ABSTRACT
The importance of insulin in the treatment of patients with diabetes mellitus has been recognized since the 1920s. Given that diabetes is characterized by an inability to produce or to effectively utilize insulin, exogenous administration of insulin has been central to diabetes therapy since that time. During the approximately 80 years of use, a number of improvements in insulin therapy have occurred. These include the purifi cation and application of animal insulins and the development, approval, and clinical use of both recombinant human insulin and insulin analogs.
