemia. A low blood sugar level is called hypoglycemia.

If you have prediabetes, you're at high risk of developing type 2 diabetes as well as the serious medical problems associated with diabetes, including heart disease  and stroke. With prediabetes, you are at a 50% higher risk of heart disease and stroke than someone who does not have prediabetes.

How is prediabetes diagnosed?

To determine if you have prediabetes, your doctor can perform one of three different blood tests – the fasting plasma glucose (FPG) test, the oral glucose tolerance test (OGTT) or the Hemoglobin A1C (or average blood sugar) test.


How is the fasting plasma glucose test (FPG) done?

The fasting plasma glucose test can be done after an overnight fast or after an eight-hour fast during the day. It is a relatively easy, inexpensive test. After the fast, a simple blood test measures glucose levels before you eat again. The test results indicate whether your blood glucose level is normal or whether you have prediabetes or diabetes:

  • Normal: Normal blood sugar levels measure less than 100 mg/dl (milligrams per deciliter) after the fasting glucose test.
  • Prediabetes: Blood glucose levels of 100-125 mg/dl after an overnight or eight-hour fast may indicate prediabetes. People with these results are considered to have impaired fasting glucose (IFG).
  • Diabetes: Diabetes is diagnosed when the blood glucose is 126 mg/dl or above.

In most cases, your doctor will repeat any abnormal test before confirming the diagnosis.


How is the oral glucose tolerance test (OGTT) done?

The OGTT usually requires that you have the fasting glucose test first. Then you take a dose of high-sugar (glucose) solution to challenge your body to clear the glucose from your blood. After two hours, another blood glucose test is done. The final test results indicate whether you have a normal level of blood glucose or may have prediabetes or diabetes:

  • Normal: Normal blood sugar levels measure less than 140 mg/dl after the oral glucose tolerance test.
  • Prediabetes: Blood glucose levels of 140-199 mg/dl after the OGTT is diagnosed as prediabetes. People with these results are considered to have impaired glucose tolerance (IGT).
  • Diabetes: Diabetes is diagnosed with blood glucose of 200 mg/dl or above.
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If the level is below 70 or you are experiencing symptoms such as shaking, sweating or difficulty thinking, you will need to raise the number immediately. A quick solution is to eat a few pieces of hard candy or 1 tablespoon of sugar or honey. Recheck your numbers again in 15 minutes to see if the number has gone up. If not, repeat the steps above or call your doctor.

People who experience hypoglycemia several times in a week should call their health care provider. It's important to monitor your levels each day so you can make sure your numbers are within the range. If you are pregnant always consult with your health care provider.

Congratulations on taking steps to manage your health.

However, it's important to continue to track your numbers so that you can make lifestyle changes if needed. If you are pregnant always consult with your physician.

Your level is high if this reading was taken before eating. Aim for 70-130 before meals and less than 180 two hours after meals.

Even if your number is high, it's not too late for you to take control of your health and lower your blood sugar.

One of the first steps is to monitor your levels each day. If you are pregnant always consult with your physician.

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