There are three approaches to diagnose someone with prediabetes. One method is to draw blood for glucose when the client has not consumed anything but water after midnight, and a result of at least 126 milligrams percent indicates the presence of diabetes mellitus. Should the fasting serum glucose return with a reading range from 100 to 125 milligrams percent, the patient has prediabetes .
The fasting serum glucose which ranges from 100 to 125 milligrams percent indicates that the client has impaired fasting glucose .
Moreover, fasting plasma glucose levels less than or equal to 99 milligrams percent--and not in the hypoglycemic range--are normal .
The most sensitive method to resolve the matter is to draw blood from the patient two hours after a 75 gram challenge with oral glucose. This two-hour sample will indicate diabetes mellitus when the result is at least 200 milligrams percent. For those whose two-hour post-challenge glucose ranges from 140 to 199 milligrams percent, the diagnosis is prediabetes as the client has impaired glucose tolerance .
In fact, the two-hour challenge approach is the gold standard to screen for diabetes or prediabetes. However, it is also the least convenient method because the patient must be present at the health care center two hours after he or she has received the 75 gram challenge with oral glucose .
A two-hour glucose challenge which yields a result less than 140 milligrams percent is normal .
The physician must also consider the hemoglobin A1C results. In normal individuals, this value will be less than or equal to 5.6 percent. Those who have prediabetes will show a hemoglobin A1C which ranges from 5.7 percent to 6.4 percent. Diabetic individuals will have a measurement of at least 6.5 percent.