Diabetes has steadily become a major public health problem over the years. According to the juvenile diabetes association and community, more than 120 million people in the United States. have diabetes, the majority of them with type 2 diabetes. As the federal government and insurance companies begin to face increasing medical costs of treating diabetes and its associated problems, there is a great incentive to begin identifying those at risk for diabetes before they actually develop this chronic disease.
One way of doing this is with various types of diabetes pre-screening tests. Diabetes is defined as a metabolism disorder where the person has excessive sugar in the blood. Testing, however, cannot be performed by simply drawing blood and measuring the glucose levels. This is because a significant portion of the public has normal blood glucose levels during the day but raised glucose levels as they eat during the day. Any valid test for diabetes has to take this into account.
There are three main tests for diabetes used by medical care practitioners. They all basically measure how fast and efficiently your body is able to clear glucose from your blood stream. A test showing results of relatively high glucose levels is a good indication that you have glucose intolerance, pre-diabetes, or diabetes. The three tests are:
1) Random or casual plasma glucose testing - the patient can be tested at any point in the day. According to the American Diabetes Association, if the test shows a casual plasma glucose concentration of 200 milligrams per deciliter (mg/dl), it has met the criteria for a diagnosis of diabetes.
2) Fasting plasma glucose (FPG) testing - often called the fasting blood sugar test due to the fact that the patient has to fast before the test is given. In this context, fasting means that the patient has not ingested food or drink, other than water, for at least 8 hours before the test. This test is probably most convenient for the patient when performed first thing in the morning after a night’s sleep. The test measures blood glucose levels. The normal glucose level after fasting is about 100 mg/dl. If the glucose concentration is 126 mg/dl or more, a diagnosis of diabetes can be made . Monitoring of the blood glucose measurements goes on throughout the day. This test is very popular with insurance companies and health care providers because it’s relatively inexpensive. This is also a standard test given to check for pre-diabetes.
3) Oral Glucose Tolerance Test (OGTT) - The best and most comprehensive of the tests. It is more sensitive than the FPG test and can test for impaired glucose intolerance which the other two cannot. It’s also the most expensive, making it the least popular with insurance companies and health providers. The test is performed two hours after orally taking 75 grams of glucose. A diagnosis of diabetes can be made if the blood glucose results show 200 mg/dl or greater.
It is possible that a test, for any number of reasons, can give a false positive and indicate that a person has diabetes when, in fact he doesn’t. This is why a diagnosis is not usually rendered until the results are confirmed with a repeat test.
