Any of the following results, confirmed on a subsequent day, can be considered diagnostic for diabetes:
- Fasting plasma or serum glucose > or =126 mg/dL after an 8-hour fast
- 2-Hour plasma or serum glucose > or =200 mg/ dL during a 75-gram oral glucose tolerance test (OGTT)
- Random glucose >200 mg/dL, plus typical symptoms
Patients with "impaired" glucose regulation are those whose fasting serum or plasma glucose fall between 101 and 126 mg/dL, or whose 2-hour value on oral glucose tolerance test fall between 140 and 199 mg/dL. These patients have a markedly increased risk of developing type 2 diabetes and should be counseled for lifestyle changes and followed up with more testing. Indications for screening and testing include strong family history, marked obesity, history of babies over 9 pounds, and recurrent skin and genitourinary infections.
Glucose levels of 25 mg/dL or lower in infants younger than 1 week are considered to be potentially life threatening, as are glucose levels of 40 mg/dL or lower in infants older than 1 week.
Glucose levels of 400 mg/dL and higher are considered a critical value.