Immune System: The body’s system for protecting itself from viruses and bacteria or any “foreign” substances.
Immunosuppressant: A drug that suppresses the natural immune responses. Immunosuppressants are given to transplant patients to prevent organ rejection or to patients with autoimmune diseases.
Impaired Fasting Glucose: A condition in which a blood glucose test, taken after an 8- to 12-hour fast, shows a level of glucose higher than normal but not high enough for a diagnosis of diabetes. IFG, also called pre-diabetes, is a level of 100 mg/dL to 125 mg/dL. Most people with pre-diabetes are at increased risk for developing type 2 diabetes.
Impaired Glucose Tolerance: A condition in which blood glucose levels are higher than normal, but are not high enough for a diagnosis of diabetes. Other names for IGT that are no longer used are “borderline,” “subclinical,” “chemical,” or “latent” diabetes.
Implantable Insulin Pump: A small pump placed inside the body to deliver insulin in response to remote-control commands from the user.
Impotence: The inability to get or maintain an erection for sexual activity. May also be referred to as erectile dysfunction.
Incidence: A measure of how often a disease occurs; the number of new cases of a disease among a certain group of people for a certain period of time.
Incontinence: Loss of bladder or bowel control; the accidental loss of urine or feces.
Inhaled Insulin: An experimental treatment that involves taking insulin through a portable device. The device allows a person to breathe in insulin.
Injection Site Rotation: Changing the places on the body where insulin is injected. Rotation prevents the formation of lipodystrophies.
Injection Sites: Places on the body where insulin is usually injected.
Injection: Inserting liquid medication or nutrients into the body with a syringe. A person with diabetes may use short needles or pinch the skin and inject at an angle to avoid an intramuscular injection of insulin.
Insulin 50/50: Premixed insulin that is 50 percent intermediate-acting (NPH) insulin and 50 percent short-acting (regular) insulin.
Insulin 70/30: Premixed insulin that is 70 percent intermediate-acting (NPH) insulin and 30 percent short-acting (regular) insulin.
Insulin Adjustment: A change in the amount of insulin a person with diabetes takes based on factors such as meal planning, activity and blood glucose levels.
Insulin Analogues: An insulin analogue is a tailored form of insulin in which certain amino acids in the insulin molecule have been modified. The analogue acts in the same way as the original insulin, but with some beneficial differences for people with diabetes.
Insulin Pen: A device for injecting insulin that looks like a fountain pen and holds replaceable cartridges of insulin.
Insulin Pump: An insulin-delivering device about the size of a deck of cards that can be worn on a belt or kept in a pocket. An insulin pump connects to narrow, flexible plastic tubing that ends with a needle inserted just under the skin. Users set the pump to give a steady trickle or basal amount of insulin continuously throughout the day. Pumps release bolus doses of insulin (several units at a time) at meals and at times when blood glucose is too high, based on programming done by the user.
Insulin Reaction: When the level of glucose in the blood is too low.
Insulin Receptors: Areas on the outer part of a cell that allow the cell to bind with insulin in the blood. When the cell and insulin bind, the cell can take glucose from the blood and use it for energy.
Insulin Resistance: The body’s inability to respond to and use the insulin it produces. Insulin resistance may be linked to obesity, hypertension, and high levels of fat in the blood.
Insulin Shock: Another term used for hypoglycemia or low blood sugar (see hypoglycemia)
Insulin: A hormone that helps the body use glucose for energy. The beta cells of the pancreas make insulin. When the body cannot make enough insulin, it is taken by injection or through use of an insulin pump.
Insulin-Dependent Diabetes Mellitus: Former term for Type 1 diabetes.
Insulinoma: A tumor of the beta cells in the pancreas. An insulinoma may cause the body to make extra insulin, leading to hypoglycemia.
Intensive Therapy: A treatment for diabetes in which blood glucose is kept as close to normal as possible through frequent injections or use of an insulin pump; meal planning; adjustment of medicines; and exercise based on blood glucose test results and frequent contact with a person’s health care team.
Intermediate-Acting Insulin: A type of insulin that starts to lower blood glucose within 1 to 2 hours after injection and has its strongest effect 6 to 12 hours after injection, depending on the type used.
Intramuscular Injection: Inserting liquid medication into a muscle with a syringe. Glucagon may be given by subcutaneous or intramuscular injection for hypoglycemia.
Ischemia: An inadequate supply of blood to body tissues or organs. It can occur if blood vessels are narrowed or constricted.
Islet Cell Autoantibodies: Proteins found in the blood of people newly diagnosed with Type 1 diabetes. They are also found in people who may be developing Type 1 diabetes. The presence of ICA indicates that the body’s immune system has been damaging beta cells in the pancreas.
Islets of Langerhans: Clusters of cells in the pancreas that produce insulin, glucagons and pancreatic polypeptide.
Islets: Groups of cells located in the pancreas that make hormones that help the body break down and use food. For example, alpha cells make glucagon and beta cells make insulin.


