Complications of Insulin Therapy

Abstract

Insulin allergic reactions were seen in the first insulin preparations used for therapy of diabetes mellitus. The use of highly purified animal insulins, semisynthetic, and recombinant DNA human insulins has resulted in a dramatic reduction in the immunological complications of insulin therapy. However, subcutaneous human insulin administration with biosynthetic insulins has been shown to incite antibody responses in nondiabetic individuals as well as in diabetic individuals via subcutaneous, respiratory, and peritoneal routes. Further, anti‐insulin antibodies commonly precede the appearance of type 1 diabetes, especially in children. Hypertrophy of subcutaneous fat at sites of repeated insulin injections continues to be a common nonimmunological complication of therapy. In addition, hypertrophy of omental fat has been reported to be a cause of catheter occlusion during the course of intraperitoneal delivery of concentrated insulin by implantable insulin pumps. Edema associated with insulin therapy is an unusual and usually self‐limited disorder. Hypoglycemia secondary to insulin therapy is the expected outcome of a mismatch between nutrients, insulin levels, insulin action, and glucose counterregulatory mechanisms. This chapter reviews insulin immunology and the immunological and nonimmunological complications of insulin therapy.