When using the glycated hemoglobin test, a result between 5.7 percent and 6.4 percent of hemoglobins with attached glucose molecules is considered prediabetic, according to the Mayo Clinic. Other tests used for analyzing blood sugar levels for prediabetes include the fasting blood sugar test and the oral glucose intolerance test.
While the glycated hemoglobin test is accurate, factors such as pregnancy or an uncommon form of hemoglobin may produce inaccurate results, notes the Mayo Clinic. Doctors may choose to conduct a fasting blood sugar test to avoid discrepancies. A prediabetic blood sugar level is between 100 and 125 milligrams per deciliter.
For the oral glucose intolerance test, a blood sugar level between 140 and 199 milligrams per deciliter is considered prediabetic, explains the Mayo Clinic. The test requires patients to drink a sugary solution to analyze how their bodies responds to the elevated glucose.