Impaired Glucose Tolerance (IGT) is a state when the person has blood glucose levels that are higher than normal, but below the level of diabetes. It is a pre-diabetic state of Dysglycemia. Impaired Glucose Tolerance occurs when there is impaired secretion of insulin or a reduction in insulin sensitivity (insulin resistance) in the body. Impaired Glucose Tolerance can easily lead to Type II Diabetes. According to the U.S. Department of Health and Human Services approximately 1-in-4 Americans over the age of 20 has pre-diabetes

The good news is that if diagnosed early enough, it’s possible that the patient can undergo lifestyle changes which include diet and exercise in order to bring the blood glucose levels under control and can therefor stop the progression of Impaired Glucose Tolerance to Type II Diabetes.


Risk Factors for Impaired Glucose Tolerance

There are a number of risk factors for Impaired Glucose Tolerance. Talk to your doctor if you have any of the following risk factors:

  • Family history of Type II Diabetes
  • Previous diagnosis of gestational diabetes and / or have had a baby weighing more than 9lbs.
  • Women with a diagnosis of polycystic ovary syndrome (PCOS)
  • An earlier abnormal glucose tolerance test
  • Inactive persons
  • Persons who are overweight or obese – with a BMI (Body Mass Index) of 25 or over
  • People having high triglycerides
  • Persons who have low HDL (good cholesterol) and a high LDL (bad cholesterol)
  • Persons who have high blood pressure
  • Older people and the aging
  • Ethnic backgrounds such as African-Americans, Native Americans, Latinos and Pacific Islanders


Because Impaired Glucose Tolerance generally shows no pronounced symptoms it is not diagnosed easily. By knowing you are at risk, getting tested and reducing your risks will help you to prevent IGT from being a part of your reality. You can lower your chances of IGT and increase your chances of a long and healthy life by increasing physical activity, eating a healthy and balanced diet which is low in simple carbohydrates keeping your BMI under 25.

Symptoms of Impaired Glucose Tolerance and Pre Diabetes

Although most people with Impaired Glucose Tolerance show no symptoms, there are some who show signs such as frequent thirst, a frequent need to urinate, blurred vision and fatigue. It’s important to know if you are at risk for Impaired Glucose Tolerance and speak to your doctor about being tested.


There are two different forms of blood tests used to diagnose Impaired Glucose Tolerance. First is the fasting plasma glucose test (FPG) which measures the blood glucose levels after an 8 hour fast. The FPG determines if your body is metabolizing glucose correctly.

The second is an oral glucose tolerance test (OGTT). With the OGTT, a blood sample is taken to give a baseline of blood glucose. The patient is then given a glucose solution to drink within a five minute time span. Subsequent blood samples are taken at regular intervals of time to determine how the body is metabolizing the glucose.