A fasting blood sugar test, also called a fasting blood glucose test, is a method used to diagnose cases of diabetes. This disorder occurs when the body cannot properly process the glucose obtained from dietary carbohydrates. Doctors preferentially use fasting glucose tests to diagnose diabetes in children, according to the National Diabetes Information Clearinghouse.
Children and Diabetes
Until the 1990's, a vast majority of children who developed diabetes had type 1 diabetes, the "Merck Manual Home Health Handbook" reports. This version of the disorder is characterized by low or absent production of the hormone insulin, which the body needs to move glucose from the bloodstream to individual cells. However, anywhere from 10 to 50 percent of children with diabetes at the time of publication, have type 2 diabetes, a version of the disorder characterized by an unusually poor glucose-related response to normal levels of insulin. Major underlying factors associated with higher levels of type 2 diabetes include a family history of the disorder and childhood obesity.
Glucose Testing
Doctors check blood glucose levels by taking blood samples and measuring the glucose content. In a fasting glucose procedure, this blood test is preceded by an overnight fast or a daytime fast of at least eight hours. Fasting allows doctors to gauge basic glucose levels without the presence of food, which increases glucose readings once it's consumed. A doctor may order a fasting glucose test if your child shows symptoms of diabetes. In children with type 2 diabetes, these symptoms can include unusual thirst, fatigue or increased urination. In addition, children with type 2 diabetes can develop severe dehydration, nausea, vomiting or abdominal pain.
Testing Results
Your child will receive a preliminary diabetes diagnosis if his fasting blood glucose test reveals a glucose level of 126 mg/dL or higher. A second test is then performed to confirm this diagnosis. If your child has a fasting glucose result between 100 and 125 mg/dL, he will receive a diagnosis of prediabetes, or impaired fasting glucose. People with prediabetes have increased risks for the development of type 2 diabetes and other serious health problems.
Considerations and Recommendations
Doctors can also diagnose diabetes with another procedure called an oral glucose tolerance test, or OGTT. This test combines a fasting glucose test with additional tests that gauge the body's response to a glucose-based liquid. The American Diabetes Association does not recommend random screening for prediabetes in children. However, the National Diabetes Information Clearinghouse recommends that children with known diabetes risk factors such as obesity and family history get tested every 2 years, beginning at age 10 or the onset of puberty. Consult your child's doctor for more information fasting blood glucose testing.
