Impaired Glucose Tolerance
The US National Diabetes Data group (1979) first introduced the term impaired glucose tolerance (IGT) to indicate a state of increased risk of progressing to diabetes. It was defined to reduce the stigma of being labeled with diabetes and was also noted that many individuals with IGT could revert back to normal.
According to the World Health Organization and the International Diabetes Foundation (World Health Organization, 2006), IGT is diagnosed if 2-h plasma glucose levels are between 7.8 and 11.1 mmol/l or 140 mg/dl and 200 mg/dl as measured by the oral glucose tolerance test, or if fasting glucose levels are less than 7.0 mmol/l. Two-hour plasma glucose is the level of glucose or the venous plasma glucose 2 h after ingestion of 75 g of oral glucose load. Blood glucose levels normally rise after eating a meal and then gradually fall as the meal is digested. However, in people with impaired glucose tolerance, these levels remain elevated.
References and Readings
- Dunstan, D., Zimmet, P., Welborn, T., de Courten, M., Cameron, A., Colagiuri, S., et al. (2002). The rising prevalence of diabetes and impaired glucose tolerance: The Australian diabetes, obesity and lifestyle study. American Diabetes Association, 25(5), 829–834.Google Scholar
- Harris, M. I., Flegal, K. M., Cowie, C. C., Eberhardt, M. S., Goldstein, D. E., Little, R. R., et al. (1998). Prevalence of diabetes, impaired fasting glucose, and impaired glucose tolerance in US adults. The third national health and nutrition examination survey, 1988–1994. Diabetes Care, 21(4), 518.PubMedCrossRefGoogle Scholar
- National Diabetes Data Group. (1979). Classification and diagnosis of diabetes mellitus and other categories of glucose intolerance. Diabetes, 28, 1039–1057.Google Scholar
- World Health Organization. (2006). Definition and diagnosis of diabetes mellitus and intermediate hyperglycemia. Report of a WHO/IDF consultation. Retrieved November 1, 2010, from http://www.who.int/diabetes/publications/en/