FDA Approves Watchlike Device for Diabetes

From the WebMD Archives

March 22, 2001 (Washington) -- Diabetics moved one step closer to eventually eliminating the need for daily fingerpricks, an inconvenient and sometimes painful procedure that all diabetics presently must perform as often as four to seven times a day.

The FDA approved Thursday the GlucoWatch Biographer for people aged 18 and older. The high-tech device measures blood sugar, or glucose, levels by extracting a fluid sample through the skin.

The FDA emphasized, however, that the device should not replace daily fingerpricks.

The GlucoWatch consists of two parts: a biographer that is worn like watch, and a disposable sensor that sticks to the skin. The sensor collects a fluid sample through the wrist using a low-level electrical current to pull the glucose through the skin, and the biographer then calculates, displays, and stores the readings for later analysis.

Glucose levels can be measured every 20 minutes for 12-hour periods -- even during sleep. The result is an "electronic diary" with up to 4,000 values that can be reviewed at the touch of a button, helping provide a more comprehensive picture of a patient's daily glucose levels.


"It is an important direction in diabetes care," Christopher Saudek, MD, president-elect of the American Diabetes Association, tells WebMD. "Continuous glucose monitoring is an important development for improving care."

However, he points out, there are other devices that can perform the same function and the fact that the device was less effective at detecting the lows may represent a slight problem.

"I think the main danger clinically is the lows, but adjusting therapies for highs is also significant," Saudek says.

Many diabetics perform just a few fingerpricks a day to monitor glucose -- possibly missing important levels at times, such as right after a meal. This diary is expected to improve diabetics' quality of life while also reducing their healthcare costs, according to Cygnus Inc. of Redwood Calif., the maker of GlucoWatch.

"With GlucoWatch Biographer, people with diabetes will have access to the type of information that may help them make better informed decisions about diet, medication, and physical activities," the company said in a prepared statement. "This may eventually lead to a better quality of life and lower healthcare costs."


Studies have shown that patients who monitor and regulate their glucose levels have a lower incidence of disease-related complications, such as heart disease, stroke, vision loss, leg amputation, and kidney disease. In the U.S., complications associated with uncontrolled diabetes have been estimated to result in $100 billion a year in medical costs.

While hailing the device as major step towards eliminating the need for fingerpricks, government officials also warned Thursday that GlucoWatch is still a far shot from actually replacing the daily fingerpricks.

Although clinical studies showed that the GlucoWatch results generally were consistent with the results derived from fingerpricks, the results differed from the fingerpricks up to 25% of the time, explains Bernard Statland, MD, PhD, director of the FDA's Office of Device Evaluation.

GlucoWatch also is ineffective if the patient's arm is sweaty and is less effective at detecting very low levels of glucose than high levels of glucose, Statland tells WebMD.

Because the new device is not quite perfect, the FDA required Cygnus to provide comprehensive educational materials for both patients and doctors with each device, Statland says. The FDA also required the device be made available by prescription only, he tells WebMD.


In response to the FDA's conditions, Cygnus confirmed that it plans to conduct a pilot marketing program to learn more about patients' and caregivers' firsthand experience using the product before they begin widespread distribution of the monitor.

Despite these apparent shortcomings, Statland says that GlucoWatch still can be considered a major advance.

"I think there are two major advantages: It is much more convenient and less painful, and it provides continuous monitoring data, from which one will be able to get trending data," Statland says.

Although there is greater variability in the results gathered by the device, the continuous monitoring should help balance those results, Statland adds.

The device also has an alarm that can alert patients if their glucose reaches dangerous levels, he points out.

In the meantime, getting a hold of the device may prove problematic. Besides the planned pilot program, Cygnus added that it plans to delay the launch until it can meet the expected demand.


"We must ensure that product supplies are adequate to meet the expected strong demand," explained Craig Carlson, senior vice president of finance at Cygnus. "Therefore, we are finalizing a large-scale manufacturing process for the consumable AutoSensors, and we will complete all related regulatory submissions."

About 100 to 150 people will get the device as part of the pilot program.

The device is expected to sell for about $400, and the 12-hour disposable sensors for $4-5 each.

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