For the test to give reliable results:
- the person must be in good health (not have any other illnesses, not even a cold).
- the person should be normally active (not lying down, for example, as an inpatient in a hospital), and
- the person should not be taking medicines that could affect the blood glucose.
- For three days before the test, the person should have eaten a diet high in carbohydrates (200-300 grams per day).
- The morning of the test, the person should not smoke or drink coffee.
The classic oral glucose tolerance test measures blood glucose levels five times over a period of three hours. Some physicians simply get a baseline blood sample followed by a sample two hours after drinking the glucose solution. In a person without diabetes, the glucose levels rise and then fall quickly. In someone with diabetes, glucose levels rise higher than normal and fail to come back down as fast.
People with glucose levels between normal and diabetic have impaired glucose tolerance (IGT). People with impaired glucose tolerance do not have diabetes, but are at high risk for progressing to diabetes. Each year, 1%-5% of people whose test results show impaired glucose tolerance actually eventually develop diabetes. Weight loss and exercise may help people with impaired glucose tolerance return their glucose levels to normal. In addition, some physicians advocate the use of medications, such as metformin (Glucophage), to help prevent/delay the onset of overt diabetes.
Recent studies have shown that impaired glucose tolerance itself may be a risk factor for the development of heart disease. In the medical community, most physicians are now understanding that impaired glucose tolerance is nor simply a precursor of diabetes, but is its own clinical disease entity that requires treatment and monitoring.
No comments:
Post a Comment