ABSTRACT

DR4. Of patients with type 1 diabetes, 95% have one or both of these antigens. In addition, most patients have circulating antibodies, islet cell antibodies (ICAs), and insulin autoantibodies (IAAs) before overt type 1 disease develops. On the other hand, patients with type 2 diabetes usually have insulin resistance with variable insulin secretion and are obese. Their blood sugars remain elevated because of tissue resistance to the action of insulin. Many patients have hypertension, dyslipidemia, and impaired fibrinolysis, a collection of conditions referred to as syndrome X. These patients are more likely to experience cardiovascular disease and develop long-term complications of diabetes. They exhibit two major metabolic defects: (1) decreased sensitivity of target tissues, primarily the liver and skeletal muscle, to the actions of insulin, and (2) relatively deficient endogenous insulin secretion. Impaired insulin secretion and increased glucagons contribute to continued hepatic glucose output, resulting in elevated fasting glucose levels.