Insulin Replacement Therapy

Insulin Replacement Therapy

Insulin replacement therapy and type 1 and 2 diabetes:

Type 1 diabetes (also called diabetes mellitus or insulin-dependent diabetes) is an autoimmune disease in which the body's immune system attacks the cells that produce insulin, resulting in no, or a low amount of, insulin. Type 1 diabetes usually occurs at a younger age, with onset often before the age of 30. Treatment for type 1 diabetes includes daily injections of insulin.

Type 2 diabetes is often a result of the body's inability to make enough of, or to properly use, the insulin that is produced. Treatment often begins with an exercise program and a healthy diet to help lower the blood sugar levels. However, if this treatment plan is ineffective, diabetic pills or daily insulin injections may be necessary.

What is insulin?

Insulin is a hormone produced by the pancreas that helps lower the blood sugar by moving sugar from the bloodstream into the cells of the body. Once inside the cells, blood sugar becomes the essential source of energy for the body.

What are the different types of insulin?

There are four types of insulin, classified according to the following:

Onset how quickly the insulin starts to work after it is injected
Peak time the period of time when the insulin is most effective in lowering blood sugar levels
Duration how long the insulin remains working in the body

Insulin may act differently when administered to different individuals, so the times of onset, peak time, and duration may vary. The four types of insulin include:

Insulin type Onset
(approximation)		 Peak time
(approximation)		 Duration
(approximation)
Rapid acting, insulin Lispro 5 to 15 minutes 45 to 90 minutes 3 to 4 hours
Short acting, Regular (R) insulin 30 minutes 2 to 5 hours 5 to 8 hours
Intermediate acting, NPH (N) or Lente (L) insulin 1 to 3 hours 6 to 12 hours 16 to 24 hours
Long acting, Ultralente (U) insulin 4 to 6 hours 8 to 20 hours 24 to 28 hours

Source: National Institute of Diabetes and Digestive and Kidney Diseases

Some people with diabetes may have to take a combination of two different types of insulin to control their blood sugar levels. Some insulin can be purchased already mixed together, such as Regular and NPH insulin, to allow for injection of both types of insulin at the same time. Other types of insulin cannot be mixed together and may require two separate injections.

Insulin is manufactured at different strengths; U-100 insulin (100 units of insulin per milliliter of fluid) is the most common strength. The syringes for administering insulin are specifically designed for each different strength. Therefore, an U-100 syringe can be used only with a U-100 insulin.

The type of insulin chosen may reflect the person's preferences and ability to adhere to any given treatment regimen. Other factors include an individual's:

How is insulin administered?

Insulin has to enter the body's bloodstream to be effective. This is accomplished through injections into the fat layer - usually in the arm, thigh, or abdomen. Different sites on the body allow the insulin to enter at different rates. Insulin injected into the abdominal wall works the fastest, whereas injection into the thigh works the slowest. Insulin must be administered to the body via an injection and cannot be taken by mouth because it is destroyed in the stomach during digestion.

The timing of insulin injections is very important. Insulin usually needs to be administered before mealtimes - before sugar from a meal starts to enter the bloodstream. Always consult your physician concerning your individual insulin treatment, including injection sites, dosage, frequency, and specific times of administration.

What are the different types of insulin injection devices?

There are many types of insulin injection devices available. Some examples of devices include:

syringe The syringe is the most common device used to administer insulin. The needle of the syringe is placed under the skin, and the insulin is injected.
insulin pen Often used for multiple, daily doses of insulin, the insulin pen holds a cartridge with insulin. The pen, which looks like a writing pen, has a small needle at the tip. A dial on the pen allows the user to set the appropriate dosage. A plunger on the other end of the pen is used to actually deliver or inject the insulin.
insulin jet injector An insulin jet injector looks like a large pen. The injector uses a mechanism to produce high-pressure air to "spray" the insulin through the skin. Insulin jet injectors may be an option for people who do not tolerate needles.
external insulin pump An insulin pump is a device that pumps insulin continuously through plastic tubing attached to a needle under the skin near the abdomen. The pump is small enough to be worn on a belt or in a pocket.

Insulin through an inhaler:

Insulin through an inhaler may soon be an option for persons with diabetes. A recent study involving portable inhalers, similar to what asthmatics use for their condition, was found to be both an effective and convenient way to administer insulin. The ease of using insulin through an inhaler has the potential to make a dramatic impact on the health of millions with the disease.

How It Works

In order to be dispensed through an inhalant, the insulin was first transformed into a powder form and then put into the aerosol device. Once inhaled, the powdered insulin is absorbed by the lungs where it quickly travels through the cells of the lung tissue and into the blood stream.

The study, published recently in the medical journal Lancet, shows promising results - with some medical experts believing that insulin through an inhaler is likely to become the method of choice among those with diabetes due to its ease of use and convenience.

The researchers conclude that, because of the inhaler's effective results and its convenience, it is likely be the preferred choice among diabetes patients who require daily insulin. And, any treatment that helps diabetes patients better control their blood-sugar levels would help to reduce the possible complications brought on by the disease.

The researchers add that large-scale studies utilizing the inhaler are currently underway in hopes that the product will receive approval by the US Food and Drug Administration (FDA) within the next year or so. Always consult your physician for more information.

Insurance and insulin pumps:

The US Health Care Financing Administration (HCFA) announced in 1999 that Medicare would cover the cost of insulin pumps for persons with type 1 diabetes. HCFA is the federal agency that administers the Medicare, Medicaid, and Child Health Insurance Programs. Always check with your insurance company to determine if insulin injection devices and supplies are covered under your plan.

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