Genetic Studies of Insulin and Diabetes

The study will allow researchers to obtain blood, plasma, DNA, and RNA for genetic studies of insulin. There will be a focus on the causes of insulin resistance and diabetes mellitus. Insulin is a hormone found in the body that controls the level of sugar in the blood. Insulin resistance refers to conditions like diabetes when insulin does not work properly. In this study researchers would like to compare patients with diabetes and other forms of insulin resistance to normal individuals. The study will investigate how insulin attaches to cells. Researchers will take 4 to 6 ounces (100-150 ml) of blood from adult patients and may request up to 12 ounces (one unit) of blood if necessary. Skin samples may be taken for a biopsy if further genetic testing is necessary. In addition some patients may be asked not to eat for up to 72 hours prior to testing....

Study Description: Insulin is the key hormone responsible for regulating the level of glucose in plasma. In several disease states (e.g., obesity, type 2 diabetes, and acromegaly), the target cells are resistant to insulin action. Insulin resistance leads to metabolic complications including diabetes, dyslipidemia, cardiovascular disease, non-alcoholic fatty liver disease, and reproductive dysfunction. The intramural research program of the NIDDK has a long history of studying patients with rare disorders of extreme insulin resistance. We use what is learned from these rare patients both to develop therapeutics for rare diseases, and to apply what is learned to understand more common forms of insulin resistance. Objectives: Primary Objectives: (1) To understand the pathophysiology of insulin resistance and its relationship to diabetes, dyslipidemia, cardiovascular disease, liver disease, kidney disease, reproductive function, bone disease, and other organ dysfunction, (2) To study the molecular genetics underlying various causes of insulin resistance and diabetes mellitus, (3) To understand the natural history of insulin resistance disorders, including their response to FDA approved therapies, and (4) To conduct ex vivo studies of the physiology and pathophysiology underlying disorders of insulin resistance, and possible treatments for these disorders, using cells and tissues collected in this study. Endpoints: Primary Endpoint: Genetic causes of insulin resistance Secondary Endpoints: Diabetes control (hemoglobin A1c) and complications (rates of micro- and macrovascular disease)