How is clinical Type 2 diabetes diagnosed?
The fasting plasma glucose (FPG) test is the preferred test for diabetes, according to the American diabetes Association. With the fasting plasma glucose test, the person’s blood glucose is measured after an 8- to 12-hour fast. The test results are interpreted as follows: Normal blood glucose is indicated by a blood glucose level below 110 mg/dL. Impaired fasting glucose is indicated by a blood glucose level between 110 and 125 mg/dL. Diabetes is indicated if the fasting blood glucose level rises to 126 mg/dL or above; this diagnosis is confirmed by a level of ≥ 126 mg/dL on 2 FPG tests given on 2 different days. A measurement known as impaired glucose tolerance (IGT) is also now used to diagnose Type 2 diabetes. IGT is diagnosed using the oral glucose tolerance test (OGTT), which measures blood glucose levels after a fast and after a glucose challenge. After an 8- to 12-hour fast, the person drinks a glucose-containing solution. The person’s blood glucose is measured just before and 2
