American Medical Association Family Medical Guide - American Medical Association [610]
Fasting plasma glucose test
A fasting plasma glucose test measures your blood glucose level after you have fasted (have not had anything to eat or drink except water for at least 8 hours, usually overnight).
• A glucose level of less than 110 milligrams per deciliter (mg/dL) is considered normal.
• A glucose level between 110 and 126 mg/dL indicates the possibility of impaired glucose tolerance, which means that you are at high risk of developing diabetes. In this case, your doctor will recommend having another blood test.
• A glucose level of 126 mg/dL or more on one fasting glucose test indicates that you have diabetes. Another blood test will be given to confirm the diagnosis.
Oral glucose tolerance test
An oral glucose tolerance test measures the body’s ability to use glucose. To prepare for this test you will be asked to eat a diet rich in carbohydrates (foods such as whole grains, dried beans, and vegetables) for 2 or 3 days and then to fast overnight, or for at least 8 hours, before the test. After having a fasting glucose test, you will be asked to drink a sweet liquid containing glucose. Then you will be asked to lie or sit quietly while samples of your blood are taken every half hour for the next 2 hours to measure the level of glucose.
• A glucose level of 200 mg/dL or higher between the first and last blood tests and still higher than 200 mg/dL on the last test indicates diabetes.
• A glucose level of 200 mg/dL or higher on any of the blood tests but less than 200 mg/dL on the last test indicates impaired glucose tolerance, which means that you are at high risk of developing diabetes.
Hemoglobin A1C test
A test called a hemoglobin A1C test (or glycohemoglobin test) measures the percentage in your blood of a particular type of hemoglobin (the substance in red blood cells that carries oxygen). If you have too much glucose in your blood, the extra glucose links with the hemoglobin. This blood test can determine the average level of glucose in your blood over the past 3 to 4 months. For this reason, doctors use it to monitor the effectiveness of treatment in people who have diabetes.
Treatment
Managing type 2 diabetes means keeping your blood glucose level as close to normal as possible. Helpful strategies include keeping your weight down or losing weight if you need to, exercising regularly, and eating a nutritious diet rich in vegetables, whole grains, and legumes such as dried peas and beans. Eat fruit in moderation, and limit fruit juice (because it can raise blood sugar quickly). Many people with type 2 diabetes can keep their blood glucose level in a healthy range by following these measures.
Your doctor may recommend that you also take medication, depending on factors such as how long you have had diabetes, how high your blood glucose level is, and other medications you are taking. Although your doctor may prescribe insulin injections, taking insulin is usually not part of the initial treatment of type 2 diabetes. Your doctor may ask you to test your blood glucose level frequently or to have a hemoglobin A1C test (see previous page) periodically to evaluate the effectiveness of your treatment. You will have frequent blood tests to determine if your treatment is effective in keeping your glucose level in the healthy range.
Medication
Many types of medication are available for treating type 2 diabetes. If you take too much of some glucose-lowering medications (particularly sulfonylureas), your blood glucose level can drop too low. This condition—called hypoglycemia (see next page)—can be serious. Like all medications, these drugs can cause side effects in some people. Tell your doctor immediately if you feel unusual in any way after you start taking a medication.
Metformin
Metformin reduces glucose level by decreasing the liver’s production of glucose. The drug also helps cells