Type 1 Diabetes: Symptoms, Causes & Treatment Take the Diabetes Quiz!

Medical Author:

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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Medical Editor:

William C. Shiel Jr., MD, FACP, FACR

William C. Shiel Jr., MD, FACP, FACR

Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

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What is an insulin pump?

The insulin pump is a device for continuous insulin delivery. An insulin pump is composed of a pump reservoir similar to that of an insulin cartridge, a battery-operated pump, and a computer chip that allows the user to control the exact amount of insulin being delivered.

How big is an insulin pump?

Currently, pumps on the market are about the size of a standard communications beeper.

How does an insulin pump work?

The pump is attached to a thin plastic tube (an infusion set) that has a soft cannula (or plastic needle) at the end through which insulin passes. This cannula is inserted under the skin, usually on the abdomen. The cannula is changed every two days. The tubing can be disconnected from the pump while showering or swimming. The pump is used for continuous insulin delivery, 24 hours a day. The amount of insulin is programmed and is administered at a constant rate (basal rate). Often, the amount of insulin needed over the course of 24 hours varies depending on factors like exercise, activity level, and sleep.

The insulin pump allows the user to program many different basal rates to allow for variation in lifestyle. In addition, the user can program the pump to deliver a bolus (large dose of insulin) during meals to cover the excess demands of carbohydrate ingestion.

How common is an insulin pump?

Hundreds of thousands of people with diabetes worldwide are using an insulin pump. Although insulin pumps were first used by people with type 1 diabetes, people with type 2 diabetes sometime use them as well. Many pediatric patients successfully use insulin pumps. Insulin pumps allow for tight blood sugar control and lifestyle flexibility while minimizing the effects of low blood sugar (hypoglycemia). At present, the pump is the closest device on the market to an artificial pancreas. Newer models of the pump have been developed that do not require a tubing, in fact - the insulin delivery device is placed directly on the skin and any adjustments needed for insulin delivery are made through a PDA like device that must be kept within a 6 foot range of the insulin delivery device, and can be worn in a pocket, kept in a purse, or on a tabletop when working.

Probably the most exciting innovation in pump technology is the ability to use the pump in tandem with newer glucose sensing technology. Glucose sensors have improved dramatically in the last few years, and are an option for patients to gain further insight into their patterns of glucose response to tailor a more individual treatment regimen. Implantable glucose sensors communicate wirelessly with a pager-sized device that has a screen to give real-time glucose readings. The sensors can be programmed to produce a "beep" if blood sugars are in a range that is selected as too high or too low. Some can provide a warning beep if the drop in blood sugar is occurring too quickly.

Further, studies are underway to examine systems that combine insulin delivery and real-time glucose monitoring. The ultimate goal of this technology is to "close the loop" by continuously sensing what the body needs, and then responding by providing the appropriate dose of insulin. Preliminary studies have already shown success with these "closed loop" systems.

REFERENCE: Bergenstal RM, et. al. Effectiveness of sensor-augmented insulin-pump therapy in type 1 diabetes. N Engl J Med. 2010;363(4):311.

Previous contributing author: Ruchi Mathur, MD FRCP(C)