Pre-diabetes is the state that occurs when a person's blood glucose (sugar) levels are higher than normal but not high enough for a diagnosis of diabetes. Other names for pre-diabetes are "impaired glucose tolerance" and "impaired fasting glucose." Studies show that most people with pre-diabetes develop type 2 diabetes in 10 years. If you have pre-diabetes, you can and should do something about it now. Studies have shown that people with pre-diabetes can prevent or delay the development of type 2 diabetes by up to 58 percent through changes to their lifestyle that include modest weight loss and regular exercise. It is recommended that people with pre-diabetes reduce their weight by 5-10 percent and participate, if they need to lose weight, with some type of modest physical activity for 30 minutes daily. For some people with pre-diabetes, intervening early can actually turn back the clock and return elevated blood sugar levels to the normal range. In order to determine whether or not a patient has pre-diabetes or diabetes, health care providers will conduct a Fasting Plasma Glucose Test (FPG) or an Oral Glucose Tolerance Test (OGTT). Either test can be used to diagnose pre-diabetes or diabetes. The American Diabetes Association recommends the FPG because it is easier, faster, and less expensive to perform. With the FPG test, a fasting blood glucose level between 100 and 125 mg/dl signals pre-diabetes. A person with a fasting blood glucose level of 126 mg/dl or higher during two consecutive tests has diabetes.

Additional Resources:

http://diabetes.niddk.nih.gov/dm/pubs/prediabetes_ES/index.htm#1

http://www.diabetes.org/diabetes-basics/prevention/pre-diabetes/
http://edis.ifas.ufl.edu/fy933