New Devices May Free Diabetics From Constant Monitoring

In fact, one manufacturer has already combined a glucose monitor and a pump into a single product that won approval from the FDA on April 13 and is going on sale now. Patients won't be able to activate the monitor portion until this summer, and the device isn't fully automatic yet -- it will require a patient to consult a glucose readout and make decisions about insulin use.

But the manufacturer, Medtronic Inc., is working on software to automate much of the decision-making. The resulting device could amount to an external, artificial pancreas that basically controls blood sugar on its own for days, with the exception that a patient would have to inform it of upcoming meals and exercise. "We're fairly close," said Alan O. Marcus, director of medical affairs for Medtronic's diabetes unit.

The body burns glucose, a simple sugar, the way a car burns gasoline. But the level in the blood must be tightly controlled to prevent short-term coma or long-term health damage. In a healthy body, the pancreas releases a hormone, insulin, to instruct tissues to absorb sugar from the blood. But this fundamental life process is broken in diabetics: Their bodies either don't make insulin or resist its effects.

Diabetes is one of the nation's most pervasive ailments, afflicting 7 percent of the population and fully 10 percent of adults. One form of the disease is linked to weight, and the problem is growing as Americans get fatter.

Pills help some people, but many need injected insulin. Until now, the state of the art in controlling diabetes has been to prick the fingers repeatedly throughout the day, drawing blood into a test strip and placing it in a glucose sensor to calculate insulin doses and guide eating.

Researchers have been trying to develop continuous glucose monitors since the early 1960s, and the field is littered with false starts and over-hyped gadgets that failed, most recently a watchlike device that caused burns and rashes. But now, doctors say, companies are finally making monitors that work.

The first of the new devices, from Medtronic, won FDA approval last year, but the company has rolled it out slowly, selling it in only seven cities to date. Medtronic is working out kinks and, like other manufacturers, studying how to educate patients in complex new procedures.

A device from DexCom Inc. of San Diego won FDA approval late last month, and one from Abbott Laboratories of North Chicago, Ill., is on the FDA's desk for approval. Overall, three or four continuous monitors are expected to be available nationwide by late this summer.

The new monitors don't entirely eliminate the need for finger-sticks, at least not yet.

Each time the sensor patch is changed, every three to five days, the glucose monitor must be calibrated using blood tests. And for the moment, the FDA and manufacturers are urging patients to draw blood to confirm a gadget reading before adjusting their blood sugar. If people follow that advice, the main advantage of the gadgets will be to alert them when to test.

But already, it's clear patients are becoming more dependent on the devices than the official instructions recommend. After finding it accurate most of the time and figuring out when it's likely to be less accurate -- during hard exercise, for example -- they start relying on the gadget with few finger-sticks.

"I trust it almost completely," Casey Burkhalter said.

The manufacturers are conducting studies to show their products can replace finger-sticks most of the time, a set of claims the diabetes foundation plans to check with its own studies.

A looming question is whether insurance companies will pay for the gadgets, expected to run from $500 to $2,000, and for the $35-and-up sensor patches that must be changed every few days. Historically, insurers have resisted new diabetes technology until studies prove it can cut costs or reduce medical complications, and those aren't finished.

Matt Vogel, a San Francisco diabetic and triathlete, ordered a DexCom monitor two days after the FDA approved the device. He has been comparing it to blood tests and keeping an Internet journal. The biggest problem so far is a time lag in detecting low sugar after exercise. But the device has awakened him at night when his sugar fell dangerously low, and overall, he rates it highly -- "about 90 percent."

A big issue for diabetics, he said, will be adjusting overnight from too little glucose information to a surfeit of it.

"This isn't going to be like a cure or any sort of silver-bullet solution," he said. "It's going to take quite a bit more thinking and quite a bit more problem-solving in order to really take advantage of it."