Instead of carrying around needles to inject themselves in their arms, thighs or abdomens, at either work or when going out to eat, diabetics in a year or so might be able to carry around a portable inhaler for their insulin, like asthmatics use for their condition.

Researchers from 10 U.S. medical centers and Pfizer Inc. are reporting in the current issue of the medical journal Lancet that people with type I diabetes who inhale insulin do as well at keeping their blood sugar stable as those who inject it.

Secreted by the pancreas, insulin is a hormone that helps regulate the amount of sugar in the blood. People with the type I disease, also known as juvenile diabetes, do not make any insulin.

Breathing Insulin Lowered Blood Sugar

In a 12-week trial sponsored by the drug company, 73 patients were randomly divided into two study groups. Half inhaled their insulin three times a day before meals and also took an injection before they went to bed. The other group had their usual two to three injections a day.

At the end of the study, the investigators found the two groups comparable in their ability to control their blood-sugar levels. The inhaled insulin had no effect on patients lungs.

“These were people who had no insulin production,"says Dr. Jay Skyler, lead author on the researcher and director of the division of endocrinology, diabetes and metabolism at the University of Miami School of Medicine, “and we asked if we could substitute their injections with an inhale-able drug and have them not lose control of their blood sugar. They didn’t. They did just as good as people who had injections."/p>

The insulin powder passes through the lung tissue into the blood to give a dose to patients. (Courtesy of Inhale Therapeutic Systems)
　　
　　 How does inhaled insulin work? Scientists transformed the hormone into a powder, which was then put into a device that aerosolized it for absorption into the alveoli of the lung. The alveoli, which has the surface area of a tennis court, is normally where the oxygen we breathe enters the blood supply. With the apparatus, the insulin dissolves into the fluid, bathing the alveoli, and passes through the cells of the lung tissue and into the blood.

Dr. Richard Hellman, a physician in North Kansas City, Mo., and member of the board of directors of the American Association of Clinical Endocrinologists, calls the results of the trial promising but said they needed to be reproduced in more patients, and for a longer period of time.

“The researchers show that the inhale-able insulin seems to be safe and it works as well as medium intensity approaches to diabetic treatment,"Hellman says, referring to the fact that some diabetics more aggressively manage their disease by taking more injections or using pumps that secrete insulin throughout the day.

Convenience Could Increase Compliance

Hellman says a treatment that makes it more convenient for diabetics to take their insulin would help more people better control their blood sugar, and therefore lessen the complications from the disease. “Many patients resist taking the three to four injections they really need to control their diabetes,"Hellman says.

He says the inhaler could also benefit type II diabetics, who represent the majority of all diabetes patients in the United States.

Approximately 16 million Americans have diabetes, the seventh-leading cause of death in the United States. Type I diabetes, believed to be an auto-immune disease in which the body does not produce insulin, most often occurs in children and young adults. It accounts for 5 percent to 10 percent of all cases of diabetes.

Type II diabetes is a metabolic disorder resulting from the body’s inability to make enough or properly use insulin, which people need to stay alive. Type II accounts for 90 percent to 95 percent of all cases of diabetes, and is nearing epidemic proportions because of an increased amount of obesity in the population. Treatment involves diet, exercise and drugs that may include insulin to control patients' sugar.

High levels of blood sugar can lead to the complications associated with diabetes, such as blindness, kidney disease, nerve problems, heart disease and stroke.

Is an Inhaler Cost-Effective?

The downside to the inhaler, though, is that it may not be cost effective, Hellman says. Only 10 percent of the hormone is absorbed into the lung "the other 90 percent of it is wasted. Yet the drug company still has to spend the resources to manufacture the insulin anyway.

But Pfizer’s team leader for diabetes research, Dr. Michael Berelowitz, says if the product is shown to be safe and effective in a larger number of patients and passes the Food and Drug Administration regulatory requirements, its ease of use may ultimately compensate for its cost. More patients would be willing to take the drug and thus save the money used in treating diabetes"numerous complications.

Another unknown is whether there may be side effects in the lung and pulmonary pathways from inhaling insulin. Berelowitz says the FDA would not have allowed the company to proceed with the trials if it posed such a danger.

Dr. Gerald Bernstein, past president of the American Diabetes Association and an endocrinologist at Beth Israel Medical Center in New York City, says he is not aware of any data indicating problems to lung tissue from inhaled insulin.

But often with drug side effects, a large population of patients must take a drug before the medical community starts seeing problems.

Pfizer is sponsoring six trials with approximately 1,000 to 2,000 Type I and Type II diabetics in the United States to obtain FDA approval for the product within the next year or so.

The product, a collaboration by Pfizer of New York, Aventis Pharma of Frankfurt, Germany, and Inhale Therapeutic Systems of San Carlos, Calif., is one among several inhaled insulin formulations under development. All aim to provide convenience for diabetics who are resistant to injections yet who need to keep their blood sugar normalized.

(From ABCNews)