PET Imaging of Regional Variation in Insulin Sensitivity of Adipose Tissue in Humans

Study Summary

The purpose of this research study is to use a relatively new technology, called Positron Emission Tomography (PET), to study how insulin works on sugar in your body's fatty tissue. PET imaging is a way of obtaining a "metabolic image" of your internal organs. It does not involve surgery and is not a high risk process. It has been used successfully to study brain, heart and more recently, skeletal muscle. In this research study, we will use PET in combination with Magnetic Resonance Imaging (MRI), to study fatty tissues in healthy people who do not have diabetes. In the future, we plan to do similar PET/MRI studies in individuals with type 2 diabetes mellitus (T2DM) and in individuals who are likely to develop T2DM. Fat tissue might have a lot to do with developing type 2 diabetes. First, it is well recognized that excess fatty tissues, especially the kind in your belly, increases risk for the development of T2DM, as well as affecting other ways the body uses insulin. Second, fatty tissue is a classic target tissue for the action of insulin, which regulates the use of sugar by fat cells and also regulates the release of fatty acids from fatty tissues. Third, studies in mice that lack fatty tissue, indicate that severe insulin resistance (lack of a normal response to insulin) can result. Other types of studies have shown that fatty tissues make proteins that affect your body's insulin and your appetite in good and bad ways. Yet despite this importance, we still lack techniques for the study of fatty tissue metabolism in humans.