Prediabetes: Impaired Glucose Tolerance and Impaired Fasting Glucose

Prediabetes forms an intermediate stage of diabetes mellitus and presents as impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT). People assessed with these conditions have a relatively high risk of developing diabetes as well as cardiovascular and cerebrovascular disease.5 IFG following an overnight fast, as defined in the clinical assessments, is not high enough to be classified as diabetes. Likewise, IGT in its defined range after a two-hour oral glucose tolerance test is also not high enough to be classified as diabetes.

The third national health and nutrition examination survey (NHANES III) examined a cross-section of U.S. adults aged 40-74 years from 1988 to 1994. The Center for Disease Control and Prevention (CDC) reported in 2005 of those tested in this study that 40% had pre-diabetes based on the recorded IGT or IFG or both.5 IFG and IGT are associated with abdominal obesity, high triglycerides and/or low HDL (good cholesterol), and hypertension. Therefore, progression to diabetes among those with pre-diabetes is not inevitable as weight loss and increased physical activity can prevent or delay diabetes and may return blood glucose levels to normal.2,3,5