Diagnosis Diabetes is diagnosed when it is determined that a
person's blood sugar is too high. It develops when the body is unable to effectively produce or use an essential hormone called
Insulin. The main effect of insulin is to regulate metabolism, the body's ability to utilize fuel. In diabetes, sugar
metabolism is directly effected, however, the metabolism of our two other fuels, fat and protein is also effected. Doctors use urine and blood tests to check for diabetes.
In both, they are checking glucose levels. Glucose in the urine can be a sign of diabetes, although it is not always so. The doctor also may give a complete physical to check the heart, eyes and kidneys.In the blood, a certain level of glucose is normal. Usually, the test is done on blood drawn before breakfast in the morning, and it is called a "fasting glucose test." If blood is
drawn after a meal, it is a "postprandial glucose test." If a doctor wants to doublecheck the blood tests, he or she may ask the patient to take an oral glucose tolerance test, which
can detect diabetes even when a regular blood test will not. For this test, the patient's blood is taken and then the patient drinks a liquid with a known amount of glucose in it. This is very sweet, but not
unpleasant. More blood samples will be taken during the hours after drinking the glucose. Comparing the samples will show how the body responds to an increase in blood glucose. Normally,
bloodglucose levels will rise after the drink and then fall gradually as the pancreas sends out insulin to cope with it. A diabetic's bloodglucose level may stay high after the glucose drink or it may fall
very slowly. The diagnosis of diabetes is made based upon results of blood tests.
For many people, the first test to suggest diabetes is a Random Plasma Glucose test. This test is relatively quick and easy to perform. It may be included in an annual physical exam or offered as part of a community health fair. The
purpose of this test is to identify people who have any degree of high blood glucose. But, it does not control for factors which can cause high blood sugar such as illness, stress, or a recent snack high in
carbohydrate. Most people show high blood sugar on a Plasma Glucose screening need to be further tested. In diagnostic testing for diabetes, conditions are controlled. This means the amount of
carbohydrate eaten prior to the test is standardized. Blood glucose must reach the cut off point established for a diagnosis to be made. In some cases, additional tests may be needed to help the physician
understand the disease process which is causing the diabetes.
The American Diabetes Association in June, 1997, announced new recommendations for how diabetes should be diagnosed |
The ADA now also recommends that all individuals age 45 and above be tested for diabetes,
and if the test is normal, they should be re-tested every three years. Testing should be conducted at earlier ages and carried out more frequently in individuals who are any of the
following: obese; have a first degree relative with diabetes; are members of a high-risk ethnic population (African-American, Hispanic, Native American, Asian); have delivered a baby
weighing more than 9 pounds; have had gestational diabetes; are hypertensive; have HDL cholesterol levels equal to or less than 35 mg/dl or triglyceride levels equal to or greater than
250 mg/dl; or who, on previous testing had impaired glucose tolerance or impaired fasting glucose. The ADA recommendations for diagnosing diabetes state that patients be told they have
diabetes if any of the criteria below applies:
- Fasting plasma glucose is above 126 mg/dl;
- Diabetes symptoms exist and casual plasma glucose is equal to or above 200 mg/dl; or
- Plasma glucose is equal to or above 200 mg/dl during an oral glucose tolerance test.
If any of these test results occurs, testing should be repeated on a different day to confirm the diagnosis. |
