two-hour glucose levels of 140 to 199 mg per dL (7.8 to 11.0 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.
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 should exercise regularly, lose 5 to 7 percent of body weight, and limit intake of (at least) sugar and highly processed carbohydrates.
^Barr EL, Zimmet PZ, Welborn TA, et al. (2007). "Risk of cardiovascular and all-cause mortality in individuals with diabetes mellitus, impaired fasting glucose, and impaired glucose tolerance: the Australian Diabetes, Obesity, and Lifestyle Study (AusDiab)". Circulation116 (2): 151–7. doi:10.1161/CIRCULATIONAHA.106.685628. PMID17576864.
^Oxford Handbook of Clinical Medicine, 7th Ed., Longmore, Wilkinson, Turmezei and Cheung. Oxford University Press 2007.
^Raina Elley C, Kenealy T (December 2008). "Lifestyle interventions reduced the long-term risk of diabetes in adults with impaired glucose tolerance". Evid Based Med13 (6): 173. doi:10.1136/ebm.13.6.173. PMID19043031.