New research shows that using a special thermometer to measure the temperature of the soles of diabetics' feet can give patients enough early warning to avoid one of the disease's most intractable complications, loss of a limb.
It is a simple-sounding protection for such a huge problem. Foot ulcers each year strike 600,000 U.S. diabetics, people slow to notice they even have a wound because diabetes has numbed their feet.
"They've lost the gift of pain," says Dr. David Armstrong of Chicago's Rosalind Franklin University of Medicine and Science, a diabetic foot specialist.
Worse, foot ulcers are so slow-healing and vulnerable to infection that they are to blame for most of the roughly 80,000 amputations of toes, feet and lower legs that diabetics in the US undergo each year.
So word that an easy-to-use gadget could help is generating excitement. Using the thermometer reduced by nearly two-thirds the number of high-risk patients who got foot ulcers, Armstrong found in a study of 225 diabetic veterans, the third in a series of government-funded research to back the approach.
How does it work?
Inflammation goes along with tissue injury, and inflammation can be measured by a bump in temperature. It's subtle — a few degrees between, say, your right big toe and your left one that can occur days before the skin breaks.
"A wound really will heat up before it breaks down," Armstrong explains.
Patients measure half a dozen spots on each foot. When the thermometer signals a hot spot, they put up their feet for a day or so until the temperature normalizes. Easing pressure before the skin cracks lets the body heal more easily than it can with a full-blown wound.
"Heat is one of the most sensitive things, one of the first things that happens when we begin to have tissue breakdown," says Dr. Crystal Holmes, a University of Michigan podiatrist who has begun prescribing the thermometers.
"It's looking positive that this sort of testing could be quite useful," adds Dr. Theresa Jones, who oversees research on diabetes complications at the National Institutes of Health. "There isn't any other treatment one knows about to (help) at that point before there's an ulcer."
This is not a standard thermometer, but a $150 infrared one with a tip that digitally measures skin temperature on contact.
Maker Xilas Medical, with a U.S. government grant, is working to make the thermometer resemble a bathroom scale: Step up, and it would automatically flash any trouble spots to the patient, and to a computer that alerts the doctor.
That is still a few years from market. For now, Xilas sells the handheld TempTouch by prescription only.
Insurance coverage is mixed. But, "how cheap compared to an amputation," says Dr. Mary Ann Banerji, who heads the State University of New York diabetes center.
Treating a simple diabetic foot ulcer can cost $8,000, double that for an infected one and even more for an amputation.
"It's basically idiot-proof," Walter Massa says of the thermometer.
"On the other hand, it's very hard to take your temperature when you don't think there's a problem there," cautions Massa, 53, who has used the thermometer since Armstrong helped him narrowly avoid amputation when the joints in his foot disintegrated. "There's something you have to teach yourself."
Millions of people have diabetes, meaning their bodies can't properly regulate blood sugar, or glucose. Over many years, high glucose levels seriously damage blood vessels and nerves that lead to, among other things, loss of sensation in the feet and poor blood flow in the lower legs — the ulcer environment.
There is little therapy to avert foot ulcers. Patients are urged to wear proper-fitting shoes and check their feet daily for redness, bumps or other signs of trouble.