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. It occurs due to impaired secretion of insulin or reduced insulin sensitivity (insulin resistance) in the body. It could easily lead to type II Diabetes.

According to WHO impaired glucose tolerance may be defined as two-hour glucose levels of 140 to 199 mg per dL (7.8 to 11.0 mmol) on the 75-g oral glucose tolerance test. If a patient exhibits an intermediately raised glucose level after 2 hours, but less than the level to qualify for type 2 diabetes mellitus, he is said to suffering from Impaired Glucose Tolerance. Patients may have either normal or mildly elevated glucose level, when tested while fasting.

Patients suffering from Impaired Glucose Tolerance are at higher risk of developing type 2 diabetes. The loss of early insulin secretion in this state is caused by malfunctioning of the pancreatic ß-cells. It further deteriorates ß-cell function and worsens blood glucose control. It increases risk of many diseases together known as the Metabolic Syndrome or Insulin Resistance Syndrome. or Syndrome X. It increases risk of high blood pressure or hypertension, High LDL-cholesterol and Low HDL-cholesterol. Around 10-15% American adults suffer from impaired glucose tolerance.

Symptoms of pre-diabetes or impaired glucose tolerance

Most of the people suffering from impaired glucose tolerance or pre-diabetes exhibit no symptoms. Some patients may show symptoms like unusual thirst, frequent urination, blurred vision, or extreme tiredness.

The best way to know whether a patient is suffering from impaired glucose tolerance is a lab test. It may show some signs of pre-diabetes.

Risk Factors for Pre-Diabetes

people who have following conditions may have higher risk of developing impaired glucose tolerance. They should get checked through lab test to find out whether they are suffering from pre diabetes or not.

•People older than 45 years of age
•People having risk factors of diabetes
•People with BMI (body mass index) over 25
•People who have earlier suffered abnormal glucose tolerance
•People with history of gestational diabetes
•Woman who have delivered heavy babies weighing more than 9 lbs.
•People having high triglycerides or cholesterol level
•Obese people
•People having high blood pressure
•People belonging to ethnic group having high risk of diabetes.

For diagnosis of impaired glucose tolerance or pre-diabetes two different blood tests are done. First one is fasting plasma glucose (FPG) test and the second one is oral glucose tolerance test (OGTT)

During the Fasting Plasma Glucose test blood glucose level is measured after an 8 hour fast. This test determines that the patient’s body is metabolizing glucose correctly or not. If it gives abnormal blood glucose level after the fasting plasma glucose (FPG) test, the patient may be suffering from “impaired fasting glucose,” which indicates pre-diabetes or impaired glucose tolerance. Fasting plasma glucose is less than 7.0mmol/l. It is above normal but below the threshold for diagnosis of diabetes.

Other method is oral glucose tolerance test or OGTT. It is tested after two hours of consuming 75g glucose. Its range is more than 7.8mmol/l (normal level) but less than 11.1mmol/l or diabetes level.

Some patients may resort to normal glucose level after suffering from impaired glucose tolerance; some may remain in this state of IGT. People suffering from impaired glucose tolerance tend to develop type 2 diabetes later.

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Author's Bio: 

Jack Taylor Powers Taylor LLP is a boutique litigation firm that represents people injured by unsafe drugs. The attorneys of Powers Taylor founded this firm to focus on client needs. We employ unique and creative litigation strategies to obtain decisive results for our clients.