What is the cut off point for diabetes?

For detecting both pre-diabetes and undiagnosed diabetes, the optimal cutoff point was 100 mg/dl for the FPG test, 5.0% for the HbA1c test, and 100 mg/dl for the CBG test. In comparison, the most efficient cutoff points for detecting undiagnosed diabetes alone were 110 mg/dl, 5.7%, and 120 mg/dl, respectively.