FAQ: Impaired Fasting Glucose (IFG)
and Impaired Glucose Tolerance (IGT)

What do the terms Impaired Fasting Glucose (IFG) and Impaired Glucose Tolerance (IGT) mean?


Pre-Diabetes is IGT or IFG.

IFG is a fasting glucose greater than 6 but less than 7 mmol/L (108-125 mg/dl). IFG usually is a manifestation of insulin deficiency. IFG alone is not associated with a particularly high rate of mortality from cardiovascular disease.

IGT is an after meal glucose (or a 2 hr post 75 gm Glucose ingestion on a Glucose tolerance test) of 7.8-11 mmol/L (140-200 mg/dl). IGT is usually a manifestation of insulin resistance & is associaated with cardiovascular risks close to that of diabetes.

Both IFG and IGT may co-exist in the same person.

The importance of these conditions and reason for treatment is to reduce the risk of conversion to diabetes and to reduce cardiovascular risks. Diabetes is still preventable in people with IGT & IFG. Treatment consists of intensive life style measures of nutrition therapy, weight loss and exercise. These measures in the Finnish Diabetes Prevention Program and in the Diabetes Prevention study in the United States resulted in close to a 60% reduction in new onset of Type 2 Diabetes over about 5 years. It should be emphasized that prevention requires intensive effort with loss of at least 5% of total body weight, marked reduction of dietary fats (particularly saturated fat and trans fats) and aerobic exercise for at least 30 minutes per day.

Dr. J. Robin Conway M.D. 23 Feb 2004