implantable insulin pump- A pump placed under the skin of the abdomen that delivers insulin at a constant rate (with added amounts for meals) through a catheter into the abdominal cavity. Not approved for use in the United States.

insulin - A hormone produced by the pancreas that regulates the production of glucose by the liver and the utilization of glucose by cells. Insulin is also a medication used by people with diabetes when the pancreas does not make enough insulin.

insulin pen - A combined insulin container and needle that makes injection of insulin more convenient.

insulin syringe - A syringe with a needle used to inject insulin; the most common way to administer insulin.

intermediate-acting insulin - Insulin medication that begins working in two to four hours, peaks at four to eight hours, and lasts for about 12–20 hours. NPH insulin is an example.

islets of Langerhans - Cellular masses in the pancreas that contain insulin- and glucagon-secreting cells; also called pancreatic islets.


jet injector - A needle-free way of injecting insulin that uses a high-pressure jet of air to send a fine stream of insulin through the skin.


ketoacidosis - Dangerously increased acidity of the blood, which occurs when extremely low insulin levels cause the breakdown of triglycerides in fat cells, releasing fatty acids into the bloodstream.

ketones - Toxic substances formed from the breakdown of fatty acids.


laser photocoagulation - A treatment for proliferative retinopathy or macular edema that slows or halts vision loss by destroying diseased blood vessels in the retina.

long-acting insulin - Insulin medication that has no peak activity and lasts for up to 18–24 hours. Examples are insulin glargine (Lantus) and insulin detemir (Levemir).

low-density lipoprotein (LDL) - A protein that transports cholesterol in the blood; excessive amounts are a major contributor to atherosclerosis.


macular edema - Swelling around the macula, a small area at the center of the retina of the eye that is responsible for central and fine-detail vision.

meglitinides - Oral diabetes drugs that promote the secretion of insulin by the pancreas when blood glucose is elevated after a meal. The only approved drug in this class is repaglinide (Prandin).

metabolic syndrome - A condition characterized by a group of findings, including elevated blood glucose levels, high triglycerides, low HDL cholesterol, high blood pressure, and obesity. Associated with an increased risk of diabetes, heart attack, and stroke.

microalbuminuria - Small amounts of a protein called albumin in the urine that are a first sign of kidney dysfunction.


nephropathy - Kidney disease.

neuropathy - Nerve damage.


oral glucose tolerance test - A test in which a person fasts overnight and then drinks a solution containing 75 g of glucose. Diabetes is diagnosed if two hours later blood glucose is 200 mg/dL or higher.


pancreas - An organ located behind and beneath the lower part of the stomach that produces and secretes insulin and glucagon.

pancreatic islets - see islets of Langerhans.

peripheral arterial disease - Atherosclerosis in the arteries leading to the legs and feet.

peripheral neuropathy - A slow, progressive loss of function of the sensory nerves in the limbs that causes numbness, tingling, and pain in the legs and hands.

prediabetes - A condition in which blood glucose levels are higher than normal (100–125 mg/dL) but not high enough for a diagnosis of diabetes (126 mg/dL or more).


rapid-acting insulin - Insulin medication that begins working in five to 15 minutes, peaks at 30–60 minutes, and lasts for about four to six hours.

regular insulin - Insulin medication that begins working in 30 minutes, peaks at 1.5–2 hours, and lasts for about eight to 10 hours.

retinopathy - Damage to the retina caused by changes in the tiny blood vessels that supply the retina.


statins - Drugs that reduce blood levels of cholesterol by blocking its formation.

sulfonylureas - Oral diabetes drugs that stimulate the pancreas to secrete more insulin. Examples are chlorpropamide (Diabinese) and glyburide (DiaBeta, Glynase, Micronase).


thiazolidinediones - Oral diabetes drugs that increase the sensitivity of cells to insulin. Examples are pioglitazone (Actos) and rosiglitazone (Avandia).

tight glucose control - Achieving near-normal levels of blood glucose by monitoring blood glucose several times a day and adjusting doses of insulin or oral diabetes drugs accordingly.

type 1 diabetes - An autoimmune disease that destroys the ability of beta cells in the pancreas to make insulin and occurs most commonly in children and young adults. Daily insulin injections are necessary to stay alive.

type 2 diabetes - The most common type of diabetes. Develops when the pancreas cannot make enough insulin to overcome the body's resistance to insulin action.


vitreous humor - A thick, gel-like substance that fills the back of the eyeball behind the lens.

Publication Review By: Written by: Christopher D. Saudek, M.D.; Simeon Margolis, M.D., Ph.D.

Published: 22 Apr 2009

Last Modified: 11 Sep 2015