Diabetes Demands a Triad of Treatments
Blood Glucose Monitoring Devices continued...
By the late 1960s, manufacturers began
introducing home blood glucose monitoring kits. These kits allowed diabetics to
detect blood sugar levels by looking at color changes on a chemical test strip
using a single drop of blood from a pricked finger. Portable meters that could
electronically read the strip and provide immediate results came along in the
Although today's monitors are small, easier
to use than early ones, and reasonably priced at between $50 and $100, they all
require users to prick their fingers to provide a blood sample for testing. So
diabetics were understandably enthusiastic when a noninvasive glucose sensor
monitoring device was developed. It doesn't require a finger prick but instead
uses infrared technology to measure blood glucose. But after reviewing data
from the device's manufacturer, the Clinical Chemistry and Clinical Toxicology
Devices Advisory Panel of FDA's Medical Devices Advisory Committee decided more
data were needed to ensure the device's safety and effectiveness.
"The idea of being able to test yourself
without a painful prick is very attractive. It would probably increase
compliance because some patients simply don't want to prick their fingers,"
Gutman says. "It's a very promising technology. But you have to balance
technology against performance."
Gutman said the criteria the company chose to
deem the device successful -- that 50 percent of readings agree with 20 percent
of readings from the patient's finger-prick device -- was not an appropriate
target. The panel agreed that success should be defined as having 80 to 90
percent of values correlating to values obtained with finger-prick tests. So,
the FDA advisory committee also recommended that the sponsor conduct more
studies, doing them at multiple sites and involving more women who develop
diabetes while pregnant and more children. Also, the committee suggested that
the sponsor base the studies on specific study objectives related to
performance claims, with the data sufficient to ensure safety and
Julio V. Santiago, M.D., an internist
specializing in diabetes and a former member of FDA's Endocrine Advisory
Committee, says, "It's an exciting new technology that diabetics could
benefit from, so we were rooting for the company. But they failed to
demonstrate that the device worked long term for home use."
Santiago says that current invasive
finger-prick devices are very reliable, with accuracy within 15 percent of real
measurements 80 to 90 percent of the time. Their biggest disadvantage is cost,
since each test strip costs 50 cents, and several are often used in one day. A
spokesman for Boehringer Mannheim Corp., Rick Naples, says the cost of test
strips and lancets needed to perform self blood-glucose monitoring can average
between $600 and $1,000 a year.
Gutman says FDA appreciates the need for
noninvasive glucose monitors and is anxious to work with companies early in the
development of these devices. The Center for Devices and Radiological Health
has implemented an expedited review program for devices like noninvasive
glucose monitors so items that may be in the interest of public health can be
made available in an expedited way without compromising the devices' safety and
effectiveness, he says. "Such expedited reviews are given precedence over
Gutman is optimistic about future approval of
a noninvasive blood glucose monitoring kit for diabetics. "I'd be very
disappointed if we don't eventually see a noninvasive model in the future,"