- Criteria for diagnosis of Impaired Fasting Glucose and Impaired Glucose Tolerance
Impaired Fasting Glucose
Fasting Glucose 100-125 mg/dl
Impaired Glucose Tolerance
2 hour post-load / post-prandial glucose 140-199 mg/dl
- Criteria for diagnosis of Diabetes Mellitus
Casual plasma glucose > 200 mg/dl
(Casual is defined as any time of day without regard to time since last meal)
Fasting > 126 mg/dl
(Fasting is defined as no caloric intake for at least 8 hours)
2 hours plasma glucose > 200 mg/dl during an OGTT or post prandial
OGTT as specified by WHO
- The test is done after at least 3 days of unrestricted diet and normal physical activity
- Following collection of Fasting Blood sample, 75 gm of glucose is dissolved in 250-300 ml of water, to be drunk over the course of about 5 minutes.
- Another sample is collected 2 hours after glucose load.
- The test results are interpreted as given in table.
|1999 WHO DIABETES CRITERIA – INTERPRETATION OF ORAL GLUCOSE TOLERANCE TEST|
|Glucose Levels||Normal||Impaired Fasting Glucose Glycaemia (IFG)||Impaired Glucose Tolerance (IFT)||Diabetes Mellitus (DM)|
|Fasting||2 hour||Fasting||2 hour||Fasting||2 hour||Fasting||2 hour|
|<110||<140||> 110 and < 126||<140||<126||> 140||> 126||> 200|
- CONCEPT OF PRE-DIABETES
A proportion of people belong to the intermediate group of subjects whose glucose levels although do not meet the criteria for diabetes or nevertheless too high to be considered normal. These patients may develop diabetes in future if the glycemic status is not maintained by modification of lifestyle.
People with or referred to as “PRE-DIABETES” indicating a relatively high risk for development of diabetes.
The significance of impaired fasting glycemia and impaired glucose tolerance
- Increased risk for cardiovascular/ cerebrovascular diseases
- Predictor to subsequent diabetes mellitus
- Diabetic range values may be unmasked with stress
|Plasma (mg/dl)||Venous whole blood (mg/dl)||Capillary whole blood (mg/dl)|
|Impaired Fasting Glucose|
|2 hours post glucose load||<140||<120||<140|
|Impaired Glucose Tolerance|
|2 hours post glucose load||140-199||120-170||140-199|