The fasting glucose test, also known as fasting plasma glucose (FPG), is commonly used to screen for or diagnose diabetes. It’s a convenient and relatively inexpensive test, though it may not detect all cases of diabetes or pre-diabetes, unlike the oral glucose tolerance test (OGTT).
This test is typically conducted in the morning after a minimum of 8 hours of fasting, during which you refrain from consuming any food or beverages, including tea or coffee. This fasting period ensures the reliability of the test results.
Diagnosis based on fasting glucose test
Fasting plasma glucose (FPG) levels are interpreted as follows:
- FPG <99 mg/dL: Considered normal fasting glucose.
- FPG between 100 to 125 mg/dL: Indicates pre-diabetes, also known as impaired fasting glucose.
- FPG >126 mg/dL: Indicates diabetes.
If your blood sugar levels are elevated, your doctor may advise repeat testing on another day to confirm the results and ensure accuracy.