Abstract

During the last century, diabetes has changed in character from a relatively rare disease which was uniformly fatal, characterized by weight loss and best treated with a low-calorie, high-protein diet (type 1), to a common disease characterized by obesity and treated with agents that promote weight loss and a low-calorie diet (type 2). Type 1 diabetes is characterized by an absolute insulin deficiency. Dr. Banting discovered the therapeutic use of insulin to treat type 1 diabetes in depancreatectomized dogs.1 The first therapeutic insulin preparations were impure and produced many reactions, but for the early patients, they were life saving. Purification resulted in usable Regular insulin, and patients had to take multiple injections each day. In 1938, the development of NPH insulin allowed patients to take fewer injections a day.2 This longer-acting insulin stayed at the injection site because of the combination with protamine (NPH). Other longer acting insulins were developed. The absorption in these insulins was variable, and they did not cover glucose changes with meals adequately. They were combined with Regular insulin for improved control. Insulin was obtained from animal sources until 1978, when the first recombinant DNA human insulin was announced.2 Human insulin was synthesized by bacteria in an extremely pure form and became the major source of insulin for human therapy. The last great advance in insulin therapy was the development of insulin analogues designed to have specific properties. The first of these was Lispro, approved by the FDA in 1996,2 which allowed more physiologic coverage of consumed carbohydrates. More analogues followed with glargine peakless insulin being approved in 20002 and radically changing the therapy of type 1 diabetes. Patients now have 24-hour basal coverage with less hypoglycemia and an insulin that is soluble until injected.3