Skip to main content
. Author manuscript; available in PMC: 2023 May 21.
Published in final edited form as: Endocr Pract. 2022 Aug 11;28(10):923–1049. doi: 10.1016/j.eprac.2022.08.002

Table 4.

Glucose Testing and Hemoglobin A1C Interpretation

Normal Prediabetes Diabetes
FPG <100 mg/dL IFG
FPG ≥100 to 125 mg/dL		 FPG ≥126 mg/dL
2-h PG <140 mg/dL IGT
2-h PG ≥140 to 199 mg/dL		 2-h PG ≥200 mg/dL Random PG ≥200 mg/dL + symptoms
A1C <5.5% 5.7% to 6.4%
For screening of prediabetesa 		≥6.5%
Secondaryb

Abbreviations: A1C = hemoglobin A1c; FPG = fasting plasma glucose; h = hour; IFG = impaired fasting glucose; IGT = impaired glucose tolerance; PG = plasma glucose

a

A1C should be used only for screening prediabetes. The diagnosis of prediabetes, which may manifest as either IFG or IGT, should be con rmed with glucose testing.

b

Glucose criteria (ie, FPG or 2-h glucose after a 75-g oral glucose load) are preferred for the diagnosis of diabetes mellitus (DM). The same testdPG or A1C measurementd—should be repeated on a different day to confirm the diagnosis of DM. Two abnormal test results from the same sample confirm the diagnosis of DM. A glucose level ≥200 mg/dL in the presence of DM symptoms does not need to be confirmed.