The goal of this clinical research study is to learn about a new minimally invasive glucose monitoring device called Fluorescence Affinity Sensor (FAS). In this study, the FAS will be used to determine its effectiveness for glucose monitoring. Researchers want to find out how the device performs at two different body sites (forearm and abdomen) over 4 hours. The safety and comfort level of the device will also be studied.

The FAS glucose monitoring system is a minimally invasive glucose monitoring device which is not yet approved by the FDA. The FAS system will be used in this study to monitor glucose levels during a glucose tolerance test (GTT) performed in Dr.Orzeck practice. The FAS measures glucose levels in skin tissue of the forearm or the abdomen at a depth of less than 1 mm by inserting a small needle-like device. During the 4-hour GTT, the needle-like FAS is left in the skin tissue. The FAS performance has indicated in prior experiments that it is more stable than competitive commercial glucose-sensing devices. Due to its unique design, its glucose response is more accurate, and less affected by certain drugs (such as pain medicine).

Inclusion Criteria:

• Female and male patients with Type I and II diabetes requiring injectable insulin from age 18-80.

Exclusion Criteria:

• Patients with fasting glucose concentration larger than 200 mg/dL will be excluded from the study.
• Children under the age of 18 will not be included because Texas state law would not allow such participants to give informed consent on their own.
• Patients who are required to take certain medications including corticosteroids, diuretics, anticonvulsants, birth-control pills, non-steroidal anti-inflammatory drugs (NSAIDs) and certain high-blood pressure medications will be excluded from the study.
• Pregnant women or any patient who cannot participate in an oral glucose tolerance test will also be excluded from the study. Presence of pacemaker or defibrillator.