New Weapons To Beat Back DiabetesKate Murphy
Pat Hernandez must put up with needle jabs several times a day to inject insulin and measure his blood sugar because he has diabetes. He also has to watch his diet carefully, even counting how many grapes he eats between his news and traffic reports for a Houston radio station. Since 1987, when Hernandez was diagnosed with diabetes at 33, he says, "Juggling my blood sugar so it fits my activity level has been a constant battle. But I hold out hope that they'll come up with something to make it all a little easier."
Luckily for Hernandez and the 8 million other diabetes sufferers in the U.S., recent developments in drugs, gene research, transplant techniques, consumer products, and diet have stirred new optimism. "We have new armaments with which to attack a disease that impacts a significant segment of the population," including another 8 million or so people who have the ailment and don't know it yet, says Dr. Frank Vinicor, president of the American Diabetes Assn. (ADA) and director of the diabetes unit at the Centers for Disease Control in Atlanta. "Diabetes is a tremendous public-health problem, which costs this country more than $90 billion annually."
This chronic disorder is characterized by high levels of blood sugar, or glucose, caused by inadequate production of or resistance to the hormone insulin. Imagine the body as a big party where every cell wants to meet up with an energy-filled glucose molecule but has to wait for insulin, a mutual friend, to make the introductions. If insulin isn't around (as in type I, or juvenile diabetes) or if the cell is unaware of insulin's overtures on glucose's behalf (type II, or adult-onset diabetes), there's no match. The lonely cells grow listless and die, while idle glucose goes on to wreak havoc elsewhere, leading to such complications as blindness, heart disease, stroke, and infections resulting in amputations.
To avoid the deleterious effects of glucose running amok in their bodies, people with diabetes have for decades relied on careful dieting (glucose is derived in varying amounts from food), insulin injections, or--in the case of type II diabetes--drugs called sulfonylureas that stimulate insulin production in the pancreas in the hope that the body will respond better when more of the hormone is available. In the past year, however, new medications have emerged that take a different approach. "These drugs operate by mechanisms that are entirely distinct from what was available," says Dr. Lisa Newman, an endocrinologist at New York's Mt. Sinai Hospital.
"EXPLOSION." Approved for use on type II diabetes but having applications in cases of type I as well, the new drugs are metformin (sold as Glucophage by Bristol-Myers Squibb), which inhibits glucose production in the liver, and acarbose (sold as Precose by Bayer), which slows the conversion of carbohydrates into glucose in the intestines. Also promising is troglitazone from Warner-Lambert's Parke-Davis subsidiary. In its final stages of clinical testing, this drug acts on skeletal muscle cells to increase insulin sensitivity and, therefore, glucose uptake.
Because the new medications lower blood-glucose levels in different ways, "there has been an explosion in the combination use of drugs to treat diabetes," says Dr. Philip Orlander, an endocrinologist at the University of Texas- Houston Health Science Center. "They work together to get blood sugar down." Furthermore, the drugs don't cause weight gain, a common side effect of sulfonylureas. Packing extra pounds is especially harmful for diabetics because it increases insulin resistance.
Troglitazone and metformin are thought to have preventive effects, too. On June 10, the National Institutes of Health (NIH) announced plans to use both drugs in its Diabetes Prevention Program (DPP), a nationwide trial to discover ways to stave off the disease and its complications among people who are at risk. "Our hope is to delay if not eliminate the need for more intensive therapies," such as insulin injections, says Dr. Richard Eastman, the NIH director who oversees the program.
If insulin is necessary, a new type will be available this summer. Eli Lilly recently received approval from the Food & Drug Administration to market lispro (trade name Humalog), a fast-acting insulin. Humalog can be injected just prior to a meal, rather than 30 minutes before eating, as with other brands. Another bright spot on the horizon is pimagedine, a drug currently under development by Alteon. Like insulin, it grabs onto glucose before it has time to build up into a sugary mess in the bloodstream.
SAVVY SHIELD. There is also encouraging news on the surgical front. A new procedure reduces the risk that the body of a patient with type I diabetes will reject transplanted insulin-producing cells. Dr. Patrick Soon-Shiong, chairman of VivoRx, a Santa Monica (Calif.) biopharmaceutical company, has accomplished three successful transplants of islet cells from the pancreas as part of an FDA-sanctioned clinical trial. "The problem with replacement therapy before was that the body's own immune system would destroy the islet cells before they could do any good," says Soon-Shiong. He developed a semipermeable membrane derived from seaweed to enclose the cells, thus allowing insulin to flow out while barricading them against marauding antibodies. While the procedure almost obviates a patient's need for insulin injections, it's expensive--$20,000 to $40,000--and it must be repeated every two years or so. Still, experts say it's a positive development, and the costs should come down over time.
Genetic investigations are also going well. After a painstaking 15-year search, researchers at the University of Texas-Houston Health Science Center announced on May 30 that they are closing in on the gene that causes diabetes. "We have narrowed down the area where the gene is to just a tiny sliver" of one chromosome, says Dr. Craig Hanis, professor of human genetics. Isolating the gene has implications not only for diagnosis but also for treatment. Says the ADA's Vinicor: "We will be able to develop new kinds of drugs to counteract the proteins the gene may produce," which would inhibit the disease. Of course, such breakthroughs may be many years away.
For those already coping with diabetes, a host of new products are out to help them control blood-glucose levels. Today's syringes are smaller and sharper, with special coatings that make injections less painful. There are even insulin "pens" that look like fountain pens and come with disposable, premeasured cartridges of the hormone. If you want to avoid needles altogether, devices called jet injectors, such as Freedom Jet by Health-Mor Personal Care ($795) and Vitajet, by a pharmaceutical outfit of the same name ($1,590), force insulin through the skin with pressure instead of a puncture.
The latest blood-glucose meters still require a finger prick, but they have been reduced to the size of a credit card and are often self-cleaning. Many, such as Precision Q.I.D. by Medisense (about $40), have downloading capabilities to transfer information to a patient's or doctor's computer. And Medilife has just released BalancePC Diabetes Software ($60), which offers a comprehensive diabetes-tracking system for Windows-based computers. It integrates meter readings, drugs, insulin injections, food consumption, and even mood changes to provide patients with clear short- and long-term pictures of their health.
BALANCE. Finally, diets for people with diabetes have become less restrictive. "We used to ignore the big picture by getting caught up with the glycemic index of foods," says Marion Franz, director of nutrition at the International Diabetes Center in Minneapolis, referring to the measurement that indicates how much blood glucose levels rise after eating a certain food. Today, nutritionists no longer tell diabetics to stay away from sweets at all costs but rather to pay attention to their daily carbohydrate consumption. "Go ahead and have that cookie," says Franz, "but compensate for it by foregoing a piece of bread later."
These are times of dramatic improvement in the care and treatment of diabetes. "Although we don't have a cure in our hands yet, we certainly have more tools available to us to minimize the problem," says Vinicor. And that's news without a sugar coating.