Sub clinical diabetes--vascular threat to Asian Indians.

Impaired glucose tolerance(IGT) is defined as a 2-hour plasma glucose value between 140 mg% (7.8 mmol/L) and 200 mg% (11.0 mmol/L) with a fasting plasma glucose 126 mg% (<7.0 mmol/L). The diagnostic category of impaired fasting glucose (IFG) was introduced by the American Diabetes Association in 1997. Patients with impaired fasting glucose are those glucose levels are clearly not normal but are not high enough to be classified as diabetes that is, fasting plasma glucose levels between 109 mg% (6.1 mmol/L) and 125 mg% (6.9 mmol/L). The category was introduced in order to distinguish people with clearly normal fasting plasma glucose levels from people with fasting plasma glucose levels that are clearly in the diabetic range. It was also introduced because it was recognized that glucose tolerance tests are done seldom if at all in many practice settings, but fasting plasma glucose levels of 109 mg% (6.1mmol/L) and higher are clearly abnormal; indeed, the normal mean fasting plasma glucose is 90 mg% (5.1 mmol/L) and the 75th percentile is 98 mg% (5.4 mmol/L). Epidemiologic analyses of the clinical significance of impaired fasting glucose are now emerging, and several studies are now exploring the relationship between impaired glucose tolerance and impaired fasting glucose.