Here is the most current reccomendations from the American Diabetes Association (which is responsible for coming up the consensus guidelines here in the states) regarding diabetes diagnosis:
"1. Symptoms of diabetes plus casual plasma glucose concentration 200 mg/dl (11.1 mmol/l). Casual is defined as any time of day without regard to time since last meal. The classic symptoms of diabetes include polyuria, polydipsia, and unexplained weight loss.
or
2. FPG 126 mg/dl (7.0 mmol/l). Fasting is defined as no caloric intake for at least 8 h.
or
3. 2-h postload glucose 200 mg/dl (11.1 mmol/l) during an OGTT. The test should be performed as described by WHO, using a glucose load containing the equivalent of 75 g anhydrous glucose dissolved in water. "
http://care.diabetesjournals.org/cgi/content/full/27/suppl_1/s5
http://www.guideline.gov/summary/summary.aspx?doc_id=3523&nbr=2749
http://care.diabetesjournals.org/cg...5fbf5438d7e6ef4dabda9157&keytype2=tf_ipsecsha
I believe that the main changes that have been instituted in the past few years is a new classification of pre-diabetes or impaired glucose tolerance:
Impaired glucose tolerance (IGT) and impaired fasting glucose (IFG)
The Expert Committee (1,2) recognized an intermediate group of subjects whose glucose levels, although not meeting criteria for diabetes, are nevertheless too high to be considered normal. This group is defined as having fasting plasma glucose (FPG) levels 100 mg/dl (5.6 mmol/l) but <126 mg/dl (7.0 mmol/l) or 2-h values in the oral glucose tolerance test (OGTT) of 140 mg/dl (7.8 mmol/l) but <200 mg/dl (11.1 mmol/l). Thus, the categories of FPG values are as follows:
FPG <100 mg/dl (5.6 mmol/l) = normal fasting glucose;
FPG 100?125 mg/dl (5.6?6.9 mmol/l) = IFG (impaired fasting glucose);
FPG 126 mg/dl (7.0 mmol/l) = provisional diagnosis of diabetes (the diagnosis must be confirmed, as described below).
The corresponding categories when the OGTT is used are the following:
2-h postload glucose <140 mg/dl (7.8 mmol/l) = normal glucose tolerance;
2-h postload glucose 140?199 mg/dl (7.8?11.1 mmol/l) = IGT (impaired glucose tolerance);
2-h postload glucose 200 mg/dl (11.1 mmol/l) = provisional diagnosis of diabetes (the diagnosis must be confirmed, as described below). "