Prediabetes or Categories of Increased Risk for Diabetes 

Clare J. Lee, M.D., MHS, Rachel Derr, M.D.

DEFINITION

  • Isolated impaired fasting glucose (IFG) and isolated impaired glucose tolerance (IGT) are intermediate states of abnormal glucose homeostasis between normal and overt diabetes.
  • Prediabetes is an unofficial designation including either IFG, IGT or both.
  • Documentation of IFG requires only a fasting plasma glucose. Documentation of IGT requires a 75-gm oral glucose tolerance test.
  • A hemoglobin A1c of 5.7 - 6.4% identifies individuals in "categories of high risk for diabetes" to whom the term "prediabetes" may be applied (ADA Standards of Medical Care in Diabetes)[4].
  • See Table Table 1 for exact definitions.
Table 1


State


Fasting Glucose (mg/dl)

2 hour Glucose (mg/dl) during a
75g OGTT


A1c (%)

Normal

< 100

< 140

< 5.7

Isolated Impaired Fasting Glucose*

100-125

< 140

-

Isolated Impaired Glucose Tolerance

< 100

140-199

-

Combined IFG and IGT

100-125

140-199

-

Prediabetes or Categories of Increased Risk**

100-125

140-199

5.7 - 6.4

Diabetes**

≥ 126

≥ 200

>6.5



* The WHO and IDF recommend that Impaired Fasting Glucose be 110-125 mg/dl
**At least one criteria needs to be satisfied for diagnosis

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Last updated: January 5, 2017