Impaired glucose tolerance (IGT) is a pre-diabetic state of hyperglycemia that is associated with insulin resistance and increased risk of cardiovascular pathology. IGT may precede type 2 diabetes mellitus by many years. IGT is also a risk factor for mortality.
Criteria
According to the criteria of the World Health Organization and the American Diabetes Association, impaired glucose tolerance is defined as:
- two-hour glucose levels of 140 to 199Â mg per dL (7.8 to 11.0Â mmol/l) on the 75-g oral glucose tolerance test. A patient is said to be under the condition of IGT when he/she has an intermediately raised glucose level after 2 hours, but less than the level that would qualify for type 2 diabetes mellitus. The fasting glucose may be either normal or mildly elevated.
From 10 to 15 percent of adults in the United States have impaired glucose tolerance or impaired fasting glucose.
Treatment
The risk of progression to diabetes and development of cardiovascular disease is greater than for impaired fasting glucose.
Although some drugs can delay the onset of diabetes, lifestyle modifications play a greater role in the prevention of diabetes. Patients identified as having an IGT may be able to prevent diabetes through a combination of increased exercise and reduction of body weight. "Drug therapy can be considered when aggressive lifestyle interventions are unsuccessful."
See also
- Glucose tolerance test
- Impaired fasting glucose
References
Further reading
- Melanie J Davies; I Peter Gray (3 February 1996). "Impaired glucose tolerance". British Medical Journal. 312 (7026): 264â€"265. PMC 2349870 . PMID 8611769. doi:10.1136/bmj.312.7026.264. - Editorial review
- Nathan, DM; Davidson, MB; DeFronzo, RA; Heine, RJ; Henry, RR; Pratley, R; Zinman, B; American Diabetes, Association (March 2007). "Impaired fasting glucose and impaired glucose tolerance: implications for care.". Diabetes Care. 30 (3): 753â€"9. PMID 17327355. doi:10.2337/dc07-9920.Â
