Table 136.2Categories of Glucose Tolerance Impairment in Nonpregnant Adults

CategoryFasting (mg/dl)½ h, 1 h, 1½ h OGTT value (mg/dl)2 h OGTT value (mg/dl)
Impaired glucose tolerance<140≥200140–200
Diabetes mellitus>140b≥200≥200

Source: Adapted from the National Diabetes Data Group categorization (National Diabetes Data Group, 1979).


All values assume venous plasma glucose measured.


Diagnosis of diabetes mellitus can be made if FBG > 140 on 2 separate days. If FBG < 140, then both 2 h sample and some other value between the fasting and 2 h value must both be ≥200 mg/dl.

From: Chapter 136, Diabetes Mellitus

Cover of Clinical Methods
Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd edition.
Walker HK, Hall WD, Hurst JW, editors.
Boston: Butterworths; 1990.
Copyright © 1990, Butterworth Publishers, a division of Reed Publishing.

NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.