Insulin is a peptide hormone produced by the cells of the pancreatic islets of Langerhans that regulates blood glucose levels by aiding cellular glucose uptake, regulating carbohydrate, lipid, and protein metabolism, and encouraging cell division and proliferation through its mitogenic activities. Insulin resistance and its consequences are becoming more prominent as obesity and diabetes reach epidemic proportions in the developed world. Insulin resistance is described as a biological response that is diminished by a normal or elevated insulin level; traditionally, this refers to impaired sensitivity to insulin-mediated glucose disposal. Insulin resistance syndrome is a collection of anomalies and physical consequences that are more likely in people who are insulin resistant.
Insulin therapy is an important aspect of treatment for persons with type 1 diabetes, as well as many people with type 2. Insulin therapy's purpose is to keep the blood sugar levels within a specific range. A syringe, insulin pen, or insulin pump tubing is used to inject insulin into the fat beneath the skin.