2-​​h PG, 2-​​h plasma glucose; DCCT, Diabetes Control and Complications Trial; FPG, fasting plasma glucose; IFG, impaired fasting glucose; IGT, impaired glucose tolerance; NGSP, National Glycohemoglobin Standardization Program; OGTT, oral glucose tolerance test; WHO, World Health Organization.  

*In the absence of unequivocal hyperglycemia, diagnosis requires two abnormal test results from the same sample or in two separate test samples.
**For all three tests, risk is continuous, extending below the lower limit of the range and becoming disproportionately greater at the higher end of the range.